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SubjectRe: [PATCH 5/7] mmc: Add Actions Semi Owl SoCs SD/MMC driver
On Sat, 8 Jun 2019 at 21:54, Manivannan Sadhasivam
<manivannan.sadhasivam@linaro.org> wrote:
>
> Add SD/MMC driver for Actions Semi Owl SoCs. This driver currently
> supports standard, high speed, SDR12, SDR25 and SDR50. DDR50 mode is
> supported but it is untested. There is no SDIO support for now.
>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> drivers/mmc/host/Kconfig | 8 +
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/owl-mmc.c | 705 +++++++++++++++++++++++++++++++++++++
> 3 files changed, 714 insertions(+)
> create mode 100644 drivers/mmc/host/owl-mmc.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 931770f17087..7ae65eff26a4 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -1006,3 +1006,11 @@ config MMC_SDHCI_AM654
> If you have a controller with this interface, say Y or M here.
>
> If unsure, say N.
> +
> +config MMC_OWL
> + tristate "Actions Semi Owl SD/MMC Host Controller support"
> + depends on HAS_DMA
> + depends on ARCH_ACTIONS || COMPILE_TEST
> + help
> + This selects support for the SD/MMC Host Controller on
> + Actions Semi Owl SoCs.
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index 73578718f119..41a0b1728389 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -73,6 +73,7 @@ obj-$(CONFIG_MMC_SUNXI) += sunxi-mmc.o
> obj-$(CONFIG_MMC_USDHI6ROL0) += usdhi6rol0.o
> obj-$(CONFIG_MMC_TOSHIBA_PCI) += toshsd.o
> obj-$(CONFIG_MMC_BCM2835) += bcm2835.o
> +obj-$(CONFIG_MMC_OWL) += owl-mmc.o
>
> obj-$(CONFIG_MMC_REALTEK_PCI) += rtsx_pci_sdmmc.o
> obj-$(CONFIG_MMC_REALTEK_USB) += rtsx_usb_sdmmc.o
> diff --git a/drivers/mmc/host/owl-mmc.c b/drivers/mmc/host/owl-mmc.c
> new file mode 100644
> index 000000000000..8158ebedb2a4
> --- /dev/null
> +++ b/drivers/mmc/host/owl-mmc.c
> @@ -0,0 +1,705 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Actions Semi Owl SoCs SD/MMC driver
> + *
> + * Copyright (c) 2014 Actions Semi Inc.
> + * Copyright (c) 2019 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> + *
> + * TODO: SDIO support
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/dmaengine.h>
> +#include <linux/dma-direction.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/interrupt.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/slot-gpio.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/reset.h>
> +#include <linux/spinlock.h>
> +
> +/*
> + * SDC registers
> + */
> +#define OWL_REG_SD_EN 0x0000
> +#define OWL_REG_SD_CTL 0x0004
> +#define OWL_REG_SD_STATE 0x0008
> +#define OWL_REG_SD_CMD 0x000c
> +#define OWL_REG_SD_ARG 0x0010
> +#define OWL_REG_SD_RSPBUF0 0x0014
> +#define OWL_REG_SD_RSPBUF1 0x0018
> +#define OWL_REG_SD_RSPBUF2 0x001c
> +#define OWL_REG_SD_RSPBUF3 0x0020
> +#define OWL_REG_SD_RSPBUF4 0x0024
> +#define OWL_REG_SD_DAT 0x0028
> +#define OWL_REG_SD_BLK_SIZE 0x002c
> +#define OWL_REG_SD_BLK_NUM 0x0030
> +#define OWL_REG_SD_BUF_SIZE 0x0034
> +
> +/* SD_EN Bits */
> +#define OWL_SD_EN_RANE BIT(31)
