[PATCH v2 8/9] mtd: rawnand: jz4780-bch: Add support for the JZ4725B

Paul Cercueil
2019-02-02T23:20:33Z

Add the backend code for the jz4780-bch driver to support the JZ4725B
SoC from Ingenic.

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

Changes:

v2: No changes

drivers/mtd/nand/raw/ingenic/Makefile | 2 +-
drivers/mtd/nand/raw/ingenic/jz4725b_bch.c | 234 ++++++++++++++++++
.../mtd/nand/raw/ingenic/jz4780_bch_common.c | 1 +
.../nand/raw/ingenic/jz4780_bch_internal.h | 1 +
4 files changed, 237 insertions(+), 1 deletion(-)
create mode 100644 drivers/mtd/nand/raw/ingenic/jz4725b_bch.c

diff --git a/drivers/mtd/nand/raw/ingenic/Makefile b/drivers/mtd/nand/raw/ingenic/Makefile
index c308062a6620..f38b467490cf 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
+ jz4780_bch.o jz4725b_bch.o
diff --git a/drivers/mtd/nand/raw/ingenic/jz4725b_bch.c b/drivers/mtd/nand/raw/ingenic/jz4725b_bch.c
new file mode 100644
index 000000000000..54f9c5796e83
--- /dev/null
+++ b/drivers/mtd/nand/raw/ingenic/jz4725b_bch.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * JZ4780 backend code for the jz4780-bch driver
+ *
+ * Copyright (C) 2018 Paul Cercueil <paul@crapouillou.net>
+ *
+ * Based on jz4780_bch.c
+ */
+
+#include <linux/bitops.h>
+#include <linux/iopoll.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/device.h>
+
+#include "jz4780_bch.h"
+#include "jz4780_bch_internal.h"
+
+#define BCH_BHCR 0x0
+#define BCH_BHCSR 0x4
+#define BCH_BHCCR 0x8
+#define BCH_BHCNT 0xc
+#define BCH_BHDR 0x10
+#define BCH_BHPAR0 0x14
+#define BCH_BHERR0 0x28
+#define BCH_BHINT 0x24
+#define BCH_BHINTES 0x3c
+#define BCH_BHINTEC 0x40
+#define BCH_BHINTE 0x38
+
+#define BCH_BHCR_BSEL_SHIFT 2
+#define BCH_BHCR_BSEL_MASK (0x1 << BCH_BHCR_BSEL_SHIFT)
+#define BCH_BHCR_ENCE BIT(3)
+#define BCH_BHCR_INIT BIT(1)
+#define BCH_BHCR_BCHE BIT(0)
+
+#define BCH_BHCNT_DEC_COUNT_SHIFT 16
+#define BCH_BHCNT_DEC_COUNT_MASK (0x3ff << BCH_BHCNT_DEC_COUNT_SHIFT)
+#define BCH_BHCNT_ENC_COUNT_SHIFT 0
+#define BCH_BHCNT_ENC_COUNT_MASK (0x3ff << BCH_BHCNT_ENC_COUNT_SHIFT)
+
+#define BCH_BHERR_INDEX0_SHIFT 0
+#define BCH_BHERR_INDEX0_MASK (0x1fff << BCH_BHERR_INDEX0_SHIFT)
+#define BCH_BHERR_INDEX1_SHIFT 16
+#define BCH_BHERR_INDEX1_MASK (0x1fff << BCH_BHERR_INDEX1_SHIFT)
+
+#define BCH_BHINT_ERRC_SHIFT 28
+#define BCH_BHINT_ERRC_MASK (0xf << BCH_BHINT_ERRC_SHIFT)
+#define BCH_BHINT_TERRC_SHIFT 16
+#define BCH_BHINT_TERRC_MASK (0x7f << BCH_BHINT_TERRC_SHIFT)
+#define BCH_BHINT_ALL_0 BIT(5)
+#define BCH_BHINT_ALL_F BIT(4)
+#define BCH_BHINT_DECF BIT(3)
+#define BCH_BHINT_ENCF BIT(2)
+#define BCH_BHINT_UNCOR BIT(1)
+#define BCH_BHINT_ERR BIT(0)
+
+/* Timeout for BCH calculation/correction. */
+#define BCH_TIMEOUT_US 100000
+
+static void jz4725b_bch_init(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params, bool encode)
+{
+ u32 reg;
+
+ /* Clear interrupt status. */
+ writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);
+
+ /* Initialise and enable BCH. */
+ writel(0x1f, bch->base + BCH_BHCCR);
+ writel(BCH_BHCR_BCHE, bch->base + BCH_BHCSR);
+
+ if (params->strength == 8)
+ writel(BCH_BHCR_BSEL_MASK, bch->base + BCH_BHCSR);
+ else
+ writel(BCH_BHCR_BSEL_MASK, bch->base + BCH_BHCCR);
+
+ if (encode)
+ writel(BCH_BHCR_ENCE, bch->base + BCH_BHCSR);
+ else
+ writel(BCH_BHCR_ENCE, bch->base + BCH_BHCCR);
+
+ writel(BCH_BHCR_INIT, bch->base + BCH_BHCSR);
+
+ /* Set up BCH count register. */
+ reg = params->size << BCH_BHCNT_ENC_COUNT_SHIFT;
+ reg |= (params->size + params->bytes) << BCH_BHCNT_DEC_COUNT_SHIFT;
+ writel(reg, bch->base + BCH_BHCNT);
+}
+
+static void jz4725b_bch_disable(struct jz4780_bch *bch)
+{
+ writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);
+ writel(BCH_BHCR_BCHE, bch->base + BCH_BHCCR);
+}
