MTD: Nand: Add JZ4740 NAND driver

Add support for the NAND controller on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1470/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 523 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index ffc3720929f1..362d177efe1b 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -526,4 +526,10 @@ config MTD_NAND_NUC900
           This enables the driver for the NAND Flash on evaluation board based
           on w90p910 / NUC9xx.
 
+config MTD_NAND_JZ4740
+        tristate "Support for JZ4740 SoC NAND controller"
+        depends on MACH_JZ4740
+        help
+                Enables support for NAND Flash on JZ4740 SoC based boards.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index e8ab884ba47b..ac83dcdac5d6 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -46,5 +46,6 @@ obj-$(CONFIG_MTD_NAND_NOMADIK)		+= nomadik_nand.o
 obj-$(CONFIG_MTD_NAND_BCM_UMI)          += bcm_umi_nand.o nand_bcm_umi.o
 obj-$(CONFIG_MTD_NAND_MPC5121_NFC)      += mpc5121_nfc.o
 obj-$(CONFIG_MTD_NAND_RICOH)            += r852.o
+obj-$(CONFIG_MTD_NAND_JZ4740)           += jz4740_nand.o
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/jz4740_nand.c b/drivers/mtd/nand/jz4740_nand.c
new file mode 100644
index 000000000000..67343fc31bd5
--- /dev/null
+++ b/drivers/mtd/nand/jz4740_nand.c
@@ -0,0 +1,516 @@
+/*
+ *  Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 SoC NAND controller driver
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/gpio.h>
+
+#include <asm/mach-jz4740/jz4740_nand.h>
+
+#define JZ_REG_NAND_CTRL        0x50
+#define JZ_REG_NAND_ECC_CTRL    0x100
+#define JZ_REG_NAND_DATA        0x104
+#define JZ_REG_NAND_PAR0        0x108
+#define JZ_REG_NAND_PAR1        0x10C
+#define JZ_REG_NAND_PAR2        0x110
+#define JZ_REG_NAND_IRQ_STAT    0x114
+#define JZ_REG_NAND_IRQ_CTRL    0x118
+#define JZ_REG_NAND_ERR(x)      (0x11C + ((x) << 2))
+
+#define JZ_NAND_ECC_CTRL_PAR_READY      BIT(4)
+#define JZ_NAND_ECC_CTRL_ENCODING       BIT(3)
+#define JZ_NAND_ECC_CTRL_RS             BIT(2)
+#define JZ_NAND_ECC_CTRL_RESET          BIT(1)
+#define JZ_NAND_ECC_CTRL_ENABLE         BIT(0)
+
+#define JZ_NAND_STATUS_ERR_COUNT        (BIT(31) | BIT(30) | BIT(29))
+#define JZ_NAND_STATUS_PAD_FINISH       BIT(4)
+#define JZ_NAND_STATUS_DEC_FINISH       BIT(3)
+#define JZ_NAND_STATUS_ENC_FINISH       BIT(2)
+#define JZ_NAND_STATUS_UNCOR_ERROR      BIT(1)
+#define JZ_NAND_STATUS_ERROR            BIT(0)
+
+#define JZ_NAND_CTRL_ENABLE_CHIP(x) BIT((x) << 1)
+#define JZ_NAND_CTRL_ASSERT_CHIP(x) BIT(((x) << 1) + 1)
+
+#define JZ_NAND_MEM_ADDR_OFFSET 0x10000
+#define JZ_NAND_MEM_CMD_OFFSET 0x08000
+
+struct jz_nand {
+        struct mtd_info mtd;
+        struct nand_chip chip;
+        void __iomem *base;
+        struct resource *mem;
+
+        void __iomem *bank_base;
+        struct resource *bank_mem;
+
+        struct jz_nand_platform_data *pdata;
+        bool is_reading;
+};
+
+static inline struct jz_nand *mtd_to_jz_nand(struct mtd_info *mtd)
+{
+        return container_of(mtd, struct jz_nand, mtd);
+}
+
+static void jz_nand_cmd_ctrl(struct mtd_info *mtd, int dat, unsigned int ctrl)
+{
+        struct jz_nand *nand = mtd_to_jz_nand(mtd);
+        struct nand_chip *chip = mtd->priv;
+        uint32_t reg;
+
+        if (ctrl & NAND_CTRL_CHANGE) {
+                BUG_ON((ctrl & NAND_ALE) && (ctrl & NAND_CLE));
+                if (ctrl & NAND_ALE)
+                        chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_ADDR_OFFSET;
+                else if (ctrl & NAND_CLE)
+                        chip->IO_ADDR_W = nand->bank_base + JZ_NAND_MEM_CMD_OFFSET;
+                else
+                        chip->IO_ADDR_W = nand->bank_base;
+
+                reg = readl(nand->base + JZ_REG_NAND_CTRL);
+                if (ctrl & NAND_NCE)
+                        reg |= JZ_NAND_CTRL_ASSERT_CHIP(0);
+                else
+                        reg &= ~JZ_NAND_CTRL_ASSERT_CHIP(0);
+                writel(reg, nand->base + JZ_REG_NAND_CTRL);
+        }
+        if (dat != NAND_CMD_NONE)
+                writeb(dat, chip->IO_ADDR_W);
+}
+
+static int jz_nand_dev_ready(struct mtd_info *mtd)
+{
+        struct jz_nand *nand = mtd_to_jz_nand(mtd);
+        return gpio_get_value_cansleep(nand->pdata->busy_gpio);
+}
+
+static void jz_nand_hwctl(struct mtd_info *mtd, int mode)