> +#define OWL_SD_EN_RAN_SEED(x) (((x) & 0x3f) << 24)
> +#define OWL_SD_EN_S18EN BIT(12)
> +#define OWL_SD_EN_RESE BIT(10)
> +#define OWL_SD_EN_DAT1_S BIT(9)
> +#define OWL_SD_EN_CLK_S BIT(8)
> +#define OWL_SD_ENABLE BIT(7)
> +#define OWL_SD_EN_BSEL BIT(6)
> +#define OWL_SD_EN_SDIOEN BIT(3)
> +#define OWL_SD_EN_DDREN BIT(2)
> +#define OWL_SD_EN_DATAWID(x) (((x) & 0x3) << 0)
> +
> +/* SD_CTL Bits */
> +#define OWL_SD_CTL_TOUTEN BIT(31)
> +#define OWL_SD_CTL_TOUTCNT(x) (((x) & 0x7f) << 24)
> +#define OWL_SD_CTL_DELAY_MSK GENMASK(23, 16)
> +#define OWL_SD_CTL_RDELAY(x) (((x) & 0xf) << 20)
> +#define OWL_SD_CTL_WDELAY(x) (((x) & 0xf) << 16)
> +#define OWL_SD_CTL_CMDLEN BIT(13)
> +#define OWL_SD_CTL_SCC BIT(12)
> +#define OWL_SD_CTL_TCN(x) (((x) & 0xf) << 8)
> +#define OWL_SD_CTL_TS BIT(7)
> +#define OWL_SD_CTL_LBE BIT(6)
> +#define OWL_SD_CTL_C7EN BIT(5)
> +#define OWL_SD_CTL_TM(x) (((x) & 0xf) << 0)
> +
> +#define OWL_SD_DELAY_LOW_CLK 0x0f
> +#define OWL_SD_DELAY_MID_CLK 0x0a
> +#define OWL_SD_DELAY_HIGH_CLK 0x09
> +#define OWL_SD_RDELAY_DDR50 0x0a
> +#define OWL_SD_WDELAY_DDR50 0x08
> +
> +/* SD_STATE Bits */
> +#define OWL_SD_STATE_DAT1BS BIT(18)
> +#define OWL_SD_STATE_SDIOB_P BIT(17)
> +#define OWL_SD_STATE_SDIOB_EN BIT(16)
> +#define OWL_SD_STATE_TOUTE BIT(15)
> +#define OWL_SD_STATE_BAEP BIT(14)
> +#define OWL_SD_STATE_MEMRDY BIT(12)
> +#define OWL_SD_STATE_CMDS BIT(11)
> +#define OWL_SD_STATE_DAT1AS BIT(10)
> +#define OWL_SD_STATE_SDIOA_P BIT(9)
> +#define OWL_SD_STATE_SDIOA_EN BIT(8)
> +#define OWL_SD_STATE_DAT0S BIT(7)
> +#define OWL_SD_STATE_TEIE BIT(6)
> +#define OWL_SD_STATE_TEI BIT(5)
> +#define OWL_SD_STATE_CLNR BIT(4)
> +#define OWL_SD_STATE_CLC BIT(3)
> +#define OWL_SD_STATE_WC16ER BIT(2)
> +#define OWL_SD_STATE_RC16ER BIT(1)
> +#define OWL_SD_STATE_CRC7ER BIT(0)
> +
> +struct owl_mmc_host {
> + struct device *dev;
> + struct reset_control *reset;
> + void __iomem *base;
> + struct clk *clk;
> + struct completion sdc_complete;
> + spinlock_t lock;
> + int irq;
> + u32 clock;
> + bool ddr_50;
> +
> + enum dma_data_direction dma_dir;
> + struct dma_chan *dma;
> + struct dma_async_tx_descriptor *desc;
> + struct dma_slave_config dma_cfg;
> + struct completion dma_complete;
> +
> + struct mmc_host *mmc;
> + struct mmc_request *mrq;
> + struct mmc_command *cmd;
> + struct mmc_data *data;
> +};
> +
> +static inline void mmc_writel(struct owl_mmc_host *owl_host, u32 reg, u32 data)
> +{
> + writel(data, owl_host->base + reg);
> +}
> +
> +static inline u32 mmc_readl(struct owl_mmc_host *owl_host, u32 reg)
> +{
> + return readl(owl_host->base + reg);
> +}

Please drop these wrappers, as they don't make the code more readable.

> +
> +static void mmc_update_reg(void __iomem *reg, unsigned int val, bool state)

Please use the "owl" as prefix for function names, that makes it more
consistent.

> +{
> + unsigned int regval;
> +
> + regval = readl(reg);

Rather than reading the register here, perhaps you could use a
variable for caching the register value. Thus avoiding to read the
register for every update.


