mtd: rawnand: ingenic: Add support for the JZ4740
authorPaul Cercueil <paul@crapouillou.net>
Tue, 19 Mar 2019 14:54:00 +0000 (15:54 +0100)
committerMiquel Raynal <miquel.raynal@bootlin.com>
Mon, 8 Apr 2019 08:21:05 +0000 (10:21 +0200)
Add support for probing the ingenic-nand driver on the JZ4740 SoC from
Ingenic, and the jz4740-ecc driver to support the JZ4740-specific
ECC hardware.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
drivers/mtd/nand/raw/ingenic/Kconfig
drivers/mtd/nand/raw/ingenic/Makefile
drivers/mtd/nand/raw/ingenic/ingenic_nand.c
drivers/mtd/nand/raw/ingenic/jz4740_ecc.c [new file with mode: 0644]

index 4bf7d7a..cc663cc 100644 (file)
@@ -17,6 +17,16 @@ if MTD_NAND_JZ4780
 config MTD_NAND_INGENIC_ECC
        tristate
 
+config MTD_NAND_JZ4740_ECC
+       tristate "Hardware BCH support for JZ4740 SoC"
+       select MTD_NAND_INGENIC_ECC
+       help
+         Enable this driver to support the Reed-Solomon error-correction
+         hardware present on the JZ4740 SoC from Ingenic.
+
+         This driver can also be built as a module. If so, the module
+         will be called jz4740-ecc.
+
 config MTD_NAND_JZ4780_BCH
        tristate "Hardware BCH support for JZ4780 SoC"
        select MTD_NAND_INGENIC_ECC
index f3c3c0f..563b7ef 100644 (file)
@@ -2,4 +2,5 @@ obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
 obj-$(CONFIG_MTD_NAND_JZ4780) += ingenic_nand.o
 
 obj-$(CONFIG_MTD_NAND_INGENIC_ECC) += ingenic_ecc.o
+obj-$(CONFIG_MTD_NAND_JZ4740_ECC) += jz4740_ecc.o
 obj-$(CONFIG_MTD_NAND_JZ4780_BCH) += jz4780_bch.o
index a5f2f21..1bd1f18 100644 (file)
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
 #define DRV_NAME       "ingenic-nand"
 
-#define OFFSET_DATA    0x00000000
-#define OFFSET_CMD     0x00400000
-#define OFFSET_ADDR    0x00800000
-
 /* Command delay when there is no R/B pin. */
 #define RB_DELAY_US    100
 
+struct jz_soc_info {
+       unsigned long data_offset;
+       unsigned long addr_offset;
+       unsigned long cmd_offset;
+};
+
 struct ingenic_nand_cs {
        unsigned int bank;
        void __iomem *base;
@@ -41,6 +44,7 @@ struct ingenic_nand_cs {
 struct ingenic_nfc {
        struct device *dev;
        struct ingenic_ecc *ecc;
+       const struct jz_soc_info *soc_info;
        struct nand_controller controller;
        unsigned int num_banks;
        struct list_head chips;
@@ -100,9 +104,9 @@ static void ingenic_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
                return;
 
        if (ctrl & NAND_ALE)
-               writeb(cmd, cs->base + OFFSET_ADDR);
+               writeb(cmd, cs->base + nfc->soc_info->addr_offset);
        else if (ctrl & NAND_CLE)
-               writeb(cmd, cs->base + OFFSET_CMD);
+               writeb(cmd, cs->base + nfc->soc_info->cmd_offset);
 }
 
 static int ingenic_nand_dev_ready(struct nand_chip *chip)
@@ -160,8 +164,13 @@ static int ingenic_nand_attach_chip(struct nand_chip *chip)
        struct ingenic_nfc *nfc = to_ingenic_nfc(chip->controller);
        int eccbytes;
 
-       chip->ecc.bytes = fls((1 + 8) * chip->ecc.size) *
-                               (chip->ecc.strength / 8);
+       if (chip->ecc.strength == 4) {
+               /* JZ4740 uses 9 bytes of ECC to correct maximum 4 errors */
+               chip->ecc.bytes = 9;
+       } else {
+               chip->ecc.bytes = fls((1 + 8) * chip->ecc.size) *
+                                 (chip->ecc.strength / 8);
+       }
 
        switch (chip->ecc.mode) {
        case NAND_ECC_HW:
@@ -270,8 +279,8 @@ static int ingenic_nand_init_chip(struct platform_device *pdev,
                return -ENOMEM;
        mtd->dev.parent = dev;
 
