[PATCH v7,2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

From: Harvey Hunt
Date: Tue Oct 06 2015 - 12:28:20 EST

From: Alex Smith <alex.smith@xxxxxxxxxx>

Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
well as the hardware BCH controller. DMA is not currently implemented.

While older 47xx SoCs also have a BCH controller, they are incompatible
with the one in the 4780 due to differing register/bit positions, which
would make implementing a common driver for them quite messy.

Signed-off-by: Alex Smith <alex.smith@xxxxxxxxxx>
Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Brian Norris <computersforpeace@xxxxxxxxx>
Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Alex Smith <alex@xxxxxxxxxxxxxxxx>
Signed-off-by: Harvey Hunt <harvey.hunt@xxxxxxxxxx>
---
v6 -> v7:
- Include linux/bitops.h.
- Default ECC mode to hw.
- Only check BCH if we're using hw ECC mode.
- Return -ENODEV if we're using hw ECC mode and can't find BCH.
- Return -ENODEV if we can't find any banks.
- Use set nand_chip->dn so we can use nand_dt_init() to read DT.

v5 -> v6:
- Remove another printk made useless by changes in v5 (due to
devm_ioremap_resource() printing errors itself).

v4 -> v5:
- Bump RB_DELAY up to be sufficient for the driver to work without a
busy GPIO available.
- Use readl_poll_timeout instead of custom polling loop.
- Remove useless printks.
- Change a BUG_ON to WARN_ON.
- Remove use of of_translate_address(), use standard platform resource
APIs.
- Add DRV_NAME define to avoid duplication of the same string.

v3 -> v4:
- Rebase to 4.2-rc4
- Change ECC_HW_OOB_FIRST to ECC_HW, reading OOB first is not necessary.
- Fix argument to get_device() in jz4780_bch_get()

v2 -> v3:
- Rebase to 4.0-rc6
- Reflect binding changes
- get/put_device in bch get/release
- Removed empty .remove() callback
- Removed .owner
- Set mtd->dev.parent

v1 -> v2:
- Fixed module license macro
- Rebase to 4.0-rc3

drivers/mtd/nand/Kconfig | 7 +
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/jz4780_bch.c | 349 +++++++++++++++++++++++++++++++++++++
drivers/mtd/nand/jz4780_bch.h | 42 +++++
drivers/mtd/nand/jz4780_nand.c | 384 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 783 insertions(+)
create mode 100644 drivers/mtd/nand/jz4780_bch.c
create mode 100644 drivers/mtd/nand/jz4780_bch.h
create mode 100644 drivers/mtd/nand/jz4780_nand.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 3324281..8ffd5cd 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -508,6 +508,13 @@ config MTD_NAND_JZ4740
help
Enables support for NAND Flash on JZ4740 SoC based boards.

