[MTD] TXx9 SoC NAND Flash Memory Controller driver

This patch adds support for the integrated NAND flash controller of the
TXx9 family.

Once upon a time there were tx4925ndfmc and tx4938ndfmc driver.  They
were removed due to bitrot in 2005.
This new driver is completely rewritten based on a driver in CELF patch
archive.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: Ralf Bächle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

3 files changed, 435 insertions, 0 deletions

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 30d6fbc30c35..68ae144ce3be 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -434,4 +434,10 @@ config MTD_NAND_DAVINCI
           Enable the driver for NAND flash chips on Texas Instruments
           DaVinci processors.
 
+config MTD_NAND_TXX9NDFMC
+        tristate "NAND Flash support for TXx9 SoC"
+        depends on SOC_TX4938 || SOC_TX4939
+        help
+          This enables the NAND flash controller on the TXx9 SoCs.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 26dc0bef68ae..d228622d5dc0 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -37,5 +37,6 @@ obj-$(CONFIG_MTD_NAND_FSL_ELBC)		+= fsl_elbc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_UPM)          += fsl_upm.o
 obj-$(CONFIG_MTD_NAND_SH_FLCTL)         += sh_flctl.o
 obj-$(CONFIG_MTD_NAND_MXC)              += mxc_nand.o
+obj-$(CONFIG_MTD_NAND_TXX9NDFMC)        += txx9ndfmc.o
 
 nand-objs := nand_base.o nand_bbt.o
diff --git a/drivers/mtd/nand/txx9ndfmc.c b/drivers/mtd/nand/txx9ndfmc.c
new file mode 100644
index 000000000000..812479264896
--- /dev/null
+++ b/drivers/mtd/nand/txx9ndfmc.c
@@ -0,0 +1,428 @@
+/*
+ * TXx9 NAND flash memory controller driver
+ * Based on RBTX49xx patch from CELF patch archive.
+ *
+ * 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.
+ *
+ * (C) Copyright TOSHIBA CORPORATION 2004-2007
+ * All Rights Reserved.
+ */
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/partitions.h>
+#include <linux/io.h>
+#include <asm/txx9/ndfmc.h>
+
+/* TXX9 NDFMC Registers */
+#define TXX9_NDFDTR     0x00
+#define TXX9_NDFMCR     0x04
+#define TXX9_NDFSR      0x08
+#define TXX9_NDFISR     0x0c
+#define TXX9_NDFIMR     0x10
+#define TXX9_NDFSPR     0x14
+#define TXX9_NDFRSTR    0x18    /* not TX4939 */
+
+/* NDFMCR : NDFMC Mode Control */
+#define TXX9_NDFMCR_WE  0x80
+#define TXX9_NDFMCR_ECC_ALL     0x60
+#define TXX9_NDFMCR_ECC_RESET   0x60
+#define TXX9_NDFMCR_ECC_READ    0x40
+#define TXX9_NDFMCR_ECC_ON      0x20
+#define TXX9_NDFMCR_ECC_OFF     0x00
+#define TXX9_NDFMCR_CE  0x10
+#define TXX9_NDFMCR_BSPRT       0x04    /* TX4925/TX4926 only */
+#define TXX9_NDFMCR_ALE 0x02
+#define TXX9_NDFMCR_CLE 0x01
+/* TX4939 only */
+#define TXX9_NDFMCR_X16 0x0400
+#define TXX9_NDFMCR_DMAREQ_MASK 0x0300
+#define TXX9_NDFMCR_DMAREQ_NODMA        0x0000
+#define TXX9_NDFMCR_DMAREQ_128  0x0100
+#define TXX9_NDFMCR_DMAREQ_256  0x0200
+#define TXX9_NDFMCR_DMAREQ_512  0x0300
+#define TXX9_NDFMCR_CS_MASK     0x0c
+#define TXX9_NDFMCR_CS(ch)      ((ch) << 2)
+
+/* NDFMCR : NDFMC Status */
+#define TXX9_NDFSR_BUSY 0x80
+/* TX4939 only */
+#define TXX9_NDFSR_DMARUN       0x40
+
+/* NDFMCR : NDFMC Reset */
+#define TXX9_NDFRSTR_RST        0x01
+
+struct txx9ndfmc_priv {
+        struct platform_device *dev;
+        struct nand_chip chip;
+        struct mtd_info mtd;
+        int cs;
+        char mtdname[BUS_ID_SIZE + 2];
+};
+
+#define MAX_TXX9NDFMC_DEV       4
+struct txx9ndfmc_drvdata {
+        struct mtd_info *mtds[MAX_TXX9NDFMC_DEV];
+        void __iomem *base;
+        unsigned char hold;     /* in gbusclock */
+        unsigned char spw;      /* in gbusclock */
+        struct nand_hw_control hw_control;
+#ifdef CONFIG_MTD_PARTITIONS
+        struct mtd_partition *parts[MAX_TXX9NDFMC_DEV];
+#endif
+};
+
+static struct platform_device *mtd_to_platdev(struct mtd_info *mtd)
+{
+        struct nand_chip *chip = mtd->priv;
+        struct txx9ndfmc_priv *txx9_priv = chip->priv;
+        return txx9_priv->dev;
+}
+
+static void __iomem *ndregaddr(struct platform_device *dev, unsigned int reg)