> +
> + if (state)
> + regval |= val;
> + else
> + regval &= ~val;
> +
> + writel(regval, reg);
> +}
> +
> +static irqreturn_t owl_irq_handler(int irq, void *devid)
> +{
> + struct owl_mmc_host *owl_host = devid;
> + unsigned long flags;
> + u32 state;
> +
> + spin_lock_irqsave(&owl_host->lock, flags);
> +
> + state = mmc_readl(owl_host, OWL_REG_SD_STATE);
> + if (state & OWL_SD_STATE_TEI) {
> + state = mmc_readl(owl_host, OWL_REG_SD_STATE);
> + state |= OWL_SD_STATE_TEI;
> + mmc_writel(owl_host, OWL_REG_SD_STATE, state);
> + complete(&owl_host->sdc_complete);
> + }
> +
> + spin_unlock_irqrestore(&owl_host->lock, flags);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static void owl_mmc_finish_request(struct owl_mmc_host *owl_host)
> +{
> + struct mmc_request *mrq = owl_host->mrq;
> + struct mmc_data *data = mrq->data;
> +
> + /* Should never be NULL */
> + WARN_ON(!mrq);
> +
> + owl_host->mrq = NULL;
> +
> + if (data)
> + dma_unmap_sg(owl_host->dma->device->dev, data->sg, data->sg_len,
> + owl_host->dma_dir);
> +
> + /* Finally finish request */
> + mmc_request_done(owl_host->mmc, mrq);
> +}
> +
> +static void owl_mmc_send_cmd(struct owl_mmc_host *owl_host,
> + struct mmc_command *cmd,
> + struct mmc_data *data)
> +{
> + u32 mode, state, resp[2];
> + u32 cmd_rsp_mask = 0;
> +
> + init_completion(&owl_host->sdc_complete);
> +
> + switch (mmc_resp_type(cmd)) {
> + case MMC_RSP_NONE:
> + mode = OWL_SD_CTL_TM(0);
> + break;
> +
> + case MMC_RSP_R1:
> + if (data) {
> + if (data->flags & MMC_DATA_READ)
> + mode = OWL_SD_CTL_TM(4);
> + else
> + mode = OWL_SD_CTL_TM(5);
> + } else {
> + mode = OWL_SD_CTL_TM(1);
> + }
> + cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
> +
> + break;
> +
> + case MMC_RSP_R1B:
> + mode = OWL_SD_CTL_TM(3);
> + cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
> + break;
> +
> + case MMC_RSP_R2:
> + mode = OWL_SD_CTL_TM(2);
> + cmd_rsp_mask = OWL_SD_STATE_CLNR | OWL_SD_STATE_CRC7ER;
> + break;
> +
> + case MMC_RSP_R3:
> + mode = OWL_SD_CTL_TM(1);
> + cmd_rsp_mask = OWL_SD_STATE_CLNR;
> + break;
> +
> + default:
> + dev_warn(owl_host->dev, "Unknown MMC command\n");
> + cmd->error = -EINVAL;
> + return;
> + }
> +
> + /* Keep current WDELAY and RDELAY */
> + mode |= (mmc_readl(owl_host, OWL_REG_SD_CTL) & (0xff << 16));
> +
> + /* Start to send corresponding command type */
> + mmc_writel(owl_host, OWL_REG_SD_ARG, cmd->arg);
> + mmc_writel(owl_host, OWL_REG_SD_CMD, cmd->opcode);
> +
> + /* Set LBE to send clk at the end of last read block */
> + if (data) {
> + mode |= (OWL_SD_CTL_TS | OWL_SD_CTL_LBE | 0x64000000);
> + } else {
> + mode &= ~(OWL_SD_CTL_TOUTEN | OWL_SD_CTL_LBE);
> + mode |= OWL_SD_CTL_TS;
> + }
> +
> + owl_host->cmd = cmd;
> +
> + /* Start transfer */
> + mmc_writel(owl_host, OWL_REG_SD_CTL, mode);
> +
> + if (data)
> + return;
> +
> + if (!wait_for_completion_timeout(&owl_host->sdc_complete, 30 * HZ)) {
> + dev_err(owl_host->dev, "CMD interrupt timeout\n");
> + cmd->error = -ETIMEDOUT;
> + return;
> + }
> +
> + state = mmc_readl(owl_host, OWL_REG_SD_STATE);
> + if (mmc_resp_type(cmd) & MMC_RSP_PRESENT) {
> + if (cmd_rsp_mask & state) {