+{
+        struct jz_nand *nand = mtd_to_jz_nand(mtd);
+        uint32_t reg;
+
+        writel(0, nand->base + JZ_REG_NAND_IRQ_STAT);
+        reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
+
+        reg |= JZ_NAND_ECC_CTRL_RESET;
+        reg |= JZ_NAND_ECC_CTRL_ENABLE;
+        reg |= JZ_NAND_ECC_CTRL_RS;
+
+        switch (mode) {
+        case NAND_ECC_READ:
+                reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
+                nand->is_reading = true;
+                break;
+        case NAND_ECC_WRITE:
+                reg |= JZ_NAND_ECC_CTRL_ENCODING;
+                nand->is_reading = false;
+                break;
+        default:
+                break;
+        }
+
+        writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
+}
+
+static int jz_nand_calculate_ecc_rs(struct mtd_info *mtd, const uint8_t *dat,
+        uint8_t *ecc_code)
+{
+        struct jz_nand *nand = mtd_to_jz_nand(mtd);
+        uint32_t reg, status;
+        int i;
+        unsigned int timeout = 1000;
+        static uint8_t empty_block_ecc[] = {0xcd, 0x9d, 0x90, 0x58, 0xf4,
+                                                0x8b, 0xff, 0xb7, 0x6f};
+
+        if (nand->is_reading)
+                return 0;
+
+        do {
+                status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
+        } while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
+
+        if (timeout == 0)
+            return -1;
+
+        reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
+        reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+        writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
+
+        for (i = 0; i < 9; ++i)
+                ecc_code[i] = readb(nand->base + JZ_REG_NAND_PAR0 + i);
+
+        /* If the written data is completly 0xff, we also want to write 0xff as
+         * ecc, otherwise we will get in trouble when doing subpage writes. */
+        if (memcmp(ecc_code, empty_block_ecc, 9) == 0)
+                memset(ecc_code, 0xff, 9);
+
+        return 0;
+}
+
+static void jz_nand_correct_data(uint8_t *dat, int index, int mask)
+{
+        int offset = index & 0x7;
+        uint16_t data;
+
+        index += (index >> 3);
+
+        data = dat[index];
+        data |= dat[index+1] << 8;
+
+        mask ^= (data >> offset) & 0x1ff;
+        data &= ~(0x1ff << offset);
+        data |= (mask << offset);
+
+        dat[index] = data & 0xff;
+        dat[index+1] = (data >> 8) & 0xff;
+}
+
+static int jz_nand_correct_ecc_rs(struct mtd_info *mtd, uint8_t *dat,
+        uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+        struct jz_nand *nand = mtd_to_jz_nand(mtd);
+        int i, error_count, index;
+        uint32_t reg, status, error;
+        uint32_t t;
+        unsigned int timeout = 1000;
+
+        t = read_ecc[0];
+
+        if (t == 0xff) {
+                for (i = 1; i < 9; ++i)
+                        t &= read_ecc[i];
+
+                t &= dat[0];
+                t &= dat[nand->chip.ecc.size / 2];
+                t &= dat[nand->chip.ecc.size - 1];
+
+                if (t == 0xff) {
+                        for (i = 1; i < nand->chip.ecc.size - 1; ++i)
+                                t &= dat[i];
+                        if (t == 0xff)
+                                return 0;
+                }
+        }
+
+        for (i = 0; i < 9; ++i)
+                writeb(read_ecc[i], nand->base + JZ_REG_NAND_PAR0 + i);
+
+        reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
+        reg |= JZ_NAND_ECC_CTRL_PAR_READY;
+        writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
+
+        do {
+                status = readl(nand->base + JZ_REG_NAND_IRQ_STAT);
+        } while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
+
+        if (timeout == 0)
+            return -1;
+
+        reg = readl(nand->base + JZ_REG_NAND_ECC_CTRL);
+        reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+        writel(reg, nand->base + JZ_REG_NAND_ECC_CTRL);
+
+        if (status & JZ_NAND_STATUS_ERROR) {
+                if (status & JZ_NAND_STATUS_UNCOR_ERROR)
+                        return -1;
+
+                error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
+
+                for (i = 0; i < error_count; ++i) {
+                        error = readl(nand->base + JZ_REG_NAND_ERR(i));
