ath79: add NAND driver for MikroTik RB91xG series

Main part is copied from ar71xx original driver rb91x_nand
written by Gabor Juhos <juhosg@openwrt.org>.

What is done:
* Support of kernel 5.4 and 5.10,
* DTS support,
* New gpio API (gpiod_*) support.

Reviewed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Denis Kalashnikov <denis281089@gmail.com>
(cherry-picked from commit 820e660cd7)
This commit is contained in:
Denis Kalashnikov 2021-05-27 11:16:45 +03:00 committed by Koen Vandeputte
parent 43723e6db9
commit bd2e070557
3 changed files with 397 additions and 0 deletions

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@ -0,0 +1,375 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* MikroTik RB91x NAND flash driver
*
* Main part is copied from original driver written by Gabor Juhos.
*
* Copyright (C) 2013-2014 Gabor Juhos <juhosg@openwrt.org>
*/
/*
* WARNING: to speed up NAND reading/writing we are working with SoC GPIO
* controller registers directly -- not through standard GPIO API.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mtd/rawnand.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/platform_device.h>
#include <linux/gpio/consumer.h>
#include <linux/version.h>
#include <linux/of_platform.h>
#include <asm/mach-ath79/ar71xx_regs.h>
/* Bit masks for NAND data lines in ath79 gpio 32-bit register */
#define RB91X_NAND_NRW_BIT BIT(12)
#define RB91X_NAND_DATA_BITS (BIT(0) | BIT(1) | BIT(2) | BIT(3) | BIT(4) \
| BIT(13) | BIT(14) | BIT(15))
#define RB91X_NAND_LOW_DATA_MASK 0x1f
#define RB91X_NAND_HIGH_DATA_MASK 0xe0
#define RB91X_NAND_HIGH_DATA_SHIFT 8
enum rb91x_nand_gpios {
RB91X_NAND_READ,/* Read */
RB91X_NAND_RDY, /* NAND Ready */
RB91X_NAND_NCE, /* Chip Enable. Active low */
RB91X_NAND_CLE, /* Command Latch Enable */
RB91X_NAND_ALE, /* Address Latch Enable */
RB91X_NAND_NRW, /* Read/Write. Active low */
RB91X_NAND_NLE, /* Latch Enable. Active low */
RB91X_NAND_GPIOS,
};
struct rb91x_nand_drvdata {
struct nand_chip chip;
struct device *dev;
struct gpio_desc **gpio;
void __iomem *ath79_gpio_base;
};
static inline void rb91x_nand_latch_lock(struct rb91x_nand_drvdata *drvdata,
int lock)
{
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_NLE], lock);
}
static int rb91x_ooblayout_ecc(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 8;
oobregion->length = 3;
return 0;
case 1:
oobregion->offset = 13;
oobregion->length = 3;
return 0;
default:
return -ERANGE;
}
}
static int rb91x_ooblayout_free(struct mtd_info *mtd, int section,
struct mtd_oob_region *oobregion)
{
switch (section) {
case 0:
oobregion->offset = 0;
oobregion->length = 4;
return 0;
case 1:
oobregion->offset = 4;
oobregion->length = 1;
return 0;
case 2:
oobregion->offset = 6;
oobregion->length = 2;
return 0;
case 3:
oobregion->offset = 11;
oobregion->length = 2;
return 0;
default:
return -ERANGE;
}
}
static const struct mtd_ooblayout_ops rb91x_nand_ecclayout_ops = {
.ecc = rb91x_ooblayout_ecc,
.free = rb91x_ooblayout_free,
};
static void rb91x_nand_write(struct rb91x_nand_drvdata *drvdata,
const u8 *buf,
unsigned len)
{
void __iomem *base = drvdata->ath79_gpio_base;
u32 oe_reg;
u32 out_reg;
u32 out;
unsigned i;
rb91x_nand_latch_lock(drvdata, 1);
oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
out_reg = __raw_readl(base + AR71XX_GPIO_REG_OUT);
/* Set data lines to output mode */
__raw_writel(oe_reg & ~(RB91X_NAND_DATA_BITS | RB91X_NAND_NRW_BIT),
base + AR71XX_GPIO_REG_OE);
out = out_reg & ~(RB91X_NAND_DATA_BITS | RB91X_NAND_NRW_BIT);
for (i = 0; i != len; i++) {
u32 data;
data = (buf[i] & RB91X_NAND_HIGH_DATA_MASK) <<
RB91X_NAND_HIGH_DATA_SHIFT;
data |= buf[i] & RB91X_NAND_LOW_DATA_MASK;
data |= out;
__raw_writel(data, base + AR71XX_GPIO_REG_OUT);
/* Deactivate WE line */
data |= RB91X_NAND_NRW_BIT;
__raw_writel(data, base + AR71XX_GPIO_REG_OUT);
/* Flush write */
__raw_readl(base + AR71XX_GPIO_REG_OUT);
}
/* Restore registers */
__raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
__raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
/* Flush write */
__raw_readl(base + AR71XX_GPIO_REG_OUT);
rb91x_nand_latch_lock(drvdata, 0);
}
static void rb91x_nand_read(struct rb91x_nand_drvdata *drvdata,
u8 *read_buf,
unsigned len)
{
void __iomem *base = drvdata->ath79_gpio_base;
u32 oe_reg;
u32 out_reg;
unsigned i;
/* Enable read mode */
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_READ], 1);
rb91x_nand_latch_lock(drvdata, 1);
/* Save registers */
oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
out_reg = __raw_readl(base + AR71XX_GPIO_REG_OUT);
/* Set data lines to input mode */
__raw_writel(oe_reg | RB91X_NAND_DATA_BITS,
base + AR71XX_GPIO_REG_OE);
for (i = 0; i < len; i++) {
u32 in;
u8 data;
/* Activate RE line */