> + if (state & OWL_SD_STATE_CLNR) {
> + dev_err(owl_host->dev, "Error CMD_NO_RSP\n");
> + cmd->error = -EILSEQ;
> + return;
> + }
> +
> + if (state & OWL_SD_STATE_CRC7ER) {
> + dev_err(owl_host->dev, "Error CMD_RSP_CRC\n");
> + cmd->error = -EILSEQ;
> + return;
> + }
> + }
> +
> + if (mmc_resp_type(cmd) & MMC_RSP_136) {
> + cmd->resp[3] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF0);
> + cmd->resp[2] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF1);
> + cmd->resp[1] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF2);
> + cmd->resp[0] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF3);
> + } else {
> + resp[0] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF0);
> + resp[1] = mmc_readl(owl_host, OWL_REG_SD_RSPBUF1);
> + cmd->resp[0] = resp[1] << 24 | resp[0] >> 8;
> + cmd->resp[1] = resp[1] >> 8;
> + }
> + }
> +}
> +
> +static void owl_mmc_dma_complete(void *param)
> +{
> + struct owl_mmc_host *owl_host = param;
> + struct mmc_data *data = owl_host->data;
> +
> + if (data)
> + complete(&owl_host->dma_complete);
> +}
> +
> +static int owl_mmc_prepare_data(struct owl_mmc_host *owl_host,
> + struct mmc_data *data)
> +{
> + u32 total;
> +
> + mmc_update_reg(owl_host->base + OWL_REG_SD_EN, OWL_SD_EN_BSEL, true);
> + mmc_writel(owl_host, OWL_REG_SD_BLK_NUM, data->blocks);
> + mmc_writel(owl_host, OWL_REG_SD_BLK_SIZE, data->blksz);
> + total = data->blksz * data->blocks;
> +
> + if (total < 512)
> + mmc_writel(owl_host, OWL_REG_SD_BUF_SIZE, total);
> + else
> + mmc_writel(owl_host, OWL_REG_SD_BUF_SIZE, 512);
> +
> + if (data->flags & MMC_DATA_WRITE) {
> + owl_host->dma_dir = DMA_TO_DEVICE;
> + owl_host->dma_cfg.direction = DMA_MEM_TO_DEV;
> + } else {
> + owl_host->dma_dir = DMA_FROM_DEVICE;
> + owl_host->dma_cfg.direction = DMA_DEV_TO_MEM;
> + }
> +
> + dma_map_sg(owl_host->dma->device->dev, data->sg,
> + data->sg_len, owl_host->dma_dir);
> +
> + dmaengine_slave_config(owl_host->dma, &owl_host->dma_cfg);
> + owl_host->desc = dmaengine_prep_slave_sg(owl_host->dma, data->sg,
> + data->sg_len,
> + owl_host->dma_cfg.direction,
> + DMA_PREP_INTERRUPT |
> + DMA_CTRL_ACK);
> + if (!owl_host->desc) {
> + dev_err(owl_host->dev, "Can't prepare slave sg\n");
> + return -EBUSY;
> + }
> +
> + owl_host->data = data;
> +
> + owl_host->desc->callback = owl_mmc_dma_complete;
> + owl_host->desc->callback_param = (void *)owl_host;
> + data->error = 0;
> +
> + return 0;
> +}
> +
> +static void owl_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> + struct owl_mmc_host *owl_host = mmc_priv(mmc);
> + struct mmc_data *data = mrq->data;
> + int ret;
> +
> + owl_host->mrq = mrq;
> + if (mrq->data) {
> + ret = owl_mmc_prepare_data(owl_host, data);
> + if (ret < 0) {
> + data->error = ret;
> + goto err_out;
> + }
> +
> + init_completion(&owl_host->dma_complete);
> + dmaengine_submit(owl_host->desc);
> + dma_async_issue_pending(owl_host->dma);
> + }
> +
> + owl_mmc_send_cmd(owl_host, mrq->cmd, data);
> +
> + if (data) {
> + if (!wait_for_completion_timeout(&owl_host->sdc_complete,
> + 10 * HZ)) {
> + dev_err(owl_host->dev, "CMD interrupt timeout\n");
> + mrq->cmd->error = -ETIMEDOUT;
> + dmaengine_terminate_all(owl_host->dma);