+                        index = ((error >> 16) & 0x1ff) - 1;
+                        if (index >= 0 && index < 512)
+                                jz_nand_correct_data(dat, index, error & 0x1ff);
+                }
+
+                return error_count;
+        }
+
+        return 0;
+}
+
+
+/* Copy paste of nand_read_page_hwecc_oob_first except for different eccpos
+ * handling. The ecc area is for 4k chips 72 bytes long and thus does not fit
+ * into the eccpos array. */
+static int jz_nand_read_page_hwecc_oob_first(struct mtd_info *mtd,
+        struct nand_chip *chip, uint8_t *buf, int page)
+{
+        int i, eccsize = chip->ecc.size;
+        int eccbytes = chip->ecc.bytes;
+        int eccsteps = chip->ecc.steps;
+        uint8_t *p = buf;
+        unsigned int ecc_offset = chip->page_shift;
+
+        /* Read the OOB area first */
+        chip->cmdfunc(mtd, NAND_CMD_READOOB, 0, page);
+        chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
+        chip->cmdfunc(mtd, NAND_CMD_READ0, 0, page);
+
+        for (i = ecc_offset; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+                int stat;
+
+                chip->ecc.hwctl(mtd, NAND_ECC_READ);
+                chip->read_buf(mtd, p, eccsize);
+
+                stat = chip->ecc.correct(mtd, p, &chip->oob_poi[i], NULL);
+                if (stat < 0)
+                        mtd->ecc_stats.failed++;
+                else
+                        mtd->ecc_stats.corrected += stat;
+        }
+        return 0;
+}
+
+/* Copy-and-paste of nand_write_page_hwecc with different eccpos handling. */
+static void jz_nand_write_page_hwecc(struct mtd_info *mtd,
+        struct nand_chip *chip, const uint8_t *buf)
+{
+        int i, eccsize = chip->ecc.size;
+        int eccbytes = chip->ecc.bytes;
+        int eccsteps = chip->ecc.steps;
+        const uint8_t *p = buf;
+        unsigned int ecc_offset = chip->page_shift;
+
+        for (i = ecc_offset; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+                chip->ecc.hwctl(mtd, NAND_ECC_WRITE);
+                chip->write_buf(mtd, p, eccsize);
+                chip->ecc.calculate(mtd, p, &chip->oob_poi[i]);
+        }
+
+        chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
+}
+
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+static const char *part_probes[] = {"cmdline", NULL};
+#endif
+
+static int jz_nand_ioremap_resource(struct platform_device *pdev,
+        const char *name, struct resource **res, void __iomem **base)
+{
+        int ret;
+
+        *res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
+        if (!*res) {
+                dev_err(&pdev->dev, "Failed to get platform %s memory\n", name);
+                ret = -ENXIO;
+                goto err;
+        }
+
+        *res = request_mem_region((*res)->start, resource_size(*res),
+                                pdev->name);
+        if (!*res) {
+                dev_err(&pdev->dev, "Failed to request %s memory region\n", name);
+                ret = -EBUSY;
+                goto err;
+        }
+
+        *base = ioremap((*res)->start, resource_size(*res));
+        if (!*base) {
+                dev_err(&pdev->dev, "Failed to ioremap %s memory region\n", name);
+                ret = -EBUSY;
+                goto err_release_mem;
+        }
+
+        return 0;
+
+err_release_mem:
+        release_mem_region((*res)->start, resource_size(*res));
+err:
+        *res = NULL;
+        *base = NULL;
+        return ret;
+}
+
+static int __devinit jz_nand_probe(struct platform_device *pdev)
+{
+        int ret;
+        struct jz_nand *nand;
+        struct nand_chip *chip;
+        struct mtd_info *mtd;
+        struct jz_nand_platform_data *pdata = pdev->dev.platform_data;
+#ifdef CONFIG_MTD_PARTITIONS
+        struct mtd_partition *partition_info;
+        int num_partitions = 0;
+#endif
+
+        nand = kzalloc(sizeof(*nand), GFP_KERNEL);
+        if (!nand) {
+                dev_err(&pdev->dev, "Failed to allocate device structure.\n");
+                return -ENOMEM;
+        }
+
+        ret = jz_nand_ioremap_resource(pdev, "mmio", &nand->mem, &nand->base);
+        if (ret)
+                goto err_free;
+        ret = jz_nand_ioremap_resource(pdev, "bank", &nand->bank_mem,
+                        &nand->bank_base);
+        if (ret)
+                goto err_iounmap_mmio;
+