-       chip->legacy.IO_ADDR_R = cs->base + OFFSET_DATA;
-       chip->legacy.IO_ADDR_W = cs->base + OFFSET_DATA;
+       chip->legacy.IO_ADDR_R = cs->base + nfc->soc_info->data_offset;
+       chip->legacy.IO_ADDR_W = cs->base + nfc->soc_info->data_offset;
        chip->legacy.chip_delay = RB_DELAY_US;
        chip->options = NAND_NO_SUBPAGE_WRITE;
        chip->legacy.select_chip = ingenic_nand_select_chip;
@@ -353,6 +362,10 @@ static int ingenic_nand_probe(struct platform_device *pdev)
        if (!nfc)
                return -ENOMEM;
 
+       nfc->soc_info = device_get_match_data(dev);
+       if (!nfc->soc_info)
+               return -EINVAL;
+
        /*
         * Check for ECC HW before we call nand_scan_ident, to prevent us from
         * having to call it again if the ECC driver returns -EPROBE_DEFER.
@@ -390,8 +403,21 @@ static int ingenic_nand_remove(struct platform_device *pdev)
        return 0;
 }
 
+static const struct jz_soc_info jz4740_soc_info = {
+       .data_offset = 0x00000000,
+       .cmd_offset = 0x00008000,
+       .addr_offset = 0x00010000,
+};
+
+static const struct jz_soc_info jz4780_soc_info = {
+       .data_offset = 0x00000000,
+       .cmd_offset = 0x00400000,
+       .addr_offset = 0x00800000,
+};
+
 static const struct of_device_id ingenic_nand_dt_match[] = {
-       { .compatible = "ingenic,jz4780-nand" },
+       { .compatible = "ingenic,jz4740-nand", .data = &jz4740_soc_info },
+       { .compatible = "ingenic,jz4780-nand", .data = &jz4780_soc_info },
        {},
 };
 MODULE_DEVICE_TABLE(of, ingenic_nand_dt_match);
diff --git a/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c b/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c
new file mode 100644 (file)
index 0000000..13fea64
--- /dev/null
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ4740 ECC controller driver
+ *
+ * Copyright (c) 2019 Paul Cercueil <paul@crapouillou.net>
+ *
+ * based on jz4740-nand.c
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include "ingenic_ecc.h"
+
+#define JZ_REG_NAND_ECC_CTRL   0x00
+#define JZ_REG_NAND_DATA       0x04
+#define JZ_REG_NAND_PAR0       0x08
+#define JZ_REG_NAND_PAR1       0x0C
+#define JZ_REG_NAND_PAR2       0x10
+#define JZ_REG_NAND_IRQ_STAT   0x14
+#define JZ_REG_NAND_IRQ_CTRL   0x18
+#define JZ_REG_NAND_ERR(x)     (0x1C + ((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)
+
+static const uint8_t empty_block_ecc[] = {
+       0xcd, 0x9d, 0x90, 0x58, 0xf4, 0x8b, 0xff, 0xb7, 0x6f
+};
+
+static void jz4740_ecc_reset(struct ingenic_ecc *ecc, bool calc_ecc)
+{
+       uint32_t reg;
+
+       /* Clear interrupt status */
+       writel(0, ecc->base + JZ_REG_NAND_IRQ_STAT);
+
+       /* Initialize and enable ECC hardware */
+       reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
+       reg |= JZ_NAND_ECC_CTRL_RESET;
+       reg |= JZ_NAND_ECC_CTRL_ENABLE;
+       reg |= JZ_NAND_ECC_CTRL_RS;
+       if (calc_ecc) /* calculate ECC from data */
+               reg |= JZ_NAND_ECC_CTRL_ENCODING;
+       else /* correct data from ECC */
+               reg &= ~JZ_NAND_ECC_CTRL_ENCODING;
+
+       writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
+}
+
+static int jz4740_ecc_calculate(struct ingenic_ecc *ecc,
+                               struct ingenic_ecc_params *params,
+                               const u8 *buf, u8 *ecc_code)
+{
+       uint32_t reg, status;
+       unsigned int timeout = 1000;
+       int i;
+
+       jz4740_ecc_reset(ecc, true);
+
+       do {
+               status = readl(ecc->base + JZ_REG_NAND_IRQ_STAT);
+       } while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
+
+       if (timeout == 0)
+               return -ETIMEDOUT;
+
