* [PATCH V4] mtd: nand: add Loongson1 NAND driver
@ 2016-11-02 1:52 Keguang Zhang
2016-11-02 7:36 ` Boris Brezillon
2016-11-02 11:33 ` kbuild test robot
0 siblings, 2 replies; 3+ messages in thread
From: Keguang Zhang @ 2016-11-02 1:52 UTC (permalink / raw)
To: linux-mtd, linux-mips, linux-kernel
Cc: Boris Brezillon, Richard Weinberger, David Woodhouse,
Brian Norris, Kelvin Cheung
From: Kelvin Cheung <keguang.zhang@gmail.com>
This patch adds NAND driver for Loongson1B.
Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
---
v4:
Retrieve the controller from nand_hw_control.
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 | 571 ++++++++++++++++++++++++++++++++++++++
3 files changed, 580 insertions(+)
create mode 100644 drivers/mtd/nand/loongson1_nand.c
diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 7b7a887..2a815c7 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -569,4 +569,12 @@ config MTD_NAND_MTK
Enables support for NAND controller on MTK SoCs.
This controller is found on mt27xx, mt81xx, mt65xx SoCs.
+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 cafde6f..04f65a6 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -58,5 +58,6 @@ 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_MTK) += mtk_nand.o mtk_ecc.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..e3999ea
--- /dev/null
+++ b/drivers/mtd/nand/loongson1_nand.c
@@ -0,0 +1,571 @@
+/*
+ * 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 NAND_RDY 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 nand_hw_control 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 struct ls1x_nand_controller *
+to_ls1x_nand_controller(struct nand_hw_control *ctrl)
+{
+ return container_of(ctrl, struct ls1x_nand_controller, controller);
+}
+
+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 =
+ to_ls1x_nand_controller(chip->controller);
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ if (nand_readl(nandc, NAND_CMD) & NAND_RDY)
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ memcpy(buf, nandc->dma_buf + nandc->buf_off, len);
+ nandc->buf_off += 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ memcpy(nandc->dma_buf + nandc->buf_off, buf, len);
+ nandc->buf_off += 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 =
+ to_ls1x_nand_controller(chip->controller);
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+ 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->controller = &nandc->controller;
+ chip->ecc.mode = NAND_ECC_SOFT;
+ chip->ecc.algo = NAND_ECC_HAMMING;
+
+ 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;
+ nand_hw_control_init(&nandc->controller);
+
+ 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 =
+ to_ls1x_nand_controller(chip->controller);
+
+ 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");
--
2.7.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH V4] mtd: nand: add Loongson1 NAND driver
2016-11-02 1:52 [PATCH V4] mtd: nand: add Loongson1 NAND driver Keguang Zhang
@ 2016-11-02 7:36 ` Boris Brezillon
2016-11-02 11:33 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: Boris Brezillon @ 2016-11-02 7:36 UTC (permalink / raw)
To: Keguang Zhang
Cc: linux-mtd, linux-mips, linux-kernel, Brian Norris,
David Woodhouse, Richard Weinberger
On Wed, 2 Nov 2016 09:52:06 +0800
Keguang Zhang <keguang.zhang@gmail.com> wrote:
> From: Kelvin Cheung <keguang.zhang@gmail.com>
>
> This patch adds NAND driver for Loongson1B.
>
> Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
>
> ---
> v4:
> Retrieve the controller from nand_hw_control.
> 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 | 571 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 580 insertions(+)
> create mode 100644 drivers/mtd/nand/loongson1_nand.c
>
[...]
> +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 =
> + to_ls1x_nand_controller(chip->controller);
> +
> + 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;
> + }
Sorry, but I'm still convinced this driver does not fit in the NAND
subsystem, or at least not the one we have now.
You're just supporting a limited number of the commands a raw NAND can
support (for example, no SET_FEATURE support, which is required for
ONFI NANDs), and your ->cmdfunc() implementation clearly shows that
you're converting all low-level commands into high-level ones.
Can you try to implement the mtd_info hooks directly? This only things
you'll miss are the nand_ids table and the BBT code, but I guess this is
something we can expose so that you don't have to re-use it.
Of course, you'll also have to convert absolute addresses into
page/block numbers, but that's not the hard part of the job.
You may also want to have a look at [1]. I started to abstract away the
NAND interface type to share some code between SPI NANDs and raw NANDs.
By implementing this interface, you'll at least be able to re-use the
BBT code.
I'm really sorry to ask you that now, after you've reworked most of the
driver to address my comments, but the more I look at it the more I
feel it's just a big hack to make it fit in a framework that was not
designed to support such "high-level" controllers.
Regards,
Boris
> +
> + /*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;
> +}
[1]http://lkml.iu.edu/hypermail/linux/kernel/1610.2/00066.html
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V4] mtd: nand: add Loongson1 NAND driver
2016-11-02 1:52 [PATCH V4] mtd: nand: add Loongson1 NAND driver Keguang Zhang
2016-11-02 7:36 ` Boris Brezillon
@ 2016-11-02 11:33 ` kbuild test robot
1 sibling, 0 replies; 3+ messages in thread
From: kbuild test robot @ 2016-11-02 11:33 UTC (permalink / raw)
To: Keguang Zhang
Cc: kbuild-all, linux-mtd, linux-mips, linux-kernel, Boris Brezillon,
Richard Weinberger, David Woodhouse, Brian Norris, Kelvin Cheung
[-- Attachment #1: Type: text/plain, Size: 2091 bytes --]
Hi Kelvin,
[auto build test ERROR on mtd/master]
[also build test ERROR on v4.9-rc3 next-20161028]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Keguang-Zhang/mtd-nand-add-Loongson1-NAND-driver/20161102-095605
base: git://git.infradead.org/linux-mtd.git master
config: mips-loongson1c_defconfig (attached as .config)
compiler: mipsel-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=mips
All errors (new ones prefixed by >>):
drivers/mtd/nand/loongson1_nand.c: In function 'setup_dma':
>> drivers/mtd/nand/loongson1_nand.c:134:18: error: 'struct plat_ls1x_nand' has no member named 'dma_filter'
if (!nand->pdata->dma_filter) {
^~
In file included from drivers/mtd/nand/loongson1_nand.c:15:0:
drivers/mtd/nand/loongson1_nand.c:148:57: error: 'struct plat_ls1x_nand' has no member named 'dma_filter'
nandc->dma_chan = dma_request_channel(mask, nand->pdata->dma_filter,
^
include/linux/dmaengine.h:1398:72: note: in definition of macro 'dma_request_channel'
#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
^
vim +134 drivers/mtd/nand/loongson1_nand.c
128 struct ls1x_nand_controller *nandc =
129 to_ls1x_nand_controller(chip->controller);
130 struct dma_slave_config cfg;
131 dma_cap_mask_t mask;
132 int ret;
133
> 134 if (!nand->pdata->dma_filter) {
135 dev_err(mtd->dev.parent, "no DMA filter\n");
136 return -ENOENT;
137 }
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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2016-11-02 1:52 [PATCH V4] mtd: nand: add Loongson1 NAND driver Keguang Zhang
2016-11-02 7:36 ` Boris Brezillon
2016-11-02 11:33 ` kbuild test robot
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