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SubjectRe: [v5 1/2] mtd: nand: Add new Cadence NAND driver to MTD subsystem
Hi Piotr,

Piotr Sroka <piotrs@cadence.com> wrote on Thu, 25 Jul 2019 16:00:12
+0100:

Subject should be: mtd: rawnand:

Last few nits in your driver which overall looks good (see below).

Now I'm waiting for Rob's ack on the bindings. This driver should be a
good candidate for 5.5.

> Add new Cadence NAND driver to MTD subsystem
>
> Signed-off-by: Piotr Sroka <piotrs@cadence.com>
> ---
> Changes for v5:
> - fix "ecc config strength" field size
> - remove unused macros
> - fix address of timing2 register
> - add guard for accessing data_control_size register
> - simplify the driver by use the same function
> for accessing main area and oob area
> - add comment to the driver describing main controller modes
> - change compatible name from cdns,hpnfc to cdns,hp-nfc
> Changes for v4:
> - fix comments issues like typos, missing capitals, missing dots etc.
> - remove unnecessary PHY options phy_dll_aging and phy_per_bit_deskew
> - replace all register access functions to "relaxed" version
> - remove all unnecessary variables initializations
> - handle error inside cadence_nand_get_ecc_strength_idx function in case
> correnction strength is not found
> - add commit message
> Changes for v3:
> - remove definitions of unused registers
> - remove configuring registers which are not expected to be configured in
> asynchronous mode
> - remove not needed function reading timing registers
> - remove information about oob size and write size from cdns_nand_chip type
> and use vales from mtd_info directly
> - use nand_cleanup instead of nand_release if mtd device is not registered yet
> - fix cadence_nand_chips_init function add garbage collection
> if a chip init fails
> - simplify PHY calculations
> Changes for v2:
> - create one universal wait function for all events instead of one
> function per event.
> - split one big function executing nand operations to separate
> functions one per each type of operation.
> - add erase atomic operation to nand operation parser
> - remove unnecessary includes.
> - remove unused register defines
> - add support for multiple nand chips
> - remove all code using legacy functions
> - remove chip dependents parameters from dts bindings, they were
> attached to the SoC specific compatible at the driver level
> - simplify interrupt handling
> - simplify timing calculations
> - fix calculation of maximum supported cs signals
> - simplify ecc size calculation
> - remove header file and put whole code to one c file
> ---
> drivers/mtd/nand/raw/Kconfig | 7 +
> drivers/mtd/nand/raw/Makefile | 1 +
> drivers/mtd/nand/raw/cadence-nand-controller.c | 3021 ++++++++++++++++++++++++
> 3 files changed, 3029 insertions(+)
> create mode 100644 drivers/mtd/nand/raw/cadence-nand-controller.c
>
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index e604625e2dfa..4d2ce3b5b2ae 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -557,5 +557,12 @@ config MTD_NAND_MESON
> help
> Enables support for NAND controller on Amlogic's Meson SoCs.
> This controller is found on Meson SoCs.

Missing space?

> +config MTD_NAND_CADENCE
> + tristate "Support Cadence NAND (HPNFC) controller"
> + depends on OF

|| COMPILE_TEST

> + help
> + Enable the driver for NAND flash on platforms using a Cadence NAND
> + controller.
> +
>
> endif # MTD_NAND
> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> index 5a5a72f0793e..f4b099f276f7 100644
> --- a/drivers/mtd/nand/raw/Makefile
> +++ b/drivers/mtd/nand/raw/Makefile
> @@ -58,6 +58,7 @@ obj-$(CONFIG_MTD_NAND_MTK) += mtk_ecc.o mtk_nand.o
> obj-$(CONFIG_MTD_NAND_TEGRA) += tegra_nand.o
> obj-$(CONFIG_MTD_NAND_STM32_FMC2) += stm32_fmc2_nand.o
> obj-$(CONFIG_MTD_NAND_MESON) += meson_nand.o
> +obj-$(CONFIG_MTD_NAND_CADENCE) += cadence-nand-controller.o
>
> nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
> nand-objs += nand_onfi.o
> diff --git a/drivers/mtd/nand/raw/cadence-nand-controller.c b/drivers/mtd/nand/raw/cadence-nand-controller.c
> new file mode 100644
> index 000000000000..a7ff4e4585d3
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/cadence-nand-controller.c
> @@ -0,0 +1,3021 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Cadence NAND flash controller driver
> + *
> + * Copyright (C) 2019 Cadence

I guess you deserve the Author: entry here :)

> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/dmaengine.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/of_device.h>
> +#include <linux/iopoll.h>
> +
> +/*
> + * HPNFC can work in 3 modes:
> + * - PIO - can work in master or slave DMA.
> + * - CDMA - needs Master DMA for accessing command descriptors.
> + * - Generic mode - can use only slave DMA.
> + * CDMA and PIO modes can be used to execute only base commands.
> + * Generic mode can be used to execute any command
> + * on NAND flash memory. Driver uses CDMA mode for
> + * block erasing, page reading, page programing.
> + * Generic mode is used for executing rest of commands.
> + */
> +
> +#define MAX_OOB_SIZE_PER_SECTOR 32
> +#define MAX_ADDRESS_CYC 6
> +#define MAX_ERASE_ADDRESS_CYC 3
> +#define MAX_DATA_SIZE 0xFFFC
> +
> +/* Register definition. */
> +/*
> + * Command register 0.
> + * Writing data to this register will initiate a new transaction
> + * of the NF controller.
> + */
> +#define CMD_REG0 0x0000
> +/* Command type field mask. */
> +#define CMD_REG0_CT GENMASK(31, 30)
> +/* Command type CDMA. */
> +#define CMD_REG0_CT_CDMA 0uL
> +/* Command type generic. */
> +#define CMD_REG0_CT_GEN 3uL
> +/* Command thread number field mask. */
> +#define CMD_REG0_TN GENMASK(27, 24)
> +
> +/* Command register 2. */
> +#define CMD_REG2 0x0008
> +/* Command register 3. */
> +#define CMD_REG3 0x000C
> +/* Pointer register to select which thread status will be selected. */
> +#define CMD_STATUS_PTR 0x0010
> +/* Command status register for selected thread. */
> +#define CMD_STATUS 0x0014
> +
> +/* Interrupt status register. */
> +#define INTR_STATUS 0x0110
> +#define INTR_STATUS_SDMA_ERR BIT(22)
> +#define INTR_STATUS_SDMA_TRIGG BIT(21)
> +#define INTR_STATUS_UNSUPP_CMD BIT(19)
> +#define INTR_STATUS_DDMA_TERR BIT(18)
> +#define INTR_STATUS_CDMA_TERR BIT(17)
> +#define INTR_STATUS_CDMA_IDL BIT(16)
> +
> +/* Interrupt enable register. */
> +#define INTR_ENABLE 0x0114
> +#define INTR_ENABLE_INTR_EN BIT(31)
> +#define INTR_ENABLE_SDMA_ERR_EN BIT(22)
> +#define INTR_ENABLE_SDMA_TRIGG_EN BIT(21)
> +#define INTR_ENABLE_UNSUPP_CMD_EN BIT(19)
> +#define INTR_ENABLE_DDMA_TERR_EN BIT(18)
> +#define INTR_ENABLE_CDMA_TERR_EN BIT(17)
> +#define INTR_ENABLE_CDMA_IDLE_EN BIT(16)
> +
> +/* Controller internal state. */
> +#define CTRL_STATUS 0x0118
> +#define CTRL_STATUS_INIT_COMP BIT(9)
> +#define CTRL_STATUS_CTRL_BUSY BIT(8)
> +
> +/* Command Engine threads state. */
> +#define TRD_STATUS 0x0120
> +
> +/* Command Engine interrupt thread error status. */
> +#define TRD_ERR_INT_STATUS 0x0128
> +/* Command Engine interrupt thread error enable. */
> +#define TRD_ERR_INT_STATUS_EN 0x0130
> +/* Command Engine interrupt thread complete status. */
> +#define TRD_COMP_INT_STATUS 0x0138
> +
> +/*
> + * Transfer config 0 register.
> + * Configures data transfer parameters.
> + */
> +#define TRAN_CFG_0 0x0400
> +/* Offset value from the beginning of the page. */
> +#define TRAN_CFG_0_OFFSET GENMASK(31, 16)
> +/* Numbers of sectors to transfer within singlNF device's page. */
> +#define TRAN_CFG_0_SEC_CNT GENMASK(7, 0)
> +
> +/*
> + * Transfer config 1 register.
> + * Configures data transfer parameters.
> + */
> +#define TRAN_CFG_1 0x0404
> +/* Size of last data sector. */
> +#define TRAN_CFG_1_LAST_SEC_SIZE GENMASK(31, 16)
> +/* Size of not-last data sector. */
> +#define TRAN_CFG_1_SECTOR_SIZE GENMASK(15, 0)
> +
> +/* ECC engine configuration register 0. */
> +#define ECC_CONFIG_0 0x0428
> +/* Correction strength. */
> +#define ECC_CONFIG_0_CORR_STR GENMASK(10, 8)
> +/* Enable erased pages detection mechanism. */
> +#define ECC_CONFIG_0_ERASE_DET_EN BIT(1)
> +/* Enable controller ECC check bits generation and correction. */
> +#define ECC_CONFIG_0_ECC_EN BIT(0)
> +
> +/* ECC engine configuration register 1. */
> +#define ECC_CONFIG_1 0x042C
> +
> +/* Multiplane settings register. */
> +#define MULTIPLANE_CFG 0x0434
> +/* Cache operation settings. */
> +#define CACHE_CFG 0x0438
> +
> +/* DMA settings register. */
> +#define DMA_SETINGS 0x043C
> +/* Enable SDMA error report on access unprepared slave DMA interface. */
> +#define DMA_SETINGS_SDMA_ERR_RSP BIT(17)
> +
> +/* Transferred data block size for the slave DMA module. */
> +#define SDMA_SIZE 0x0440
> +
> +/* Thread number associated with transferred data block
> + * for the slave DMA module.
> + */
> +#define SDMA_TRD_NUM 0x0444
> +/* Thread number mask. */
> +#define SDMA_TRD_NUM_SDMA_TRD GENMASK(2, 0)
> +
> +#define CONTROL_DATA_CTRL 0x0494
> +/* Thread number mask. */
> +#define CONTROL_DATA_CTRL_SIZE GENMASK(15, 0)
> +
> +#define CTRL_VERSION 0x800
> +
> +/* Available hardware features of the controller. */
> +#define CTRL_FEATURES 0x804
> +/* Support for NV-DDR2/3 work mode. */
> +#define CTRL_FEATURES_NVDDR_2_3 BIT(28)
> +/* Support for NV-DDR work mode. */
> +#define CTRL_FEATURES_NVDDR BIT(27)
> +/* Support for asynchronous work mode. */
> +#define CTRL_FEATURES_ASYNC BIT(26)
> +/* Support for asynchronous work mode. */
> +#define CTRL_FEATURES_N_BANKS GENMASK(25, 24)
> +/* Slave and Master DMA data width. */
> +#define CTRL_FEATURES_DMA_DWITH64 BIT(21)
> +/* Availability of Control Data feature.*/
> +#define CTRL_FEATURES_CONTROL_DATA BIT(10)
> +
> +/* BCH Engine identification register 0 - correction strengths. */
> +#define BCH_CFG_0 0x838
> +#define BCH_CFG_0_CORR_CAP_0 GENMASK(7, 0)
> +#define BCH_CFG_0_CORR_CAP_1 GENMASK(15, 8)
> +#define BCH_CFG_0_CORR_CAP_2 GENMASK(23, 16)
> +#define BCH_CFG_0_CORR_CAP_3 GENMASK(31, 24)
> +
> +/* BCH Engine identification register 1 - correction strengths. */
> +#define BCH_CFG_1 0x83C
> +#define BCH_CFG_1_CORR_CAP_4 GENMASK(7, 0)
> +#define BCH_CFG_1_CORR_CAP_5 GENMASK(15, 8)
> +#define BCH_CFG_1_CORR_CAP_6 GENMASK(23, 16)
> +#define BCH_CFG_1_CORR_CAP_7 GENMASK(31, 24)
> +
> +/* BCH Engine identification register 2 - sector sizes. */
> +#define BCH_CFG_2 0x840
> +#define BCH_CFG_2_SECT_0 GENMASK(15, 0)
> +#define BCH_CFG_2_SECT_1 GENMASK(31, 16)
> +
> +/* BCH Engine identification register 3. */
> +#define BCH_CFG_3 0x844
> +
> +/* Ready/Busy# line status. */
> +#define RBN_SETINGS 0x1004
> +
> +/* Common settings. */
> +#define COMMON_SET 0x1008
> +/* 16 bit device connected to the NAND Flash interface. */
> +#define COMMON_SET_DEVICE_16BIT BIT(8)
> +
> +/* Skip_bytes registers. */
> +#define SKIP_BYTES_CONF 0x100C
> +#define SKIP_BYTES_MARKER_VALUE GENMASK(31, 16)
> +#define SKIP_BYTES_NUM_OF_BYTES GENMASK(7, 0)
> +
> +#define SKIP_BYTES_OFFSET 0x1010
> +#define SKIP_BYTES_OFFSET_VALUE GENMASK(23, 0)
> +
> +/* Timings configuration. */
> +#define ASYNC_TOGGLE_TIMINGS 0x101c
> +#define ASYNC_TOGGLE_TIMINGS_TRH GENMASK(28, 24)
> +#define ASYNC_TOGGLE_TIMINGS_TRP GENMASK(20, 16)
> +#define ASYNC_TOGGLE_TIMINGS_TWH GENMASK(12, 8)
> +#define ASYNC_TOGGLE_TIMINGS_TWP GENMASK(4, 0)
> +
> +#define TIMINGS0 0x1024
> +#define TIMINGS0_TADL GENMASK(31, 24)
> +#define TIMINGS0_TCCS GENMASK(23, 16)
> +#define TIMINGS0_TWHR GENMASK(15, 8)
> +#define TIMINGS0_TRHW GENMASK(7, 0)
> +
> +#define TIMINGS1 0x1028
> +#define TIMINGS1_TRHZ GENMASK(31, 24)
> +#define TIMINGS1_TWB GENMASK(23, 16)
> +#define TIMINGS1_TVDLY GENMASK(7, 0)
> +
> +#define TIMINGS2 0x102c
> +#define TIMINGS2_TFEAT GENMASK(25, 16)
> +#define TIMINGS2_CS_HOLD_TIME GENMASK(13, 8)
> +#define TIMINGS2_CS_SETUP_TIME GENMASK(5, 0)
> +
> +/* Configuration of the resynchronization of slave DLL of PHY. */
> +#define DLL_PHY_CTRL 0x1034
> +#define DLL_PHY_CTRL_DLL_RST_N BIT(24)
> +#define DLL_PHY_CTRL_EXTENDED_WR_MODE BIT(17)
> +#define DLL_PHY_CTRL_EXTENDED_RD_MODE BIT(16)
> +#define DLL_PHY_CTRL_RS_HIGH_WAIT_CNT GENMASK(11, 8)
> +#define DLL_PHY_CTRL_RS_IDLE_CNT GENMASK(7, 0)
> +
> +/* Register controlling DQ related timing. */
> +#define PHY_DQ_TIMING 0x2000
> +/* Register controlling DSQ related timing. */
> +#define PHY_DQS_TIMING 0x2004
> +#define PHY_DQS_TIMING_DQS_SEL_OE_END GENMASK(3, 0)
> +#define PHY_DQS_TIMING_PHONY_DQS_SEL BIT(16)
> +#define PHY_DQS_TIMING_USE_PHONY_DQS BIT(20)
> +
> +/* Register controlling the gate and loopback control related timing. */
> +#define PHY_GATE_LPBK_CTRL 0x2008
> +#define PHY_GATE_LPBK_CTRL_RDS GENMASK(24, 19)
> +
> +/* Register holds the control for the master DLL logic. */
> +#define PHY_DLL_MASTER_CTRL 0x200C
> +#define PHY_DLL_MASTER_CTRL_BYPASS_MODE BIT(23)
> +
> +/* Register holds the control for the slave DLL logic. */
> +#define PHY_DLL_SLAVE_CTRL 0x2010
> +
> +/* This register handles the global control settings for the PHY. */
> +#define PHY_CTRL 0x2080
> +#define PHY_CTRL_SDR_DQS BIT(14)
> +#define PHY_CTRL_PHONY_DQS GENMASK(9, 4)
> +
> +/*
> + * This register handles the global control settings
> + * for the termination selects for reads.
> + */
> +#define PHY_TSEL 0x2084
> +
> +/* Generic command layout. */
> +#define GCMD_LAY_CS GENMASK_ULL(11, 8)
> +/*
> + * This bit informs the minicotroller if it has to wait for tWB
> + * after sending the last CMD/ADDR/DATA in the sequence.
> + */
> +#define GCMD_LAY_TWB BIT_ULL(6)
> +/* Type of generic instruction. */
> +#define GCMD_LAY_INSTR GENMASK_ULL(5, 0)
> +
> +/* Generic CMD sequence type. */
> +#define GCMD_LAY_INSTR_CMD 0
> +/* Generic ADDR sequence type. */
> +#define GCMD_LAY_INSTR_ADDR 1
> +/* Generic data transfer sequence type. */
> +#define GCMD_LAY_INSTR_DATA 2
> +
> +/* Input part of generic command type of input is command. */
> +#define GCMD_LAY_INPUT_CMD GENMASK_ULL(23, 16)
> +
> +/* Generic command address sequence - address fields. */
> +#define GCMD_LAY_INPUT_ADDR GENMASK_ULL(63, 16)
> +/* Generic command address sequence - address size. */
> +#define GCMD_LAY_INPUT_ADDR_SIZE GENMASK_ULL(13, 11)
> +
> +/* Transfer direction field of generic command data sequence. */
> +#define GCMD_DIR BIT_ULL(11)
> +/* Read transfer direction of generic command data sequence. */
> +#define GCMD_DIR_READ 0
> +/* Write transfer direction of generic command data sequence. */
> +#define GCMD_DIR_WRITE 1
> +
> +/* ECC enabled flag of generic command data sequence - ECC enabled. */
> +#define GCMD_ECC_EN BIT_ULL(12)
> +/* Generic command data sequence - sector size. */
> +#define GCMD_SECT_SIZE GENMASK_ULL(31, 16)
> +/* Generic command data sequence - sector count. */
> +#define GCMD_SECT_CNT GENMASK_ULL(39, 32)
> +/* Generic command data sequence - last sector size. */
> +#define GCMD_LAST_SIZE GENMASK_ULL(55, 40)
> +
> +/* CDMA descriptor fields. */
> +/* Erase command type of CDMA descriptor. */
> +#define CDMA_CT_ERASE 0x1000
> +/* Program page command type of CDMA descriptor. */
> +#define CDMA_CT_WR 0x2100
> +/* Read page command type of CDMA descriptor. */
> +#define CDMA_CT_RD 0x2200
> +
> +/* Flash pointer memory shift. */
> +#define CDMA_CFPTR_MEM_SHIFT 24
> +/* Flash pointer memory mask. */
> +#define CDMA_CFPTR_MEM GENMASK(26, 24)
> +
> +/*
> + * Command DMA descriptor flags. If set causes issue interrupt after
> + * the completion of descriptor processing.
> + */
> +#define CDMA_CF_INT BIT(8)
> +/*
> + * Command DMA descriptor flags - the next descriptor
> + * address field is valid and descriptor processing should continue.
> + */
> +#define CDMA_CF_CONT BIT(9)
> +/* DMA master flag of command DMA descriptor. */
> +#define CDMA_CF_DMA_MASTER BIT(10)
> +
> +/* Operation complete status of command descriptor. */
> +#define CDMA_CS_COMP BIT(15)
> +/* Operation complete status of command descriptor. */
> +/* Command descriptor status - operation fail. */
> +#define CDMA_CS_FAIL BIT(14)
> +/* Command descriptor status - page erased. */
> +#define CDMA_CS_ERP BIT(11)
> +/* Command descriptor status - timeout occurred. */
> +#define CDMA_CS_TOUT BIT(10)
> +/*
> + * Maximum amount of correction applied to one ECC sector.
> + * It is part of command descriptor status.
> + */
> +#define CDMA_CS_MAXERR GENMASK(9, 2)
> +/* Command descriptor status - uncorrectable ECC error. */
> +#define CDMA_CS_UNCE BIT(1)
> +/* Command descriptor status - descriptor error. */
> +#define CDMA_CS_ERR BIT(0)
> +
> +/* Status of operation - OK. */
> +#define STAT_OK 0
> +/* Status of operation - FAIL. */
> +#define STAT_FAIL 2
> +/* Status of operation - uncorrectable ECC error. */
> +#define STAT_ECC_UNCORR 3
> +/* Status of operation - page erased. */
> +#define STAT_ERASED 5
> +/* Status of operation - correctable ECC error. */
> +#define STAT_ECC_CORR 6
> +/* Status of operation - unsuspected state. */
> +#define STAT_UNKNOWN 7
> +/* Status of operation - operation is not completed yet. */
> +#define STAT_BUSY 0xFF
> +
> +#define BCH_MAX_NUM_CORR_CAPS 8
> +#define BCH_MAX_NUM_SECTOR_SIZES 2
> +
> +struct cadence_nand_timings {
> + u32 async_toggle_timings;
> + u32 timings0;
> + u32 timings1;
> + u32 timings2;
> + u32 dll_phy_ctrl;
> + u32 phy_ctrl;
> + u32 phy_dqs_timing;
> + u32 phy_gate_lpbk_ctrl;
> +};
> +
> +/* Command DMA descriptor. */
> +struct cadence_nand_cdma_desc {
> + /* Next descriptor address. */
> + u64 next_pointer;
> +
> + /* Flash address is a 32-bit address comprising of BANK and ROW ADDR. */
> + u32 flash_pointer;
> + u32 rsvd0;
> +
> + /* Operation the controller needs to perform. */
> + u16 command_type;
> + u16 rsvd1;
> + /* Flags for operation of this command. */
> + u16 command_flags;
> + u16 rsvd2;
> +
> + /* System/host memory address required for data DMA commands. */
> + u64 memory_pointer;
> +
> + /* Status of operation. */
> + u32 status;
> + u32 rsvd3;
> +
> + /* Address pointer to sync buffer location. */
> + u64 sync_flag_pointer;
> +
> + /* Controls the buffer sync mechanism. */
> + u32 sync_arguments;
> + u32 rsvd4;
> +
> + /* Control data pointer. */
> + u64 ctrl_data_ptr;
> +};
> +
> +/* Interrupt status. */
> +struct cadence_nand_irq_status {
> + /* Thread operation complete status. */
> + u32 trd_status;
> + /* Thread operation error. */
> + u32 trd_error;
> + /* Controller status. */
> + u32 status;
> +};
> +
> +/* Cadence NAND flash controller capabilities get from driver data. */
> +struct cadence_nand_dt_devdata {
> + /* Skew value of the output signals of the NAND Flash interface. */
> + u32 if_skew;
> + /* It informs if slave DMA interface is connected to DMA engine. */
> + unsigned int has_dma:1;
> +};
> +
> +/* Cadence NAND flash controller capabilities read from registers. */
> +struct cdns_nand_caps {
> + /* Maximum number of banks supported by hardware. */
> + u8 max_banks;
> + /* Slave and Master DMA data width in bytes (4 or 8). */
> + u8 data_dma_width;
> + /* Control Data feature supported. */
> + u8 data_control_supp;
> + /* Is PHY type DLL. */
> + u8 is_phy_type_dll;
> +};
> +
> +struct cdns_nand_ctrl {
> + struct device *dev;
> + struct nand_controller controller;
> + struct cadence_nand_cdma_desc *cdma_desc;
> + /* IP capability. */
> + const struct cadence_nand_dt_devdata *caps1;
> + struct cdns_nand_caps caps2;
> + dma_addr_t dma_cdma_desc;
> + u8 *buf;
> + u32 buf_size;
> + u8 curr_corr_str_idx;
> +
> + /* Register interface. */
> + void __iomem *reg;
> +
> + struct {
> + void __iomem *virt;
> + dma_addr_t dma;
> + } io;
> +
> + int irq;
> + /* Interrupts that have happened. */
> + struct cadence_nand_irq_status irq_status;
> + /* Interrupts we are waiting for. */
> + struct cadence_nand_irq_status irq_mask;
> + struct completion complete;
> + /* Protect irq_mask and irq_status. */
> + spinlock_t irq_lock;
> +
> + int ecc_strengths[BCH_MAX_NUM_CORR_CAPS];
> + struct nand_ecc_step_info ecc_stepinfos[BCH_MAX_NUM_SECTOR_SIZES];
> + struct nand_ecc_caps ecc_caps;
> +
> + int curr_trans_type;
> +
> + struct dma_chan *dmac;
> +
> + u32 nf_clk_rate;
> + /*
> + * Estimated Board delay. The value includes the total
> + * round trip delay for the signals and is used for deciding on values
> + * associated with data read capture.
> + */
> + u32 board_delay;
> +
> + struct nand_chip *selected_chip;
> +
> + unsigned long assigned_cs;
> + struct list_head chips;
> +};
> +
> +struct cdns_nand_chip {
> + struct cadence_nand_timings timings;
> + struct nand_chip chip;
> + u8 nsels;
> + struct list_head node;
> +
> + /*
> + * part of oob area of NAND flash memory page.
> + * This part is available for user to read or write.
> + */
> + u32 avail_oob_size;
> +
> + /* Sector size. There are few sectors per mtd->writesize */
> + u32 sector_size;
> + u32 sector_count;
> +
> + /* Offset of BBM. */
> + u8 bbm_offs;
> + /* Number of bytes reserved for BBM. */
> + u8 bbm_len;
> + /* ECC strength index. */
> + u8 corr_str_idx;
> +
> + u8 cs[];
> +};
> +
> +struct ecc_info {
> + int (*calc_ecc_bytes)(int step_size, int strength);
> + int max_step_size;
> +};
> +
> +static inline struct
> +cdns_nand_chip *to_cdns_nand_chip(struct nand_chip *chip)
> +{
> + return container_of(chip, struct cdns_nand_chip, chip);
> +}
> +
> +static inline struct
> +cdns_nand_ctrl *to_cdns_nand_ctrl(struct nand_controller *controller)
> +{
> + return container_of(controller, struct cdns_nand_ctrl, controller);
> +}
> +
> +static bool
> +cadence_nand_dma_buf_ok(struct cdns_nand_ctrl *cdns_ctrl, const void *buf,
> + u32 buf_len)
> +{
> + u8 data_dma_width = cdns_ctrl->caps2.data_dma_width;
> +
> + return buf && virt_addr_valid(buf) &&
> + likely(IS_ALIGNED((uintptr_t)buf, data_dma_width)) &&
> + likely(IS_ALIGNED(buf_len, data_dma_width));
> +}
> +
> +static int cadence_nand_wait_for_value(struct cdns_nand_ctrl *cdns_ctrl,
> + u32 reg_offset, u32 timeout_us,
> + u32 mask, bool is_clear)
> +{
> + u32 val;
> + int ret;
> +
> + ret = readl_relaxed_poll_timeout(cdns_ctrl->reg + reg_offset,
> + val, !(val & mask) == is_clear,
> + 10, timeout_us);
> +
> + if (ret < 0) {
> + dev_err(cdns_ctrl->dev,
> + "Timeout while waiting for reg %x with mask %x is clear %d\n",
> + reg_offset, mask, is_clear);
> + }
> +
> + return ret;
> +}
> +
> +static int cadence_nand_set_ecc_enable(struct cdns_nand_ctrl *cdns_ctrl,
> + bool enable)
> +{
> + u32 reg;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);
> +
> + if (enable)
> + reg |= ECC_CONFIG_0_ECC_EN;
> + else
> + reg &= ~ECC_CONFIG_0_ECC_EN;
> +
> + writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);
> +
> + return 0;
> +}
> +
> +static void cadence_nand_set_ecc_strength(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 corr_str_idx)
> +{
> + u32 reg;
> +
> + if (cdns_ctrl->curr_corr_str_idx == corr_str_idx)
> + return;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);
> + reg &= ~ECC_CONFIG_0_CORR_STR;
> + reg |= FIELD_PREP(ECC_CONFIG_0_CORR_STR, corr_str_idx);
> + writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);
> +
> + cdns_ctrl->curr_corr_str_idx = corr_str_idx;
> +}
> +
> +static int cadence_nand_get_ecc_strength_idx(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 strength)
> +{
> + int i, corr_str_idx = -1;
> +
> + for (i = 0; i < BCH_MAX_NUM_CORR_CAPS; i++) {
> + if (cdns_ctrl->ecc_strengths[i] == strength) {
> + corr_str_idx = i;
> + break;
> + }
> + }
> +
> + return corr_str_idx;
> +}
> +
> +static int cadence_nand_set_skip_marker_val(struct cdns_nand_ctrl *cdns_ctrl,
> + u16 marker_value)
> +{
> + u32 reg;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + SKIP_BYTES_CONF);
> + reg &= ~SKIP_BYTES_MARKER_VALUE;
> + reg |= FIELD_PREP(SKIP_BYTES_MARKER_VALUE,
> + marker_value);
> +
> + writel_relaxed(reg, cdns_ctrl->reg + SKIP_BYTES_CONF);
> +
> + return 0;
> +}
> +
> +static int cadence_nand_set_skip_bytes_conf(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 num_of_bytes,
> + u32 offset_value,
> + int enable)
> +{
> + u32 reg, skip_bytes_offset;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + if (!enable) {
> + num_of_bytes = 0;
> + offset_value = 0;
> + }
> +
> + reg = readl_relaxed(cdns_ctrl->reg + SKIP_BYTES_CONF);
> + reg &= ~SKIP_BYTES_NUM_OF_BYTES;
> + reg |= FIELD_PREP(SKIP_BYTES_NUM_OF_BYTES,
> + num_of_bytes);
> + skip_bytes_offset = FIELD_PREP(SKIP_BYTES_OFFSET_VALUE,
> + offset_value);
> +
> + writel_relaxed(reg, cdns_ctrl->reg + SKIP_BYTES_CONF);
> + writel_relaxed(skip_bytes_offset, cdns_ctrl->reg + SKIP_BYTES_OFFSET);
> +
> + return 0;
> +}
> +
> +/* Functions enables/disables hardware detection of erased data */
> +static void cadence_nand_set_erase_detection(struct cdns_nand_ctrl *cdns_ctrl,
> + bool enable,
> + u8 bitflips_threshold)
> +{
> + u32 reg;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + ECC_CONFIG_0);
> +
> + if (enable)
> + reg |= ECC_CONFIG_0_ERASE_DET_EN;
> + else
> + reg &= ~ECC_CONFIG_0_ERASE_DET_EN;
> +
> + writel_relaxed(reg, cdns_ctrl->reg + ECC_CONFIG_0);
> + writel_relaxed(bitflips_threshold, cdns_ctrl->reg + ECC_CONFIG_1);
> +}
> +
> +static int cadence_nand_set_access_width16(struct cdns_nand_ctrl *cdns_ctrl,
> + bool bit_bus16)
> +{
> + u32 reg;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + COMMON_SET);
> +
> + if (!bit_bus16)
> + reg &= ~COMMON_SET_DEVICE_16BIT;
> + else
> + reg |= COMMON_SET_DEVICE_16BIT;
> + writel_relaxed(reg, cdns_ctrl->reg + COMMON_SET);
> +
> + return 0;
> +}
> +
> +static void
> +cadence_nand_clear_interrupt(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_irq_status *irq_status)
> +{
> + writel_relaxed(irq_status->status, cdns_ctrl->reg + INTR_STATUS);
> + writel_relaxed(irq_status->trd_status,
> + cdns_ctrl->reg + TRD_COMP_INT_STATUS);
> + writel_relaxed(irq_status->trd_error,
> + cdns_ctrl->reg + TRD_ERR_INT_STATUS);
> +}
> +
> +static void
> +cadence_nand_read_int_status(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_irq_status *irq_status)
> +{
> + irq_status->status = readl_relaxed(cdns_ctrl->reg + INTR_STATUS);
> + irq_status->trd_status = readl_relaxed(cdns_ctrl->reg
> + + TRD_COMP_INT_STATUS);
> + irq_status->trd_error = readl_relaxed(cdns_ctrl->reg
> + + TRD_ERR_INT_STATUS);
> +}
> +
> +static u32 irq_detected(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_irq_status *irq_status)
> +{
> + cadence_nand_read_int_status(cdns_ctrl, irq_status);
> +
> + return irq_status->status || irq_status->trd_status ||
> + irq_status->trd_error;
> +}
> +
> +static void cadence_nand_reset_irq(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + spin_lock(&cdns_ctrl->irq_lock);
> + memset(&cdns_ctrl->irq_status, 0, sizeof(cdns_ctrl->irq_status));
> + memset(&cdns_ctrl->irq_mask, 0, sizeof(cdns_ctrl->irq_mask));
> + spin_unlock(&cdns_ctrl->irq_lock);
> +}
> +
> +/*
> + * This is the interrupt service routine. It handles all interrupts
> + * sent to this device.
> + */
> +static irqreturn_t cadence_nand_isr(int irq, void *dev_id)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = dev_id;
> + struct cadence_nand_irq_status irq_status;
> + irqreturn_t result = IRQ_NONE;
> +
> + spin_lock(&cdns_ctrl->irq_lock);
> +
> + if (irq_detected(cdns_ctrl, &irq_status)) {
> + /* Handle interrupt. */
> + /* First acknowledge it. */
> + cadence_nand_clear_interrupt(cdns_ctrl, &irq_status);
> + /* Status in the device context for someone to read. */
> + cdns_ctrl->irq_status.status |= irq_status.status;
> + cdns_ctrl->irq_status.trd_status |= irq_status.trd_status;
> + cdns_ctrl->irq_status.trd_error |= irq_status.trd_error;
> + /* Notify anyone who cares that it happened. */
> + complete(&cdns_ctrl->complete);
> + /* Tell the OS that we've handled this. */
> + result = IRQ_HANDLED;
> + }
> + spin_unlock(&cdns_ctrl->irq_lock);

