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SubjectRe: [PATCH 2/2] mtd: spi-nor: Altera ASMI Parallel II IP Core
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On 08/06/2017 08:24 PM, matthew.gerlach@linux.intel.com wrote:
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>

Thanks for the descriptive commit message. Could you explain what this
patch is all about ?

> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>

[...]

> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index c5f171d..1c79324 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -1,4 +1,5 @@
> obj-$(CONFIG_MTD_SPI_NOR) += spi-nor.o
> +obj-$(CONFIG_SPI_ALTERA_ASMIP2) += altera-asmip2.o
> obj-$(CONFIG_SPI_ASPEED_SMC) += aspeed-smc.o
> obj-$(CONFIG_SPI_ATMEL_QUADSPI) += atmel-quadspi.o
> obj-$(CONFIG_SPI_CADENCE_QUADSPI) += cadence-quadspi.o
> @@ -9,4 +10,4 @@ obj-$(CONFIG_SPI_NXP_SPIFI) += nxp-spifi.o
> obj-$(CONFIG_SPI_INTEL_SPI) += intel-spi.o
> obj-$(CONFIG_SPI_INTEL_SPI_PCI) += intel-spi-pci.o
> obj-$(CONFIG_SPI_INTEL_SPI_PLATFORM) += intel-spi-platform.o
> -obj-$(CONFIG_SPI_STM32_QUADSPI) += stm32-quadspi.o
> \ No newline at end of file
> +obj-$(CONFIG_SPI_STM32_QUADSPI) += stm32-quadspi.o

Drop this hunk

> diff --git a/drivers/mtd/spi-nor/altera-asmip2.c b/drivers/mtd/spi-nor/altera-asmip2.c
> new file mode 100644
> index 0000000..2095f2e
> --- /dev/null
> +++ b/drivers/mtd/spi-nor/altera-asmip2.c
> @@ -0,0 +1,474 @@
> +/*
> + * Copyright (C) 2017 Intel Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/mtd/altera-asmip2.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/spi-nor.h>
> +#include <linux/of_device.h>
> +
> +#define QSPI_ACTION_REG 0
> +#define QSPI_ACTION_RST BIT(0)
> +#define QSPI_ACTION_EN BIT(1)
> +#define QSPI_ACTION_SC BIT(2)
> +#define QSPI_ACTION_CHIP_SEL_SFT 4
> +#define QSPI_ACTION_DUMMY_SFT 8
> +#define QSPI_ACTION_READ_BACK_SFT 16
> +
> +#define QSPI_FIFO_CNT_REG 4
> +#define QSPI_FIFO_DEPTH 0x200
> +#define QSPI_FIFO_CNT_MSK 0x3ff
> +#define QSPI_FIFO_CNT_RX_SFT 0
> +#define QSPI_FIFO_CNT_TX_SFT 12

Indent the value with a tab at least ...

> +#define QSPI_DATA_REG 0x8
> +
> +#define QSPI_POLL_TIMEOUT 10000000

In what units is this ?

> +#define QSPI_POLL_INTERVAL 5
> +
> +struct altera_asmip2 {
> + void __iomem *csr_base;
> + u32 num_flashes;
> + struct device *dev;
> + struct altera_asmip2_flash *flash[ALTERA_ASMIP2_MAX_NUM_FLASH_CHIP];
> + struct mutex bus_mutex;
> +};
> +
> +struct altera_asmip2_flash {
> + struct spi_nor nor;
> + struct altera_asmip2 *q;
> + u32 bank;
> +};
> +
> +static int altera_asmip2_write_reg(struct spi_nor *nor, u8 opcode, u8 *val,
> + int len)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> + u32 reg;
> + int ret;
> + int i;
> +
> + if ((len + 1) > QSPI_FIFO_DEPTH) {
> + dev_err(q->dev, "%s bad len %d > %d\n",
> + __func__, len + 1, QSPI_FIFO_DEPTH);
> + return -EINVAL;
> + }
> +
> + writel(opcode, q->csr_base + QSPI_DATA_REG);
> +
> + for (i = 0; i < len; i++) {
> + writel((u32)val[i], q->csr_base + QSPI_DATA_REG);

iowrite32_rep() ?

