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Subject[PATCH V3] mtd: nand: add Loongson1 NAND driver
Date
From: Kelvin Cheung <keguang.zhang@gmail.com>

This patch adds NAND driver for Loongson1B.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>

---
v3:
Replace __raw_readl/__raw_writel with readl/writel.
Split ls1x_nand into two structures: ls1x_nand_chip and ls1x_nand_controller.
V2:
Modify the dependency in Kconfig due to the changes of DMA module.
---
drivers/mtd/nand/Kconfig | 8 +
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/loongson1_nand.c | 555 ++++++++++++++++++++++++++++++++++++++
3 files changed, 564 insertions(+)
create mode 100644 drivers/mtd/nand/loongson1_nand.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index f05e0e9..be20fb8 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -563,4 +563,12 @@ config MTD_NAND_QCOM
Enables support for NAND flash chips on SoCs containing the EBI2 NAND
controller. This controller is found on IPQ806x SoC.

+config MTD_NAND_LOONGSON1
+ tristate "Support for Loongson1 SoC NAND controller"
+ depends on MACH_LOONGSON32
+ select DMADEVICES
+ select LOONGSON1_DMA
+ help
+ Enables support for NAND Flash on Loongson1 SoC based boards.
+
endif # MTD_NAND
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index f553353..0310c0b 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -57,5 +57,6 @@ obj-$(CONFIG_MTD_NAND_SUNXI) += sunxi_nand.o
obj-$(CONFIG_MTD_NAND_HISI504) += hisi504_nand.o
obj-$(CONFIG_MTD_NAND_BRCMNAND) += brcmnand/
obj-$(CONFIG_MTD_NAND_QCOM) += qcom_nandc.o
+obj-$(CONFIG_MTD_NAND_LOONGSON1) += loongson1_nand.o

nand-objs := nand_base.o nand_bbt.o nand_timings.o
diff --git a/drivers/mtd/nand/loongson1_nand.c b/drivers/mtd/nand/loongson1_nand.c
new file mode 100644
index 0000000..86831773
--- /dev/null
+++ b/drivers/mtd/nand/loongson1_nand.c
@@ -0,0 +1,555 @@
+/*
+ * NAND Flash Driver for Loongson 1 SoC
+ *
+ * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/sizes.h>
+
+#include <nand.h>
+
+/* Loongson 1 NAND Register Definitions */
+#define NAND_CMD 0x0
+#define NAND_ADDRL 0x4
+#define NAND_ADDRH 0x8
+#define NAND_TIMING 0xc
+#define NAND_IDL 0x10
+#define NAND_IDH 0x14
+#define NAND_STATUS 0x14
+#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 LS1X_NAND_TIMEOUT 20
+
+/* macros for registers read/write */
+#define nand_readl(nandc, off) \
+ readl((nandc)->reg_base + (off))
+
+#define nand_writel(nandc, off, val) \
+ writel((val), (nandc)->reg_base + (off))
+
+#define set_cmd(nandc, ctrl) \
+ nand_writel(nandc, NAND_CMD, ctrl)
+
+#define start_nand(nandc) \
+ nand_writel(nandc, NAND_CMD, nand_readl(nandc, NAND_CMD) | CMD_VALID)
+
+struct ls1x_nand_chip {
+ struct nand_chip chip;
+ struct plat_ls1x_nand *pdata;
+};
+
+struct ls1x_nand_controller {
+ struct clk *clk;
+ void __iomem *reg_base;
+
+ int cmd_ctrl;
+ char datareg[8];
+ char *data_ptr;
+
+ /* DMA stuff */
+ unsigned char *dma_buf;
+ unsigned int buf_off;
+ unsigned int buf_len;
+
+ /* DMA Engine stuff */
+ unsigned int dma_chan_id;
+ struct dma_chan *dma_chan;
+ dma_cookie_t dma_cookie;
+ struct completion dma_complete;
+ void __iomem *dma_desc;
+};
+
+static inline struct ls1x_nand_chip *to_ls1x_nand_chip(struct mtd_info *mtd)
+{
+ return container_of(mtd_to_nand(mtd), struct ls1x_nand_chip, chip);
+}
+
+static void dma_callback(void *data)
+{
+ struct mtd_info *mtd = (struct mtd_info *)data;
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+ struct dma_tx_state state;
+ enum dma_status status;
+
+ status =
+ dmaengine_tx_status(nandc->dma_chan, nandc->dma_cookie, &state);