> + goto err_out;
> + }
> +
> + if (!wait_for_completion_timeout(&owl_host->dma_complete,
> + 5 * HZ)) {
> + dev_err(owl_host->dev, "DMA interrupt timeout\n");
> + mrq->cmd->error = -ETIMEDOUT;
> + dmaengine_terminate_all(owl_host->dma);
> + goto err_out;
> + }
> +
> + if (data->stop)
> + owl_mmc_send_cmd(owl_host, data->stop, NULL);
> +
> + data->bytes_xfered = data->blocks * data->blksz;
> + }
> +
> +err_out:
> + owl_mmc_finish_request(owl_host);
> +}
> +
> +static int owl_mmc_set_clk_rate(struct owl_mmc_host *owl_host,
> + unsigned int rate)
> +{
> + unsigned long clk_rate;
> + int ret;
> + u32 reg;
> +
> + reg = mmc_readl(owl_host, OWL_REG_SD_CTL);
> + reg &= ~OWL_SD_CTL_DELAY_MSK;
> +
> + /* Set RDELAY and WDELAY based on the clock */
> + if (rate <= 1000000) {
> + mmc_writel(owl_host, OWL_REG_SD_CTL, reg |
> + OWL_SD_CTL_RDELAY(OWL_SD_DELAY_LOW_CLK) |
> + OWL_SD_CTL_WDELAY(OWL_SD_DELAY_LOW_CLK));
> + } else if ((rate > 1000000) && (rate <= 26000000)) {
> + mmc_writel(owl_host, OWL_REG_SD_CTL, reg |
> + OWL_SD_CTL_RDELAY(OWL_SD_DELAY_MID_CLK) |
> + OWL_SD_CTL_WDELAY(OWL_SD_DELAY_MID_CLK));
> + } else if ((rate > 26000000) && (rate <= 52000000) && !owl_host->ddr_50) {
> + mmc_writel(owl_host, OWL_REG_SD_CTL, reg |
> + OWL_SD_CTL_RDELAY(OWL_SD_DELAY_HIGH_CLK) |
> + OWL_SD_CTL_WDELAY(OWL_SD_DELAY_HIGH_CLK));
> + /* DDR50 mode has special delay chain */
> + } else if ((rate > 26000000) && (rate <= 52000000) && owl_host->ddr_50) {
> + mmc_writel(owl_host, OWL_REG_SD_CTL, reg |
> + OWL_SD_CTL_RDELAY(OWL_SD_RDELAY_DDR50) |
> + OWL_SD_CTL_WDELAY(OWL_SD_WDELAY_DDR50));
> + } else {
> + dev_err(owl_host->dev, "SD clock rate not supported\n");
> + return -EINVAL;
> + }
> +
> + clk_rate = clk_round_rate(owl_host->clk, rate << 1);
> + ret = clk_set_rate(owl_host->clk, clk_rate);
> +
> + return ret;
> +}
> +
> +static void owl_mmc_set_clk(struct owl_mmc_host *owl_host, struct mmc_ios *ios)
> +{
> + if (!ios->clock)
> + return;
> +
> + owl_host->clock = ios->clock;
> + owl_mmc_set_clk_rate(owl_host, ios->clock);
> +}
> +
> +static void owl_mmc_set_bus_width(struct owl_mmc_host *owl_host,
> + struct mmc_ios *ios)
> +{
> + u32 reg;
> +
> + reg = mmc_readl(owl_host, OWL_REG_SD_EN);
> + reg &= ~0x03;
> + switch (ios->bus_width) {
> + case MMC_BUS_WIDTH_1:
> + break;
> + case MMC_BUS_WIDTH_4:
> + reg |= OWL_SD_EN_DATAWID(1);
> + break;
> + case MMC_BUS_WIDTH_8:
> + reg |= OWL_SD_EN_DATAWID(2);
> + break;
> + }
> +
> + mmc_writel(owl_host, OWL_REG_SD_EN, reg);
> +}
> +
> +static void owl_mmc_ctr_reset(struct owl_mmc_host *owl_host)
> +{
> + reset_control_assert(owl_host->reset);
> + udelay(20);
> + reset_control_deassert(owl_host->reset);
> +}
> +
> +static void owl_mmc_power_on(struct owl_mmc_host *owl_host)
> +{
> + u32 mode;
> +
> + init_completion(&owl_host->sdc_complete);
> +
> + /* Enable transfer end IRQ */
> + mmc_update_reg(owl_host->base + OWL_REG_SD_STATE,
> + OWL_SD_STATE_TEIE, true);
> +
> + /* Send init clk */
> + mode = (mmc_readl(owl_host, OWL_REG_SD_CTL) & (0xff << 16));
> + mode |= OWL_SD_CTL_TS | OWL_SD_CTL_TCN(5) | OWL_SD_CTL_TM(8);
> + mmc_writel(owl_host, OWL_REG_SD_CTL, mode);