+        if (pdata && gpio_is_valid(pdata->busy_gpio)) {
+                ret = gpio_request(pdata->busy_gpio, "NAND busy pin");
+                if (ret) {
+                        dev_err(&pdev->dev,
+                                "Failed to request busy gpio %d: %d\n",
+                                pdata->busy_gpio, ret);
+                        goto err_iounmap_mem;
+                }
+        }
+
+        mtd             = &nand->mtd;
+        chip            = &nand->chip;
+        mtd->priv       = chip;
+        mtd->owner      = THIS_MODULE;
+        mtd->name       = "jz4740-nand";
+
+        chip->ecc.hwctl         = jz_nand_hwctl;
+        chip->ecc.calculate     = jz_nand_calculate_ecc_rs;
+        chip->ecc.correct       = jz_nand_correct_ecc_rs;
+        chip->ecc.mode          = NAND_ECC_HW_OOB_FIRST;
+        chip->ecc.size          = 512;
+        chip->ecc.bytes         = 9;
+
+        chip->ecc.read_page     = jz_nand_read_page_hwecc_oob_first;
+        chip->ecc.write_page    = jz_nand_write_page_hwecc;
+
+        if (pdata)
+                chip->ecc.layout = pdata->ecc_layout;
+
+        chip->chip_delay = 50;
+        chip->cmd_ctrl = jz_nand_cmd_ctrl;
+
+        if (pdata && gpio_is_valid(pdata->busy_gpio))
+                chip->dev_ready = jz_nand_dev_ready;
+
+        chip->IO_ADDR_R = nand->bank_base;
+        chip->IO_ADDR_W = nand->bank_base;
+
+        nand->pdata = pdata;
+        platform_set_drvdata(pdev, nand);
+
+        writel(JZ_NAND_CTRL_ENABLE_CHIP(0), nand->base + JZ_REG_NAND_CTRL);
+
+        ret = nand_scan_ident(mtd, 1, NULL);
+        if (ret) {
+                dev_err(&pdev->dev,  "Failed to scan nand\n");
+                goto err_gpio_free;
+        }
+
+        if (pdata && pdata->ident_callback) {
+                pdata->ident_callback(pdev, chip, &pdata->partitions,
+                                        &pdata->num_partitions);
+        }
+
+        ret = nand_scan_tail(mtd);
+        if (ret) {
+                dev_err(&pdev->dev,  "Failed to scan nand\n");
+                goto err_gpio_free;
+        }
+
+#ifdef CONFIG_MTD_PARTITIONS
+#ifdef CONFIG_MTD_CMDLINE_PARTS
+        num_partitions = parse_mtd_partitions(mtd, part_probes,
+                                                &partition_info, 0);
+#endif
+        if (num_partitions <= 0 && pdata) {
+                num_partitions = pdata->num_partitions;
+                partition_info = pdata->partitions;
+        }
+
+        if (num_partitions > 0)
+                ret = add_mtd_partitions(mtd, partition_info, num_partitions);
+        else
+#endif
+        ret = add_mtd_device(mtd);
+
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to add mtd device\n");
+                goto err_nand_release;
+        }
+
+        dev_info(&pdev->dev, "Successfully registered JZ4740 NAND driver\n");
+
+        return 0;
+
+err_nand_release:
+        nand_release(&nand->mtd);
+err_gpio_free:
+        platform_set_drvdata(pdev, NULL);
+        gpio_free(pdata->busy_gpio);
+err_iounmap_mem:
+        iounmap(nand->bank_base);
+err_iounmap_mmio:
+        iounmap(nand->base);
+err_free:
+        kfree(nand);
+        return ret;
+}
+
+static int __devexit jz_nand_remove(struct platform_device *pdev)
+{
+        struct jz_nand *nand = platform_get_drvdata(pdev);
+
+        nand_release(&nand->mtd);
+
+        /* Deassert and disable all chips */
+        writel(0, nand->base + JZ_REG_NAND_CTRL);
+
+        iounmap(nand->bank_base);
+        release_mem_region(nand->bank_mem->start, resource_size(nand->bank_mem));
+        iounmap(nand->base);
+        release_mem_region(nand->mem->start, resource_size(nand->mem));
+
+        platform_set_drvdata(pdev, NULL);
+        kfree(nand);
+
+        return 0;
+}
+
+struct platform_driver jz_nand_driver = {
+        .probe = jz_nand_probe,
+        .remove = __devexit_p(jz_nand_remove),
+        .driver = {
+                .name = "jz4740-nand",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init jz_nand_init(void)
+{
+        return platform_driver_register(&jz_nand_driver);
+}
+module_init(jz_nand_init);
+
+static void __exit jz_nand_exit(void)
+{
+        platform_driver_unregister(&jz_nand_driver);
+}
+module_exit(jz_nand_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("NAND controller driver for JZ4740 SoC");
+MODULE_ALIAS("platform:jz4740-nand");