+config MTD_NAND_JZ4780
+ tristate "Support for NAND on JZ4780 SoC"
+ depends on MACH_JZ4780 && JZ4780_NEMC
+ help
+ Enables support for NAND Flash connected to the NEMC on JZ4780 SoC
+ based boards, using the BCH controller for hardware error correction.
+
config MTD_NAND_FSMC
tristate "Support for NAND on ST Micros FSMC"
depends on PLAT_SPEAR || ARCH_NOMADIK || ARCH_U8500 || MACH_U300
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 075a027..604b166 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_MTD_NAND_NUC900) += nuc900_nand.o
obj-$(CONFIG_MTD_NAND_MPC5121_NFC) += mpc5121_nfc.o
obj-$(CONFIG_MTD_NAND_RICOH) += r852.o
obj-$(CONFIG_MTD_NAND_JZ4740) += jz4740_nand.o
+obj-$(CONFIG_MTD_NAND_JZ4780) += jz4780_nand.o jz4780_bch.o
obj-$(CONFIG_MTD_NAND_GPMI_NAND) += gpmi-nand/
obj-$(CONFIG_MTD_NAND_XWAY) += xway_nand.o
obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH) += bcm47xxnflash/
diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
new file mode 100644
index 0000000..047d351
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_bch.c
@@ -0,0 +1,349 @@
+/*
+ * JZ4780 BCH controller
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "jz4780_bch.h"
+
+#define BCH_BHCR 0x0
+#define BCH_BHCCR 0x8
+#define BCH_BHCNT 0xc
+#define BCH_BHDR 0x10
+#define BCH_BHPAR0 0x14
+#define BCH_BHERR0 0x84
+#define BCH_BHINT 0x184
+#define BCH_BHINTES 0x188
+#define BCH_BHINTEC 0x18c
+#define BCH_BHINTE 0x190
+
+#define BCH_BHCR_BSEL_SHIFT 4
+#define BCH_BHCR_BSEL_MASK (0x7f << BCH_BHCR_BSEL_SHIFT)
+#define BCH_BHCR_ENCE BIT(2)
+#define BCH_BHCR_INIT BIT(1)
+#define BCH_BHCR_BCHE BIT(0)
+
+#define BCH_BHCNT_PARITYSIZE_SHIFT 16
+#define BCH_BHCNT_PARITYSIZE_MASK (0x7f << BCH_BHCNT_PARITYSIZE_SHIFT)
+#define BCH_BHCNT_BLOCKSIZE_SHIFT 0
+#define BCH_BHCNT_BLOCKSIZE_MASK (0x7ff << BCH_BHCNT_BLOCKSIZE_SHIFT)
+
+#define BCH_BHERR_MASK_SHIFT 16
+#define BCH_BHERR_MASK_MASK (0xffff << BCH_BHERR_MASK_SHIFT)
+#define BCH_BHERR_INDEX_SHIFT 0
+#define BCH_BHERR_INDEX_MASK (0x7ff << BCH_BHERR_INDEX_SHIFT)
+
+#define BCH_BHINT_ERRC_SHIFT 24
+#define BCH_BHINT_ERRC_MASK (0x7f << BCH_BHINT_ERRC_SHIFT)
+#define BCH_BHINT_TERRC_SHIFT 16
+#define BCH_BHINT_TERRC_MASK (0x7f << BCH_BHINT_TERRC_SHIFT)
+#define BCH_BHINT_DECF BIT(3)
+#define BCH_BHINT_ENCF BIT(2)
+#define BCH_BHINT_UNCOR BIT(1)
+#define BCH_BHINT_ERR BIT(0)
+
+#define BCH_CLK_RATE (200 * 1000 * 1000)
+
+/* Timeout for BCH calculation/correction in microseconds. */
+#define BCH_TIMEOUT 100000
+
+struct jz4780_bch {
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static void jz4780_bch_init(struct jz4780_bch *bch,
+ struct jz4780_bch_params *params, bool encode)
+{
+ uint32_t reg;
+
+ /* Clear interrupt status. */
+ writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);
+
+ /* Set up BCH count register. */
+ reg = params->size << BCH_BHCNT_BLOCKSIZE_SHIFT;
+ reg |= params->bytes << BCH_BHCNT_PARITYSIZE_SHIFT;
+ writel(reg, bch->base + BCH_BHCNT);
+
+ /* Initialise and enable BCH. */
+ reg = BCH_BHCR_BCHE | BCH_BHCR_INIT;
+ reg |= params->strength << BCH_BHCR_BSEL_SHIFT;
+ if (encode)
+ reg |= BCH_BHCR_ENCE;
+ writel(reg, bch->base + BCH_BHCR);
+}
+
+static void jz4780_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 jz4780_bch_write_data(struct jz4780_bch *bch, const void *buf,
+ size_t size)
+{