+ if (likely(status == DMA_COMPLETE))
+ dev_dbg(mtd->dev.parent, "DMA complete with cookie=%d\n",
+ nandc->dma_cookie);
+ else
+ dev_err(mtd->dev.parent, "DMA error with cookie=%d\n",
+ nandc->dma_cookie);
+
+ complete(&nandc->dma_complete);
+}
+
+static int setup_dma(struct mtd_info *mtd)
+{
+ struct ls1x_nand_chip *nand = to_ls1x_nand_chip(mtd);
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+ struct dma_slave_config cfg;
+ dma_cap_mask_t mask;
+ int ret;
+
+ if (!nand->pdata->dma_filter) {
+ dev_err(mtd->dev.parent, "no DMA filter\n");
+ return -ENOENT;
+ }
+
+ /* allocate DMA buffer */
+ nandc->dma_buf = devm_kzalloc(mtd->dev.parent,
+ mtd->writesize + mtd->oobsize,
+ GFP_KERNEL);
+ if (!nandc->dma_buf)
+ return -ENOMEM;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ nandc->dma_chan = dma_request_channel(mask, nand->pdata->dma_filter,
+ &nandc->dma_chan_id);
+ if (!nandc->dma_chan) {
+ dev_err(mtd->dev.parent, "failed to request DMA channel\n");
+ return -EBUSY;
+ }
+ dev_info(mtd->dev.parent, "got %s for %s access\n",
+ dma_chan_name(nandc->dma_chan), dev_name(mtd->dev.parent));
+
+ cfg.src_addr = CPHYSADDR(nandc->reg_base + NAND_DMA_ADDR);
+ cfg.dst_addr = CPHYSADDR(nandc->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(nandc->dma_chan, &cfg);
+ if (ret) {
+ dev_err(mtd->dev.parent, "failed to config DMA channel\n");
+ dma_release_channel(nandc->dma_chan);
+ return ret;
+ }
+
+ init_completion(&nandc->dma_complete);
+
+ return 0;
+}
+
+static int start_dma(struct mtd_info *mtd, unsigned int len, bool is_write)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+ struct dma_chan *chan = nandc->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, nandc->dma_buf, len, data_dir);
+ if (dma_mapping_error(chan->device->dev, dma_addr)) {
+ dev_err(mtd->dev.parent, "failed to map DMA buffer\n");
+ return -ENXIO;
+ }
+
+ desc = dmaengine_prep_slave_single(chan, dma_addr, len, xfer_dir,
+ DMA_PREP_INTERRUPT);
+ if (!desc) {
+ dev_err(mtd->dev.parent, "failed to prepare DMA descriptor\n");
+ ret = PTR_ERR(desc);
+ goto err;
+ }
+ desc->callback = dma_callback;
+ desc->callback_param = mtd;
+
+ nandc->dma_cookie = dmaengine_submit(desc);
+ ret = dma_submit_error(nandc->dma_cookie);
+ if (ret) {
+ dev_err(mtd->dev.parent, "failed to submit DMA descriptor\n");
+ goto err;
+ }
+
+ dev_dbg(mtd->dev.parent, "issue DMA with cookie=%d\n",
+ nandc->dma_cookie);
+ dma_async_issue_pending(chan);
+
+ ret = wait_for_completion_timeout(&nandc->dma_complete,
+ msecs_to_jiffies(LS1X_NAND_TIMEOUT));
+ if (ret <= 0) {
+ dev_err(mtd->dev.parent, "DMA timeout\n");
+ dmaengine_terminate_all(chan);
+ ret = -EIO;
+ }
+ ret = 0;
+err:
+ dma_unmap_single(chan->device->dev, dma_addr, len, data_dir);
+
+ return ret;
+}
+
+static void ls1x_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+}
+
+static int ls1x_nand_dev_ready(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ if (nand_readl(nandc, NAND_CMD) & OP_DONE)
+ return 1;
+
+ return 0;
+}
+
+static uint8_t ls1x_nand_read_byte(struct mtd_info *mtd)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ return *(nandc->data_ptr++);
+}
+
+static void ls1x_nand_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ int real_len = min_t(size_t, len, nandc->buf_len - nandc->buf_off);
+
+ memcpy(buf, nandc->dma_buf + nandc->buf_off, real_len);
+ nandc->buf_off += real_len;
+}
+
+static void ls1x_nand_write_buf(struct mtd_info *mtd, const uint8_t *buf,
+ int len)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ int real_len = min_t(size_t, len, nandc->buf_len - nandc->buf_off);
