[PATCH V5 RESEND] mtd: rawnand: Add Loongson1 NAND driver

[Keguang Zhang]

From: Kelvin Cheung <keguang.zhang@xxxxxxxxx>

This patch adds NAND driver for Loongson1B.

Signed-off-by: Kelvin Cheung <keguang.zhang@xxxxxxxxx>
---
V4 -> V5:
   Update the driver to fit the raw NAND framework.
   Implement exec_op() instead of legacy cmdfunc().
   Use dma_request_chan() instead of dma_request_channel().
   Some minor fixes and cleanups.
V3 -> V4:
   Retrieve the controller from nand_hw_control.
V2 -> V3:
   Replace __raw_readl/__raw_writel with readl/writel.
   Split ls1x_nand into two structures: ls1x_nand_chip and
   ls1x_nand_controller.
V1 -> V2:
   Modify the dependency in Kconfig due to the changes of DMA
   module.
---
 drivers/mtd/nand/raw/Kconfig          |   8 +
 drivers/mtd/nand/raw/Makefile         |   1 +
 drivers/mtd/nand/raw/loongson1_nand.c | 770 ++++++++++++++++++++++++++
 3 files changed, 779 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/loongson1_nand.c

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 30f061939560..63402e335df4 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -453,6 +453,14 @@ config MTD_NAND_ROCKCHIP
 	    NFC v800: RK3308, RV1108
 	    NFC v900: PX30, RK3326
 
+config MTD_NAND_LOONGSON1
+	tristate "Support for Loongson1 SoC NAND controller"
+	depends on MACH_LOONGSON32
+	select MTD_NAND_ECC_SW_HAMMING
+	select LOONGSON1_DMA
+	help
+	  Enables support for NAND controller on Loongson1 SoCs.
+
 comment "Misc"
 
 config MTD_SM_COMMON
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index d011c6c53f8f..50a51ad6ec21 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_MTD_NAND_CADENCE)		+= cadence-nand-controller.o
 obj-$(CONFIG_MTD_NAND_ARASAN)		+= arasan-nand-controller.o
 obj-$(CONFIG_MTD_NAND_INTEL_LGM)	+= intel-nand-controller.o
 obj-$(CONFIG_MTD_NAND_ROCKCHIP)		+= rockchip-nand-controller.o
+obj-$(CONFIG_MTD_NAND_LOONGSON1)        += loongson1_nand.o
 
 nand-objs := nand_base.o nand_legacy.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_onfi.o
diff --git a/drivers/mtd/nand/raw/loongson1_nand.c b/drivers/mtd/nand/raw/loongson1_nand.c
new file mode 100644
index 000000000000..b06e36ec32da
--- /dev/null
+++ b/drivers/mtd/nand/raw/loongson1_nand.c
@@ -0,0 +1,770 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * NAND Flash Driver for Loongson 1 SoC
+ *
+ * Copyright (C) 2015-2021 Zhang, Keguang <keguang.zhang@xxxxxxxxx>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+
+#include <nand.h>
+
+/* Loongson 1 NAND Register Definitions */
+#define NAND_CMD		0x0
+#define NAND_ADDR1		0x4
+#define NAND_ADDR2		0x8
+#define NAND_TIMING		0xc
+#define NAND_IDL		0x10
+#define NAND_IDH		0x14
+#define NAND_STATUS		0x15
+#define NAND_PARAM		0x18
+#define NAND_OP_NUM		0x1c
+#define NAND_CS_RDY		0x20
+
+#define NAND_DMA_ADDR		0x40
+
+/* NAND Command Register Bits */
+#define OP_DONE			BIT(10)
+#define OP_SPARE		BIT(9)
+#define OP_MAIN			BIT(8)
+#define CMD_STATUS		BIT(7)
+#define CMD_RESET		BIT(6)
+#define CMD_READID		BIT(5)
+#define BLOCKS_ERASE		BIT(4)
+#define CMD_ERASE		BIT(3)
+#define CMD_WRITE		BIT(2)
+#define CMD_READ		BIT(1)
+#define CMD_VALID		BIT(0)
+
+#define MAX_ADDR_CYC		5U
+#define MAX_ID_SIZE		(NAND_STATUS - NAND_IDL)
+#define SIZE_MASK		GENMASK(11, 8)
+
+#define BITS_PER_WORD		32
+
+/* macros for registers read/write */
+#define nand_readl(nc, off)		\
+	readl((nc)->reg_base + (off))
+
+#define nand_writel(nc, off, val)	\
+	writel((val), (nc)->reg_base + (off))
+
+struct ls1x_nand_controller {
+	void __iomem *reg_base;
+	__le32 addr1_reg;