Your locking scheme seems wrong (maybe I'm not going deep enough in the
code), can you please try with LOCKDEP enabled?

> +
> + return result;
> +}
> +
> +static void cadence_nand_set_irq_mask(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_irq_status *irq_mask)
> +{
> + writel_relaxed(INTR_ENABLE_INTR_EN | irq_mask->status,
> + cdns_ctrl->reg + INTR_ENABLE);
> +
> + writel_relaxed(irq_mask->trd_error,
> + cdns_ctrl->reg + TRD_ERR_INT_STATUS_EN);
> +}
> +
> +static void
> +cadence_nand_wait_for_irq(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_irq_status *irq_mask,
> + struct cadence_nand_irq_status *irq_status)
> +{
> + unsigned long timeout = msecs_to_jiffies(10000);
> + unsigned long time_left;
> +
> + time_left = wait_for_completion_timeout(&cdns_ctrl->complete,
> + timeout);
> +
> + *irq_status = cdns_ctrl->irq_status;
> + if (time_left == 0) {
> + /* Timeout error. */
> + dev_err(cdns_ctrl->dev, "timeout occurred:\n");
> + dev_err(cdns_ctrl->dev, "\tstatus = 0x%x, mask = 0x%x\n",
> + irq_status->status, irq_mask->status);
> + dev_err(cdns_ctrl->dev,
> + "\ttrd_status = 0x%x, trd_status mask = 0x%x\n",
> + irq_status->trd_status, irq_mask->trd_status);
> + dev_err(cdns_ctrl->dev,
> + "\t trd_error = 0x%x, trd_error mask = 0x%x\n",
> + irq_status->trd_error, irq_mask->trd_error);
> + }
> +}
> +
> +static void
> +cadence_nand_irq_cleanup(int irqnum, struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + /* Disable interrupts. */
> + writel_relaxed(INTR_ENABLE_INTR_EN, cdns_ctrl->reg + INTR_ENABLE);
> +}

Would you mind moving this helper to the bottom, where it is used
(closer to the remove/cleanup functions).

> +
> +/* Execute generic command on NAND controller. */
> +static int cadence_nand_generic_cmd_send(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 chip_nr,
> + u64 mini_ctrl_cmd)
> +{
> + u32 mini_ctrl_cmd_l, mini_ctrl_cmd_h, reg;
> +
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_CS, chip_nr);
> + mini_ctrl_cmd_l = mini_ctrl_cmd & 0xFFFFFFFF;
> + mini_ctrl_cmd_h = mini_ctrl_cmd >> 32;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + cadence_nand_reset_irq(cdns_ctrl);
> +
> + writel_relaxed(mini_ctrl_cmd_l, cdns_ctrl->reg + CMD_REG2);
> + writel_relaxed(mini_ctrl_cmd_h, cdns_ctrl->reg + CMD_REG3);
> +
> + /* Select generic command. */
> + reg = FIELD_PREP(CMD_REG0_CT, CMD_REG0_CT_GEN);
> + /* Thread number. */
> + reg |= FIELD_PREP(CMD_REG0_TN, 0);
> +
> + /* Issue command. */
> + writel_relaxed(reg, cdns_ctrl->reg + CMD_REG0);
> +
> + return 0;
> +}
> +
> +/* Wait for data on slave DMA interface. */
> +static int cadence_nand_wait_on_sdma(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 *out_sdma_trd,
> + u32 *out_sdma_size)
> +{
> + struct cadence_nand_irq_status irq_mask, irq_status;
> +
> + irq_mask.trd_status = 0;
> + irq_mask.trd_error = 0;
> + irq_mask.status = INTR_STATUS_SDMA_TRIGG
> + | INTR_STATUS_SDMA_ERR
> + | INTR_STATUS_UNSUPP_CMD;
> +
> + cadence_nand_set_irq_mask(cdns_ctrl, &irq_mask);
> + cadence_nand_wait_for_irq(cdns_ctrl, &irq_mask, &irq_status);
> + if (irq_status.status == 0) {
> + dev_err(cdns_ctrl->dev, "Timeout while waiting for SDMA\n");
> + return -ETIMEDOUT;
> + }
> +
> + if (irq_status.status & INTR_STATUS_SDMA_TRIGG) {
> + *out_sdma_size = readl_relaxed(cdns_ctrl->reg + SDMA_SIZE);
> + *out_sdma_trd = readl_relaxed(cdns_ctrl->reg + SDMA_TRD_NUM);
> + *out_sdma_trd =
> + FIELD_GET(SDMA_TRD_NUM_SDMA_TRD, *out_sdma_trd);
> + } else {
> + dev_err(cdns_ctrl->dev, "SDMA error - irq_status %x\n",
> + irq_status.status);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static void cadence_nand_get_caps(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + u32 reg;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + CTRL_FEATURES);
> +
> + cdns_ctrl->caps2.max_banks = 1 << FIELD_GET(CTRL_FEATURES_N_BANKS, reg);
> +
> + if (FIELD_GET(CTRL_FEATURES_DMA_DWITH64, reg))
> + cdns_ctrl->caps2.data_dma_width = 8;
> + else
> + cdns_ctrl->caps2.data_dma_width = 4;
> +
> + if (reg & CTRL_FEATURES_CONTROL_DATA)
> + cdns_ctrl->caps2.data_control_supp = 1;
> +
> + if (reg & (CTRL_FEATURES_NVDDR_2_3
> + | CTRL_FEATURES_NVDDR))
> + cdns_ctrl->caps2.is_phy_type_dll = 1;
> +}
> +
> +/* Prepare CDMA descriptor. */
> +static void
> +cadence_nand_cdma_desc_prepare(struct cadence_nand_cdma_desc *cdma_desc,
> + char nf_mem, u32 flash_ptr, char *mem_ptr,
> + char *ctrl_data_ptr, u16 ctype)
> +{
> + memset(cdma_desc, 0, sizeof(struct cadence_nand_cdma_desc));
> +
> + /* Set fields for one descriptor. */
> + cdma_desc->flash_pointer = (nf_mem << CDMA_CFPTR_MEM_SHIFT)
> + + flash_ptr;
> + cdma_desc->command_flags |= CDMA_CF_DMA_MASTER;
> + cdma_desc->command_flags |= CDMA_CF_INT;
> +
> + cdma_desc->memory_pointer = (uintptr_t)mem_ptr;
> + cdma_desc->status = 0;
> + cdma_desc->sync_flag_pointer = 0;
> + cdma_desc->sync_arguments = 0;
> +
> + cdma_desc->command_type = ctype;
> + cdma_desc->ctrl_data_ptr = (uintptr_t)ctrl_data_ptr;
> +}
> +
> +static u8 cadence_nand_check_desc_error(struct cdns_nand_ctrl *cdns_ctrl,
> + u32 desc_status)
> +{
> + if (desc_status & CDMA_CS_ERP)
> + return STAT_ERASED;
> +
> + if (desc_status & CDMA_CS_UNCE)
> + return STAT_ECC_UNCORR;
> +
> + if (desc_status & CDMA_CS_ERR) {
> + dev_err(cdns_ctrl->dev, ":CDMA desc error flag detected.\n");
> + return STAT_FAIL;
> + }
> +
> + if (FIELD_GET(CDMA_CS_MAXERR, desc_status))
> + return STAT_ECC_CORR;
> +
> + return STAT_FAIL;
> +}
> +
> +static int cadence_nand_cdma_finish(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_cdma_desc *cdma_desc)
> +{
> + struct cadence_nand_cdma_desc *desc_ptr = cdma_desc;
> + u8 status = STAT_BUSY;
> +
> + if (desc_ptr->status & CDMA_CS_FAIL) {
> + status = cadence_nand_check_desc_error(cdns_ctrl,
> + desc_ptr->status);
> + dev_err(cdns_ctrl->dev, ":CDMA error %x\n", desc_ptr->status);
> + } else if (desc_ptr->status & CDMA_CS_COMP) {
> + /* Descriptor finished with no errors. */
> + if (desc_ptr->command_flags & CDMA_CF_CONT) {
> + dev_info(cdns_ctrl->dev, "DMA unsupported flag is set");
> + status = STAT_UNKNOWN;
> + } else {
> + /* Last descriptor. */
> + status = STAT_OK;
> + }
> + }
> +
> + return status;
> +}
> +
> +static int cadence_nand_cdma_send(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 thread)
> +{
> + u32 reg;
> + int status;
> +
> + /* Wait for thread ready. */
> + status = cadence_nand_wait_for_value(cdns_ctrl, TRD_STATUS,
> + 1000000,
> + 1U << thread, true);
> + if (status)
> + return status;
> +
> + cadence_nand_reset_irq(cdns_ctrl);
> +
> + writel_relaxed((u32)cdns_ctrl->dma_cdma_desc,
> + cdns_ctrl->reg + CMD_REG2);
> + writel_relaxed(0, cdns_ctrl->reg + CMD_REG3);
> +
> + /* Select CDMA mode. */
> + reg = FIELD_PREP(CMD_REG0_CT, CMD_REG0_CT_CDMA);
> + /* Thread number. */
> + reg |= FIELD_PREP(CMD_REG0_TN, thread);
> + /* Issue command. */
> + writel_relaxed(reg, cdns_ctrl->reg + CMD_REG0);
> +
> + return 0;
> +}
> +
> +/* Send SDMA command and wait for finish. */
> +static u32
> +cadence_nand_cdma_send_and_wait(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 thread)
> +{
> + struct cadence_nand_irq_status irq_mask, irq_status = {0};
> + int status;
> +
> + irq_mask.trd_status = 1 << thread;
> + irq_mask.trd_error = 1 << thread;
> + irq_mask.status = INTR_STATUS_CDMA_TERR;
> +
> + cadence_nand_set_irq_mask(cdns_ctrl, &irq_mask);
> +
> + status = cadence_nand_cdma_send(cdns_ctrl, thread);
> + if (status)
> + return status;
> +
> + cadence_nand_wait_for_irq(cdns_ctrl, &irq_mask, &irq_status);
> +
> + if (irq_status.status == 0 && irq_status.trd_status == 0 &&
> + irq_status.trd_error == 0) {
> + dev_err(cdns_ctrl->dev, "CDMA command timeout\n");
> + return -ETIMEDOUT;
> + }
> + if (irq_status.status & irq_mask.status) {
> + dev_err(cdns_ctrl->dev, "CDMA command failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * ECC size depends on configured ECC strength and on maximum supported
> + * ECC step size.
> + */
> +static int cadence_nand_calc_ecc_bytes(int max_step_size, int strength)
> +{
> + int nbytes = DIV_ROUND_UP(fls(8 * max_step_size) * strength, 8);
> +
> + return ALIGN(nbytes, 2);
> +}
> +
> +#define CADENCE_NAND_CALC_ECC_BYTES(max_step_size) \
> + static int \
> + cadence_nand_calc_ecc_bytes_##max_step_size(int step_size, \
> + int strength)\
> + {\
> + return cadence_nand_calc_ecc_bytes(max_step_size, strength);\
> + }
> +
> +CADENCE_NAND_CALC_ECC_BYTES(256)
> +CADENCE_NAND_CALC_ECC_BYTES(512)
> +CADENCE_NAND_CALC_ECC_BYTES(1024)
> +CADENCE_NAND_CALC_ECC_BYTES(2048)
> +CADENCE_NAND_CALC_ECC_BYTES(4096)
> +
> +/* Function reads BCH capabilities. */
> +static int cadence_nand_read_bch_caps(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + struct nand_ecc_caps *ecc_caps = &cdns_ctrl->ecc_caps;
> + int max_step_size = 0, nstrengths, i;
> + u32 reg;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_0);
> + cdns_ctrl->ecc_strengths[0] = FIELD_GET(BCH_CFG_0_CORR_CAP_0, reg);
> + cdns_ctrl->ecc_strengths[1] = FIELD_GET(BCH_CFG_0_CORR_CAP_1, reg);
> + cdns_ctrl->ecc_strengths[2] = FIELD_GET(BCH_CFG_0_CORR_CAP_2, reg);
> + cdns_ctrl->ecc_strengths[3] = FIELD_GET(BCH_CFG_0_CORR_CAP_3, reg);
> +
> + reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_1);
> + cdns_ctrl->ecc_strengths[4] = FIELD_GET(BCH_CFG_1_CORR_CAP_4, reg);
> + cdns_ctrl->ecc_strengths[5] = FIELD_GET(BCH_CFG_1_CORR_CAP_5, reg);
> + cdns_ctrl->ecc_strengths[6] = FIELD_GET(BCH_CFG_1_CORR_CAP_6, reg);
> + cdns_ctrl->ecc_strengths[7] = FIELD_GET(BCH_CFG_1_CORR_CAP_7, reg);
> +
> + reg = readl_relaxed(cdns_ctrl->reg + BCH_CFG_2);
> + cdns_ctrl->ecc_stepinfos[0].stepsize =
> + FIELD_GET(BCH_CFG_2_SECT_0, reg);
> +
> + cdns_ctrl->ecc_stepinfos[1].stepsize =
> + FIELD_GET(BCH_CFG_2_SECT_1, reg);
> +
> + nstrengths = 0;
> + for (i = 0; i < BCH_MAX_NUM_CORR_CAPS; i++) {
> + if (cdns_ctrl->ecc_strengths[i] != 0)
> + nstrengths++;
> + }
> +
> + ecc_caps->nstepinfos = 0;
> + for (i = 0; i < BCH_MAX_NUM_SECTOR_SIZES; i++) {
> + /* ECC strengths are common for all step infos. */
> + cdns_ctrl->ecc_stepinfos[i].nstrengths = nstrengths;
> + cdns_ctrl->ecc_stepinfos[i].strengths =
> + cdns_ctrl->ecc_strengths;
> +
> + if (cdns_ctrl->ecc_stepinfos[i].stepsize != 0)
> + ecc_caps->nstepinfos++;
> +
> + if (cdns_ctrl->ecc_stepinfos[i].stepsize > max_step_size)
> + max_step_size = cdns_ctrl->ecc_stepinfos[i].stepsize;
> + }
> + ecc_caps->stepinfos = &cdns_ctrl->ecc_stepinfos[0];
> +
> + switch (max_step_size) {
> + case 256:
> + ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_256;
> + break;
> + case 512:
> + ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_512;
> + break;
> + case 1024:
> + ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_1024;
> + break;
> + case 2048:
> + ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_2048;
> + break;
> + case 4096:
> + ecc_caps->calc_ecc_bytes = &cadence_nand_calc_ecc_bytes_4096;
> + break;
> + default:
> + dev_err(cdns_ctrl->dev,
> + "Unsupported sector size(ecc step size) %d\n",
> + max_step_size);
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +/* Hardware initialization. */
> +static int cadence_nand_hw_init(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + int status;
> + u32 reg;
> +
> + status = cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_INIT_COMP, false);
> + if (status)
> + return status;
> +
> + reg = readl_relaxed(cdns_ctrl->reg + CTRL_VERSION);
> +
> + dev_info(cdns_ctrl->dev,
> + "%s: cadence nand controller version reg %x\n",
> + __func__, reg);
> +
> + /* Disable cache and multiplane. */
> + writel_relaxed(0, cdns_ctrl->reg + MULTIPLANE_CFG);
> + writel_relaxed(0, cdns_ctrl->reg + CACHE_CFG);