__raw_writel(RB91X_NAND_NRW_BIT, base + AR71XX_GPIO_REG_CLEAR);
/* Flush write */
__raw_readl(base + AR71XX_GPIO_REG_CLEAR);
/* Read input lines */
in = __raw_readl(base + AR71XX_GPIO_REG_IN);
/* Deactivate RE line */
__raw_writel(RB91X_NAND_NRW_BIT, base + AR71XX_GPIO_REG_SET);
data = (in & RB91X_NAND_LOW_DATA_MASK);
data |= (in >> RB91X_NAND_HIGH_DATA_SHIFT) &
RB91X_NAND_HIGH_DATA_MASK;
read_buf[i] = data;
}
/* Restore registers */
__raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
__raw_writel(oe_reg, base + AR71XX_GPIO_REG_OE);
/* Flush write */
__raw_readl(base + AR71XX_GPIO_REG_OUT);
rb91x_nand_latch_lock(drvdata, 0);
/* Disable read mode */
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_READ], 0);
}
static int rb91x_nand_dev_ready(struct nand_chip *chip)
{
struct rb91x_nand_drvdata *drvdata = (struct rb91x_nand_drvdata *)(chip->priv);
return gpiod_get_value_cansleep(drvdata->gpio[RB91X_NAND_RDY]);
}
static void rb91x_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
unsigned int ctrl)
{
struct rb91x_nand_drvdata *drvdata = chip->priv;
if (ctrl & NAND_CTRL_CHANGE) {
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_CLE],
(ctrl & NAND_CLE) ? 1 : 0);
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_ALE],
(ctrl & NAND_ALE) ? 1 : 0);
gpiod_set_value_cansleep(drvdata->gpio[RB91X_NAND_NCE],
(ctrl & NAND_NCE) ? 1 : 0);
}
if (cmd != NAND_CMD_NONE) {
u8 t = cmd;
rb91x_nand_write(drvdata, &t, 1);
}
}
static u8 rb91x_nand_read_byte(struct nand_chip *chip)
{
u8 data = 0xff;
rb91x_nand_read(chip->priv, &data, 1);
return data;
}
static void rb91x_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
{
rb91x_nand_read(chip->priv, buf, len);
}
static void rb91x_nand_write_buf(struct nand_chip *chip, const u8 *buf, int len)
{
rb91x_nand_write(chip->priv, buf, len);
}
static void rb91x_nand_release(struct rb91x_nand_drvdata *drvdata)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,8,0)
mtd_device_unregister(nand_to_mtd(&drvdata->chip));
nand_cleanup(&drvdata->chip);
#else
nand_release(&drvdata->chip);
#endif
}
static int rb91x_nand_probe(struct platform_device *pdev)
{
struct rb91x_nand_drvdata *drvdata;
struct mtd_info *mtd;
int r;
struct device *dev = &pdev->dev;
struct gpio_descs *gpios;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
platform_set_drvdata(pdev, drvdata);
gpios = gpiod_get_array(dev, NULL, GPIOD_OUT_LOW);
if (IS_ERR(gpios)) {
dev_err(dev, "failed to get gpios: %d\n", (int)gpios);
return -EINVAL;
}
if (gpios->ndescs != RB91X_NAND_GPIOS) {
dev_err(dev, "expected %d gpios\n", RB91X_NAND_GPIOS);
return -EINVAL;
}
drvdata->gpio = gpios->desc;
gpiod_direction_input(drvdata->gpio[RB91X_NAND_RDY]);
drvdata->ath79_gpio_base = ioremap(AR71XX_GPIO_BASE, AR71XX_GPIO_SIZE);
drvdata->dev = dev;
drvdata->chip.priv = drvdata;
drvdata->chip.legacy.cmd_ctrl = rb91x_nand_cmd_ctrl;
drvdata->chip.legacy.dev_ready = rb91x_nand_dev_ready;
drvdata->chip.legacy.read_byte = rb91x_nand_read_byte;
drvdata->chip.legacy.write_buf = rb91x_nand_write_buf;
drvdata->chip.legacy.read_buf = rb91x_nand_read_buf;
drvdata->chip.legacy.chip_delay = 25;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0)
drvdata->chip.ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
drvdata->chip.ecc.algo = NAND_ECC_ALGO_HAMMING;
#else
drvdata->chip.ecc.mode = NAND_ECC_SOFT;
drvdata->chip.ecc.algo = NAND_ECC_HAMMING;
#endif
drvdata->chip.options = NAND_NO_SUBPAGE_WRITE;
r = nand_scan(&drvdata->chip, 1);
if (r) {
dev_err(dev, "nand_scan() failed: %d\n", r);
return r;
}
mtd = nand_to_mtd(&drvdata->chip);
mtd->dev.parent = dev;
mtd_set_of_node(mtd, dev->of_node);
mtd->owner = THIS_MODULE;
if (mtd->writesize == 512)
mtd_set_ooblayout(mtd, &rb91x_nand_ecclayout_ops);
r = mtd_device_register(mtd, NULL, 0);
if (r) {
dev_err(dev, "mtd_device_register() failed: %d\n",
r);
goto err_release_nand;
}
return 0;
err_release_nand:
rb91x_nand_release(drvdata);
return r;
}
static int rb91x_nand_remove(struct platform_device *pdev)
{
struct rb91x_nand_drvdata *drvdata = platform_get_drvdata(pdev);
rb91x_nand_release(drvdata);
return 0;
}
static const struct of_device_id rb91x_nand_match[] = {
{ .compatible = "mikrotik,rb91x-nand" },
{},
};
MODULE_DEVICE_TABLE(of, rb91x_nand_match);
static struct platform_driver rb91x_nand_driver = {
.probe = rb91x_nand_probe,
.remove = rb91x_nand_remove,
.driver = {
.name = "rb91x-nand",
.owner = THIS_MODULE,
.of_match_table = rb91x_nand_match,
},
};
module_platform_driver(rb91x_nand_driver);
MODULE_DESCRIPTION("MikrotTik RB91x NAND flash driver");
MODULE_VERSION(DRV_VERSION);
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_AUTHOR("Denis Kalashnikov <denis281089@gmail.com>");
MODULE_LICENSE("GPL v2");