+ size_t size32 = size / sizeof(uint32_t);
+ size_t size8 = size & (sizeof(uint32_t) - 1);
+ const uint32_t *src32;
+ const uint8_t *src8;
+
+ src32 = (const uint32_t *)buf;
+ while (size32--)
+ writel(*src32++, bch->base + BCH_BHDR);
+
+ src8 = (const uint8_t *)src32;
+ while (size8--)
+ writeb(*src8++, bch->base + BCH_BHDR);
+}
+
+static void jz4780_bch_read_parity(struct jz4780_bch *bch, void *buf,
+ size_t size)
+{
+ size_t size32 = size / sizeof(uint32_t);
+ size_t size8 = size & (sizeof(uint32_t) - 1);
+ uint32_t *dest32;
+ uint8_t *dest8;
+ uint32_t val, offset = 0;
+
+ dest32 = (uint32_t *)buf;
+ while (size32--) {
+ *dest32++ = readl(bch->base + BCH_BHPAR0 + offset);
+ offset += sizeof(uint32_t);
+ }
+
+ dest8 = (uint8_t *)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 jz4780_bch_wait_complete(struct jz4780_bch *bch, unsigned int irq,
+ uint32_t *status)
+{
+ uint32_t reg;
+ int ret;
+
+ /*
+ * While we could use use interrupts here and sleep until the operation
+ * completes, the controller works fairly quickly (usually a few
+ * microseconds), so the overhead of sleeping until we get an interrupt
+ * actually quite noticeably decreases performance.
+ */
+ ret = readl_poll_timeout(bch->base + BCH_BHINT, reg,
+ (reg & irq) == irq, 0, BCH_TIMEOUT);
+ if (ret)
+ return false;
+
+ if (status)
+ *status = reg;
+
+ writel(reg, bch->base + BCH_BHINT);
+ return true;
+}
+
+/**
+ * jz4780_bch_calculate() - calculate ECC for a data buffer
+ * @dev: BCH device.
+ * @params: BCH parameters.
+ * @buf: input buffer with raw data.
+ * @ecc_code: output buffer with ECC.
+ *
+ * Return: 0 on success, -ETIMEDOUT if timed out while waiting for BCH
+ * controller.
+ */
+int jz4780_bch_calculate(struct device *dev, struct jz4780_bch_params *params,
+ const uint8_t *buf, uint8_t *ecc_code)
+{
+ struct jz4780_bch *bch = dev_get_drvdata(dev);
+ int ret = 0;
+
+ jz4780_bch_init(bch, params, true);
+ jz4780_bch_write_data(bch, buf, params->size);
+
+ if (jz4780_bch_wait_complete(bch, BCH_BHINT_ENCF, NULL)) {
+ jz4780_bch_read_parity(bch, ecc_code, params->bytes);
+ } else {
+ dev_err(dev, "timed out while calculating ECC\n");
+ ret = -ETIMEDOUT;
+ }
+
+ jz4780_bch_disable(bch);
+ return ret;
+}
+EXPORT_SYMBOL(jz4780_bch_calculate);
+
+/**
+ * jz4780_bch_correct() - detect and correct bit errors
+ * @dev: BCH device.
+ * @params: BCH parameters.
+ * @buf: raw data read from the chip.
+ * @ecc_code: ECC read from the chip.
+ *
+ * Given the raw data and the ECC read from the NAND device, detects and
+ * corrects errors in the data.
+ *
+ * Return: the number of bit errors corrected, or -1 if there are too many
+ * errors to correct or we timed out waiting for the controller.
+ */
+int jz4780_bch_correct(struct device *dev, struct jz4780_bch_params *params,
+ uint8_t *buf, uint8_t *ecc_code)
+{
+ struct jz4780_bch *bch = dev_get_drvdata(dev);
+ uint32_t reg, mask, index;
+ int i, ret, count;
+
+ jz4780_bch_init(bch, params, false);
+ jz4780_bch_write_data(bch, buf, params->size);
+ jz4780_bch_write_data(bch, ecc_code, params->bytes);
+
+ if (!jz4780_bch_wait_complete(bch, BCH_BHINT_DECF, &reg)) {
+ dev_err(dev, "timed out while correcting data\n");
+ ret = -1;
+ goto out;
+ }
+
+ if (reg & BCH_BHINT_UNCOR) {
+ dev_warn(dev, "uncorrectable ECC error\n");
+ ret = -1;
+ goto out;
+ }
+