+{
+        struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
+        struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
+
+        return drvdata->base + (reg << plat->shift);
+}
+
+static u32 txx9ndfmc_read(struct platform_device *dev, unsigned int reg)
+{
+        return __raw_readl(ndregaddr(dev, reg));
+}
+
+static void txx9ndfmc_write(struct platform_device *dev,
+                            u32 val, unsigned int reg)
+{
+        __raw_writel(val, ndregaddr(dev, reg));
+}
+
+static uint8_t txx9ndfmc_read_byte(struct mtd_info *mtd)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+
+        return txx9ndfmc_read(dev, TXX9_NDFDTR);
+}
+
+static void txx9ndfmc_write_buf(struct mtd_info *mtd, const uint8_t *buf,
+                                int len)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+        void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);
+        u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);
+
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_WE, TXX9_NDFMCR);
+        while (len--)
+                __raw_writel(*buf++, ndfdtr);
+        txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
+}
+
+static void txx9ndfmc_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+        void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);
+
+        while (len--)
+                *buf++ = __raw_readl(ndfdtr);
+}
+
+static int txx9ndfmc_verify_buf(struct mtd_info *mtd, const uint8_t *buf,
+                                int len)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+        void __iomem *ndfdtr = ndregaddr(dev, TXX9_NDFDTR);
+
+        while (len--)
+                if (*buf++ != (uint8_t)__raw_readl(ndfdtr))
+                        return -EFAULT;
+        return 0;
+}
+
+static void txx9ndfmc_cmd_ctrl(struct mtd_info *mtd, int cmd,
+                               unsigned int ctrl)
+{
+        struct nand_chip *chip = mtd->priv;
+        struct txx9ndfmc_priv *txx9_priv = chip->priv;
+        struct platform_device *dev = txx9_priv->dev;
+        struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
+
+        if (ctrl & NAND_CTRL_CHANGE) {
+                u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);
+
+                mcr &= ~(TXX9_NDFMCR_CLE | TXX9_NDFMCR_ALE | TXX9_NDFMCR_CE);
+                mcr |= ctrl & NAND_CLE ? TXX9_NDFMCR_CLE : 0;
+                mcr |= ctrl & NAND_ALE ? TXX9_NDFMCR_ALE : 0;
+                /* TXX9_NDFMCR_CE bit is 0:high 1:low */
+                mcr |= ctrl & NAND_NCE ? TXX9_NDFMCR_CE : 0;
+                if (txx9_priv->cs >= 0 && (ctrl & NAND_NCE)) {
+                        mcr &= ~TXX9_NDFMCR_CS_MASK;
+                        mcr |= TXX9_NDFMCR_CS(txx9_priv->cs);
+                }
+                txx9ndfmc_write(dev, mcr, TXX9_NDFMCR);
+        }
+        if (cmd != NAND_CMD_NONE)
+                txx9ndfmc_write(dev, cmd & 0xff, TXX9_NDFDTR);
+        if (plat->flags & NDFMC_PLAT_FLAG_DUMMYWRITE) {
+                /* dummy write to update external latch */
+                if ((ctrl & NAND_CTRL_CHANGE) && cmd == NAND_CMD_NONE)
+                        txx9ndfmc_write(dev, 0, TXX9_NDFDTR);
+        }
+        mmiowb();
+}
+
+static int txx9ndfmc_dev_ready(struct mtd_info *mtd)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+
+        return !(txx9ndfmc_read(dev, TXX9_NDFSR) & TXX9_NDFSR_BUSY);
+}
+
+static int txx9ndfmc_calculate_ecc(struct mtd_info *mtd, const uint8_t *dat,
+                                   uint8_t *ecc_code)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+        u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);
+
+        mcr &= ~TXX9_NDFMCR_ECC_ALL;
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_READ, TXX9_NDFMCR);
+        ecc_code[1] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+        ecc_code[0] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+        ecc_code[2] = txx9ndfmc_read(dev, TXX9_NDFDTR);
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
