diff options
Diffstat (limited to 'target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c')
| -rw-r--r-- | target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c b/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c new file mode 100644 index 0000000..f0aa3c3 --- /dev/null +++ b/target/linux/ar71xx/files/drivers/mtd/nand/rb91x_nand.c @@ -0,0 +1,377 @@ +/* + * NAND flash driver for the MikroTik RouterBOARD 91x series + * + * Copyright (C) 2013-2014 Gabor Juhos <juhosg@openwrt.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/module.h> +#include <linux/mtd/nand.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/partitions.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/gpio.h> +#include <linux/platform_data/rb91x_nand.h> + +#include <asm/mach-ath79/ar71xx_regs.h> +#include <asm/mach-ath79/ath79.h> + +#define DRV_DESC "NAND flash driver for the RouterBOARD 91x series" + +#define RB91X_NAND_NRWE 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_INPUT_BITS (RB91X_NAND_DATA_BITS | RB91X_NAND_RDY) +#define RB91X_NAND_OUTPUT_BITS (RB91X_NAND_DATA_BITS | RB91X_NAND_NRWE) + +#define RB91X_NAND_LOW_DATA_MASK 0x1f +#define RB91X_NAND_HIGH_DATA_MASK 0xe0 +#define RB91X_NAND_HIGH_DATA_SHIFT 8 + +struct rb91x_nand_info { + struct nand_chip chip; + struct mtd_info mtd; + struct device *dev; + + int gpio_nce; + int gpio_ale; + int gpio_cle; + int gpio_rdy; + int gpio_read; + int gpio_nrw; + int gpio_nle; +}; + +static inline struct rb91x_nand_info *mtd_to_rbinfo(struct mtd_info *mtd) +{ + return container_of(mtd, struct rb91x_nand_info, mtd); +} + +/* + * We need to use the OLD Yaffs-1 OOB layout, otherwise the RB bootloader + * will not be able to find the kernel that we load. + */ +static struct nand_ecclayout rb91x_nand_ecclayout = { + .eccbytes = 6, + .eccpos = { 8, 9, 10, 13, 14, 15 }, + .oobavail = 9, + .oobfree = { { 0, 4 }, { 6, 2 }, { 11, 2 }, { 4, 1 } } +}; + +static struct mtd_partition rb91x_nand_partitions[] = { + { + .name = "booter", + .offset = 0, + .size = (256 * 1024), + .mask_flags = MTD_WRITEABLE, + }, { + .name = "kernel", + .offset = (256 * 1024), + .size = (4 * 1024 * 1024) - (256 * 1024), + }, { + .name = "rootfs", + .offset = MTDPART_OFS_NXTBLK, + .size = MTDPART_SIZ_FULL, + }, +}; + +static void rb91x_nand_write(struct rb91x_nand_info *rbni, + const u8 *buf, + unsigned len) +{ + void __iomem *base = ath79_gpio_base; + u32 oe_reg; + u32 out_reg; + u32 out; + unsigned i; + + /* enable the latch */ + gpio_set_value_cansleep(rbni->gpio_nle, 0); + + 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_NRWE), + base + AR71XX_GPIO_REG_OE); + + out = out_reg & ~(RB91X_NAND_DATA_BITS | RB91X_NAND_NRWE); + 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_NRWE; + __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); + + /* disable the latch */ + gpio_set_value_cansleep(rbni->gpio_nle, 1); +} + +static void rb91x_nand_read(struct rb91x_nand_info *rbni, + u8 *read_buf, + unsigned len) +{ + void __iomem *base = ath79_gpio_base; + u32 oe_reg; + u32 out_reg; + unsigned i; + + /* enable read mode */ + gpio_set_value_cansleep(rbni->gpio_read, 1); + + /* enable latch */ + gpio_set_value_cansleep(rbni->gpio_nle, 0); + + /* 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_NRWE, 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_NRWE, 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); + + /* disable latch */ + gpio_set_value_cansleep(rbni->gpio_nle, 1); + + /* disable read mode */ + gpio_set_value_cansleep(rbni->gpio_read, 0); +} + +static int rb91x_nand_dev_ready(struct mtd_info *mtd) +{ + struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd); + + return gpio_get_value_cansleep(rbni->gpio_rdy); +} + +static void rb91x_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, + unsigned int ctrl) +{ + struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd); + + if (ctrl & NAND_CTRL_CHANGE) { + gpio_set_value_cansleep(rbni->gpio_cle, + (ctrl & NAND_CLE) ? 