Cache?

> +
> + /* Clear all interrupts. */
> + writel_relaxed(0xFFFFFFFF, cdns_ctrl->reg + INTR_STATUS);
> +
> + cadence_nand_get_caps(cdns_ctrl);
> + cadence_nand_read_bch_caps(cdns_ctrl);
> +
> + /*
> + * Set IO width access to 8.
> + * It is because during SW device discovering width access
> + * is expected to be 8.
> + */
> + status = cadence_nand_set_access_width16(cdns_ctrl, false);
> +
> + return status;
> +}
> +
> +#define TT_MAIN_OOB_AREAS 2
> +#define TT_RAW_PAGE 3
> +#define TT_BBM 4
> +#define TT_MAIN_OOB_AREA_EXT 5
> +
> +/* Prepare size of data to transfer. */
> +static void
> +cadence_nand_prepare_data_size(struct nand_chip *chip,
> + int transfer_type)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + u32 sec_size = 0, offset = 0, sec_cnt = 1;
> + u32 last_sec_size = cdns_chip->sector_size;
> + u32 ecc_size = chip->ecc.bytes;
> + u32 data_ctrl_size = 0;
> + u32 reg = 0;
> +
> + if (cdns_ctrl->curr_trans_type == transfer_type)
> + return;
> +
> + switch (transfer_type) {
> + case TT_MAIN_OOB_AREA_EXT:
> + sec_cnt = cdns_chip->sector_count;
> + sec_size = cdns_chip->sector_size;
> + data_ctrl_size = cdns_chip->avail_oob_size;
> + break;
> + case TT_MAIN_OOB_AREAS:
> + sec_cnt = cdns_chip->sector_count;
> + last_sec_size = cdns_chip->sector_size
> + + cdns_chip->avail_oob_size;
> + sec_size = cdns_chip->sector_size;
> + break;
> + case TT_RAW_PAGE:
> + last_sec_size = mtd->writesize + mtd->oobsize;
> + break;
> + case TT_BBM:
> + offset = mtd->writesize + cdns_chip->bbm_offs;
> + last_sec_size = 8;
> + break;
> + }
> +
> + reg = 0;
> + reg |= FIELD_PREP(TRAN_CFG_0_OFFSET, offset);
> + reg |= FIELD_PREP(TRAN_CFG_0_SEC_CNT, sec_cnt);
> + writel_relaxed(reg, cdns_ctrl->reg + TRAN_CFG_0);
> +
> + reg = 0;
> + reg |= FIELD_PREP(TRAN_CFG_1_LAST_SEC_SIZE, last_sec_size);
> + reg |= FIELD_PREP(TRAN_CFG_1_SECTOR_SIZE, sec_size);
> + writel_relaxed(reg, cdns_ctrl->reg + TRAN_CFG_1);
> +
> + if (cdns_ctrl->caps2.data_control_supp == 1) {
> + reg = readl_relaxed(cdns_ctrl->reg + CONTROL_DATA_CTRL);
> + reg &= ~CONTROL_DATA_CTRL_SIZE;
> + reg |= FIELD_PREP(CONTROL_DATA_CTRL_SIZE, data_ctrl_size);
> + writel_relaxed(reg, cdns_ctrl->reg + CONTROL_DATA_CTRL);
> + }
> +
> + cdns_ctrl->curr_trans_type = transfer_type;
> +}
> +
> +static int
> +cadence_nand_cdma_transfer(struct cdns_nand_ctrl *cdns_ctrl, u8 chip_nr,
> + int page, void *buf, void *ctrl_dat, u32 buf_size,
> + u32 ctrl_dat_size, enum dma_data_direction dir,
> + bool with_ecc)
> +{
> + struct cadence_nand_cdma_desc *cdma_desc = cdns_ctrl->cdma_desc;
> + dma_addr_t dma_buf, dma_ctrl_dat = 0;
> + u8 thread_nr = chip_nr;
> + int status;
> + u16 ctype;
> +
> + if (dir == DMA_FROM_DEVICE)
> + ctype = CDMA_CT_RD;
> + else
> + ctype = CDMA_CT_WR;
> +
> + cadence_nand_set_ecc_enable(cdns_ctrl, with_ecc);
> +
> + dma_buf = dma_map_single(cdns_ctrl->dev, buf, buf_size, dir);
> + if (dma_mapping_error(cdns_ctrl->dev, dma_buf)) {
> + dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
> + return -EIO;
> + }
> +
> + if (ctrl_dat && ctrl_dat_size) {
> + dma_ctrl_dat = dma_map_single(cdns_ctrl->dev, ctrl_dat,
> + ctrl_dat_size, dir);
> + if (dma_mapping_error(cdns_ctrl->dev, dma_ctrl_dat)) {
> + dma_unmap_single(cdns_ctrl->dev, dma_buf,
> + buf_size, dir);
> + dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
> + return -EIO;
> + }
> + }
> +
> + cadence_nand_cdma_desc_prepare(cdma_desc, chip_nr, page,
> + (void *)dma_buf, (void *)dma_ctrl_dat,
> + ctype);
> +
> + status = cadence_nand_cdma_send_and_wait(cdns_ctrl, thread_nr);
> +
> + dma_unmap_single(cdns_ctrl->dev, dma_buf,
> + buf_size, dir);
> +
> + if (ctrl_dat && ctrl_dat_size)
> + dma_unmap_single(cdns_ctrl->dev, dma_ctrl_dat,
> + ctrl_dat_size, dir);
> + if (status)
> + return status;
> +
> + return cadence_nand_cdma_finish(cdns_ctrl, cdns_ctrl->cdma_desc);
> +}
> +
> +static void cadence_nand_set_timings(struct cdns_nand_ctrl *cdns_ctrl,
> + struct cadence_nand_timings *t)
> +{
> + writel_relaxed(t->async_toggle_timings,
> + cdns_ctrl->reg + ASYNC_TOGGLE_TIMINGS);
> + writel_relaxed(t->timings0, cdns_ctrl->reg + TIMINGS0);
> + writel_relaxed(t->timings1, cdns_ctrl->reg + TIMINGS1);
> + writel_relaxed(t->timings2, cdns_ctrl->reg + TIMINGS2);
> +
> + if (cdns_ctrl->caps2.is_phy_type_dll)
> + writel_relaxed(t->dll_phy_ctrl, cdns_ctrl->reg + DLL_PHY_CTRL);
> +
> + writel_relaxed(t->phy_ctrl, cdns_ctrl->reg + PHY_CTRL);
> +
> + if (cdns_ctrl->caps2.is_phy_type_dll) {
> + writel_relaxed(0, cdns_ctrl->reg + PHY_TSEL);
> + writel_relaxed(2, cdns_ctrl->reg + PHY_DQ_TIMING);
> + writel_relaxed(t->phy_dqs_timing,
> + cdns_ctrl->reg + PHY_DQS_TIMING);
> + writel_relaxed(t->phy_gate_lpbk_ctrl,
> + cdns_ctrl->reg + PHY_GATE_LPBK_CTRL);
> + writel_relaxed(PHY_DLL_MASTER_CTRL_BYPASS_MODE,
> + cdns_ctrl->reg + PHY_DLL_MASTER_CTRL);
> + writel_relaxed(0, cdns_ctrl->reg + PHY_DLL_SLAVE_CTRL);
> + }
> +}
> +
> +static int cadence_nand_select_target(struct nand_chip *chip)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> +
> + if (chip == cdns_ctrl->selected_chip)
> + return 0;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + cadence_nand_set_timings(cdns_ctrl, &cdns_chip->timings);
> +
> + cadence_nand_set_ecc_strength(cdns_ctrl,
> + cdns_chip->corr_str_idx);
> +
> + cadence_nand_set_erase_detection(cdns_ctrl, true,
> + chip->ecc.strength);
> +
> + cdns_ctrl->curr_trans_type = -1;
> + cdns_ctrl->selected_chip = chip;
> +
> + return 0;
> +}
> +
> +static int cadence_nand_erase(struct nand_chip *chip, u32 page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + int status;
> + u8 thread_nr = cdns_chip->cs[chip->cur_cs];
> +
> + cadence_nand_cdma_desc_prepare(cdns_ctrl->cdma_desc,
> + cdns_chip->cs[chip->cur_cs],
> + page, NULL, NULL,
> + CDMA_CT_ERASE);
> + status = cadence_nand_cdma_send_and_wait(cdns_ctrl, thread_nr);
> + if (status) {
> + dev_err(cdns_ctrl->dev, "erase operation failed\n");
> + return -EIO;
> + }
> +
> + status = cadence_nand_cdma_finish(cdns_ctrl, cdns_ctrl->cdma_desc);
> + if (status)
> + return status;
> +
> + return 0;
> +}
> +
> +static int cadence_nand_read_bbm(struct nand_chip *chip, int page, u8 *buf)
> +{
> + int status;
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> +
> + cadence_nand_prepare_data_size(chip, TT_BBM);
> +
> + cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);
> +
> + /*
> + * Read only bad block marker from offset
> + * defined by a memory manufacturer.
> + */
> + status = cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, cdns_ctrl->buf, NULL,
> + mtd->oobsize,
> + 0, DMA_FROM_DEVICE, false);
> + if (status) {
> + dev_err(cdns_ctrl->dev, "read BBM failed\n");
> + return -EIO;
> + }
> +
> + memcpy(buf + cdns_chip->bbm_offs, cdns_ctrl->buf, cdns_chip->bbm_len);
> +
> + return 0;
> +}

Not sure this function is relevant, see below.