+        return 0;
+}
+
+static void txx9ndfmc_enable_hwecc(struct mtd_info *mtd, int mode)
+{
+        struct platform_device *dev = mtd_to_platdev(mtd);
+        u32 mcr = txx9ndfmc_read(dev, TXX9_NDFMCR);
+
+        mcr &= ~TXX9_NDFMCR_ECC_ALL;
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_RESET, TXX9_NDFMCR);
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_OFF, TXX9_NDFMCR);
+        txx9ndfmc_write(dev, mcr | TXX9_NDFMCR_ECC_ON, TXX9_NDFMCR);
+}
+
+static void txx9ndfmc_initialize(struct platform_device *dev)
+{
+        struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
+        struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
+        int tmout = 100;
+
+        if (plat->flags & NDFMC_PLAT_FLAG_NO_RSTR)
+                ; /* no NDFRSTR.  Write to NDFSPR resets the NDFMC. */
+        else {
+                /* reset NDFMC */
+                txx9ndfmc_write(dev,
+                                txx9ndfmc_read(dev, TXX9_NDFRSTR) |
+                                TXX9_NDFRSTR_RST,
+                                TXX9_NDFRSTR);
+                while (txx9ndfmc_read(dev, TXX9_NDFRSTR) & TXX9_NDFRSTR_RST) {
+                        if (--tmout == 0) {
+                                dev_err(&dev->dev, "reset failed.\n");
+                                break;
+                        }
+                        udelay(1);
+                }
+        }
+        /* setup Hold Time, Strobe Pulse Width */
+        txx9ndfmc_write(dev, (drvdata->hold << 4) | drvdata->spw, TXX9_NDFSPR);
+        txx9ndfmc_write(dev,
+                        (plat->flags & NDFMC_PLAT_FLAG_USE_BSPRT) ?
+                        TXX9_NDFMCR_BSPRT : 0, TXX9_NDFMCR);
+}
+
+#define TXX9NDFMC_NS_TO_CYC(gbusclk, ns) \
+        DIV_ROUND_UP((ns) * DIV_ROUND_UP(gbusclk, 1000), 1000000)
+
+static int __init txx9ndfmc_probe(struct platform_device *dev)
+{
+        struct txx9ndfmc_platform_data *plat = dev->dev.platform_data;
+#ifdef CONFIG_MTD_PARTITIONS
+        static const char *probes[] = { "cmdlinepart", NULL };
+#endif
+        int hold, spw;
+        int i;
+        struct txx9ndfmc_drvdata *drvdata;
+        unsigned long gbusclk = plat->gbus_clock;
+        struct resource *res;
+
+        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENODEV;
+        drvdata = devm_kzalloc(&dev->dev, sizeof(*drvdata), GFP_KERNEL);
+        if (!drvdata)
+                return -ENOMEM;
+        if (!devm_request_mem_region(&dev->dev, res->start,
+                                     resource_size(res), dev_name(&dev->dev)))
+                return -EBUSY;
+        drvdata->base = devm_ioremap(&dev->dev, res->start,
+                                     resource_size(res));
+        if (!drvdata->base)
+                return -EBUSY;
+
+        hold = plat->hold ?: 20; /* tDH */
+        spw = plat->spw ?: 90; /* max(tREADID, tWP, tRP) */
+
+        hold = TXX9NDFMC_NS_TO_CYC(gbusclk, hold);
+        spw = TXX9NDFMC_NS_TO_CYC(gbusclk, spw);
+        if (plat->flags & NDFMC_PLAT_FLAG_HOLDADD)
+                hold -= 2;      /* actual hold time : (HOLD + 2) BUSCLK */
+        spw -= 1;       /* actual wait time : (SPW + 1) BUSCLK */
+        hold = clamp(hold, 1, 15);
+        drvdata->hold = hold;
+        spw = clamp(spw, 1, 15);
+        drvdata->spw = spw;
+        dev_info(&dev->dev, "CLK:%ldMHz HOLD:%d SPW:%d\n",
+                 (gbusclk + 500000) / 1000000, hold, spw);
+
+        spin_lock_init(&drvdata->hw_control.lock);
+        init_waitqueue_head(&drvdata->hw_control.wq);
+
+        platform_set_drvdata(dev, drvdata);
+        txx9ndfmc_initialize(dev);
+
+        for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
+                struct txx9ndfmc_priv *txx9_priv;
+                struct nand_chip *chip;
+                struct mtd_info *mtd;
+#ifdef CONFIG_MTD_PARTITIONS
+                int nr_parts;
+#endif
+
+                if (!(plat->ch_mask & (1 << i)))
+                        continue;
+                txx9_priv = kzalloc(sizeof(struct txx9ndfmc_priv),