+	__le32 addr2_reg;
+
+	char *buf;
+	unsigned int len;
+	unsigned int rdy_timeout;
+
+	/* DMA Engine stuff */
+	struct dma_chan *dma_chan;
+	dma_cookie_t dma_cookie;
+	struct completion dma_complete;
+};
+
+struct ls1x_nand {
+	struct device *dev;
+	struct clk *clk;
+	struct nand_chip chip;
+	struct nand_controller controller;
+	struct ls1x_nand_controller nc;
+	struct plat_ls1x_nand *pdata;
+};
+
+static void ls1x_nand_dump_regs(struct nand_chip *chip)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+
+	print_hex_dump(KERN_INFO, "REG: ", DUMP_PREFIX_OFFSET, 16, 4,
+		       nc->reg_base, 0x44, false);
+}
+
+static void ls1x_nand_dma_callback(void *data)
+{
+	struct ls1x_nand *nand = (struct ls1x_nand *)data;
+	struct ls1x_nand_controller *nc = &nand->nc;
+	enum dma_status status;
+
+	status = dmaengine_tx_status(nc->dma_chan, nc->dma_cookie, NULL);
+	if (likely(status == DMA_COMPLETE))
+		dev_dbg(nand->dev, "DMA complete with cookie=%d\n",
+			nc->dma_cookie);
+	else
+		dev_err(nand->dev, "DMA error with cookie=%d\n",
+			nc->dma_cookie);
+
+	complete(&nc->dma_complete);
+}
+
+static int ls1x_nand_dma_transfer(struct ls1x_nand *nand, bool is_write)
+{
+	struct ls1x_nand_controller *nc = &nand->nc;
+	struct dma_chan *chan = nc->dma_chan;
+	struct dma_async_tx_descriptor *desc;
+	enum dma_data_direction data_dir =
+	    is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+	enum dma_transfer_direction xfer_dir =
+	    is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM;
+	dma_addr_t dma_addr;
+	int ret;
+
+	dma_addr = dma_map_single(chan->device->dev, nc->buf, nc->len,
+				  data_dir);
+	if (dma_mapping_error(chan->device->dev, dma_addr)) {
+		dev_err(nand->dev, "failed to map DMA buffer!\n");
+		return -ENXIO;
+	}
+
+	desc = dmaengine_prep_slave_single(chan, dma_addr, nc->len, xfer_dir,
+					   DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(nand->dev, "failed to prepare DMA descriptor!\n");
+		ret = PTR_ERR(desc);
+		goto err;
+	}
+	desc->callback = ls1x_nand_dma_callback;
+	desc->callback_param = nand;
+
+	nc->dma_cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(nc->dma_cookie);
+	if (ret) {
+		dev_err(nand->dev, "failed to submit DMA descriptor!\n");
+		goto err;
+	}
+
+	dev_dbg(nand->dev, "issue DMA with cookie=%d\n", nc->dma_cookie);
+	dma_async_issue_pending(chan);
+
+	ret = wait_for_completion_timeout(&nc->dma_complete,
+					  msecs_to_jiffies(nc->rdy_timeout));
+	if (ret <= 0) {
+		dev_err(nand->dev, "DMA timeout!\n");
+		dmaengine_terminate_all(chan);
+		ret = -EIO;
+	}
+	ret = 0;
+err:
+	dma_unmap_single(chan->device->dev, dma_addr, nc->len, data_dir);
+
+	return ret;
+}
+
+static inline void ls1x_nand_parse_address(struct nand_chip *chip,
+					   const u8 *addrs,
+					   unsigned int naddrs, int cmd)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+#if defined(CONFIG_LOONGSON1_LS1B)
+	unsigned int page_shift = chip->page_shift + 1;
+#endif
+	int i;
+
+	nc->addr1_reg = 0;
+	nc->addr2_reg = 0;
+#if defined(CONFIG_LOONGSON1_LS1B)
+	if (cmd == CMD_ERASE) {
+		page_shift = chip->page_shift;
+
+		for (i = 0; i < min(MAX_ADDR_CYC - 2, naddrs); i++)
+			nc->addr1_reg |=
+			    (u32)addrs[i] << (page_shift + BITS_PER_BYTE * i);
+		if (i == MAX_ADDR_CYC - 2)
+			nc->addr2_reg |=
+			    (u32)addrs[i] >> (BITS_PER_WORD - page_shift -
+					      BITS_PER_BYTE * (i - 1));
+
+		return;
+	}
+
+	for (i = 0; i < min(2U, naddrs); i++)
+		nc->addr1_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
+	for (i = 2; i < min(MAX_ADDR_CYC, naddrs); i++)
+		nc->addr1_reg |=