> + }
> +
> + reg = QSPI_ACTION_EN | QSPI_ACTION_SC;
> +
> + writel(reg, q->csr_base + QSPI_ACTION_REG);
> +
> + ret = readl_poll_timeout(q->csr_base + QSPI_FIFO_CNT_REG, reg,
> + (((reg >> QSPI_FIFO_CNT_TX_SFT) &
> + QSPI_FIFO_CNT_MSK) == 0), QSPI_POLL_INTERVAL,
> + QSPI_POLL_TIMEOUT);
> + if (ret)
> + dev_err(q->dev, "%s timed out\n", __func__);

So if the poll fails , you ignore the failure and continue enabling
whatever action you enable here ?

> + reg = QSPI_ACTION_EN;
> +
> + writel(reg, q->csr_base + QSPI_ACTION_REG);
> +
> + return ret;
> +}
> +
> +static int altera_asmip2_read_reg(struct spi_nor *nor, u8 opcode, u8 *val,
> + int len)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> + u32 reg;
> + int ret;
> + int i;
> +
> + if (len > QSPI_FIFO_DEPTH) {
> + dev_err(q->dev, "%s bad len %d > %d\n",
> + __func__, len, QSPI_FIFO_DEPTH);
> + return -EINVAL;
> + }
> +
> + writel(opcode, q->csr_base + QSPI_DATA_REG);
> +
> + reg = QSPI_ACTION_EN | QSPI_ACTION_SC |
> + (len << QSPI_ACTION_READ_BACK_SFT);
> +
> + writel(reg, q->csr_base + QSPI_ACTION_REG);
> +
> + ret = readl_poll_timeout(q->csr_base + QSPI_FIFO_CNT_REG, reg,
> + ((reg & QSPI_FIFO_CNT_MSK) == len),
> + QSPI_POLL_INTERVAL, QSPI_POLL_TIMEOUT);
> +
> + if (!ret)
> + for (i = 0; i < len; i++) {
> + reg = readl(q->csr_base + QSPI_DATA_REG);
> + val[i] = (u8)(reg & 0xff);

ioread32_rep , plus same comments as for the write function

> + }
> + else
> + dev_err(q->dev, "%s timeout\n", __func__);
> +
> + writel(QSPI_ACTION_EN, q->csr_base + QSPI_ACTION_REG);
> +
> + return ret;
> +}
> +
> +static ssize_t altera_asmip2_read(struct spi_nor *nor, loff_t from, size_t len,
> + u_char *buf)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> + size_t bytes_to_read, i;
> + u32 reg;
> + int ret;
> +
> + bytes_to_read = min_t(size_t, len, QSPI_FIFO_DEPTH);
> +
> + writel(nor->read_opcode, q->csr_base + QSPI_DATA_REG);
> +
> + writel((from & 0xff000000) >> 24, q->csr_base + QSPI_DATA_REG);
> + writel((from & 0x00ff0000) >> 16, q->csr_base + QSPI_DATA_REG);
> + writel((from & 0x0000ff00) >> 8, q->csr_base + QSPI_DATA_REG);
> + writel((from & 0x000000ff), q->csr_base + QSPI_DATA_REG);

Use a for() loop ?