+                                    GFP_KERNEL);
+                if (!txx9_priv) {
+                        dev_err(&dev->dev, "Unable to allocate "
+                                "TXx9 NDFMC MTD device structure.\n");
+                        continue;
+                }
+                chip = &txx9_priv->chip;
+                mtd = &txx9_priv->mtd;
+                mtd->owner = THIS_MODULE;
+
+                mtd->priv = chip;
+
+                chip->read_byte = txx9ndfmc_read_byte;
+                chip->read_buf = txx9ndfmc_read_buf;
+                chip->write_buf = txx9ndfmc_write_buf;
+                chip->verify_buf = txx9ndfmc_verify_buf;
+                chip->cmd_ctrl = txx9ndfmc_cmd_ctrl;
+                chip->dev_ready = txx9ndfmc_dev_ready;
+                chip->ecc.calculate = txx9ndfmc_calculate_ecc;
+                chip->ecc.correct = nand_correct_data;
+                chip->ecc.hwctl = txx9ndfmc_enable_hwecc;
+                chip->ecc.mode = NAND_ECC_HW;
+                chip->ecc.size = 256;
+                chip->ecc.bytes = 3;
+                chip->chip_delay = 100;
+                chip->controller = &drvdata->hw_control;
+
+                chip->priv = txx9_priv;
+                txx9_priv->dev = dev;
+
+                if (plat->ch_mask != 1) {
+                        txx9_priv->cs = i;
+                        sprintf(txx9_priv->mtdname, "%s.%u",
+                                dev_name(&dev->dev), i);
+                } else {
+                        txx9_priv->cs = -1;
+                        strcpy(txx9_priv->mtdname, dev_name(&dev->dev));
+                }
+                if (plat->wide_mask & (1 << i))
+                        chip->options |= NAND_BUSWIDTH_16;
+
+                if (nand_scan(mtd, 1)) {
+                        kfree(txx9_priv);
+                        continue;
+                }
+                mtd->name = txx9_priv->mtdname;
+
+#ifdef CONFIG_MTD_PARTITIONS
+                nr_parts = parse_mtd_partitions(mtd, probes,
+                                                &drvdata->parts[i], 0);
+                if (nr_parts > 0)
+                        add_mtd_partitions(mtd, drvdata->parts[i], nr_parts);
+#endif
+                add_mtd_device(mtd);
+                drvdata->mtds[i] = mtd;
+        }
+
+        return 0;
+}
+
+static int __exit txx9ndfmc_remove(struct platform_device *dev)
+{
+        struct txx9ndfmc_drvdata *drvdata = platform_get_drvdata(dev);
+        int i;
+
+        platform_set_drvdata(dev, NULL);
+        if (!drvdata)
+                return 0;
+        for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
+                struct mtd_info *mtd = drvdata->mtds[i];
+                struct nand_chip *chip;
+                struct txx9ndfmc_priv *txx9_priv;
+
+                if (!mtd)
+                        continue;
+                chip = mtd->priv;
+                txx9_priv = chip->priv;
+
+#ifdef CONFIG_MTD_PARTITIONS
+                del_mtd_partitions(mtd);
+                kfree(drvdata->parts[i]);
+#endif
+                del_mtd_device(mtd);
+                kfree(txx9_priv);
+        }
+        return 0;
+}
+
+#ifdef CONFIG_PM
+static int txx9ndfmc_resume(struct platform_device *dev)
+{
+        if (platform_get_drvdata(dev))
+                txx9ndfmc_initialize(dev);
+        return 0;
+}
+#else
+#define txx9ndfmc_resume NULL
+#endif
+
+static struct platform_driver txx9ndfmc_driver = {
+        .remove         = __exit_p(txx9ndfmc_remove),
+        .resume         = txx9ndfmc_resume,
+        .driver         = {
+                .name   = "txx9ndfmc",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init txx9ndfmc_init(void)
+{
+        return platform_driver_probe(&txx9ndfmc_driver, txx9ndfmc_probe);
+}
+
+static void __exit txx9ndfmc_exit(void)
+{
+        platform_driver_unregister(&txx9ndfmc_driver);
+}
+
+module_init(txx9ndfmc_init);
+module_exit(txx9ndfmc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("TXx9 SoC NAND flash controller driver");
+MODULE_ALIAS("platform:txx9ndfmc");