> +
> +static int cadence_nand_write_page(struct nand_chip *chip,
> + const u8 *buf, int oob_required,
> + int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + int status;
> + u16 marker_val = 0xFFFF;
> +
> + status = cadence_nand_select_target(chip);
> + if (status)
> + return status;
> +
> + cadence_nand_set_skip_bytes_conf(cdns_ctrl, cdns_chip->bbm_len,
> + mtd->writesize
> + + cdns_chip->bbm_offs,
> + 1);
> +
> + if (oob_required) {
> + marker_val = *(u16 *)(chip->oob_poi
> + + cdns_chip->bbm_offs);
> + } else {
> + /* Set oob data to 0xFF. */
> + memset(cdns_ctrl->buf + mtd->writesize, 0xFF,
> + cdns_chip->avail_oob_size);
> + }
> +
> + cadence_nand_set_skip_marker_val(cdns_ctrl, marker_val);
> +
> + cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREA_EXT);
> +
> + if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, mtd->writesize) &&
> + cdns_ctrl->caps2.data_control_supp) {
> + u8 *oob;
> +
> + if (oob_required)
> + oob = chip->oob_poi;
> + else
> + oob = cdns_ctrl->buf + mtd->writesize;
> +
> + status = cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, (void *)buf, oob,
> + mtd->writesize,
> + cdns_chip->avail_oob_size,
> + DMA_TO_DEVICE, true);
> + if (status) {
> + dev_err(cdns_ctrl->dev, "write page failed\n");
> + return -EIO;
> + }
> +
> + return 0;
> + }
> +
> + if (oob_required) {
> + /* Transfer the data to the oob area. */
> + memcpy(cdns_ctrl->buf + mtd->writesize, chip->oob_poi,
> + cdns_chip->avail_oob_size);
> + }
> +
> + memcpy(cdns_ctrl->buf, buf, mtd->writesize);
> +
> + cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREAS);
> +
> + return cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, cdns_ctrl->buf, NULL,
> + mtd->writesize
> + + cdns_chip->avail_oob_size,
> + 0, DMA_TO_DEVICE, true);
> +}
> +
> +static int cadence_nand_write_oob(struct nand_chip *chip, int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> +
> + memset(cdns_ctrl->buf, 0xFF, mtd->writesize);
> +
> + return cadence_nand_write_page(chip, cdns_ctrl->buf, 1, page);
> +}
> +
> +static int cadence_nand_write_page_raw(struct nand_chip *chip,
> + const u8 *buf, int oob_required,
> + int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + int writesize = mtd->writesize;
> + int oobsize = mtd->oobsize;
> + int ecc_steps = chip->ecc.steps;
> + int ecc_size = chip->ecc.size;
> + int ecc_bytes = chip->ecc.bytes;
> + void *tmp_buf = cdns_ctrl->buf;
> + int oob_skip = cdns_chip->bbm_len;
> + size_t size = writesize + oobsize;
> + int i, pos, len;
> + int status = 0;
> +
> + status = cadence_nand_select_target(chip);
> + if (status)
> + return status;
> +
> + /*
> + * Fill the buffer with 0xff first except the full page transfer.
> + * This simplifies the logic.
> + */
> + if (!buf || !oob_required)
> + memset(tmp_buf, 0xff, size);
> +
> + cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);
> +
> + /* Arrange the buffer for syndrome payload/ecc layout. */
> + if (buf) {
> + for (i = 0; i < ecc_steps; i++) {
> + pos = i * (ecc_size + ecc_bytes);
> + len = ecc_size;
> +
> + if (pos >= writesize)
> + pos += oob_skip;
> + else if (pos + len > writesize)
> + len = writesize - pos;
> +
> + memcpy(tmp_buf + pos, buf, len);
> + buf += len;
> + if (len < ecc_size) {
> + len = ecc_size - len;
> + memcpy(tmp_buf + writesize + oob_skip, buf,
> + len);
> + buf += len;
> + }
> + }
> + }
> +
> + if (oob_required) {
> + const u8 *oob = chip->oob_poi;
> + u32 oob_data_offset = (cdns_chip->sector_count - 1) *
> + (cdns_chip->sector_size + chip->ecc.bytes)
> + + cdns_chip->sector_size + oob_skip;
> +
> + /* BBM at the beginning of the OOB area. */
> + memcpy(tmp_buf + writesize, oob, oob_skip);
> +
> + /* OOB free. */
> + memcpy(tmp_buf + oob_data_offset, oob,
> + cdns_chip->avail_oob_size);
> + oob += cdns_chip->avail_oob_size;
> +
> + /* OOB ECC. */
> + for (i = 0; i < ecc_steps; i++) {
> + pos = ecc_size + i * (ecc_size + ecc_bytes);
> + if (i == (ecc_steps - 1))
> + pos += cdns_chip->avail_oob_size;
> +
> + len = ecc_bytes;
> +
> + if (pos >= writesize)
> + pos += oob_skip;
> + else if (pos + len > writesize)
> + len = writesize - pos;
> +
> + memcpy(tmp_buf + pos, oob, len);
> + oob += len;
> + if (len < ecc_bytes) {
> + len = ecc_bytes - len;
> + memcpy(tmp_buf + writesize + oob_skip, oob,
> + len);
> + oob += len;
> + }
> + }
> + }
> +
> + cadence_nand_prepare_data_size(chip, TT_RAW_PAGE);
> +
> + return cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, cdns_ctrl->buf, NULL,
> + mtd->writesize +
> + mtd->oobsize,
> + 0, DMA_TO_DEVICE, false);
> +}
> +
> +static int cadence_nand_write_oob_raw(struct nand_chip *chip,
> + int page)
> +{
> + return cadence_nand_write_page_raw(chip, NULL, true, page);
> +}
> +
> +static int cadence_nand_read_page(struct nand_chip *chip,
> + u8 *buf, int oob_required, int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + int status = 0;
> + int ecc_err_count = 0;
> +
> + status = cadence_nand_select_target(chip);
> + if (status)
> + return status;
> +
> + cadence_nand_set_skip_bytes_conf(cdns_ctrl, cdns_chip->bbm_len,
> + mtd->writesize
> + + cdns_chip->bbm_offs, 1);
> +
> + /*
> + * If data buffer can be accessed by DMA and data_control feature
> + * is supported then transfer data and oob directly.
> + */
> + if (cadence_nand_dma_buf_ok(cdns_ctrl, buf, mtd->writesize) &&
> + cdns_ctrl->caps2.data_control_supp) {
> + u8 *oob;
> +
> + if (oob_required)
> + oob = chip->oob_poi;
> + else
> + oob = cdns_ctrl->buf + mtd->writesize;
> +
> + cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREA_EXT);
> + status = cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, buf, oob,
> + mtd->writesize,
> + cdns_chip->avail_oob_size,
> + DMA_FROM_DEVICE, true);
> + /* Otherwise use bounce buffer. */
> + } else {
> + cadence_nand_prepare_data_size(chip, TT_MAIN_OOB_AREAS);
> + status = cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, cdns_ctrl->buf,
> + NULL, mtd->writesize
> + + cdns_chip->avail_oob_size,
> + 0, DMA_FROM_DEVICE, true);
> +
> + memcpy(buf, cdns_ctrl->buf, mtd->writesize);
> + if (oob_required)
> + memcpy(chip->oob_poi,
> + cdns_ctrl->buf + mtd->writesize,
> + mtd->oobsize);
> + }
> +
> + switch (status) {
> + case STAT_ECC_UNCORR:
> + mtd->ecc_stats.failed++;
> + ecc_err_count++;
> + break;
> + case STAT_ECC_CORR:
> + ecc_err_count = FIELD_GET(CDMA_CS_MAXERR,
> + cdns_ctrl->cdma_desc->status);
> + mtd->ecc_stats.corrected += ecc_err_count;

Is this value the maximum number of bitflips in each chunk of the page?
If it returns the total number of bitflips corrected in the entire page
we have a problem.

> + break;
> + case STAT_ERASED:
> + case STAT_OK:
> + break;
> + default:
> + dev_err(cdns_ctrl->dev, "read page failed\n");
> + return -EIO;
> + }
> +
> + if (oob_required)
> + if (cadence_nand_read_bbm(chip, page, chip->oob_poi))
> + return -EIO;

Do we really care about the BBM at this level? If we are requested to
read the page, I suppose we must do what is in our hands to return the
data? Normally this is handled in userspace directly.

