[PATCH v3 7/9] mtd: rawnand: ingenic: Add support for the JZ4740

From: Paul Cercueil
Date: Mon Feb 04 2019 - 14:05:19 EST


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@xxxxxxxxxxxxxxx>
---

Changes:

v2: New patch

v3: Also add support for the hardware ECC of the JZ4740 in this patch

drivers/mtd/nand/raw/ingenic/Kconfig | 10 ++
drivers/mtd/nand/raw/ingenic/Makefile | 1 +
drivers/mtd/nand/raw/ingenic/ingenic_nand.c | 48 +++++--
drivers/mtd/nand/raw/ingenic/jz4740_ecc.c | 192 ++++++++++++++++++++++++++++
4 files changed, 240 insertions(+), 11 deletions(-)
create mode 100644 drivers/mtd/nand/raw/ingenic/jz4740_ecc.c

diff --git a/drivers/mtd/nand/raw/ingenic/Kconfig b/drivers/mtd/nand/raw/ingenic/Kconfig
index 4bf7d7af3b0a..cc663cc15119 100644
--- a/drivers/mtd/nand/raw/ingenic/Kconfig
+++ b/drivers/mtd/nand/raw/ingenic/Kconfig
@@ -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
diff --git a/drivers/mtd/nand/raw/ingenic/Makefile b/drivers/mtd/nand/raw/ingenic/Makefile
index f3c3c0f230b0..563b7effcf59 100644
--- a/drivers/mtd/nand/raw/ingenic/Makefile
+++ b/drivers/mtd/nand/raw/ingenic/Makefile
@@ -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
diff --git a/drivers/mtd/nand/raw/ingenic/ingenic_nand.c b/drivers/mtd/nand/raw/ingenic/ingenic_nand.c
index 0f51fd15fe79..3fd078920b17 100644
--- a/drivers/mtd/nand/raw/ingenic/ingenic_nand.c
+++ b/drivers/mtd/nand/raw/ingenic/ingenic_nand.c
@@ -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>
@@ -26,13 +27,15 @@

#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
index 000000000000..16b42556be7f
--- /dev/null
+++ b/drivers/mtd/nand/raw/ingenic/jz4740_ecc.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ4740 ECC controller driver
+ *
+ * Copyright (c) 2019 Paul Cercueil <paul@xxxxxxxxxxxxxxx>
+ *
+ * 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_init(struct ingenic_ecc *ecc, bool encode)
+{
+ 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 (encode)
+ reg |= JZ_NAND_ECC_CTRL_ENCODING;
+ else
+ 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_init(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_init(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);
--
2.11.0