> + reg = QSPI_ACTION_EN | QSPI_ACTION_SC |
> + (10 << QSPI_ACTION_DUMMY_SFT) |
> + (bytes_to_read << QSPI_ACTION_READ_BACK_SFT);
> +
> + writel(reg, q->csr_base + QSPI_ACTION_REG);
> +
> + ret = readl_poll_timeout(q->csr_base + QSPI_FIFO_CNT_REG, reg,
> + ((reg & QSPI_FIFO_CNT_MSK) ==
> + bytes_to_read), QSPI_POLL_INTERVAL,
> + QSPI_POLL_TIMEOUT);
> + if (ret) {
> + dev_err(q->dev, "%s timed out\n", __func__);
> + bytes_to_read = 0;
> + } else
> + for (i = 0; i < bytes_to_read; i++) {
> + reg = readl(q->csr_base + QSPI_DATA_REG);
> + *buf++ = (u8)(reg & 0xff);

ioread8_rep or something ?

> + }
> +
> + writel(QSPI_ACTION_EN, q->csr_base + QSPI_ACTION_REG);
> +
> + return bytes_to_read;
> +}
> +
> +static ssize_t altera_asmip2_write(struct spi_nor *nor, loff_t to,
> + size_t len, const u_char *buf)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> + size_t bytes_to_write, i;
> + u32 reg;
> + int ret;
> +
> + bytes_to_write = min_t(size_t, len, (QSPI_FIFO_DEPTH - 5));
> +
> + writel(nor->program_opcode, q->csr_base + QSPI_DATA_REG);
> +
> + writel((to & 0xff000000) >> 24, q->csr_base + QSPI_DATA_REG);
> + writel((to & 0x00ff0000) >> 16, q->csr_base + QSPI_DATA_REG);
> + writel((to & 0x0000ff00) >> 8, q->csr_base + QSPI_DATA_REG);
> + writel((to & 0x000000ff), q->csr_base + QSPI_DATA_REG);
> +
> + for (i = 0; i < bytes_to_write; i++) {
> + reg = (u32)*buf++;
> + writel(reg, q->csr_base + QSPI_DATA_REG);
> + }
> +
> + reg = QSPI_ACTION_EN | QSPI_ACTION_SC;
> +
> + writel(reg, q->csr_base + QSPI_ACTION_REG);
> +
> + ret = readl_poll_timeout(q->csr_base + QSPI_FIFO_CNT_REG, reg,
> + (((reg >> QSPI_FIFO_CNT_TX_SFT) &
> + QSPI_FIFO_CNT_MSK) == 0), QSPI_POLL_INTERVAL,
> + QSPI_POLL_TIMEOUT);
> +
> + if (ret) {
> + dev_err(q->dev,
> + "%s timed out waiting for fifo to clear\n",
> + __func__);
> + bytes_to_write = 0;
> + }
> +
> + writel(QSPI_ACTION_EN, q->csr_base + QSPI_ACTION_REG);
> +
> + return bytes_to_write;
> +
> +}
> +
> +static int altera_asmip2_prep(struct spi_nor *nor, enum spi_nor_ops ops)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> +
> + mutex_lock(&q->bus_mutex);

We should factor this mutex stuff into the SPI NOR framework, this
pattern is repeating itself way too often.

> + return 0;
> +}
> +
> +static void altera_asmip2_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
> +{
> + struct altera_asmip2_flash *flash = nor->priv;
> + struct altera_asmip2 *q = flash->q;
> +
> + mutex_unlock(&q->bus_mutex);
> +}
> +
> +static int altera_asmip2_setup_banks(struct device *dev,
> + u32 bank, struct device_node *np)
> +{
> + const struct spi_nor_hwcaps hwcaps = {
> + .mask = SNOR_HWCAPS_READ |
> + SNOR_HWCAPS_READ_FAST |
> + SNOR_HWCAPS_PP,
> + };
> + struct altera_asmip2 *q = dev_get_drvdata(dev);
> + struct altera_asmip2_flash *flash;
> + struct spi_nor *nor;
> + int ret = 0;
> + char modalias[40] = {0};
> +
> + if (bank > q->num_flashes - 1)
> + return -EINVAL;
> +
> + flash = devm_kzalloc(q->dev, sizeof(*flash), GFP_KERNEL);
> + if (!flash)
> + return -ENOMEM;
> +
> + q->flash[bank] = flash;
> + flash->q = q;
> + flash->bank = bank;
> +
> + nor = &flash->nor;
> + nor->dev = dev;
> + nor->priv = flash;
> + nor->mtd.priv = nor;
> + spi_nor_set_flash_node(nor, np);
> +
> + /* spi nor framework*/
> + nor->read_reg = altera_asmip2_read_reg;
> + nor->write_reg = altera_asmip2_write_reg;
> + nor->read = altera_asmip2_read;
> + nor->write = altera_asmip2_write;
> + nor->prepare = altera_asmip2_prep;
> + nor->unprepare = altera_asmip2_unprep;
> +
> + /* scanning flash and checking dev id */
> +#ifdef CONFIG_OF