> +
> + return ecc_err_count;
> +}
> +
> +/* Reads OOB data from the device. */
> +static int cadence_nand_read_oob(struct nand_chip *chip, int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> +
> + return cadence_nand_read_page(chip, cdns_ctrl->buf, 1, page);
> +}
> +
> +static int cadence_nand_read_page_raw(struct nand_chip *chip,
> + u8 *buf, int oob_required, int page)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + int oob_skip = cdns_chip->bbm_len;
> + int writesize = mtd->writesize;
> + int ecc_steps = chip->ecc.steps;
> + int ecc_size = chip->ecc.size;
> + int ecc_bytes = chip->ecc.bytes;
> + void *tmp_buf = cdns_ctrl->buf;
> + int i, pos, len;
> + int status = 0;
> +
> + status = cadence_nand_select_target(chip);
> + if (status)
> + return status;
> +
> + cadence_nand_set_skip_bytes_conf(cdns_ctrl, 0, 0, 0);
> +
> + cadence_nand_prepare_data_size(chip, TT_RAW_PAGE);
> + status = cadence_nand_cdma_transfer(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + page, cdns_ctrl->buf, NULL,
> + mtd->writesize
> + + mtd->oobsize,
> + 0, DMA_FROM_DEVICE, false);
> +
> + switch (status) {
> + case STAT_ERASED:
> + case STAT_OK:
> + break;
> + default:
> + dev_err(cdns_ctrl->dev, "read raw page failed\n");
> + return -EIO;
> + }
> +
> + /* Arrange the buffer for syndrome payload/ecc layout. */
> + if (buf) {
> + for (i = 0; i < ecc_steps; i++) {
> + pos = i * (ecc_size + ecc_bytes);
> + len = ecc_size;
> +
> + if (pos >= writesize)
> + pos += oob_skip;
> + else if (pos + len > writesize)
> + len = writesize - pos;
> +
> + memcpy(buf, tmp_buf + pos, len);
> + buf += len;
> + if (len < ecc_size) {
> + len = ecc_size - len;
> + memcpy(buf, tmp_buf + writesize + oob_skip,
> + len);
> + buf += len;
> + }
> + }
> + }
> +
> + if (oob_required) {
> + u8 *oob = chip->oob_poi;
> + u32 oob_data_offset = (cdns_chip->sector_count - 1) *
> + (cdns_chip->sector_size + chip->ecc.bytes)
> + + cdns_chip->sector_size + oob_skip;
> +
> + /* OOB free. */
> + memcpy(oob, tmp_buf + oob_data_offset,
> + cdns_chip->avail_oob_size);
> +
> + /* BBM at the beginning of the OOB area. */
> + memcpy(oob, tmp_buf + writesize, oob_skip);
> +
> + oob += cdns_chip->avail_oob_size;
> +
> + /* OOB ECC */
> + for (i = 0; i < ecc_steps; i++) {
> + pos = ecc_size + i * (ecc_size + ecc_bytes);
> + len = ecc_bytes;
> +
> + if (i == (ecc_steps - 1))
> + pos += cdns_chip->avail_oob_size;
> +
> + if (pos >= writesize)
> + pos += oob_skip;
> + else if (pos + len > writesize)
> + len = writesize - pos;
> +
> + memcpy(oob, tmp_buf + pos, len);
> + oob += len;
> + if (len < ecc_bytes) {
> + len = ecc_bytes - len;
> + memcpy(oob, tmp_buf + writesize + oob_skip,
> + len);
> + oob += len;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int cadence_nand_read_oob_raw(struct nand_chip *chip,
> + int page)
> +{
> + return cadence_nand_read_page_raw(chip, NULL, true, page);
> +}
> +
> +static void cadence_nand_slave_dma_transfer_finished(void *data)
> +{
> + struct completion *finished = data;
> +
> + complete(finished);
> +}
> +
> +static int cadence_nand_slave_dma_transfer(struct cdns_nand_ctrl *cdns_ctrl,
> + void *buf,
> + dma_addr_t dev_dma, size_t len,
> + enum dma_data_direction dir)
> +{
> + DECLARE_COMPLETION_ONSTACK(finished);
> + struct dma_chan *chan;
> + struct dma_device *dma_dev;
> + dma_addr_t src_dma, dst_dma, buf_dma;
> + struct dma_async_tx_descriptor *tx;
> + dma_cookie_t cookie;
> +
> + chan = cdns_ctrl->dmac;
> + dma_dev = chan->device;
> +
> + buf_dma = dma_map_single(dma_dev->dev, buf, len, dir);
> + if (dma_mapping_error(dma_dev->dev, buf_dma)) {
> + dev_err(cdns_ctrl->dev, "Failed to map DMA buffer\n");
> + goto err;
> + }
> +
> + if (dir == DMA_FROM_DEVICE) {
> + src_dma = cdns_ctrl->io.dma;
> + dst_dma = buf_dma;
> + } else {
> + src_dma = buf_dma;
> + dst_dma = cdns_ctrl->io.dma;
> + }
> +
> + tx = dmaengine_prep_dma_memcpy(cdns_ctrl->dmac, dst_dma, src_dma, len,
> + DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> + if (!tx) {
> + dev_err(cdns_ctrl->dev, "Failed to prepare DMA memcpy\n");
> + goto err_unmap;
> + }
> +
> + tx->callback = cadence_nand_slave_dma_transfer_finished;
> + tx->callback_param = &finished;
> +
> + cookie = dmaengine_submit(tx);
> + if (dma_submit_error(cookie)) {
> + dev_err(cdns_ctrl->dev, "Failed to do DMA tx_submit\n");
> + goto err_unmap;
> + }
> +
> + dma_async_issue_pending(cdns_ctrl->dmac);
> + wait_for_completion(&finished);
> +
> + dma_unmap_single(cdns_ctrl->dev, buf_dma, len, dir);
> +
> + return 0;
> +
> +err_unmap:
> + dma_unmap_single(cdns_ctrl->dev, buf_dma, len, dir);
> +
> +err:
> + dev_dbg(cdns_ctrl->dev, "Fall back to CPU I/O\n");
> +
> + return -EIO;
> +}
> +
> +static int cadence_nand_read_buf(struct cdns_nand_ctrl *cdns_ctrl,
> + u8 *buf, int len)
> +{
> + int len_aligned = ALIGN(len, cdns_ctrl->caps2.data_dma_width);
> + u8 thread_nr = 0;
> + u32 sdma_size;
> + int status;
> +
> + if (!cdns_ctrl->caps1->has_dma) {
> + if (len & 3) {
> + dev_err(cdns_ctrl->dev, "unaligned data\n");
> + return -EIO;
> + }
> + readsl(cdns_ctrl->io.virt, buf, len / 4);
> + return 0;
> + }
> +
> + /* Wait until slave DMA interface is ready to data transfer. */
> + status = cadence_nand_wait_on_sdma(cdns_ctrl, &thread_nr, &sdma_size);
> + if (status)
> + return status;
> +
> + if (sdma_size != len_aligned) {
> + dev_err(cdns_ctrl->dev, "unexpected scenario\n");
> + return -EIO;
> + }
> +
> + if (cdns_ctrl->dmac && cadence_nand_dma_buf_ok(cdns_ctrl, buf, len)) {
> + status = cadence_nand_slave_dma_transfer(cdns_ctrl, buf,
> + cdns_ctrl->io.dma,
> + len, DMA_FROM_DEVICE);
> + if (status == 0)
> + return 0;
> +
> + dev_warn(cdns_ctrl->dev,
> + "Slave DMA transfer failed. Try again using bounce buffer.");
> + }
> +
> + /* If DMA transfer is not possible or failed then use bounce buffer. */
> + status = cadence_nand_slave_dma_transfer(cdns_ctrl, cdns_ctrl->buf,
> + cdns_ctrl->io.dma,
> + len_aligned, DMA_FROM_DEVICE);
> +
> + if (status) {
> + dev_err(cdns_ctrl->dev, "Slave DMA transfer failed");
> + return status;
> + }
> +
> + memcpy(buf, cdns_ctrl->buf, len);
> +
> + return 0;
> +}
> +
> +static int cadence_nand_write_buf(struct cdns_nand_ctrl *cdns_ctrl,
> + const u8 *buf, int len)
> +{
> + u8 thread_nr = 0;
> + u32 sdma_size;
> + int status;
> + int len_aligned = ALIGN(len, cdns_ctrl->caps2.data_dma_width);
> +
> + if (!cdns_ctrl->caps1->has_dma) {
> + if (len & 3) {
> + dev_err(cdns_ctrl->dev, "unaligned data\n");
> + return -EIO;
> + }
> + writesl(cdns_ctrl->io.virt, buf, len / 4);
> + return 0;
> + }
> +
> + /* Wait until slave DMA interface is ready to data transfer. */
> + status = cadence_nand_wait_on_sdma(cdns_ctrl, &thread_nr, &sdma_size);
> + if (status)
> + return status;
> +
> + if (sdma_size != len_aligned) {
> + dev_err(cdns_ctrl->dev, "Error unexpected scenario\n");
> + return -EIO;
> + }
> +
> + if (cdns_ctrl->dmac && cadence_nand_dma_buf_ok(cdns_ctrl, buf, len)) {
> + status = cadence_nand_slave_dma_transfer(cdns_ctrl, (void *)buf,
> + cdns_ctrl->io.dma,
> + len, DMA_TO_DEVICE);
> + if (status == 0)
> + return 0;
> +
> + dev_warn(cdns_ctrl->dev,
> + "Slave DMA transfer failed. Try again using bounce buffer.");
> + }
> +
> + /* If DMA transfer is not possible or failed then use bounce buffer. */
> + memcpy(cdns_ctrl->buf, buf, len);
> +
> + status = cadence_nand_slave_dma_transfer(cdns_ctrl, cdns_ctrl->buf,
> + cdns_ctrl->io.dma,
> + len_aligned, DMA_TO_DEVICE);
> +
> + if (status)
> + dev_err(cdns_ctrl->dev, "Slave DMA transfer failed");
> +
> + return status;
> +}
> +
> +static int cadence_nand_force_byte_access(struct nand_chip *chip,
> + bool force_8bit)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + int status;
> +
> + /*
> + * Callers of this function do not verify if the NAND is using a 16-bit
> + * an 8-bit bus for normal operations, so we need to take care of that
> + * here by leaving the configuration unchanged if the NAND does not have
> + * the NAND_BUSWIDTH_16 flag set.
> + */
> + if (!(chip->options & NAND_BUSWIDTH_16))
> + return 0;
> +
> + status = cadence_nand_set_access_width16(cdns_ctrl, !force_8bit);
> +
> + return status;
> +}
> +
> +static int cadence_nand_cmd_opcode(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + const struct nand_op_instr *instr;
> + unsigned int op_id = 0;
> + u64 mini_ctrl_cmd = 0;
> + int ret;
> +
> + instr = &subop->instrs[op_id];
> +
> + if (instr->delay_ns > 0)
> + mini_ctrl_cmd |= GCMD_LAY_TWB;
> +
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
> + GCMD_LAY_INSTR_CMD);
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_CMD,
> + instr->ctx.cmd.opcode);
> +
> + ret = cadence_nand_generic_cmd_send(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + mini_ctrl_cmd);
> + if (ret)
> + dev_err(cdns_ctrl->dev, "send cmd %x failed\n",
> + instr->ctx.cmd.opcode);
> +
> + return ret;
> +}
> +
> +static int cadence_nand_cmd_address(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + const struct nand_op_instr *instr;
> + unsigned int op_id = 0;
> + u64 mini_ctrl_cmd = 0;
> + unsigned int offset, naddrs;
> + u64 address = 0;
> + const u8 *addrs;
> + int ret;
> + int i;
> +
> + instr = &subop->instrs[op_id];
> +
> + if (instr->delay_ns > 0)
> + mini_ctrl_cmd |= GCMD_LAY_TWB;
> +
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
> + GCMD_LAY_INSTR_ADDR);
> +
> + offset = nand_subop_get_addr_start_off(subop, op_id);
> + naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> + addrs = &instr->ctx.addr.addrs[offset];
> +
> + for (i = 0; i < naddrs; i++)
> + address |= (u64)addrs[i] << (8 * i);
> +
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_ADDR,
> + address);
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INPUT_ADDR_SIZE,
> + naddrs - 1);
> +
> + ret = cadence_nand_generic_cmd_send(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + mini_ctrl_cmd);
> + if (ret)
> + dev_err(cdns_ctrl->dev, "send address %llx failed\n", address);
> +
> + return ret;
> +}
> +
> +static int cadence_nand_cmd_erase(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + unsigned int op_id;
> +
> + if (subop->instrs[0].ctx.cmd.opcode == NAND_CMD_ERASE1) {
> + int i;
> + const struct nand_op_instr *instr = NULL;
> + unsigned int offset, naddrs;
> + const u8 *addrs;
> + u32 page = 0;
> +
> + instr = &subop->instrs[1];
> + offset = nand_subop_get_addr_start_off(subop, 1);
> + naddrs = nand_subop_get_num_addr_cyc(subop, 1);
> + addrs = &instr->ctx.addr.addrs[offset];
> +
> + for (i = 0; i < naddrs; i++)
> + page |= (u32)addrs[i] << (8 * i);
> +
> + return cadence_nand_erase(chip, page);
> + }
> +
> + /*
> + * If it is not an erase operation then handle operation
> + * by calling exec_op function.
> + */
> + for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> + int ret;
> + const struct nand_operation nand_op = {
> + .cs = chip->cur_cs,
> + .instrs = &subop->instrs[op_id],
> + .ninstrs = 1};
> + ret = chip->controller->ops->exec_op(chip, &nand_op, false);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int cadence_nand_cmd_data(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + const struct nand_op_instr *instr;
> + unsigned int offset, op_id = 0;
> + u64 mini_ctrl_cmd = 0;
> + int len = 0;
> + int ret;
> +
> + instr = &subop->instrs[op_id];
> +
> + if (instr->delay_ns > 0)
> + mini_ctrl_cmd |= GCMD_LAY_TWB;
> +
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAY_INSTR,
> + GCMD_LAY_INSTR_DATA);
> +
> + if (instr->type == NAND_OP_DATA_OUT_INSTR)
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_DIR,
> + GCMD_DIR_WRITE);
> +
> + len = nand_subop_get_data_len(subop, op_id);
> + offset = nand_subop_get_data_start_off(subop, op_id);
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_SECT_CNT, 1);
> + mini_ctrl_cmd |= FIELD_PREP(GCMD_LAST_SIZE, len);
> + if (instr->ctx.data.force_8bit) {
> + ret = cadence_nand_force_byte_access(chip, true);
> + if (ret) {
> + dev_err(cdns_ctrl->dev,
> + "cannot change byte access generic data cmd failed\n");
> + return ret;
> + }
> + }
> +
> + ret = cadence_nand_generic_cmd_send(cdns_ctrl,
> + cdns_chip->cs[chip->cur_cs],
> + mini_ctrl_cmd);
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "send generic data cmd failed\n");
> + return ret;
> + }
> +
> + if (instr->type == NAND_OP_DATA_IN_INSTR) {
> + void *buf = instr->ctx.data.buf.in + offset;
> +
> + ret = cadence_nand_read_buf(cdns_ctrl, buf, len);
> + } else {
> + const void *buf = instr->ctx.data.buf.out + offset;
> +
> + ret = cadence_nand_write_buf(cdns_ctrl, buf, len);
> + }
> +
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "data transfer failed for generic command\n");
> + return ret;
> + }
> +
> + if (instr->ctx.data.force_8bit) {
> + ret = cadence_nand_force_byte_access(chip, false);
> + if (ret) {
> + dev_err(cdns_ctrl->dev,
> + "cannot change byte access generic data cmd failed\n");
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int cadence_nand_cmd_waitrdy(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + int status;
> + unsigned int op_id = 0;
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + const struct nand_op_instr *instr = &subop->instrs[op_id];
> + u32 timeout_us = instr->ctx.waitrdy.timeout_ms * 1000;
> +
> + status = cadence_nand_wait_for_value(cdns_ctrl, RBN_SETINGS,
> + timeout_us,
> + 1U << cdns_chip->cs[chip->cur_cs],

BIT() ?

