--- /dev/null
+/*
+ * NAND flash driver for the MikroTik RouterBOARD 91x series
+ *
+ * Copyright (C) 2013 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 <asm/mach-ath79/ar71xx_regs.h>
+#include <asm/mach-ath79/ath79.h>
+
+#define DRV_NAME "rb91x-nand"
+#define DRV_DESC "NAND flash driver for the RouterBOARD 91x series"
+
+#define RB91X_NAND_NRE_ENABLE BIT(3)
+#define RB91X_NAND_RDY BIT(4)
+#define RB91X_LATCH_ENABLE BIT(11)
+#define RB91X_NAND_NRWE BIT(12)
+#define RB91X_NAND_NCE BIT(13)
+#define RB91X_NAND_CLE BIT(14)
+#define RB91X_NAND_ALE BIT(15)
+
+#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;
+};
+
+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_change_gpo(u32 clear, u32 set)
+{
+ void __iomem *base = ath79_gpio_base;
+ static unsigned on = 0xE002800;
+ static unsigned off = 0x0000C008;
+ static unsigned oe = 0;
+ static DEFINE_SPINLOCK(lock);
+ unsigned long flags;
+
+ spin_lock_irqsave(&lock, flags);
+
+ on = (on | set) & ~clear;
+ off = (off | clear) & ~set;
+
+ if (!oe)
+ oe = __raw_readl(base + AR71XX_GPIO_REG_OE);
+
+ if (on & RB91X_LATCH_ENABLE) {
+ u32 t;
+
+ t = oe & __raw_readl(base + AR71XX_GPIO_REG_OE);
+ t &= ~(on | off);
+ __raw_writel(t, base + AR71XX_GPIO_REG_OE);
+ __raw_writel(off, base + AR71XX_GPIO_REG_CLEAR);
+ __raw_writel(on, base + AR71XX_GPIO_REG_SET);
+ } else if (clear & RB91X_LATCH_ENABLE) {
+ oe = __raw_readl(base + AR71XX_GPIO_REG_OE);
+ __raw_writel(RB91X_LATCH_ENABLE,
+ base + AR71XX_GPIO_REG_CLEAR);
+ /* flush write */
+ __raw_readl(base + AR71XX_GPIO_REG_CLEAR);
+ }
+
+ spin_unlock_irqrestore(&lock, flags);
+}
+
+static inline void rb91x_latch_enable(void)
+{
+ rb91x_change_gpo(RB91X_LATCH_ENABLE, 0);
+}
+
+static inline void rb91x_latch_disable(void)
+{
+ rb91x_change_gpo(0, RB91X_LATCH_ENABLE);
+}
+
+static void rb91x_nand_write(const u8 *buf, unsigned len)
+{
+ void __iomem *base = ath79_gpio_base;
+ u32 oe_reg;
+ u32 out_reg;
+ u32 out;
+ unsigned i;
+
+ rb91x_latch_enable();
+
+ 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(oe_reg, base + AR71XX_GPIO_REG_OE);
+ __raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
+ /* flush write */
+ __raw_readl(base + AR71XX_GPIO_REG_OUT);
+
+ rb91x_latch_disable();
+}
+
+static void rb91x_nand_read(u8 *read_buf, unsigned len)
+{
+ void __iomem *base = ath79_gpio_base;
+ u32 oe_reg;
+ u32 out_reg;
+ unsigned i;
+
+ /* save registers */
+ oe_reg = __raw_readl(base + AR71XX_GPIO_REG_OE);
+
+ /* select nRE mode */
+ rb91x_change_gpo(0, RB91X_NAND_NRE_ENABLE);
+
+ /* enable latch */
+ rb91x_latch_enable();
+
+ 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(oe_reg, base + AR71XX_GPIO_REG_OE);
+ __raw_writel(out_reg, base + AR71XX_GPIO_REG_OUT);
+ /* flush write */
+ __raw_readl(base + AR71XX_GPIO_REG_OUT);
+
+ /* disable latch */
+ rb91x_latch_disable();
+
+ /* deselect nRE mode */
+ rb91x_change_gpo(RB91X_NAND_NRE_ENABLE, 0);
+}
+
+static int rb91x_nand_dev_ready(struct mtd_info *mtd)
+{
+ void __iomem *base = ath79_gpio_base;
+
+ return !!(__raw_readl(base + AR71XX_GPIO_REG_IN) & RB91X_NAND_RDY);
+}
+
+static void rb91x_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
+ unsigned int ctrl)
+{
+ if (ctrl & NAND_CTRL_CHANGE) {
+ u32 on = 0;
+ u32 off;
+
+ if (!(ctrl & NAND_NCE))
+ on |= RB91X_NAND_NCE;
+
+ if (ctrl & NAND_CLE)
+ on |= RB91X_NAND_CLE;
+
+ if (ctrl & NAND_ALE)
+ on |= RB91X_NAND_ALE;
+
+ off = on ^ (RB91X_NAND_ALE | RB91X_NAND_NCE | RB91X_NAND_CLE);
+ rb91x_change_gpo(off, on);
+ }
+
+ if (cmd != NAND_CMD_NONE) {
+ u8 t = cmd;
+
+ rb91x_nand_write(&t, 1);
+ }
+}
+
+static u8 rb91x_nand_read_byte(struct mtd_info *mtd)
+{
+ u8 data = 0xff;
+
+ rb91x_nand_read(&data, 1);
+
+ return data;
+}
+
+static void rb91x_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+ rb91x_nand_read(buf, len);
+}
+
+static void rb91x_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+ rb91x_nand_write(buf, len);
+}
+
+static int rb91x_nand_probe(struct platform_device *pdev)
+{
+ struct rb91x_nand_info *info;
+ int ret;
+
+ pr_info(DRV_DESC "\n");
+
+ info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->chip.priv = &info;
+ info->mtd.priv = &info->chip;
+ info->mtd.owner = THIS_MODULE;
+
+ info->chip.cmd_ctrl = rb91x_nand_cmd_ctrl;
+ info->chip.dev_ready = rb91x_nand_dev_ready;
+ info->chip.read_byte = rb91x_nand_read_byte;
+ info->chip.write_buf = rb91x_nand_write_buf;
+ info->chip.read_buf = rb91x_nand_read_buf;
+
+ info->chip.chip_delay = 25;
+ info->chip.ecc.mode = NAND_ECC_SOFT;
+
+ platform_set_drvdata(pdev, info);
+
+ ret = nand_scan_ident(&info->mtd, 1, NULL);
+ if (ret)
+ return ret;
+
+ if (info->mtd.writesize == 512)
+ info->chip.ecc.layout = &rb91x_nand_ecclayout;
+
+ ret = nand_scan_tail(&info->mtd);
+ if (ret)
+ return ret;
+
+ ret = mtd_device_register(&info->mtd, rb91x_nand_partitions,
+ ARRAY_SIZE(rb91x_nand_partitions));
+ if (ret)
+ goto err_release_nand;
+
+ return 0;
+
+err_release_nand:
+ nand_release(&info->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 = DRV_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");
projects / openwrt / staging / nbd.git / commitdiff