+       reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
+       reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+       writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
+
+       for (i = 0; i < params->bytes; ++i)
+               ecc_code[i] = readb(ecc->base + JZ_REG_NAND_PAR0 + i);
+
+       /*
+        * If the written data is completely 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, ARRAY_SIZE(empty_block_ecc)) == 0)
+               memset(ecc_code, 0xff, ARRAY_SIZE(empty_block_ecc));
+
+       return 0;
+}
+
+static void jz_nand_correct_data(uint8_t *buf, int index, int mask)
+{
+       int offset = index & 0x7;
+       uint16_t data;
+
+       index += (index >> 3);
+
+       data = buf[index];
+       data |= buf[index + 1] << 8;
+
+       mask ^= (data >> offset) & 0x1ff;
+       data &= ~(0x1ff << offset);
+       data |= (mask << offset);
+
+       buf[index] = data & 0xff;
+       buf[index + 1] = (data >> 8) & 0xff;
+}
+
+static int jz4740_ecc_correct(struct ingenic_ecc *ecc,
+                             struct ingenic_ecc_params *params,
+                             u8 *buf, u8 *ecc_code)
+{
+       int i, error_count, index;
+       uint32_t reg, status, error;
+       unsigned int timeout = 1000;
+
+       jz4740_ecc_reset(ecc, false);
+
+       for (i = 0; i < params->bytes; ++i)
+               writeb(ecc_code[i], ecc->base + JZ_REG_NAND_PAR0 + i);
+
+       reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
+       reg |= JZ_NAND_ECC_CTRL_PAR_READY;
+       writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
+
+       do {
+               status = readl(ecc->base + JZ_REG_NAND_IRQ_STAT);
+       } while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
+
+       if (timeout == 0)
+               return -ETIMEDOUT;
+
+       reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
+       reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+       writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
+
+       if (status & JZ_NAND_STATUS_ERROR) {
+               if (status & JZ_NAND_STATUS_UNCOR_ERROR)
+                       return -EBADMSG;
+
+               error_count = (status & JZ_NAND_STATUS_ERR_COUNT) >> 29;
+
+               for (i = 0; i < error_count; ++i) {
+                       error = readl(ecc->base + JZ_REG_NAND_ERR(i));
+                       index = ((error >> 16) & 0x1ff) - 1;
+                       if (index >= 0 && index < params->size)
+                               jz_nand_correct_data(buf, index, error & 0x1ff);
+               }
+
+               return error_count;
+       }
+
+       return 0;
+}
+
+static void jz4740_ecc_disable(struct ingenic_ecc *ecc)
+{
+       u32 reg;
+
+       writel(0, ecc->base + JZ_REG_NAND_IRQ_STAT);
+       reg = readl(ecc->base + JZ_REG_NAND_ECC_CTRL);
+       reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+       writel(reg, ecc->base + JZ_REG_NAND_ECC_CTRL);
+}
+
+static const struct ingenic_ecc_ops jz4740_ecc_ops = {
+       .disable = jz4740_ecc_disable,
+       .calculate = jz4740_ecc_calculate,
+       .correct = jz4740_ecc_correct,
+};
+
+static const struct of_device_id jz4740_ecc_dt_match[] = {
+       { .compatible = "ingenic,jz4740-ecc", .data = &jz4740_ecc_ops },
+       {},
+};
+MODULE_DEVICE_TABLE(of, jz4740_ecc_dt_match);
+
+static struct platform_driver jz4740_ecc_driver = {
+       .probe          = ingenic_ecc_probe,
+       .driver = {
+               .name   = "jz4740-ecc",
+               .of_match_table = jz4740_ecc_dt_match,
+       },
+};
+module_platform_driver(jz4740_ecc_driver);
+
+MODULE_AUTHOR("Paul Cercueil <paul@crapouillou.net>");
+MODULE_DESCRIPTION("Ingenic JZ4740 ECC controller driver");
+MODULE_LICENSE("GPL v2");