+
+ memcpy(nandc->dma_buf + nandc->buf_off, buf, real_len);
+ nandc->buf_off += real_len;
+}
+
+static inline void set_addr_len(struct mtd_info *mtd, unsigned int command,
+ int column, int page_addr)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+ int page_shift, addr_low, addr_high;
+
+ if (command == NAND_CMD_ERASE1)
+ page_shift = chip->page_shift;
+ else
+ page_shift = chip->page_shift + 1;
+
+ addr_low = page_addr << page_shift;
+
+ if (column != -1) {
+ if (command == NAND_CMD_READOOB)
+ column += mtd->writesize;
+ addr_low += column;
+ nandc->buf_off = 0;
+ }
+
+ addr_high =
+ page_addr >> (sizeof(page_addr) * BITS_PER_BYTE - page_shift);
+
+ if (command == NAND_CMD_ERASE1)
+ nandc->buf_len = 1;
+ else
+ nandc->buf_len = mtd->writesize + mtd->oobsize - column;
+
+ nand_writel(nandc, NAND_ADDRL, addr_low);
+ nand_writel(nandc, NAND_ADDRH, addr_high);
+ nand_writel(nandc, NAND_OP_NUM, nandc->buf_len);
+}
+
+static void ls1x_nand_cmdfunc(struct mtd_info *mtd, unsigned int command,
+ int column, int page_addr)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ dev_dbg(mtd->dev.parent, "cmd = 0x%02x, col = 0x%08x, page = 0x%08x\n",
+ command, column, page_addr);
+
+ if (command == NAND_CMD_RNDOUT) {
+ nandc->buf_off = column;
+ return;
+ }
+
+ /*set address, buffer length and buffer offset */
+ if (column != -1 || page_addr != -1)
+ set_addr_len(mtd, command, column, page_addr);
+
+ /*prepare NAND command */
+ switch (command) {
+ case NAND_CMD_RESET:
+ nandc->cmd_ctrl = CMD_RESET;
+ break;
+ case NAND_CMD_STATUS:
+ nandc->cmd_ctrl = CMD_STATUS;
+ break;
+ case NAND_CMD_READID:
+ nandc->cmd_ctrl = CMD_READID;
+ break;
+ case NAND_CMD_READ0:
+ nandc->cmd_ctrl = OP_SPARE | OP_MAIN | CMD_READ;
+ break;
+ case NAND_CMD_READOOB:
+ nandc->cmd_ctrl = OP_SPARE | CMD_READ;
+ break;
+ case NAND_CMD_ERASE1:
+ nandc->cmd_ctrl = CMD_ERASE;
+ break;
+ case NAND_CMD_PAGEPROG:
+ break;
+ case NAND_CMD_SEQIN:
+ if (column < mtd->writesize)
+ nandc->cmd_ctrl = OP_SPARE | OP_MAIN | CMD_WRITE;
+ else
+ nandc->cmd_ctrl = OP_SPARE | CMD_WRITE;
+ default:
+ return;
+ }
+
+ /*set NAND command */
+ set_cmd(nandc, nandc->cmd_ctrl);
+ /*trigger NAND operation */
+ start_nand(nandc);
+ /*trigger DMA for R/W operation */
+ if (command == NAND_CMD_READ0 || command == NAND_CMD_READOOB)
+ start_dma(mtd, nandc->buf_len, false);
+ else if (command == NAND_CMD_PAGEPROG)
+ start_dma(mtd, nandc->buf_len, true);
+ nand_wait_ready(mtd);
+
+ if (command == NAND_CMD_STATUS) {
+ nandc->datareg[0] = (char)(nand_readl(nandc, NAND_STATUS) >> 8);
+ /*work around hardware bug for invalid STATUS */
+ nandc->datareg[0] |= 0xc0;
+ nandc->data_ptr = nandc->datareg;
+ } else if (command == NAND_CMD_READID) {
+ nandc->datareg[0] = (char)(nand_readl(nandc, NAND_IDH));
+ nandc->datareg[1] = (char)(nand_readl(nandc, NAND_IDL) >> 24);
+ nandc->datareg[2] = (char)(nand_readl(nandc, NAND_IDL) >> 16);
+ nandc->datareg[3] = (char)(nand_readl(nandc, NAND_IDL) >> 8);
+ nandc->datareg[4] = (char)(nand_readl(nandc, NAND_IDL));
+ nandc->data_ptr = nandc->datareg;
+ }
+
+ nandc->cmd_ctrl = 0;
+}
+
+static void ls1x_nand_hw_init(struct mtd_info *mtd, int hold_cycle,
+ int wait_cycle)
+{
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+ int chipsize = (int)(chip->chipsize >> 20);
+ int cell_size = 0x0;
+
+ switch (chipsize) {
+ case SZ_128: /*128M */
+ cell_size = 0x0;
+ break;
+ case SZ_256: /*256M */
+ cell_size = 0x1;
+ break;
+ case SZ_512: /*512M */
+ cell_size = 0x2;
+ break;
+ case SZ_1K: /*1G */