+		    (u32)addrs[i] << (page_shift + BITS_PER_BYTE * (i - 2));
+	if (i == MAX_ADDR_CYC)
+		nc->addr2_reg |=
+		    (u32)addrs[i] >> (BITS_PER_WORD - page_shift -
+				      BITS_PER_BYTE * (i - 1));
+#elif defined(CONFIG_LOONGSON1_LS1C)
+	if (cmd == CMD_ERASE) {
+		for (i = 0; i < min(MAX_ADDR_CYC, naddrs); i++)
+			nc->addr2_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
+
+		return;
+	}
+
+	for (i = 0; i < min(MAX_ADDR_CYC, naddrs); i++) {
+		if (i < 2)
+			nc->addr1_reg |= (u32)addrs[i] << BITS_PER_BYTE * i;
+		else
+			nc->addr2_reg |=
+			    (u32)addrs[i] << BITS_PER_BYTE * (i - 2);
+	}
+#endif
+}
+
+static int ls1x_nand_set_controller(struct nand_chip *chip,
+				    const struct nand_subop *subop, int cmd)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	unsigned int op_id;
+
+	nc->buf = NULL;
+	nc->len = 0;
+	nc->rdy_timeout = 0;
+
+	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
+		const struct nand_op_instr *instr = &subop->instrs[op_id];
+		unsigned int offset, naddrs;
+		const u8 *addrs;
+
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			break;
+		case NAND_OP_ADDR_INSTR:
+			offset = nand_subop_get_addr_start_off(subop, op_id);
+			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
+			addrs = &instr->ctx.addr.addrs[offset];
+
+			ls1x_nand_parse_address(chip, addrs, naddrs, cmd);
+			/* set NAND address */
+			nand_writel(nc, NAND_ADDR1, nc->addr1_reg);
+			nand_writel(nc, NAND_ADDR2, nc->addr2_reg);
+			break;
+		case NAND_OP_DATA_IN_INSTR:
+			offset = nand_subop_get_data_start_off(subop, op_id);
+			nc->len = nand_subop_get_data_len(subop, op_id);
+			nc->buf = instr->ctx.data.buf.in + offset;
+
+			if (!IS_ALIGNED(nc->len, chip->buf_align) ||
+			    !IS_ALIGNED((unsigned int)nc->buf, chip->buf_align))
+				return -ENOTSUPP;
+			/* set NAND data length */
+			nand_writel(nc, NAND_OP_NUM, nc->len);
+			break;
+		case NAND_OP_DATA_OUT_INSTR:
+			offset = nand_subop_get_data_start_off(subop, op_id);
+			nc->len = nand_subop_get_data_len(subop, op_id);
+			nc->buf = (void *)instr->ctx.data.buf.out + offset;
+
+			if (!IS_ALIGNED(nc->len, chip->buf_align) ||
+			    !IS_ALIGNED((unsigned int)nc->buf, chip->buf_align))
+				return -ENOTSUPP;
+			/* set NAND data length */
+			nand_writel(nc, NAND_OP_NUM, nc->len);
+			break;
+		case NAND_OP_WAITRDY_INSTR:
+			nc->rdy_timeout = instr->ctx.waitrdy.timeout_ms;
+			break;
+		}
+	}
+
+	/*set NAND erase block count */
+	if (cmd & CMD_ERASE)
+		nand_writel(nc, NAND_OP_NUM, 1);
+	/*set NAND operation region */
+	if (nc->buf && nc->len) {
+		if (nc->addr1_reg & BIT(chip->page_shift))
+			cmd |= OP_SPARE;
+		else
+			cmd |= OP_SPARE | OP_MAIN;
+	}
+
+	/*set NAND command */
+	nand_writel(nc, NAND_CMD, cmd);
+	/* Trigger operation */
+	nand_writel(nc, NAND_CMD, nand_readl(nc, NAND_CMD) | CMD_VALID);
+
+	return 0;
+}
+
+static inline int ls1x_nand_wait_for_op_done(struct ls1x_nand_controller *nc)
+{
+	unsigned int val;
+	int ret = 0;
+
+	/* Wait for operation done */
+	if (nc->rdy_timeout)
+		ret = readl_relaxed_poll_timeout(nc->reg_base + NAND_CMD, val,
+						 val & OP_DONE, 0,
+						 nc->rdy_timeout * 1000);
+
+	return ret;
+}
+
+static int ls1x_nand_reset_exec(struct nand_chip *chip,
+				const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_RESET);
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret)
+		dev_err(nand->dev, "CMD_RESET failed! %d\n", ret);
+
+	return ret;
+}
+
+static int ls1x_nand_read_id_exec(struct nand_chip *chip,
+				  const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int idl, i;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_READID);