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@ -15,6 +15,7 @@ CONFIG_MTD_NAND_AR934X=y
CONFIG_MTD_NAND_CORE=y
CONFIG_MTD_NAND_ECC=y
CONFIG_MTD_NAND_RB4XX=y
CONFIG_MTD_NAND_RB91X=y
CONFIG_MTD_RAW_NAND=y
CONFIG_MTD_ROUTERBOOT_PARTS=y
CONFIG_MTD_SPI_NAND=y

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@ -1,3 +1,24 @@
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -559,4 +559,8 @@ config MTD_NAND_RB4XX
Enables support for the NAND flash chip on Mikrotik Routerboard
RB4xx series.
+config MTD_NAND_RB91X
+ tristate "MikroTik RB91x NAND driver support"
+ depends on ATH79 && MTD_RAW_NAND
+
endif # MTD_RAW_NAND
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_MTD_NAND_STM32_FMC2) += stm
obj-$(CONFIG_MTD_NAND_MESON) += meson_nand.o
obj-$(CONFIG_MTD_NAND_AR934X) += ar934x_nand.o
obj-$(CONFIG_MTD_NAND_RB4XX) += nand_rb4xx.o
+obj-$(CONFIG_MTD_NAND_RB91X) += rb91x_nand.o
nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
nand-objs += nand_onfi.o
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -130,6 +130,10 @@ config GPIO_ATH79