> + false);
> + return status;
> +}
> +
> +static const struct nand_op_parser cadence_nand_op_parser = NAND_OP_PARSER(
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_erase,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ERASE_ADDRESS_CYC),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_opcode,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_address,
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYC)),
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_data,
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, MAX_DATA_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_data,
> + NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, MAX_DATA_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + cadence_nand_cmd_waitrdy,
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false))
> + );
> +
> +static int cadence_nand_exec_op(struct nand_chip *chip,
> + const struct nand_operation *op,
> + bool check_only)
> +{
> + int status = cadence_nand_select_target(chip);
> +
> + if (status)
> + return status;
> +
> + return nand_op_parser_exec_op(chip, &cadence_nand_op_parser, op,
> + check_only);
> +}
> +
> +static int cadence_nand_ooblayout_free(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> +
> + if (section)
> + return -ERANGE;
> +
> + oobregion->offset = cdns_chip->bbm_len;
> + oobregion->length = cdns_chip->avail_oob_size
> + - cdns_chip->bbm_len;
> +
> + return 0;
> +}
> +
> +static int cadence_nand_ooblayout_ecc(struct mtd_info *mtd, int section,
> + struct mtd_oob_region *oobregion)
> +{
> + struct nand_chip *chip = mtd_to_nand(mtd);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> +
> + if (section)
> + return -ERANGE;
> +
> + oobregion->offset = cdns_chip->avail_oob_size;
> + oobregion->length = chip->ecc.total;
> +
> + return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops cadence_nand_ooblayout_ops = {
> + .free = cadence_nand_ooblayout_free,
> + .ecc = cadence_nand_ooblayout_ecc,
> +};
> +
> +static int calc_cycl(u32 timing, u32 clock)
> +{
> + if (timing == 0 || clock == 0)
> + return 0;
> +
> + if ((timing % clock) > 0)
> + return timing / clock;
> + else
> + return timing / clock - 1;
> +}
> +
> +/* Calculate max data valid window. */
> +static inline u32 calc_tdvw_max(u32 trp_cnt, u32 clk_period, u32 trhoh_min,
> + u32 board_delay_skew_min, u32 ext_mode)
> +{
> + if (ext_mode == 0)
> + clk_period /= 2;
> +
> + return (trp_cnt + 1) * clk_period + trhoh_min +
> + board_delay_skew_min;
> +}
> +
> +/* Calculate data valid window. */
> +static inline u32 calc_tdvw(u32 trp_cnt, u32 clk_period, u32 trhoh_min,
> + u32 trea_max, u32 ext_mode)
> +{
> + if (ext_mode == 0)
> + clk_period /= 2;
> +
> + return (trp_cnt + 1) * clk_period + trhoh_min - trea_max;
> +}
> +
> +static int
> +cadence_nand_setup_data_interface(struct nand_chip *chip, int chipnr,
> + const struct nand_data_interface *conf)
> +{
> + const struct nand_sdr_timings *sdr;
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct cadence_nand_timings *t = &cdns_chip->timings;
> + u32 reg;
> + u32 board_delay = cdns_ctrl->board_delay;
> + u32 clk_period = DIV_ROUND_DOWN_ULL(1000000000000ULL,
> + cdns_ctrl->nf_clk_rate);
> + u32 tceh_cnt, tcs_cnt, tadl_cnt, tccs_cnt;
> + u32 tfeat_cnt, trhz_cnt, tvdly_cnt;
> + u32 trhw_cnt, twb_cnt, twh_cnt = 0, twhr_cnt;
> + u32 twp_cnt = 0, trp_cnt = 0, trh_cnt = 0;
> + u32 if_skew = cdns_ctrl->caps1->if_skew;
> + u32 board_delay_skew_min = board_delay - if_skew;
> + u32 board_delay_skew_max = board_delay + if_skew;
> + u32 dqs_sampl_res, phony_dqs_mod;
> + u32 tdvw, tdvw_min, tdvw_max;
> + u32 ext_rd_mode, ext_wr_mode;
> + u32 dll_phy_dqs_timing = 0, phony_dqs_timing = 0, rd_del_sel = 0;
> + u32 sampling_point;
> +
> + sdr = nand_get_sdr_timings(conf);
> + if (IS_ERR(sdr))
> + return PTR_ERR(sdr);
> +
> + memset(t, 0, sizeof(*t));
> + /* Sampling point calculation. */
> +
> + if (cdns_ctrl->caps2.is_phy_type_dll)
> + phony_dqs_mod = 2;
> + else
> + phony_dqs_mod = 1;
> +
> + dqs_sampl_res = clk_period / phony_dqs_mod;
> +
> + tdvw_min = sdr->tREA_max + board_delay_skew_max;
> + /*
> + * The idea of those calculation is to get the optimum value
> + * for tRP and tRH timings. If it is NOT possible to sample data
> + * with optimal tRP/tRH settings, the parameters will be extended.
> + * If clk_period is 50ns (the lowest value) this condition is met
> + * for asynchronous timing modes 1, 2, 3, 4 and 5.
> + * If clk_period is 20ns the condition is met only
> + * for asynchronous timing mode 5.
> + */
> + if (sdr->tRC_min <= clk_period &&
> + sdr->tRP_min <= (clk_period / 2) &&
> + sdr->tREH_min <= (clk_period / 2)) {
> + /* Performance mode. */
> + ext_rd_mode = 0;
> + tdvw = calc_tdvw(trp_cnt, clk_period, sdr->tRHOH_min,
> + sdr->tREA_max, ext_rd_mode);
> + tdvw_max = calc_tdvw_max(trp_cnt, clk_period, sdr->tRHOH_min,
> + board_delay_skew_min,
> + ext_rd_mode);
> + /*
> + * Check if data valid window and sampling point can be found
> + * and is not on the edge (ie. we have hold margin).
> + * If not extend the tRP timings.
> + */
> + if (tdvw > 0) {
> + if (tdvw_max <= tdvw_min ||
> + (tdvw_max % dqs_sampl_res) == 0) {
> + /*
> + * No valid sampling point so the RE pulse need
> + * to be widen widening by half clock cycle.
> + */
> + ext_rd_mode = 1;
> + }
> + } else {
> + /*
> + * There is no valid window
> + * to be able to sample data the tRP need to be widen.
> + * Very safe calculations are performed here.
> + */
> + trp_cnt = (sdr->tREA_max + board_delay_skew_max
> + + dqs_sampl_res) / clk_period;
> + ext_rd_mode = 1;
> + }
> +
> + } else {
> + /* Extended read mode. */
> + u32 trh;
> +
> + ext_rd_mode = 1;
> + trp_cnt = calc_cycl(sdr->tRP_min, clk_period);
> + trh = sdr->tRC_min - ((trp_cnt + 1) * clk_period);
> + if (sdr->tREH_min >= trh)
> + trh_cnt = calc_cycl(sdr->tREH_min, clk_period);
> + else
> + trh_cnt = calc_cycl(trh, clk_period);
> +
> + tdvw = calc_tdvw(trp_cnt, clk_period, sdr->tRHOH_min,
> + sdr->tREA_max, ext_rd_mode);
> + /*
> + * Check if data valid window and sampling point can be found
> + * or if it is at the edge check if previous is valid
> + * - if not extend the tRP timings.
> + */
> + if (tdvw > 0) {
> + tdvw_max = calc_tdvw_max(trp_cnt, clk_period,
> + sdr->tRHOH_min,
> + board_delay_skew_min,
> + ext_rd_mode);
> +
> + if ((((tdvw_max / dqs_sampl_res)
> + * dqs_sampl_res) <= tdvw_min) ||
> + (((tdvw_max % dqs_sampl_res) == 0) &&
> + (((tdvw_max / dqs_sampl_res - 1)
> + * dqs_sampl_res) <= tdvw_min))) {
> + /*
> + * Data valid window width is lower than
> + * sampling resolution and do not hit any
> + * sampling point to be sure the sampling point
> + * will be found the RE low pulse width will be
> + * extended by one clock cycle.
> + */
> + trp_cnt = trp_cnt + 1;
> + }
> + } else {
> + /*
> + * There is no valid window to be able to sample data.
> + * The tRP need to be widen.
> + * Very safe calculations are performed here.
> + */
> + trp_cnt = (sdr->tREA_max + board_delay_skew_max
> + + dqs_sampl_res) / clk_period;
> + }
> + }
> +
> + tdvw_max = calc_tdvw_max(trp_cnt, clk_period,
> + sdr->tRHOH_min,
> + board_delay_skew_min, ext_rd_mode);
> +
> + if (sdr->tWC_min <= clk_period &&
> + (sdr->tWP_min + if_skew) <= (clk_period / 2) &&
> + (sdr->tWH_min + if_skew) <= (clk_period / 2)) {
> + ext_wr_mode = 0;
> + } else {
> + u32 twh;
> +
> + ext_wr_mode = 1;
> + twp_cnt = calc_cycl(sdr->tWP_min + if_skew, clk_period);
> + if ((twp_cnt + 1) * clk_period < (sdr->tALS_min + if_skew))
> + twp_cnt = calc_cycl(sdr->tALS_min + if_skew,
> + clk_period);
> +
> + twh = (sdr->tWC_min - (twp_cnt + 1) * clk_period);
> + if (sdr->tWH_min >= twh)
> + twh = sdr->tWH_min;
> +
> + twh_cnt = calc_cycl(twh + if_skew, clk_period);
> + }
> +
> + reg = FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TRH, trh_cnt);
> + reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TRP, trp_cnt);
> + reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TWH, twh_cnt);
> + reg |= FIELD_PREP(ASYNC_TOGGLE_TIMINGS_TWP, twp_cnt);
> + t->async_toggle_timings = reg;
> + dev_dbg(cdns_ctrl->dev, "ASYNC_TOGGLE_TIMINGS_SDR\t%x\n", reg);
> +
> + tadl_cnt = calc_cycl((sdr->tADL_min + if_skew), clk_period);
> + tccs_cnt = calc_cycl((sdr->tCCS_min + if_skew), clk_period);
> + twhr_cnt = calc_cycl((sdr->tWHR_min + if_skew), clk_period);
> + trhw_cnt = calc_cycl((sdr->tRHW_min + if_skew), clk_period);
> + reg = FIELD_PREP(TIMINGS0_TADL, tadl_cnt);
> +
> + /*
> + * If timing exceeds delay field in timing register
> + * then use maximum value.
> + */
> + if (FIELD_FIT(TIMINGS0_TCCS, tccs_cnt))
> + reg |= FIELD_PREP(TIMINGS0_TCCS, tccs_cnt);
> + else
> + reg |= TIMINGS0_TCCS;
> +
> + reg |= FIELD_PREP(TIMINGS0_TWHR, twhr_cnt);
> + reg |= FIELD_PREP(TIMINGS0_TRHW, trhw_cnt);
> + t->timings0 = reg;
> + dev_dbg(cdns_ctrl->dev, "TIMINGS0_SDR\t%x\n", reg);
> +
> + /* The following is related to single signal so skew is not needed. */
> + trhz_cnt = calc_cycl(sdr->tRHZ_max, clk_period);
> + trhz_cnt = trhz_cnt + 1;
> + twb_cnt = calc_cycl((sdr->tWB_max + board_delay), clk_period);
> + /*
> + * Because of the two stage syncflop the value must be increased by 3
> + * first value is related with sync, second value is related
> + * with output if delay.
> + */
> + twb_cnt = twb_cnt + 3 + 5;
> + /*
> + * The following is related to the we edge of the random data input
> + * sequence so skew is not needed.
> + */
> + tvdly_cnt = calc_cycl(500000 + if_skew, clk_period);
> + reg = FIELD_PREP(TIMINGS1_TRHZ, trhz_cnt);
> + reg |= FIELD_PREP(TIMINGS1_TWB, twb_cnt);
> + reg |= FIELD_PREP(TIMINGS1_TVDLY, tvdly_cnt);
> + t->timings1 = reg;
> + dev_dbg(cdns_ctrl->dev, "TIMINGS1_SDR\t%x\n", reg);
> +
> + tfeat_cnt = calc_cycl(sdr->tFEAT_max, clk_period);
> + if (tfeat_cnt < twb_cnt)
> + tfeat_cnt = twb_cnt;
> +
> + tceh_cnt = calc_cycl(sdr->tCEH_min, clk_period);
> + tcs_cnt = calc_cycl((sdr->tCS_min + if_skew), clk_period);
> +
> + reg = FIELD_PREP(TIMINGS2_TFEAT, tfeat_cnt);
> + reg |= FIELD_PREP(TIMINGS2_CS_HOLD_TIME, tceh_cnt);
> + reg |= FIELD_PREP(TIMINGS2_CS_SETUP_TIME, tcs_cnt);
> + t->timings2 = reg;
> + dev_dbg(cdns_ctrl->dev, "TIMINGS2_SDR\t%x\n", reg);
> +
> + if (cdns_ctrl->caps2.is_phy_type_dll) {
> + reg = DLL_PHY_CTRL_DLL_RST_N;
> + if (ext_wr_mode)
> + reg |= DLL_PHY_CTRL_EXTENDED_WR_MODE;
> + if (ext_rd_mode)
> + reg |= DLL_PHY_CTRL_EXTENDED_RD_MODE;
> +
> + reg |= FIELD_PREP(DLL_PHY_CTRL_RS_HIGH_WAIT_CNT, 7);
> + reg |= FIELD_PREP(DLL_PHY_CTRL_RS_IDLE_CNT, 7);
> + t->dll_phy_ctrl = reg;
> + dev_dbg(cdns_ctrl->dev, "DLL_PHY_CTRL_SDR\t%x\n", reg);
> + }
> +
> + /* Sampling point calculation. */
> + if ((tdvw_max % dqs_sampl_res) > 0)
> + sampling_point = tdvw_max / dqs_sampl_res;
> + else
> + sampling_point = (tdvw_max / dqs_sampl_res - 1);
> +
> + if (sampling_point * dqs_sampl_res > tdvw_min) {
> + dll_phy_dqs_timing =
> + FIELD_PREP(PHY_DQS_TIMING_DQS_SEL_OE_END, 4);
> + dll_phy_dqs_timing |= PHY_DQS_TIMING_USE_PHONY_DQS;
> + phony_dqs_timing = sampling_point / phony_dqs_mod;
> +
> + if ((sampling_point % 2) > 0) {
> + dll_phy_dqs_timing |= PHY_DQS_TIMING_PHONY_DQS_SEL;
> + if ((tdvw_max % dqs_sampl_res) == 0)
> + /*
> + * Calculation for sampling point at the edge
> + * of data and being odd number.
> + */
> + phony_dqs_timing = (tdvw_max / dqs_sampl_res)
> + / phony_dqs_mod - 1;
> +
> + if (!cdns_ctrl->caps2.is_phy_type_dll)
> + phony_dqs_timing--;
> +
> + } else {
> + phony_dqs_timing--;
> + }
> + rd_del_sel = phony_dqs_timing + 3;
> + } else {
> + dev_warn(cdns_ctrl->dev,
> + "ERROR : cannot find valid sampling point\n");
> + }
> +
> + reg = FIELD_PREP(PHY_CTRL_PHONY_DQS, phony_dqs_timing);
> + if (cdns_ctrl->caps2.is_phy_type_dll)
> + reg |= PHY_CTRL_SDR_DQS;
> + t->phy_ctrl = reg;
> + dev_dbg(cdns_ctrl->dev, "PHY_CTRL_REG_SDR\t%x\n", reg);
> +
> + if (cdns_ctrl->caps2.is_phy_type_dll) {
> + dev_dbg(cdns_ctrl->dev, "PHY_TSEL_REG_SDR\t%x\n", 0);
> + dev_dbg(cdns_ctrl->dev, "PHY_DQ_TIMING_REG_SDR\t%x\n", 2);
> + dev_dbg(cdns_ctrl->dev, "PHY_DQS_TIMING_REG_SDR\t%x\n",
> + dll_phy_dqs_timing);
> + t->phy_dqs_timing = dll_phy_dqs_timing;
> +
> + reg = FIELD_PREP(PHY_GATE_LPBK_CTRL_RDS, rd_del_sel);
> + dev_dbg(cdns_ctrl->dev, "PHY_GATE_LPBK_CTRL_REG_SDR\t%x\n",
> + reg);
> + t->phy_gate_lpbk_ctrl = reg;
> +
> + dev_dbg(cdns_ctrl->dev, "PHY_DLL_MASTER_CTRL_REG_SDR\t%lx\n",
> + PHY_DLL_MASTER_CTRL_BYPASS_MODE);
> + dev_dbg(cdns_ctrl->dev, "PHY_DLL_SLAVE_CTRL_REG_SDR\t%x\n", 0);
> + }
> +
> + return 0;
> +}
> +
> +int cadence_nand_attach_chip(struct nand_chip *chip)
> +{
> + struct cdns_nand_ctrl *cdns_ctrl = to_cdns_nand_ctrl(chip->controller);
> + struct cdns_nand_chip *cdns_chip = to_cdns_nand_chip(chip);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + u32 max_oob_data_size;
> + int ret;
> +
> + if (chip->options & NAND_BUSWIDTH_16) {
> + ret = cadence_nand_set_access_width16(cdns_ctrl, true);
> + if (ret)
> + goto free_buf;
> + }
> +
> + chip->bbt_options |= NAND_BBT_USE_FLASH;
> + chip->bbt_options |= NAND_BBT_NO_OOB;
> + chip->ecc.mode = NAND_ECC_HW;
> +
> + chip->options |= NAND_NO_SUBPAGE_WRITE;
> +
> + cdns_chip->bbm_offs = chip->badblockpos;
> + if (chip->options & NAND_BUSWIDTH_16) {
> + cdns_chip->bbm_offs &= ~0x01;
> + cdns_chip->bbm_len = 2;
> + } else {
> + cdns_chip->bbm_len = 1;
> + }
> +
> + ret = nand_ecc_choose_conf(chip,
> + &cdns_ctrl->ecc_caps,
> + mtd->oobsize - cdns_chip->bbm_len);
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "ECC configuration failed\n");
> + goto free_buf;
> + }
> +
> + dev_dbg(cdns_ctrl->dev,
> + "chosen ECC settings: step=%d, strength=%d, bytes=%d\n",
> + chip->ecc.size, chip->ecc.strength, chip->ecc.bytes);
> +
> + /* Error correction configuration. */
> + cdns_chip->sector_size = chip->ecc.size;
> + cdns_chip->sector_count = mtd->writesize / cdns_chip->sector_size;
> +
> + cdns_chip->avail_oob_size = mtd->oobsize
> + - cdns_chip->sector_count * chip->ecc.bytes;
> +
> + max_oob_data_size = MAX_OOB_SIZE_PER_SECTOR;
> +
> + if (cdns_chip->avail_oob_size > max_oob_data_size)
> + cdns_chip->avail_oob_size = max_oob_data_size;
> +
> + if ((cdns_chip->avail_oob_size + cdns_chip->bbm_len
> + + cdns_chip->sector_count
> + * chip->ecc.bytes) > mtd->oobsize)

If the line is not readable enough you can use intermediate variables.
Also the priority of the '*' operator could be enforced with
parenthesis. Really this is just a nit pick :)