Why is this here ?

> + if (np && (of_modalias_node(np, modalias, sizeof(modalias)) < 0))
> + return -EINVAL;
> +#endif
> +
> + ret = spi_nor_scan(nor, modalias, &hwcaps);
> + if (ret) {
> + dev_err(nor->dev, "flash not found\n");
> + return ret;
> + }
> +
> + ret = mtd_device_register(&nor->mtd, NULL, 0);
> +
> + return ret;
> +}
> +
> +static int altera_asmip2_create(struct device *dev, void __iomem *csr_base)
> +{
> + struct altera_asmip2 *q;
> + u32 reg;
> +
> + q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
> + if (!q)
> + return -ENOMEM;
> +
> + q->dev = dev;
> + q->csr_base = csr_base;
> +
> + mutex_init(&q->bus_mutex);
> +
> + dev_set_drvdata(dev, q);
> +
> + reg = readl(q->csr_base + QSPI_ACTION_REG);
> + if (!(reg & QSPI_ACTION_RST)) {
> + writel((reg | QSPI_ACTION_RST), q->csr_base + QSPI_ACTION_REG);
> + dev_info(dev, "%s asserting reset\n", __func__);
> + udelay(10);
> + }
> +
> + writel((reg & ~QSPI_ACTION_RST), q->csr_base + QSPI_ACTION_REG);
> + udelay(10);
> +
> + return 0;
> +}
> +
> +static int altera_qspi_add_bank(struct device *dev,
> + u32 bank, struct device_node *np)
> +{
> + struct altera_asmip2 *q = dev_get_drvdata(dev);
> +
> + if (q->num_flashes >= ALTERA_ASMIP2_MAX_NUM_FLASH_CHIP)
> + return -ENOMEM;
> +
> + q->num_flashes++;
> +
> + return altera_asmip2_setup_banks(dev, bank, np);
> +}
> +
> +static int altera_asmip2_remove_banks(struct device *dev)
> +{
> + struct altera_asmip2 *q = dev_get_drvdata(dev);
> + struct altera_asmip2_flash *flash;
> + int i;
> + int ret = 0;
> +
> + if (!q)
> + return -EINVAL;
> +
> + /* clean up for all nor flash */
> + for (i = 0; i < q->num_flashes; i++) {
> + flash = q->flash[i];
> + if (!flash)
> + continue;
> +
> + /* clean up mtd stuff */
> + ret = mtd_device_unregister(&flash->nor.mtd);
> + if (ret) {
> + dev_err(dev, "error removing mtd\n");
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int __probe_with_data(struct platform_device *pdev,
> + struct altera_asmip2_plat_data *qdata)
> +{
> + struct device *dev = &pdev->dev;
> + int ret, i;
> +
> + ret = altera_asmip2_create(dev, qdata->csr_base);
> +
> + if (ret) {
> + dev_err(dev, "failed to create qspi device %d\n", ret);
> + return ret;
> + }
> +
> + for (i = 0; i < qdata->num_chip_sel; i++) {
> + ret = altera_qspi_add_bank(dev, i, NULL);
> + if (ret) {
> + dev_err(dev, "failed to add qspi bank %d\n", ret);
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int altera_asmip2_probe(struct platform_device *pdev)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device *dev = &pdev->dev;
> + struct altera_asmip2_plat_data *qdata;
> + struct resource *res;
> + void __iomem *csr_base;
> + u32 bank;
> + int ret;
> + struct device_node *pp;
> +
> + qdata = dev_get_platdata(dev);
> +
> + if (qdata)
> + return __probe_with_data(pdev, qdata);

Avoid function names with __ prefix.