+ /* Correct any detected errors. */
+ if (reg & BCH_BHINT_ERR) {
+ count = (reg & BCH_BHINT_ERRC_MASK) >> BCH_BHINT_ERRC_SHIFT;
+ ret = (reg & BCH_BHINT_TERRC_MASK) >> BCH_BHINT_TERRC_SHIFT;
+
+ for (i = 0; i < count; i++) {
+ reg = readl(bch->base + BCH_BHERR0 + (i * 4));
+ mask = (reg & BCH_BHERR_MASK_MASK) >>
+ BCH_BHERR_MASK_SHIFT;
+ index = (reg & BCH_BHERR_INDEX_MASK) >>
+ BCH_BHERR_INDEX_SHIFT;
+ buf[(index * 2) + 0] ^= mask;
+ buf[(index * 2) + 1] ^= mask >> 8;
+ }
+ } else {
+ ret = 0;
+ }
+
+out:
+ jz4780_bch_disable(bch);
+ return ret;
+}
+EXPORT_SYMBOL(jz4780_bch_correct);
+
+/**
+ * jz4780_bch_get() - get the BCH controller device
+ * @np: BCH device tree node.
+ * @dev: where to store pointer to BCH controller device.
+ *
+ * Gets the BCH controller device from the specified device tree node. The
+ * device must be released with jz4780_bch_release() when it is no longer being
+ * used.
+ *
+ * Return: 0 on success, -EPROBE_DEFER if the controller has not yet been
+ * initialised.
+ */
+int jz4780_bch_get(struct device_node *np, struct device **dev)
+{
+ struct platform_device *pdev;
+ struct jz4780_bch *bch;
+
+ pdev = of_find_device_by_node(np);
+ if (!pdev || !platform_get_drvdata(pdev))
+ return -EPROBE_DEFER;
+
+ get_device(&pdev->dev);
+
+ bch = platform_get_drvdata(pdev);
+ clk_prepare_enable(bch->clk);
+
+ *dev = &pdev->dev;
+ return 0;
+}
+EXPORT_SYMBOL(jz4780_bch_get);
+
+/**
+ * jz4780_bch_release() - release the BCH controller device
+ * @dev: BCH device.
+ */
+void jz4780_bch_release(struct device *dev)
+{
+ struct jz4780_bch *bch = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(bch->clk);
+ put_device(dev);
+}
+EXPORT_SYMBOL(jz4780_bch_release);
+
+static int jz4780_bch_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct jz4780_bch *bch;
+ struct resource *res;
+
+ bch = devm_kzalloc(dev, sizeof(*bch), GFP_KERNEL);
+ if (!bch)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ bch->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(bch->base))
+ return PTR_ERR(bch->base);
+
+ jz4780_bch_disable(bch);
+
+ bch->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(bch->clk)) {
+ dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(bch->clk));
+ return PTR_ERR(bch->clk);
+ }
+
+ clk_set_rate(bch->clk, BCH_CLK_RATE);
+
+ platform_set_drvdata(pdev, bch);
+ return 0;
+}
+
+static const struct of_device_id jz4780_bch_dt_match[] = {
+ { .compatible = "ingenic,jz4780-bch" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, jz4780_bch_dt_match);
+
+static struct platform_driver jz4780_bch_driver = {
+ .probe = jz4780_bch_probe,
+ .driver = {
+ .name = "jz4780-bch",
+ .of_match_table = of_match_ptr(jz4780_bch_dt_match),
+ },
+};
+module_platform_driver(jz4780_bch_driver);
+
+MODULE_AUTHOR("Alex Smith <alex.smith@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Ingenic JZ4780 BCH error correction driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mtd/nand/jz4780_bch.h b/drivers/mtd/nand/jz4780_bch.h
new file mode 100644
index 0000000..a5dfde5
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_bch.h
@@ -0,0 +1,42 @@
+/*
+ * JZ4780 BCH controller
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef __DRIVERS_MTD_NAND_JZ4780_BCH_H__
+#define __DRIVERS_MTD_NAND_JZ4780_BCH_H__
+
+#include <linux/types.h>
+
+struct device;
+struct device_node;
+