> + cdns_chip->avail_oob_size -= 4;
> +
> + cdns_chip->corr_str_idx =
> + cadence_nand_get_ecc_strength_idx(cdns_ctrl,
> + chip->ecc.strength);
> + if (cdns_chip->corr_str_idx < 0)
> + return -EINVAL;
> +
> + if (cadence_nand_wait_for_value(cdns_ctrl, CTRL_STATUS,
> + 1000000,
> + CTRL_STATUS_CTRL_BUSY, true))
> + return -ETIMEDOUT;
> +
> + cadence_nand_set_ecc_strength(cdns_ctrl,
> + cdns_chip->corr_str_idx);
> +
> + cadence_nand_set_erase_detection(cdns_ctrl, true,
> + chip->ecc.strength);
> +
> + /* Override the default read operations. */
> + chip->ecc.read_page = cadence_nand_read_page;
> + chip->ecc.read_page_raw = cadence_nand_read_page_raw;
> + chip->ecc.write_page = cadence_nand_write_page;
> + chip->ecc.write_page_raw = cadence_nand_write_page_raw;
> + chip->ecc.read_oob = cadence_nand_read_oob;
> + chip->ecc.write_oob = cadence_nand_write_oob;
> + chip->ecc.read_oob_raw = cadence_nand_read_oob_raw;
> + chip->ecc.write_oob_raw = cadence_nand_write_oob_raw;
> +
> + if ((mtd->writesize + mtd->oobsize) > cdns_ctrl->buf_size) {
> + cdns_ctrl->buf_size = mtd->writesize + mtd->oobsize;
> + kfree(cdns_ctrl->buf);
> + cdns_ctrl->buf = kzalloc(cdns_ctrl->buf_size, GFP_KERNEL);
> + if (!cdns_ctrl->buf) {
> + ret = -ENOMEM;
> + goto free_buf;
> + }
> + }
> +
> + /* Is 32-bit DMA supported? */
> + ret = dma_set_mask(cdns_ctrl->dev, DMA_BIT_MASK(32));
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "no usable DMA configuration\n");
> + goto free_buf;
> + }
> +
> + mtd_set_ooblayout(mtd, &cadence_nand_ooblayout_ops);
> +
> + return 0;
> +
> +free_buf:
> + kfree(cdns_ctrl->buf);
> +
> + return ret;
> +}
> +
> +static const struct nand_controller_ops cadence_nand_controller_ops = {
> + .attach_chip = cadence_nand_attach_chip,
> + .exec_op = cadence_nand_exec_op,
> + .setup_data_interface = cadence_nand_setup_data_interface,
> +};
> +
> +static int cadence_nand_chip_init(struct cdns_nand_ctrl *cdns_ctrl,
> + struct device_node *np)
> +{
> + struct cdns_nand_chip *cdns_chip;
> + struct mtd_info *mtd;
> + struct nand_chip *chip;
> + int nsels, ret, i;
> + u32 cs;
> +
> + nsels = of_property_count_elems_of_size(np, "reg", sizeof(u32));
> + if (nsels <= 0) {
> + dev_err(cdns_ctrl->dev, "missing/invalid reg property\n");
> + return -EINVAL;
> + }
> +
> + /* Allocate the nand chip structure. */
> + cdns_chip = devm_kzalloc(cdns_ctrl->dev, sizeof(*cdns_chip) +
> + (nsels * sizeof(u8)),
> + GFP_KERNEL);
> + if (!cdns_chip) {
> + dev_err(cdns_ctrl->dev, "could not allocate chip structure\n");
> + return -ENOMEM;
> + }
> +
> + cdns_chip->nsels = nsels;
> +
> + for (i = 0; i < nsels; i++) {
> + /* Retrieve CS id. */
> + ret = of_property_read_u32_index(np, "reg", i, &cs);
> + if (ret) {
> + dev_err(cdns_ctrl->dev,
> + "could not retrieve reg property: %d\n",
> + ret);
> + return ret;
> + }
> +
> + if (cs >= cdns_ctrl->caps2.max_banks) {
> + dev_err(cdns_ctrl->dev,
> + "invalid reg value: %u (max CS = %d)\n",
> + cs, cdns_ctrl->caps2.max_banks);
> + return -EINVAL;
> + }
> +
> + if (test_and_set_bit(cs, &cdns_ctrl->assigned_cs)) {
> + dev_err(cdns_ctrl->dev,
> + "CS %d already assigned\n", cs);
> + return -EINVAL;
> + }
> +
> + cdns_chip->cs[i] = cs;
> + }
> +
> + chip = &cdns_chip->chip;
> + chip->controller = &cdns_ctrl->controller;
> + nand_set_flash_node(chip, np);
> +
> + mtd = nand_to_mtd(chip);
> + mtd->dev.parent = cdns_ctrl->dev;
> +
> + /*
> + * Default to HW ECC engine mode. If the nand-ecc-mode property is given
> + * in the DT node, this entry will be overwritten in nand_scan_ident().
> + */
> + chip->ecc.mode = NAND_ECC_HW;
> +
> + ret = nand_scan(chip, cdns_chip->nsels);
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "could not scan the nand chip\n");
> + return ret;
> + }
> +
> + ret = mtd_device_register(mtd, NULL, 0);
> + if (ret) {
> + dev_err(cdns_ctrl->dev,
> + "failed to register mtd device: %d\n", ret);
> + nand_cleanup(chip);
> + return ret;
> + }
> +
> + list_add_tail(&cdns_chip->node, &cdns_ctrl->chips);
> +
> + return 0;
> +}
> +
> +static void cadence_nand_chips_cleanup(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + struct cdns_nand_chip *entry, *temp;
> +
> + list_for_each_entry_safe(entry, temp, &cdns_ctrl->chips, node) {
> + nand_release(&entry->chip);
> + list_del(&entry->node);
> + }
> +}
> +
> +static int cadence_nand_chips_init(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + struct device_node *np = cdns_ctrl->dev->of_node;
> + struct device_node *nand_np;
> + int max_cs = cdns_ctrl->caps2.max_banks;
> + int nchips, ret;
> +
> + nchips = of_get_child_count(np);
> +
> + if (nchips > max_cs) {
> + dev_err(cdns_ctrl->dev,
> + "too many NAND chips: %d (max = %d CS)\n",
> + nchips, max_cs);
> + return -EINVAL;
> + }
> +
> + for_each_child_of_node(np, nand_np) {
> + ret = cadence_nand_chip_init(cdns_ctrl, nand_np);
> + if (ret) {
> + of_node_put(nand_np);
> + cadence_nand_chips_cleanup(cdns_ctrl);
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int cadence_nand_init(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + dma_cap_mask_t mask;
> + int ret;
> +
> + cdns_ctrl->cdma_desc = dma_alloc_coherent(cdns_ctrl->dev,
> + sizeof(*cdns_ctrl->cdma_desc),
> + &cdns_ctrl->dma_cdma_desc,
> + GFP_KERNEL);
> + if (!cdns_ctrl->dma_cdma_desc)
> + return -ENOMEM;
> +
> + cdns_ctrl->buf_size = SZ_16K;
> + cdns_ctrl->buf = kmalloc(cdns_ctrl->buf_size, GFP_KERNEL);
> + if (!cdns_ctrl->buf) {
> + goto free_buf_desc;
> + ret = -ENOMEM;
> + }
> +
> + if (devm_request_irq(cdns_ctrl->dev, cdns_ctrl->irq, cadence_nand_isr,
> + IRQF_SHARED, "cadence-nand-controller",
> + cdns_ctrl)) {
> + dev_err(cdns_ctrl->dev, "Unable to allocate IRQ\n");
> + ret = -ENODEV;
> + goto free_buf;
> + }
> +
> + spin_lock_init(&cdns_ctrl->irq_lock);
> + init_completion(&cdns_ctrl->complete);
> +
> + ret = cadence_nand_hw_init(cdns_ctrl);
> + if (ret)
> + goto disable_irq;
> +
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_MEMCPY, mask);
> +
> + if (cdns_ctrl->caps1->has_dma) {
> + cdns_ctrl->dmac = dma_request_channel(mask, NULL, NULL);
> + if (!cdns_ctrl->dmac) {
> + dev_err(cdns_ctrl->dev,
> + "Unable to get a DMA channel\n");
> + ret = -EBUSY;
> + goto disable_irq;
> + }
> + }
> +
> + nand_controller_init(&cdns_ctrl->controller);
> + INIT_LIST_HEAD(&cdns_ctrl->chips);
> +
> + cdns_ctrl->controller.ops = &cadence_nand_controller_ops;
> + cdns_ctrl->curr_corr_str_idx = 0xFF;
> +
> + ret = cadence_nand_chips_init(cdns_ctrl);
> + if (ret) {
> + dev_err(cdns_ctrl->dev, "Failed to register MTD: %d\n",
> + ret);
> + goto dma_release_chnl;
> + }
> +
> + return 0;
> +
> +dma_release_chnl:
> + if (cdns_ctrl->dmac)
> + dma_release_channel(cdns_ctrl->dmac);
> +
> +disable_irq:
> + cadence_nand_irq_cleanup(cdns_ctrl->irq, cdns_ctrl);
> +
> +free_buf:
> + kfree(cdns_ctrl->buf);
> +
> +free_buf_desc:
> + dma_free_coherent(cdns_ctrl->dev, sizeof(struct cadence_nand_cdma_desc),
> + cdns_ctrl->cdma_desc, cdns_ctrl->dma_cdma_desc);
> +
> + return ret;
> +}
> +
> +/* Driver exit point. */
> +static void cadence_nand_remove(struct cdns_nand_ctrl *cdns_ctrl)
> +{
> + cadence_nand_chips_cleanup(cdns_ctrl);
> + cadence_nand_irq_cleanup(cdns_ctrl->irq, cdns_ctrl);
> + kfree(cdns_ctrl->buf);
> + dma_free_coherent(cdns_ctrl->dev, sizeof(struct cadence_nand_cdma_desc),
> + cdns_ctrl->cdma_desc, cdns_ctrl->dma_cdma_desc);
> +
> + if (cdns_ctrl->dmac)
> + dma_release_channel(cdns_ctrl->dmac);
> +}
> +
> +struct cadence_nand_dt {
> + struct cdns_nand_ctrl cdns_ctrl;
> + struct clk *clk;
> +};
> +
> +static const struct cadence_nand_dt_devdata cadence_nand_default = {
> + .if_skew = 0,
> + .has_dma = 1,
> +};
> +
> +static const struct of_device_id cadence_nand_dt_ids[] = {
> + {
> + .compatible = "cdns,hp-nfc",
> + .data = &cadence_nand_default
> + }, {}
> +};
> +
> +MODULE_DEVICE_TABLE(of, cadence_nand_dt_ids);
> +
> +static int cadence_nand_dt_probe(struct platform_device *ofdev)
> +{
> + struct resource *res;
> + struct cadence_nand_dt *dt;
> + struct cdns_nand_ctrl *cdns_ctrl;
> + int ret;
> + const struct of_device_id *of_id;
> + const struct cadence_nand_dt_devdata *devdata;
> + u32 val;
> +
> + of_id = of_match_device(cadence_nand_dt_ids, &ofdev->dev);
> + if (of_id) {
> + ofdev->id_entry = of_id->data;
> + devdata = of_id->data;
> + } else {
> + pr_err("Failed to find the right device id.\n");
> + return -ENOMEM;
> + }
> +
> + dt = devm_kzalloc(&ofdev->dev, sizeof(*dt), GFP_KERNEL);
> + if (!dt)
> + return -ENOMEM;
> +
> + cdns_ctrl = &dt->cdns_ctrl;
> + cdns_ctrl->caps1 = devdata;
> +
> + cdns_ctrl->dev = &ofdev->dev;
> + cdns_ctrl->irq = platform_get_irq(ofdev, 0);
> + if (cdns_ctrl->irq < 0) {
> + dev_err(&ofdev->dev, "no irq defined\n");
> + return cdns_ctrl->irq;
> + }
> + dev_info(cdns_ctrl->dev, "IRQ: nr %d\n", cdns_ctrl->irq);
> +
> + res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
> + cdns_ctrl->reg = devm_ioremap_resource(cdns_ctrl->dev, res);

I think this will be refused by robots, you have to squash the two
lines into

cdns_ctrl->reg = devm_platform_ioremap_resource(ofdev, 0);

> + if (IS_ERR(cdns_ctrl->reg)) {
> + dev_err(&ofdev->dev, "devm_ioremap_resource res 0 failed\n");
> + return PTR_ERR(cdns_ctrl->reg);
> + }
> +
> + res = platform_get_resource(ofdev, IORESOURCE_MEM, 1);
> + cdns_ctrl->io.dma = res->start;
> + cdns_ctrl->io.virt = devm_ioremap_resource(&ofdev->dev, res);
> + if (IS_ERR(cdns_ctrl->io.virt)) {
> + dev_err(cdns_ctrl->dev, "devm_ioremap_resource res 1 failed\n");
> + return PTR_ERR(cdns_ctrl->io.virt);
> + }
> +
> + dt->clk = devm_clk_get(cdns_ctrl->dev, "nf_clk");
> + if (IS_ERR(dt->clk))
> + return PTR_ERR(dt->clk);
> +
> + cdns_ctrl->nf_clk_rate = clk_get_rate(dt->clk);
> +
> + ret = of_property_read_u32(ofdev->dev.of_node,
> + "cdns,board-delay-ps", &val);
> + if (ret) {
> + dev_warn(cdns_ctrl->dev, "missing cdns,board-delay-ps property\n");

Maybe you could turn this property into an optional one, with a default
value?

> + val = 0;
> + }
> + cdns_ctrl->board_delay = val;
> +
> + ret = cadence_nand_init(cdns_ctrl);
> + if (ret)
> + return ret;
> +
> + platform_set_drvdata(ofdev, dt);
> + return 0;
> +}
> +
> +static int cadence_nand_dt_remove(struct platform_device *ofdev)
> +{
> + struct cadence_nand_dt *dt = platform_get_drvdata(ofdev);
> +
> + cadence_nand_remove(&dt->cdns_ctrl);
> +
> + return 0;
> +}
> +
> +static struct platform_driver cadence_nand_dt_driver = {
> + .probe = cadence_nand_dt_probe,
> + .remove = cadence_nand_dt_remove,
> + .driver = {
> + .name = "cadence-nand-controller",
> + .of_match_table = cadence_nand_dt_ids,
> + },
> +};
> +
> +module_platform_driver(cadence_nand_dt_driver);
> +
> +MODULE_AUTHOR("Piotr Sroka <piotrs@cadence.com>");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Driver for Cadence NAND flash controller");
> +

Would you mind adding yourself in MAINTAINERS for this driver (+
bindings)?

Thanks,
Miquèl

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