+
+static void jz4725b_bch_write_data(struct jz4780_bch *bch, const u8 *buf,
+ size_t size)
+{
+ while (size--)
+ writeb(*buf++, bch->base + BCH_BHDR);
+}
+
+static void jz4725b_bch_read_parity(struct jz4780_bch *bch, u8 *buf,
+ size_t size)
+{
+ size_t size32 = size / sizeof(u32);
+ size_t size8 = size % sizeof(u32);
+ u32 *dest32;
+ u8 *dest8;
+ u32 val, offset = 0;
+
+ dest32 = (u32 *)buf;
+ while (size32--) {
+ *dest32++ = readl(bch->base + BCH_BHPAR0 + offset);
+ offset += sizeof(u32);
+ }
+
+ dest8 = (u8 *)dest32;
+ val = readl(bch->base + BCH_BHPAR0 + offset);
+ switch (size8) {
+ case 3:
+ dest8[2] = (val >> 16) & 0xff;
+ case 2:
+ dest8[1] = (val >> 8) & 0xff;
+ case 1:
+ dest8[0] = val & 0xff;
+ break;
+ }
+}
+
+static bool jz4725b_bch_wait_complete(struct jz4780_bch *bch, unsigned int irq,
+ u32 *status)
+{
+ u32 reg;
+ int ret;
+
+ /*
+ * While we could use interrupts here and sleep until the operation
+ * completes, the controller works fairly quickly (usually a few
+ * microseconds) and so the overhead of sleeping until we get an
+ * interrupt quite noticeably decreases performance.
+ */
+ ret = readl_poll_timeout(bch->base + BCH_BHINT, reg,
+ (reg & irq) == irq, 0, BCH_TIMEOUT_US);
+ if (ret)
+ return false;
+
+ if (status)
+ *status = reg;
+
+ writel(reg, bch->base + BCH_BHINT);
+ return true;
+}
+
+static int jz4725b_calculate(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params,
+ const u8 *buf, u8 *ecc_code)
+{
+ int ret = 0;
+
+ mutex_lock(&bch->lock);
+ jz4725b_bch_init(bch, params, true);
+ jz4725b_bch_write_data(bch, buf, params->size);
+
+ if (jz4725b_bch_wait_complete(bch, BCH_BHINT_ENCF, NULL)) {
+ jz4725b_bch_read_parity(bch, ecc_code, params->bytes);
+ } else {
+ dev_err(bch->dev, "timed out while calculating ECC\n");
+ ret = -ETIMEDOUT;
+ }
+
+ jz4725b_bch_disable(bch);
+ mutex_unlock(&bch->lock);
+ return ret;
+}
+
+static int jz4725b_correct(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params,
+ u8 *buf, u8 *ecc_code)
+{
+ u32 reg, errors, bit;
+ unsigned int i;
+ int ret = 0;
+
+ mutex_lock(&bch->lock);
+
+ jz4725b_bch_init(bch, params, false);
+ jz4725b_bch_write_data(bch, buf, params->size);
+ jz4725b_bch_write_data(bch, ecc_code, params->bytes);
+
+ if (!jz4725b_bch_wait_complete(bch, BCH_BHINT_DECF, &reg)) {
+ dev_err(bch->dev, "timed out while correcting data\n");
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ if (reg & (BCH_BHINT_ALL_F | BCH_BHINT_ALL_0)) {
+ /* Data and ECC is all 0xff or 0x00 - nothing to correct */
+ ret = 0;
+ goto out;
+ }
+
+ if (reg & BCH_BHINT_UNCOR) {
+ /* Uncorrectable ECC error */
+ ret = -EBADMSG;
+ goto out;
+ }
+
+ errors = (reg & BCH_BHINT_ERRC_MASK) >> BCH_BHINT_ERRC_SHIFT;
+
+ /* Correct any detected errors. */
+ for (i = 0; i < errors; i++) {
+ if (i & 1) {
+ bit = (reg & BCH_BHERR_INDEX1_MASK) >> BCH_BHERR_INDEX1_SHIFT;
+ } else {
+ reg = readl(bch->base + BCH_BHERR0 + (i * 4));
+ bit = (reg & BCH_BHERR_INDEX0_MASK) >> BCH_BHERR_INDEX0_SHIFT;
+ }
+
+ buf[(bit >> 3)] ^= BIT(bit & 0x7);
+ }
+
+out:
+ jz4725b_bch_disable(bch);
+ mutex_unlock(&bch->lock);
+ return ret;
+}
+
+const struct jz4780_bch_ops jz4780_bch_jz4725b_ops = {
+ .disable = jz4725b_bch_disable,
+ .calculate = jz4725b_calculate,
+ .correct = jz4725b_correct,
+};
diff --git a/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c b/drivers/mtd/nand/raw/ingenic/jz4780_bch_common.c
index 1c1fc418ce8e..f505816193a8 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,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 f109b3c8d039..462aded811b1 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_jz4725b_ops;
extern const struct jz4780_bch_ops jz4780_bch_jz4780_ops;

#endif /* __DRIVERS_MTD_NAND_JZ4780_BCH_INTERNAL_H__ */
--
2.20.1