+/**
+ * struct jz4780_bch_params - BCH parameters
+ * @size: data bytes per ECC step.
+ * @bytes: ECC bytes per step.
+ * @strength: number of correctable bits per ECC step.
+ */
+struct jz4780_bch_params {
+ int size;
+ int bytes;
+ int strength;
+};
+
+extern int jz4780_bch_calculate(struct device *dev,
+ struct jz4780_bch_params *params,
+ const uint8_t *buf, uint8_t *ecc_code);
+extern int jz4780_bch_correct(struct device *dev,
+ struct jz4780_bch_params *params, uint8_t *buf,
+ uint8_t *ecc_code);
+
+extern int jz4780_bch_get(struct device_node *np, struct device **dev);
+extern void jz4780_bch_release(struct device *dev);
+
+#endif /* __DRIVERS_MTD_NAND_JZ4780_BCH_H__ */
diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
new file mode 100644
index 0000000..4100ddc9
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_nand.c
@@ -0,0 +1,384 @@
+/*
+ * JZ4780 NAND driver
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@xxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_gpio.h>
+#include <linux/of_mtd.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/jz4780-nemc.h>
+
+#include "jz4780_bch.h"
+
+#define DRV_NAME "jz4780-nand"
+
+#define OFFSET_DATA 0x00000000
+#define OFFSET_CMD 0x00400000
+#define OFFSET_ADDR 0x00800000
+
+/* Command delay when there is no R/B pin (in microseconds). */
+#define RB_DELAY 100
+
+struct jz4780_nand_chip {
+ unsigned int bank;
+ void __iomem *base;
+};
+
+struct jz4780_nand {
+ struct mtd_info mtd;
+ struct nand_chip chip;
+
+ struct device *dev;
+ struct device *bch;
+
+ struct nand_ecclayout ecclayout;
+
+ int busy_gpio;
+ int wp_gpio;
+ unsigned int busy_gpio_active_low: 1;
+ unsigned int wp_gpio_active_low: 1;
+ unsigned int reading: 1;
+
+ unsigned int num_banks;
+ int selected;
+ struct jz4780_nand_chip chips[];
+};
+
+static inline struct jz4780_nand *to_jz4780_nand(struct mtd_info *mtd)
+{
+ return container_of(mtd, struct jz4780_nand, mtd);
+}
+
+static void jz4780_nand_select_chip(struct mtd_info *mtd, int chipnr)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+ struct jz4780_nand_chip *chip;
+
+ if (chipnr == -1) {
+ /* Ensure the currently selected chip is deasserted. */
+ if (nand->selected >= 0) {
+ chip = &nand->chips[nand->selected];
+ jz4780_nemc_assert(nand->dev, chip->bank, false);
+ }
+ } else {
+ chip = &nand->chips[chipnr];
+ nand->chip.IO_ADDR_R = chip->base + OFFSET_DATA;
+ nand->chip.IO_ADDR_W = chip->base + OFFSET_DATA;
+ }
+
+ nand->selected = chipnr;
+}
+
+static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
+ unsigned int ctrl)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+ struct jz4780_nand_chip *chip;
+
+ if (WARN_ON(nand->selected < 0))
+ return;
+
+ chip = &nand->chips[nand->selected];
+
+ if (ctrl & NAND_CTRL_CHANGE) {
+ if (ctrl & NAND_ALE)
+ nand->chip.IO_ADDR_W = chip->base + OFFSET_ADDR;
+ else if (ctrl & NAND_CLE)
+ nand->chip.IO_ADDR_W = chip->base + OFFSET_CMD;
+ else
+ nand->chip.IO_ADDR_W = chip->base + OFFSET_DATA;
+
+ jz4780_nemc_assert(nand->dev, chip->bank, ctrl & NAND_NCE);
+ }
+
+ if (cmd != NAND_CMD_NONE)
+ writeb(cmd, nand->chip.IO_ADDR_W);
+}
+
+static int jz4780_nand_dev_ready(struct mtd_info *mtd)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+
+ return !(gpio_get_value(nand->busy_gpio) ^ nand->busy_gpio_active_low);
+}
+
