[PATCH v2 9/9] mtd: rawnand: jz4780-bch: Add support for the JZ4740

Paul Cercueil
2019-02-02T23:20:42Z

Add the backend code for the jz4780-bch driver to support the JZ4740
SoC from Ingenic.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---

Changes:

v2: New patch

drivers/mtd/nand/raw/ingenic/Makefile | 2 +-
drivers/mtd/nand/raw/ingenic/jz4740_bch.c | 173 ++++++++++++++++++
.../mtd/nand/raw/ingenic/jz4780_bch_common.c | 1 +
.../nand/raw/ingenic/jz4780_bch_internal.h | 1 +
4 files changed, 176 insertions(+), 1 deletion(-)
create mode 100644 drivers/mtd/nand/raw/ingenic/jz4740_bch.c

diff --git a/drivers/mtd/nand/raw/ingenic/Makefile b/drivers/mtd/nand/raw/ingenic/Makefile
index f38b467490cf..d16c96113a93 100644
--- a/drivers/mtd/nand/raw/ingenic/Makefile
+++ b/drivers/mtd/nand/raw/ingenic/Makefile
@@ -1,3 +1,3 @@
obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
obj-$(CONFIG_MTD_NAND_JZ4780) += jz4780_nand.o jz4780_bch_common.o \
- jz4780_bch.o jz4725b_bch.o
+ jz4780_bch.o jz4725b_bch.o jz4740_bch.o
diff --git a/drivers/mtd/nand/raw/ingenic/jz4740_bch.c b/drivers/mtd/nand/raw/ingenic/jz4740_bch.c
new file mode 100644
index 000000000000..61ea109cee9d
--- /dev/null
+++ b/drivers/mtd/nand/raw/ingenic/jz4740_bch.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ4740 backend code for the jz4780-bch driver
+ * based on jz4740-nand.c
+ *
+ * Copyright (c) 2019 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+
+#include "jz4780_bch.h"
+#include "jz4780_bch_internal.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_bch_init(struct jz4780_bch *bch, bool encode)
+{
+ uint32_t reg;
+
+ /* Clear interrupt status */
+ writel(0, bch->base + JZ_REG_NAND_IRQ_STAT);
+
+ /* Initialize and enable BCH */
+ reg = readl(bch->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, bch->base + JZ_REG_NAND_ECC_CTRL);
+}
+
+static int jz4740_bch_calculate(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params,
+ const u8 *buf, u8 *ecc_code)
+{
+ uint32_t reg, status;
+ unsigned int timeout = 1000;
+ int i;
+
+ jz4740_bch_init(bch, true);
+
+ do {
+ status = readl(bch->base + JZ_REG_NAND_IRQ_STAT);
+ } while (!(status & JZ_NAND_STATUS_ENC_FINISH) && --timeout);
+
+ if (timeout == 0)
+ return -ETIMEDOUT;
+
+ reg = readl(bch->base + JZ_REG_NAND_ECC_CTRL);
+ reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+ writel(reg, bch->base + JZ_REG_NAND_ECC_CTRL);
+
+ for (i = 0; i < params->bytes; ++i)
+ ecc_code[i] = readb(bch->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_bch_correct(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params,
+ u8 *buf, u8 *ecc_code)
+{
+ int i, error_count, index;
+ uint32_t reg, status, error;
+ unsigned int timeout = 1000;
+
+ jz4740_bch_init(bch, false);
+
+ for (i = 0; i < params->bytes; ++i)
+ writeb(ecc_code[i], bch->base + JZ_REG_NAND_PAR0 + i);
+
+ reg = readl(bch->base + JZ_REG_NAND_ECC_CTRL);
+ reg |= JZ_NAND_ECC_CTRL_PAR_READY;
+ writel(reg, bch->base + JZ_REG_NAND_ECC_CTRL);
+
+ do {
+ status = readl(bch->base + JZ_REG_NAND_IRQ_STAT);
+ } while (!(status & JZ_NAND_STATUS_DEC_FINISH) && --timeout);
+
+ if (timeout == 0)
+ return -ETIMEDOUT;
+
+ reg = readl(bch->base + JZ_REG_NAND_ECC_CTRL);
+ reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+ writel(reg, bch->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(bch->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_bch_disable(struct jz4780_bch *bch)
+{
+ u32 reg;
+
+ writel(0, bch->base + JZ_REG_NAND_IRQ_STAT);
+ reg = readl(bch->base + JZ_REG_NAND_ECC_CTRL);
+ reg &= ~JZ_NAND_ECC_CTRL_ENABLE;
+ writel(reg, bch->base + JZ_REG_NAND_ECC_CTRL);
+}
+
+const struct jz4780_bch_ops jz4780_bch_jz4740_ops = {
+ .disable = jz4740_bch_disable,
+ .calculate = jz4740_bch_calculate,
+ .correct = jz4740_bch_correct,
+};
diff --git a/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c b/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c
index f505816193a8..c2326286abb2 100644
--- a/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c
+++ b/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c
@@ -157,6 +157,7 @@ static int jz4780_bch_probe(struct platform_device *pdev)
}

static const struct of_device_id jz4780_bch_dt_match[] = {
+ { .compatible = "ingenic,jz4740-bch", .data = &jz4780_bch_jz4740_ops},
{ .compatible = "ingenic,jz4725b-bch", .data = &jz4780_bch_jz4725b_ops},
{ .compatible = "ingenic,jz4780-bch", .data = &jz4780_bch_jz4780_ops },
{},
diff --git a/drivers/mtd/nand/raw/ingenic/jz4780_bch_internal.h b/drivers/mtd/nand/raw/ingenic/jz4780_bch_internal.h
index 462aded811b1..7909a49c57db 100644
--- a/drivers/mtd/nand/raw/ingenic/jz4780_bch_internal.h
+++ b/drivers/mtd/nand/raw/ingenic/jz4780_bch_internal.h
@@ -30,6 +30,7 @@ struct jz4780_bch {
struct mutex lock;
};

+extern const struct jz4780_bch_ops jz4780_bch_jz4740_ops;
extern const struct jz4780_bch_ops jz4780_bch_jz4725b_ops;
extern const struct jz4780_bch_ops jz4780_bch_jz4780_ops;

--
2.20.1