1 : 0); + gpio_set_value_cansleep(rbni->gpio_ale, + (ctrl & NAND_ALE) ? 1 : 0); + gpio_set_value_cansleep(rbni->gpio_nce, + (ctrl & NAND_NCE) ? 0 : 1); + } + + if (cmd != NAND_CMD_NONE) { + u8 t = cmd; + + rb91x_nand_write(rbni, &t, 1); + } +} + +static u8 rb91x_nand_read_byte(struct mtd_info *mtd) +{ + struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd); + u8 data = 0xff; + + rb91x_nand_read(rbni, &data, 1); + + return data; +} + +static void rb91x_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len) +{ + struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd); + + rb91x_nand_read(rbni, buf, len); +} + +static void rb91x_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len) +{ + struct rb91x_nand_info *rbni = mtd_to_rbinfo(mtd); + + rb91x_nand_write(rbni, buf, len); +} + +static int rb91x_nand_gpio_init(struct rb91x_nand_info *info) +{ + int ret; + + /* + * Ensure that the LATCH is disabled before initializing + * control lines. + */ + ret = devm_gpio_request_one(info->dev, info->gpio_nle, + GPIOF_OUT_INIT_HIGH, "LATCH enable"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_nce, + GPIOF_OUT_INIT_HIGH, "NAND nCE"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_nrw, + GPIOF_OUT_INIT_HIGH, "NAND nRW"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_cle, + GPIOF_OUT_INIT_LOW, "NAND CLE"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_ale, + GPIOF_OUT_INIT_LOW, "NAND ALE"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_read, + GPIOF_OUT_INIT_LOW, "NAND READ"); + if (ret) + return ret; + + ret = devm_gpio_request_one(info->dev, info->gpio_rdy, + GPIOF_IN, "NAND RDY"); + return ret; +} + +static int rb91x_nand_probe(struct platform_device *pdev) +{ + struct rb91x_nand_info *rbni; + struct rb91x_nand_platform_data *pdata; + int ret; + + pr_info(DRV_DESC "\n"); + + pdata = dev_get_platdata(&pdev->dev); + if (!pdata) + return -EINVAL; + + rbni = devm_kzalloc(&pdev->dev, sizeof(*rbni), GFP_KERNEL); + if (!rbni) + return -ENOMEM; + + rbni->dev = &pdev->dev; + rbni->gpio_nce = pdata->gpio_nce; + rbni->gpio_ale = pdata->gpio_ale; + rbni->gpio_cle = pdata->gpio_cle; + rbni->gpio_read = pdata->gpio_read; + rbni->gpio_nrw = pdata->gpio_nrw; + rbni->gpio_rdy = pdata->gpio_rdy; + rbni->gpio_nle = pdata->gpio_nle; + + rbni->chip.priv = &rbni; + rbni->mtd.priv = &rbni->chip; + rbni->mtd.owner = THIS_MODULE; + + rbni->chip.cmd_ctrl = rb91x_nand_cmd_ctrl; + rbni->chip.dev_ready = rb91x_nand_dev_ready; + rbni->chip.read_byte = rb91x_nand_read_byte; + rbni->chip.write_buf = rb91x_nand_write_buf; + rbni->chip.read_buf = rb91x_nand_read_buf; + + rbni->chip.chip_delay = 25; + rbni->chip.ecc.mode = NAND_ECC_SOFT; + + platform_set_drvdata(pdev, rbni); + + ret = rb91x_nand_gpio_init(rbni); + if (ret) + return ret; + + ret = nand_scan_ident(&rbni->mtd, 1, NULL); + if (ret) + return ret; + + if (rbni->mtd.writesize == 512) + rbni->chip.ecc.layout = &rb91x_nand_ecclayout; + + ret = nand_scan_tail(&rbni->mtd); + if (ret) + return ret; + + ret = mtd_device_register(&rbni->mtd, rb91x_nand_partitions, + ARRAY_SIZE(rb91x_nand_partitions)); + if (ret) + goto err_release_nand; + + return 0; + +err_release_nand: + nand_release(&rbni->mtd); + return ret; +} + +static int rb91x_nand_remove(struct platform_device *pdev) +{ + struct rb91x_nand_info *info = platform_get_drvdata(pdev); + + nand_release(&info->mtd); + + return 0; +} + +static struct platform_driver rb91x_nand_driver = { + .probe = rb91x_nand_probe, + .remove = rb91x_nand_remove, + .driver = { + .name = RB91X_NAND_DRIVER_NAME, + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(rb91x_nand_driver); + +MODULE_DESCRIPTION(DRV_DESC); +MODULE_VERSION(DRV_VERSION); +MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>"); +MODULE_LICENSE("GPL v2"); |