+static void jz4780_nand_ecc_hwctl(struct mtd_info *mtd, int mode)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+
+ nand->reading = (mode == NAND_ECC_READ);
+}
+
+static int jz4780_nand_ecc_calculate(struct mtd_info *mtd, const uint8_t *dat,
+ uint8_t *ecc_code)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+ struct jz4780_bch_params params;
+
+ /*
+ * Don't need to generate the ECC when reading, BCH does it for us as
+ * part of decoding/correction.
+ */
+ if (nand->reading)
+ return 0;
+
+ params.size = nand->chip.ecc.size;
+ params.bytes = nand->chip.ecc.bytes;
+ params.strength = nand->chip.ecc.strength;
+
+ return jz4780_bch_calculate(nand->bch, &params, dat, ecc_code);
+}
+
+static int jz4780_nand_ecc_correct(struct mtd_info *mtd, uint8_t *dat,
+ uint8_t *read_ecc, uint8_t *calc_ecc)
+{
+ struct jz4780_nand *nand = to_jz4780_nand(mtd);
+ struct jz4780_bch_params params;
+
+ params.size = nand->chip.ecc.size;
+ params.bytes = nand->chip.ecc.bytes;
+ params.strength = nand->chip.ecc.strength;
+
+ return jz4780_bch_correct(nand->bch, &params, dat, read_ecc);
+}
+
+static int jz4780_nand_init_ecc(struct jz4780_nand *nand, struct device *dev)
+{
+ struct mtd_info *mtd = &nand->mtd;
+ struct nand_chip *chip = &nand->chip;
+ struct nand_ecclayout *layout = &nand->ecclayout;
+ struct device_node *bch_np;
+ int ret = 0;
+ uint32_t start, i;
+
+ if (!chip->ecc.size)
+ chip->ecc.size = 1024;
+
+ if (!chip->ecc.strength)
+ chip->ecc.strength = 24;
+
+ chip->ecc.bytes = fls(1 + 8 * chip->ecc.size) * chip->ecc.strength / 8;
+
+ dev_info(dev, "using %s BCH (strength %d, size %d, bytes %d)\n",
+ (nand->bch) ? "hardware" : "software", chip->ecc.strength,
+ chip->ecc.size, chip->ecc.bytes);
+
+ if (chip->ecc.mode == NAND_ECC_HW) {
+ bch_np = of_parse_phandle(dev->of_node,
+ "ingenic,bch-controller", 0);
+ if (bch_np) {
+ ret = jz4780_bch_get(bch_np, &nand->bch);
+ of_node_put(bch_np);
+ if (ret)
+ return ret;
+ } else {
+ dev_err(dev, "no bch controller in DT\n");
+ return -ENODEV;
+ }
+
+ chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
+ chip->ecc.calculate = jz4780_nand_ecc_calculate;
+ chip->ecc.correct = jz4780_nand_ecc_correct;
+ }
+
+ /* Generate ECC layout. ECC codes are right aligned in the OOB area. */
+ layout->eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
+ start = mtd->oobsize - layout->eccbytes;
+ for (i = 0; i < layout->eccbytes; i++)
+ layout->eccpos[i] = start + i;
+
+ layout->oobfree[0].offset = 2;
+ layout->oobfree[0].length = mtd->oobsize - layout->eccbytes - 2;
+
+ chip->ecc.layout = layout;
+
+ return 0;
+}
+
+static int jz4780_nand_init_chips(struct jz4780_nand *nand,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct jz4780_nand_chip *chip;
+ const __be32 *prop;
+ struct resource *res;
+ int i = 0;
+
+ /*
+ * Iterate over each bank assigned to this device and request resources.
+ * The bank numbers may not be consecutive, but nand_scan_ident()
+ * expects chip numbers to be, so fill out a consecutive array of chips
+ * which map chip number to actual bank number.
+ */
+ while ((prop = of_get_address(dev->of_node, i, NULL, NULL))) {
+ chip = &nand->chips[i];
+ chip->bank = of_read_number(prop, 1);
+
+ jz4780_nemc_set_type(nand->dev, chip->bank,
+ JZ4780_NEMC_BANK_NAND);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, i);