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret) {
+		dev_err(nand->dev, "CMD_READID failed! %d\n", ret);
+		return ret;
+	}
+
+	idl = (nand_readl(nc, NAND_IDL));
+	for (i = 0; i < min_t(unsigned int, nc->len, MAX_ID_SIZE); i++)
+		if (i > 0)
+			nc->buf[i] = *((char *)&idl + 4 - i);
+		else
+			nc->buf[i] = (char)(nand_readl(nc, NAND_IDH));
+
+	return ret;
+}
+
+static int ls1x_nand_erase_exec(struct nand_chip *chip,
+				const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_ERASE);
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret)
+		dev_err(nand->dev, "CMD_ERASE failed! %d\n", ret);
+
+	return ret;
+}
+
+static int ls1x_nand_read_exec(struct nand_chip *chip,
+			       const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_READ);
+
+	ret = ls1x_nand_dma_transfer(nand, false);
+	if (ret)
+		return ret;
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret)
+		dev_err(nand->dev, "CMD_READ failed! %d\n", ret);
+
+	return ret;
+}
+
+static int ls1x_nand_write_exec(struct nand_chip *chip,
+				const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_WRITE);
+
+	ret = ls1x_nand_dma_transfer(nand, true);
+	if (ret)
+		return ret;
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret)
+		dev_err(nand->dev, "CMD_WRITE failed! %d\n", ret);
+
+	return ret;
+}
+
+static int ls1x_nand_read_status_exec(struct nand_chip *chip,
+				      const struct nand_subop *subop)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	int ret;
+
+	ls1x_nand_set_controller(chip, subop, CMD_STATUS);
+
+	ret = ls1x_nand_wait_for_op_done(nc);
+	if (ret) {
+		dev_err(nand->dev, "CMD_STATUS failed! %d\n", ret);
+		return ret;
+	}
+
+	nc->buf[0] = nand_readl(nc, NAND_IDH) >> BITS_PER_BYTE;
+
+	return ret;
+}
+
+static const struct nand_op_parser ls1x_nand_op_parser = NAND_OP_PARSER(
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_reset_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_read_id_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 8)),
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_erase_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_read_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 0)),
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_write_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDR_CYC),
+		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 0),
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
+	NAND_OP_PARSER_PATTERN(
+		ls1x_nand_read_status_exec,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 1)),
+	);
+
+static int ls1x_nand_exec_op(struct nand_chip *chip,
+			     const struct nand_operation *op, bool check_only)
+{
+	return nand_op_parser_exec_op(chip, &ls1x_nand_op_parser, op,
+				      check_only);
+}
+
+static int ls1x_nand_read_subpage(struct nand_chip *chip,
+				  unsigned int data_offs, unsigned int readlen,
+				  unsigned char *bufpoi, int page)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	int start_step, end_step, num_steps, ret;
+	char *p;
+	int data_col_addr, i;
+	int datafrag_len, eccfrag_len, aligned_len, aligned_pos;
+	int busw = (chip->options & NAND_BUSWIDTH_16) ? 2 : 1;
+	int index, section = 0;
+	unsigned int max_bitflips = 0;
+	struct mtd_oob_region oobregion = { };
+
+	/* Read the whole page and OOB data */
+	ret = chip->ecc.read_page_raw(chip, bufpoi, 1, page);
+	if (ret)
+		return ret;
+
+	/* Column address within the page aligned to ECC size (256bytes) */
+	start_step = data_offs / chip->ecc.size;