> +
> + if (!wait_for_completion_timeout(&owl_host->sdc_complete, HZ)) {
> + dev_err(owl_host->dev, "CMD interrupt timeout\n");
> + return;
> + }
> +}
> +
> +static void owl_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> + struct owl_mmc_host *owl_host = mmc_priv(mmc);
> +
> + switch (ios->power_mode) {
> + case MMC_POWER_UP:
> + dev_dbg(owl_host->dev, "Powering card up\n");
> +
> + /* Reset the SDC controller to clear all previous states */
> + owl_mmc_ctr_reset(owl_host);
> + clk_prepare_enable(owl_host->clk);
> + mmc_writel(owl_host, OWL_REG_SD_EN, OWL_SD_ENABLE |
> + OWL_SD_EN_RESE);
> +
> + break;
> +
> + case MMC_POWER_ON:
> + dev_dbg(owl_host->dev, "Powering card on\n");
> + owl_mmc_power_on(owl_host);
> +
> + break;
> +
> + case MMC_POWER_OFF:
> + dev_dbg(owl_host->dev, "Powering card off\n");
> + clk_disable_unprepare(owl_host->clk);
> +
> + return;
> +
> + default:
> + dev_dbg(owl_host->dev, "Ignoring unknown card power state\n");
> + break;
> + }
> +
> + if (ios->clock != owl_host->clock)
> + owl_mmc_set_clk(owl_host, ios);
> +
> + owl_mmc_set_bus_width(owl_host, ios);
> +
> + /* Enable DDR mode if requested */
> + if (ios->timing == MMC_TIMING_UHS_DDR50) {
> + owl_host->ddr_50 = 1;
> + mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
> + OWL_SD_EN_DDREN, true);
> + } else {
> + owl_host->ddr_50 = 0;
> + }
> +}
> +
> +static int owl_mmc_start_signal_voltage_switch(struct mmc_host *mmc,
> + struct mmc_ios *ios)
> +{
> + struct owl_mmc_host *owl_host = mmc_priv(mmc);
> +
> + /* It is enough to change the pad ctrl bit for voltage switch */
> + switch (ios->signal_voltage) {
> + case MMC_SIGNAL_VOLTAGE_330:
> + mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
> + OWL_SD_EN_S18EN, false);
> + break;
> + case MMC_SIGNAL_VOLTAGE_180:
> + mmc_update_reg(owl_host->base + OWL_REG_SD_EN,
> + OWL_SD_EN_S18EN, true);
> + break;
> + default:
> + return -ENOTSUPP;
> + }
> +
> + return 0;
> +}
> +
> +static const struct mmc_host_ops owl_mmc_ops = {
> + .request = owl_mmc_request,
> + .set_ios = owl_mmc_set_ios,
> + .get_ro = mmc_gpio_get_ro,
> + .get_cd = mmc_gpio_get_cd,
> + .start_signal_voltage_switch = owl_mmc_start_signal_voltage_switch,
> +};
> +
> +static int owl_mmc_probe(struct platform_device *pdev)
> +{
> + struct owl_mmc_host *owl_host;
> + struct mmc_host *mmc;
> + struct resource *res;
> + int ret;
> +
> + mmc = mmc_alloc_host(sizeof(struct owl_mmc_host), &pdev->dev);
> + if (!mmc) {
> + dev_err(&pdev->dev, "mmc alloc host failed\n");
> + return -ENOMEM;
> + }
> + platform_set_drvdata(pdev, mmc);
> +
> + owl_host = mmc_priv(mmc);
> + owl_host->dev = &pdev->dev;
> + owl_host->mmc = mmc;
> + spin_lock_init(&owl_host->lock);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + owl_host->base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(owl_host->base)) {
> + dev_err(&pdev->dev, "Failed to remap registers\n");
> + ret = PTR_ERR(owl_host->base);
> + goto err_free_host;
> + }
> +
> + owl_host->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(owl_host->clk)) {
> + dev_err(&pdev->dev, "No clock defined\n");
> + ret = PTR_ERR(owl_host->clk);
> + goto err_free_host;