+ chip->base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(chip->base))
+ return PTR_ERR(chip->base);
+
+ i++;
+ }
+
+ return 0;
+}
+
+static int jz4780_nand_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ unsigned int num_banks;
+ struct jz4780_nand *nand;
+ struct mtd_info *mtd;
+ struct nand_chip *chip;
+ enum of_gpio_flags flags;
+ struct mtd_part_parser_data ppdata;
+ int ret;
+
+ num_banks = jz4780_nemc_num_banks(dev);
+ if (num_banks == 0) {
+ dev_err(dev, "no banks found\n");
+ return -ENODEV;
+ }
+
+ nand = devm_kzalloc(dev,
+ sizeof(*nand) + (sizeof(nand->chips[0]) * num_banks),
+ GFP_KERNEL);
+ if (!nand)
+ return -ENOMEM;
+
+ nand->dev = dev;
+ nand->num_banks = num_banks;
+ nand->selected = -1;
+
+ mtd = &nand->mtd;
+ chip = &nand->chip;
+ mtd->priv = chip;
+ mtd->owner = THIS_MODULE;
+ mtd->name = DRV_NAME;
+ mtd->dev.parent = dev;
+
+ chip->dn = dev->of_node;
+ chip->chip_delay = RB_DELAY;
+ chip->options = NAND_NO_SUBPAGE_WRITE;
+ chip->select_chip = jz4780_nand_select_chip;
+ chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
+
+ nand->busy_gpio = of_get_named_gpio_flags(dev->of_node,
+ "rb-gpios",
+ 0, &flags);
+ if (gpio_is_valid(nand->busy_gpio)) {
+ ret = devm_gpio_request(dev, nand->busy_gpio, "NAND busy");
+ if (ret) {
+ dev_err(dev, "failed to request busy GPIO %d: %d\n",
+ nand->busy_gpio, ret);
+ return ret;
+ }
+
+ nand->busy_gpio_active_low = flags & OF_GPIO_ACTIVE_LOW;
+ gpio_direction_input(nand->busy_gpio);
+
+ chip->dev_ready = jz4780_nand_dev_ready;
+ }
+
+ nand->wp_gpio = of_get_named_gpio_flags(dev->of_node, "wp-gpios",
+ 0, &flags);
+ if (gpio_is_valid(nand->wp_gpio)) {
+ ret = devm_gpio_request(dev, nand->wp_gpio, "NAND WP");
+ if (ret) {
+ dev_err(dev, "failed to request WP GPIO %d: %d\n",
+ nand->wp_gpio, ret);
+ return ret;
+ }
+
+ nand->wp_gpio_active_low = flags & OF_GPIO_ACTIVE_LOW;
+ gpio_direction_output(nand->wp_gpio, nand->wp_gpio_active_low);
+ }
+
+ ret = jz4780_nand_init_chips(nand, pdev);
+ if (ret)
+ return ret;
+
+ chip->ecc.mode = NAND_ECC_HW;
+
+ ret = nand_scan_ident(mtd, num_banks, NULL);
+ if (ret)
+ return ret;
+
+ ret = jz4780_nand_init_ecc(nand, dev);
+ if (ret)
+ return ret;
+
+ ret = nand_scan_tail(mtd);
+ if (ret)
+ goto err_release_bch;
+
+ ppdata.of_node = dev->of_node;
+ ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
+ if (ret)
+ goto err_release_nand;
+
+ platform_set_drvdata(pdev, nand);
+ return 0;
+
+err_release_nand:
+ nand_release(mtd);
+
+err_release_bch:
+ if (nand->bch)
+ jz4780_bch_release(nand->bch);
+
+ return ret;
+}
+
+static int jz4780_nand_remove(struct platform_device *pdev)
+{
+ struct jz4780_nand *nand = platform_get_drvdata(pdev);
+
+ if (nand->bch)
+ jz4780_bch_release(nand->bch);
+
+ return 0;
+}
+
+static const struct of_device_id jz4780_nand_dt_match[] = {
+ { .compatible = "ingenic,jz4780-nand" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
+
+static struct platform_driver jz4780_nand_driver = {
+ .probe = jz4780_nand_probe,
+ .remove = jz4780_nand_remove,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = of_match_ptr(jz4780_nand_dt_match),
+ },
+};
+module_platform_driver(jz4780_nand_driver);
+
+MODULE_AUTHOR("Alex Smith <alex.smith@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
+MODULE_LICENSE("GPL v2");
--
2.6.0

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