+	end_step = (data_offs + readlen - 1) / chip->ecc.size;
+	num_steps = end_step - start_step + 1;
+	index = start_step * chip->ecc.bytes;
+
+	/* Data size aligned to ECC ecc.size */
+	datafrag_len = num_steps * chip->ecc.size;
+	eccfrag_len = num_steps * chip->ecc.bytes;
+
+	data_col_addr = start_step * chip->ecc.size;
+	/* If we read not a page aligned data */
+	p = bufpoi + data_col_addr;
+
+	/* Calculate ECC */
+	for (i = 0; i < eccfrag_len; i += chip->ecc.bytes, p += chip->ecc.size)
+		chip->ecc.calculate(chip, p, &chip->ecc.calc_buf[i]);
+
+	ret = mtd_ooblayout_find_eccregion(mtd, index, &section, &oobregion);
+	if (ret)
+		return ret;
+
+	aligned_pos = oobregion.offset & ~(busw - 1);
+	aligned_len = eccfrag_len;
+	if (oobregion.offset & (busw - 1))
+		aligned_len++;
+	if ((oobregion.offset + (num_steps * chip->ecc.bytes)) & (busw - 1))
+		aligned_len++;
+
+	memcpy(&chip->oob_poi[aligned_pos],
+	       bufpoi + mtd->writesize + aligned_pos, aligned_len);
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, chip->ecc.code_buf,
+					 chip->oob_poi, index, eccfrag_len);
+	if (ret)
+		return ret;
+
+	p = bufpoi + data_col_addr;
+	for (i = 0; i < eccfrag_len; i += chip->ecc.bytes, p += chip->ecc.size) {
+		int stat;
+
+		stat = chip->ecc.correct(chip, p, &chip->ecc.code_buf[i],
+					 &chip->ecc.calc_buf[i]);
+		if (stat)
+			ls1x_nand_dump_regs(chip);
+
+		if (stat == -EBADMSG &&
+		    (chip->ecc.options & NAND_ECC_GENERIC_ERASED_CHECK)) {
+			/* check for empty pages with bitflips */
+			stat = nand_check_erased_ecc_chunk(p, chip->ecc.size,
+							&chip->ecc.code_buf[i],
+							chip->ecc.bytes,
+							NULL, 0,
+							chip->ecc.strength);
+		}
+
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+	return max_bitflips;
+}
+
+static int ls1x_nand_attach_chip(struct nand_chip *chip)
+{
+	struct ls1x_nand *nand = nand_get_controller_data(chip);
+	struct ls1x_nand_controller *nc = &nand->nc;
+	struct plat_ls1x_nand *pdata = nand->pdata;
+	int hold_cycle = pdata->hold_cycle;
+	int wait_cycle = pdata->wait_cycle;
+	u64 chipsize = nanddev_target_size(&chip->base);
+	int cell_size = 0;
+
+	switch (chipsize) {
+	case SZ_128M:
+		cell_size = 0x0;
+		break;
+	case SZ_256M:
+		cell_size = 0x1;
+		break;
+	case SZ_512M:
+		cell_size = 0x2;
+		break;
+	case SZ_1G:
+		cell_size = 0x3;
+		break;
+	case SZ_2G:
+		cell_size = 0x4;
+		break;
+	case SZ_4G:
+		cell_size = 0x5;
+		break;
+	case (SZ_2G * SZ_4G):	/*8G */
+		cell_size = 0x6;
+		break;
+	case (SZ_4G * SZ_4G):	/*16G */
+		cell_size = 0x7;
+		break;
+	default:
+		dev_err(nand->dev, "unsupported chip size: %llu MB\n",
+			chipsize);
+		break;
+	}
+
+	if (hold_cycle && wait_cycle)
+		nand_writel(nc, NAND_TIMING,
+			    (hold_cycle << BITS_PER_BYTE) | wait_cycle);
+	nand_writel(nc, NAND_PARAM,
+		    (nand_readl(nc, NAND_PARAM) & ~SIZE_MASK) | cell_size <<
+		    BITS_PER_BYTE);
+
+	chip->ecc.read_page_raw = nand_monolithic_read_page_raw;
+	chip->ecc.write_page_raw = nand_monolithic_write_page_raw;
+
+	return 0;
+}
+
+static const struct nand_controller_ops ls1x_nc_ops = {
+	.exec_op = ls1x_nand_exec_op,
+	.attach_chip = ls1x_nand_attach_chip,
+};
+
+static void ls1x_nand_controller_cleanup(struct ls1x_nand *nand)
+{
+	if (nand->nc.dma_chan)
+		dma_release_channel(nand->nc.dma_chan);
+}
+
+static int ls1x_nand_controller_init(struct ls1x_nand *nand,
+				     struct platform_device *pdev)
+{
+	struct ls1x_nand_controller *nc = &nand->nc;
+	struct device *dev = &pdev->dev;
+	struct dma_slave_config cfg;
+	struct resource *res;
+	int ret;
+