+ cell_size = 0x3;
+ break;
+ case SZ_2K: /*2G */
+ cell_size = 0x4;
+ break;
+ case SZ_4K: /*4G */
+ cell_size = 0x5;
+ break;
+ case SZ_8K: /*8G */
+ cell_size = 0x6;
+ break;
+ case SZ_16K: /*16G */
+ cell_size = 0x7;
+ break;
+ default:
+ dev_warn(mtd->dev.parent, "unsupported chip size: %d MB\n",
+ chipsize);
+ }
+
+ nand_writel(nandc, NAND_TIMING, (hold_cycle << 8) | wait_cycle);
+ nand_writel(nandc, NAND_PARAM,
+ (nand_readl(nandc, NAND_PARAM) & 0xfffff0ff) | (cell_size <<
+ 8));
+}
+
+static int ls1x_nand_init(struct platform_device *pdev,
+ struct ls1x_nand_controller *nandc)
+{
+ struct device *dev = &pdev->dev;
+ struct ls1x_nand_chip *nand;
+ struct plat_ls1x_nand *pdata;
+ struct nand_chip *chip;
+ struct mtd_info *mtd;
+ int ret = 0;
+
+ nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
+ if (!nand)
+ return -ENOMEM;
+
+ pdata = dev_get_platdata(dev);
+ if (!pdata) {
+ dev_err(dev, "platform data missing\n");
+ return -EINVAL;
+ }
+ nand->pdata = pdata;
+
+ chip = &nand->chip;
+ chip->read_byte = ls1x_nand_read_byte;
+ chip->read_buf = ls1x_nand_read_buf;
+ chip->write_buf = ls1x_nand_write_buf;
+ chip->select_chip = ls1x_nand_select_chip;
+ chip->dev_ready = ls1x_nand_dev_ready;
+ chip->cmdfunc = ls1x_nand_cmdfunc;
+ chip->options = NAND_NO_SUBPAGE_WRITE;
+ chip->ecc.mode = NAND_ECC_SOFT;
+ nand_set_controller_data(chip, nandc);
+
+ mtd = nand_to_mtd(chip);
+ mtd->name = "ls1x-nand";
+ mtd->owner = THIS_MODULE;
+ mtd->dev.parent = dev;
+
+ ret = nand_scan_ident(mtd, 1, NULL);
+ if (ret)
+ return ret;
+
+ ls1x_nand_hw_init(mtd, pdata->hold_cycle, pdata->wait_cycle);
+
+ ret = setup_dma(mtd);
+ if (ret)
+ return ret;
+
+ ret = nand_scan_tail(mtd);
+ if (ret) {
+ dma_release_channel(nandc->dma_chan);
+ return ret;
+ }
+
+ ret = mtd_device_register(mtd, pdata->parts, pdata->nr_parts);
+ if (ret) {
+ dev_err(dev, "failed to register MTD device: %d\n", ret);
+ dma_release_channel(nandc->dma_chan);
+ }
+
+ platform_set_drvdata(pdev, mtd);
+ return ret;
+}
+
+static int ls1x_nand_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ls1x_nand_controller *nandc;
+ struct resource *res;
+ int ret;
+
+ nandc = devm_kzalloc(dev, sizeof(*nandc), GFP_KERNEL);
+ if (!nandc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "failed to get I/O memory\n");
+ return -ENXIO;
+ }
+
+ nandc->reg_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(nandc->reg_base))
+ return PTR_ERR(nandc->reg_base);
+
+ res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
+ if (!res) {
+ dev_err(dev, "failed to get DMA information\n");
+ return -ENXIO;
+ }
+ nandc->dma_chan_id = res->start;
+
+ nandc->clk = devm_clk_get(dev, pdev->name);
+ if (IS_ERR(nandc->clk)) {
+ dev_err(dev, "failed to get %s clock\n", pdev->name);
+ return PTR_ERR(nandc->clk);
+ }
+ clk_prepare_enable(nandc->clk);
+
+ ret = ls1x_nand_init(pdev, nandc);
+ if (ret) {
+ clk_disable_unprepare(nandc->clk);
+ return ret;
+ }
+
+ dev_info(dev, "Loongson1 NAND driver registered\n");
+ return 0;
+}
+
+static int ls1x_nand_remove(struct platform_device *pdev)
+{
+ struct mtd_info *mtd = platform_get_drvdata(pdev);
+ struct nand_chip *chip = mtd_to_nand(mtd);
+ struct ls1x_nand_controller *nandc = nand_get_controller_data(chip);
+
+ if (nandc->dma_chan)
+ dma_release_channel(nandc->dma_chan);
+ nand_release(mtd);
+ clk_disable_unprepare(nandc->clk);
+
+ 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@gmail.com>");
+MODULE_DESCRIPTION("Loongson1 NAND Flash driver");
+MODULE_LICENSE("GPL");
--
1.9.1
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