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SubjectRe: [PATCH 10/14] qcom: mtd: nand: support for QPIC Page read/write
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On 06/29/2017 12:46 PM, Abhishek Sahu wrote:
> 1. Add the function for command descriptor preparation which
> will be used only by BAM DMA and it will form the DMA descriptors
> containing command elements.
>
> 2. Add the data descriptor preparation function which will be used
> only by BAM DMA for forming the data SGL’s.
>
> 3. Add clear BAM transaction and call it before every new request
>
> 4. Check DMA mode for ADM or BAM and call the appropriate
> descriptor formation function.
>
> 5. Enable the BAM in NAND_CTRL.
>
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
> drivers/mtd/nand/qcom_nandc.c | 190 +++++++++++++++++++++++++++++++++++++++---
> 1 file changed, 180 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
> index 17766af..4c6e594 100644
> --- a/drivers/mtd/nand/qcom_nandc.c
> +++ b/drivers/mtd/nand/qcom_nandc.c
> @@ -156,6 +156,8 @@
> #define FETCH_ID 0xb
> #define RESET_DEVICE 0xd
>
> +/* NAND_CTRL bits */
> +#define BAM_MODE_EN BIT(0)
> /*
> * the NAND controller performs reads/writes with ECC in 516 byte chunks.
> * the driver calls the chunks 'step' or 'codeword' interchangeably
> @@ -190,6 +192,14 @@
> */
> #define NAND_ERASED_CW_SET (0x0008)
>
> +/* Returns the dma address for reg read buffer */
> +#define REG_BUF_DMA_ADDR(chip, vaddr) \
> + ((chip)->reg_read_buf_phys + \
> + ((uint8_t *)(vaddr) - (uint8_t *)(chip)->reg_read_buf))
> +
> +/* Returns the NAND register physical address */
> +#define NAND_REG_PHYS(chip, offset) ((chip)->base_phys + (offset))
> +
> #define QPIC_PER_CW_MAX_CMD_ELEMENTS (32)
> #define QPIC_PER_CW_MAX_CMD_SGL (32)
> #define QPIC_PER_CW_MAX_DATA_SGL (8)
> @@ -287,7 +297,8 @@ struct nandc_regs {
> * controller
> * @dev: parent device
> * @base: MMIO base
> - * @base_dma: physical base address of controller registers
> + * @base_phys: physical base address of controller registers
> + * @base_dma: dma base address of controller registers
> * @core_clk: controller clock
> * @aon_clk: another controller clock
> *
> @@ -323,6 +334,7 @@ struct qcom_nand_controller {
> struct device *dev;
>
> void __iomem *base;
> + phys_addr_t base_phys;
> dma_addr_t base_dma;
>
> struct clk *core_clk;
> @@ -467,6 +479,29 @@ static void free_bam_transaction(struct qcom_nand_controller *nandc)
> return bam_txn;
> }
>
> +/* Clears the BAM transaction indexes */
> +static void clear_bam_transaction(struct qcom_nand_controller *nandc)
> +{
> + struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> + if (!nandc->dma_bam_enabled)
> + return;
> +
> + bam_txn->bam_ce_pos = 0;
> + bam_txn->bam_ce_start = 0;
> + bam_txn->cmd_sgl_pos = 0;
> + bam_txn->cmd_sgl_start = 0;
> + bam_txn->tx_sgl_pos = 0;
> + bam_txn->tx_sgl_start = 0;
> + bam_txn->rx_sgl_pos = 0;
> + bam_txn->rx_sgl_start = 0;
> +
> + sg_init_table(bam_txn->cmd_sgl, nandc->max_cwperpage *
> + QPIC_PER_CW_MAX_CMD_SGL);
> + sg_init_table(bam_txn->data_sg, nandc->max_cwperpage *
> + QPIC_PER_CW_MAX_DATA_SGL);
> +}
> +
> static inline struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
> {
> return container_of(chip, struct qcom_nand_host, chip);
> @@ -682,6 +717,102 @@ static int prepare_bam_async_desc(struct qcom_nand_controller *nandc,
> return 0;
> }
>
> +/*
> + * Prepares the command descriptor for BAM DMA which will be used for NAND
> + * register reads and writes. The command descriptor requires the command
> + * to be formed in command element type so this function uses the command
> + * element from bam transaction ce array and fills the same with required
> + * data. A single SGL can contain multiple command elements so
> + * NAND_BAM_NEXT_SGL will be used for starting the separate SGL
> + * after the current command element.