+	nc->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(nc->reg_base))
+		return PTR_ERR(nc->reg_base);
+
+	res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+	if (!res) {
+		dev_err(dev, "failed to get DMA information!\n");
+		return -ENXIO;
+	}
+
+	nc->dma_chan = dma_request_chan(dev, res->name);
+	if (!nc->dma_chan) {
+		dev_err(dev, "failed to request DMA channel!\n");
+		return -EBUSY;
+	}
+	dev_info(dev, "got %s for %s access\n",
+		 dma_chan_name(nc->dma_chan), dev_name(dev));
+
+	cfg.src_addr = CPHYSADDR(nc->reg_base + NAND_DMA_ADDR);
+	cfg.dst_addr = CPHYSADDR(nc->reg_base + NAND_DMA_ADDR);
+	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	ret = dmaengine_slave_config(nc->dma_chan, &cfg);
+	if (ret) {
+		dev_err(dev, "failed to config DMA channel!\n");
+		dma_release_channel(nc->dma_chan);
+		return ret;
+	}
+
+	init_completion(&nc->dma_complete);
+
+	return 0;
+}
+
+static int ls1x_nand_chip_init(struct ls1x_nand *nand)
+{
+	struct nand_chip *chip = &nand->chip;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct plat_ls1x_nand *pdata = nand->pdata;
+	int ret = 0;
+
+	chip->controller = &nand->controller;
+	chip->options = NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA | NAND_BROKEN_XD;
+	chip->buf_align = 16;
+	chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
+	chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
+	nand_set_controller_data(chip, nand);
+
+	mtd->dev.parent = nand->dev;
+	mtd->name = "ls1x-nand";
+	mtd->owner = THIS_MODULE;
+
+	ret = nand_scan(chip, 1);
+	if (ret)
+		return ret;
+
+	chip->ecc.read_subpage = ls1x_nand_read_subpage;
+
+	ret = mtd_device_register(mtd, pdata->parts, pdata->nr_parts);
+	if (ret) {
+		dev_err(nand->dev, "failed to register MTD device! %d\n", ret);
+		nand_cleanup(chip);
+	}
+
+	return ret;
+}
+
+static int ls1x_nand_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct plat_ls1x_nand *pdata;
+	struct ls1x_nand *nand;
+	int ret;
+
+	pdata = dev_get_platdata(dev);
+	if (!pdata) {
+		dev_err(dev, "platform data missing!\n");
+		return -EINVAL;
+	}
+
+	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
+	if (!nand)
+		return -ENOMEM;
+
+	nand->pdata = pdata;
+	nand->dev = dev;
+	nand->controller.ops = &ls1x_nc_ops;
+	nand_controller_init(&nand->controller);
+
+	ret = ls1x_nand_controller_init(nand, pdev);
+	if (ret)
+		return ret;
+
+	nand->clk = devm_clk_get(dev, pdev->name);
+	if (IS_ERR(nand->clk)) {
+		dev_err(dev, "failed to get %s clock!\n", pdev->name);
+		return PTR_ERR(nand->clk);
+	}
+	clk_prepare_enable(nand->clk);
+
+	ret = ls1x_nand_chip_init(nand);
+	if (ret) {
+		clk_disable_unprepare(nand->clk);
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, nand);
+	dev_info(dev, "Loongson1 NAND driver registered\n");
+
+	return 0;
+err:
+	ls1x_nand_controller_cleanup(nand);
+	return ret;
+}
+
+static int ls1x_nand_remove(struct platform_device *pdev)
+{
+	struct ls1x_nand *nand = platform_get_drvdata(pdev);
+	struct nand_chip *chip = &nand->chip;
+
+	mtd_device_unregister(nand_to_mtd(chip));
+	nand_cleanup(chip);
+	clk_disable_unprepare(nand->clk);
+	ls1x_nand_controller_cleanup(nand);
+
+	return 0;
+}
+
+static struct platform_driver ls1x_nand_driver = {
+	.probe	= ls1x_nand_probe,
+	.remove	= ls1x_nand_remove,
+	.driver	= {
+		.name	= "ls1x-nand",
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(ls1x_nand_driver);
+
+MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@xxxxxxxxx>");
+MODULE_DESCRIPTION("Loongson1 NAND Flash driver");
+MODULE_LICENSE("GPL");

base-commit: fd0d8d85f7230052e638a56d1bfea170c488e6bc
-- 
2.30.2