> + if (!np) {
> + dev_err(dev, "no device tree found %p\n", pdev);
> + return -ENODEV;
> + }

You might as well introduce a function to probe with of to be consistent
... or convert between pdata and ofdata and have one function for both.

> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + csr_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(csr_base)) {
> + dev_err(dev, "%s: ERROR: failed to map csr base\n", __func__);
> + return PTR_ERR(csr_base);
> + }
> +
> + ret = altera_asmip2_create(dev, csr_base);
> +
> + if (ret) {
> + dev_err(dev, "failed to create qspi device\n");
> + return ret;
> + }
> +
> + for_each_available_child_of_node(np, pp) {
> + of_property_read_u32(pp, "reg", &bank);
> + if (bank >= ALTERA_ASMIP2_MAX_NUM_FLASH_CHIP) {
> + dev_err(dev, "bad reg value %u >= %u\n", bank,
> + ALTERA_ASMIP2_MAX_NUM_FLASH_CHIP);
> + goto error;
> + }
> +
> + if (altera_qspi_add_bank(dev, bank, pp)) {
> + dev_err(dev, "failed to add bank %u\n", bank);
> + goto error;
> + }
> + }
> +
> + return 0;
> +error:
> + altera_asmip2_remove_banks(dev);
> + return -EIO;
> +}
> +
> +static int altera_asmip2_remove(struct platform_device *pdev)
> +{
> + if (!pdev) {
> + dev_err(&pdev->dev, "%s NULL\n", __func__);
> + return -EINVAL;

Can this really happen ?

> + } else {
> + return altera_asmip2_remove_banks(&pdev->dev);
> + }
> +}
> +
> +static const struct of_device_id altera_asmip2_id_table[] = {
> +
> + { .compatible = "altr,asmi_parallel2",},
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, altera_asmip2_id_table);
> +
> +static struct platform_driver altera_asmip2_driver = {
> + .driver = {
> + .name = ALTERA_ASMIP2_DRV_NAME,
> + .of_match_table = altera_asmip2_id_table,
> + },
> + .probe = altera_asmip2_probe,
> + .remove = altera_asmip2_remove,
> +};
> +module_platform_driver(altera_asmip2_driver);
> +
> +MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach@linux.intel.com>");
> +MODULE_DESCRIPTION("Altera ASMI Parallel II");
> +MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("platform:" ALTERA_ASMIP2_DRV_NAME);
> diff --git a/include/linux/mtd/altera-asmip2.h b/include/linux/mtd/altera-asmip2.h
> new file mode 100644
> index 0000000..580c43c
> --- /dev/null
> +++ b/include/linux/mtd/altera-asmip2.h
> @@ -0,0 +1,24 @@
> +/*
> + *
> + * Copyright 2017 Intel Corporation, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +#ifndef __ALTERA_QUADSPI_H
> +#define __ALTERA_QUADSPI_H
> +
> +#include <linux/device.h>
> +
> +#define ALTERA_ASMIP2_DRV_NAME "altr-asmip2"
> +#define ALTERA_ASMIP2_MAX_NUM_FLASH_CHIP 3
> +#define ALTERA_ASMIP2_RESOURCE_SIZE 0x10
> +
> +struct altera_asmip2_plat_data {
> + void __iomem *csr_base;
> + u32 num_chip_sel;
> +};
> +
> +#endif
>


--
Best regards,
Marek Vasut

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