> + }
> +
> + owl_host->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
> + if (IS_ERR(owl_host->reset)) {
> + dev_err(&pdev->dev, "Could not get reset control\n");
> + ret = PTR_ERR(owl_host->reset);
> + goto err_free_host;
> + }
> +
> + mmc->ops = &owl_mmc_ops;
> + mmc->max_blk_count = 512;
> + mmc->max_blk_size = 512;
> + mmc->max_segs = 256;
> + mmc->max_seg_size = 262144;
> + mmc->max_req_size = 262144;
> + /* 100kHz ~ 52MHz */
> + mmc->f_min = 100000;
> + mmc->f_max = 52000000;
> + mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> + MMC_CAP_4_BIT_DATA;
> + mmc->caps2 = (MMC_CAP2_BOOTPART_NOACC | MMC_CAP2_NO_SDIO);
> + mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34 |
> + MMC_VDD_165_195;
> +
> + ret = mmc_of_parse(mmc);
> + if (ret)
> + goto err_free_host;
> +
> + pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
> + pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> + owl_host->dma = dma_request_slave_channel(&pdev->dev, "mmc");
> + if (!owl_host->dma) {
> + dev_err(owl_host->dev, "Failed to get external DMA channel.\n");
> + ret = -ENXIO;
> + goto err_free_host;
> + }
> +
> + dev_info(&pdev->dev, "Using %s for DMA transfers\n",
> + dma_chan_name(owl_host->dma));
> +
> + owl_host->dma_cfg.src_addr = res->start + OWL_REG_SD_DAT;
> + owl_host->dma_cfg.dst_addr = res->start + OWL_REG_SD_DAT;
> + owl_host->dma_cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + owl_host->dma_cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
> + owl_host->dma_cfg.device_fc = false;
> +
> + owl_host->irq = platform_get_irq(pdev, 0);
> + if (owl_host->irq < 0) {
> + ret = -EINVAL;
> + goto err_free_host;
> + }
> +
> + ret = devm_request_irq(&pdev->dev, owl_host->irq, owl_irq_handler,
> + 0, dev_name(&pdev->dev), owl_host);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to request irq %d\n",
> + owl_host->irq);
> + goto err_free_host;
> + }
> +
> + ret = mmc_add_host(mmc);
> + if (ret) {
> + dev_err(&pdev->dev, "Failed to add host\n");
> + goto err_free_host;
> + }
> +
> + dev_dbg(&pdev->dev, "Owl MMC Controller Initialized\n");
> +
> + return 0;
> +
> +err_free_host:
> + mmc_free_host(mmc);
> +
> + return ret;
> +}
> +
> +static int owl_mmc_remove(struct platform_device *pdev)
> +{
> + struct mmc_host *mmc = platform_get_drvdata(pdev);
> + struct owl_mmc_host *owl_host = mmc_priv(mmc);
> +
> + mmc_remove_host(mmc);
> + disable_irq(owl_host->irq);
> + mmc_free_host(mmc);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id owl_mmc_of_match[] = {
> + {.compatible = "actions,owl-mmc",},
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, owl_mmc_of_match);
> +
> +static struct platform_driver owl_mmc_driver = {
> + .driver = {
> + .name = "owl_mmc",
> + .of_match_table = of_match_ptr(owl_mmc_of_match),
> + },
> + .probe = owl_mmc_probe,
> + .remove = owl_mmc_remove,
> +};
> +module_platform_driver(owl_mmc_driver);
> +
> +MODULE_DESCRIPTION("Actions Semi Owl SoCs SD/MMC Driver");
> +MODULE_AUTHOR("Actions Semi");
> +MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
> +MODULE_LICENSE("GPL");
> --
> 2.17.1
>

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