> + */
> +static int prep_dma_desc_command(struct qcom_nand_controller *nandc, bool read,
> + int reg_off, const void *vaddr,
> + int size, unsigned int flags)
> +{
> + int bam_ce_size;
> + int i, ret;
> + struct bam_cmd_element *bam_ce_buffer;
> + struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> + bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_pos];
> +
> + /* fill the command desc */
> + for (i = 0; i < size; i++) {
> + if (read)
> + bam_prep_ce(&bam_ce_buffer[i],
> + NAND_REG_PHYS(nandc, reg_off + 4 * i),
> + BAM_READ_COMMAND,
> + REG_BUF_DMA_ADDR(nandc,
> + (__le32 *)vaddr + i));
> + else
> + bam_prep_ce_le32(&bam_ce_buffer[i],
> + NAND_REG_PHYS(nandc, reg_off + 4 * i),
> + BAM_WRITE_COMMAND,
> + *((__le32 *)vaddr + i));
> + }
> +
> + bam_txn->bam_ce_pos += size;
> +
> + /* use the separate sgl after this command */
> + if (flags & NAND_BAM_NEXT_SGL) {
> + bam_ce_buffer = &bam_txn->bam_ce[bam_txn->bam_ce_start];
> + bam_ce_size = (bam_txn->bam_ce_pos -
> + bam_txn->bam_ce_start) *
> + sizeof(struct bam_cmd_element);
> + sg_set_buf(&bam_txn->cmd_sgl[bam_txn->cmd_sgl_pos],
> + bam_ce_buffer, bam_ce_size);
> + bam_txn->cmd_sgl_pos++;
> + bam_txn->bam_ce_start = bam_txn->bam_ce_pos;
> +
> + if (flags & NAND_BAM_NWD) {
> + ret = prepare_bam_async_desc(nandc, nandc->cmd_chan,
> + DMA_PREP_FENCE |
> + DMA_PREP_CMD);
> + if (ret)
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Prepares the data descriptor for BAM DMA which will be used for NAND
> + * data reads and writes.
> + */
> +static int prep_dma_desc_data_bam(struct qcom_nand_controller *nandc, bool read,
> + int reg_off, const void *vaddr,
> + int size, unsigned int flags)
> +{
> + int ret;
> + struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> + if (read) {
> + sg_set_buf(&bam_txn->data_sg[bam_txn->rx_sgl_pos],
> + vaddr, size);
> + bam_txn->rx_sgl_pos++;
> + } else {
> + sg_set_buf(&bam_txn->data_sg[bam_txn->tx_sgl_pos],
> + vaddr, size);
> + bam_txn->tx_sgl_pos++;
> +
> + /*
> + * BAM will only set EOT for DMA_PREP_INTERRUPT so if this flag
> + * is not set, form the DMA descriptor
> + */
> + if (!(flags & NAND_BAM_NO_EOT)) {
> + ret = prepare_bam_async_desc(nandc, nandc->tx_chan,
> + DMA_PREP_INTERRUPT);
> + if (ret)
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/* Prepares the dma descriptor for adm dma engine */
> static int prep_dma_desc(struct qcom_nand_controller *nandc, bool read,
> int reg_off, const void *vaddr, int size,
> bool flow_control)
> @@ -764,16 +895,19 @@ static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
> {
> bool flow_control = false;
> void *vaddr;
> - int size;
>
> if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
> flow_control = true;
>
> - size = num_regs * sizeof(u32);
> vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
> nandc->reg_read_pos += num_regs;
>
> - return prep_dma_desc(nandc, true, first, vaddr, size, flow_control);
> + if (nandc->dma_bam_enabled)
> + return prep_dma_desc_command(nandc, true, first, vaddr,
> + num_regs, flags);
> +
> + return prep_dma_desc(nandc, true, first, vaddr, num_regs * sizeof(u32),
> + flow_control);
> }
>
> /*
> @@ -789,7 +923,6 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> bool flow_control = false;
> struct nandc_regs *regs = nandc->regs;
> void *vaddr;
> - int size;
>
> vaddr = offset_to_nandc_reg(regs, first);
>
> @@ -812,9 +945,12 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> if (first == NAND_DEV_CMD_VLD_RESTORE)
> first = NAND_DEV_CMD_VLD;
>
> - size = num_regs * sizeof(u32);
> + if (nandc->dma_bam_enabled)
> + return prep_dma_desc_command(nandc, false, first, vaddr,
> + num_regs, flags);
>
> - return prep_dma_desc(nandc, false, first, vaddr, size, flow_control);
> + return prep_dma_desc(nandc, false, first, vaddr, num_regs * sizeof(u32),
> + flow_control);
> }
>
> /*
> @@ -828,6 +964,10 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
> static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> const u8 *vaddr, int size, unsigned int flags)
> {
> + if (nandc->dma_bam_enabled)
> + return prep_dma_desc_data_bam(nandc, true, reg_off, vaddr, size,
> + flags);
> +
> return prep_dma_desc(nandc, true, reg_off, vaddr, size, false);
> }
>
> @@ -842,6 +982,10 @@ static int read_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> static int write_data_dma(struct qcom_nand_controller *nandc, int reg_off,
> const u8 *vaddr, int size, unsigned int flags)
> {
> + if (nandc->dma_bam_enabled)
> + return prep_dma_desc_data_bam(nandc, false, reg_off, vaddr,
> + size, flags);
> +
> return prep_dma_desc(nandc, false, reg_off, vaddr, size, false);
> }
>
> @@ -931,6 +1075,8 @@ static int nandc_param(struct qcom_nand_host *host)
> struct nand_chip *chip = &host->chip;
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> + clear_bam_transaction(nandc);

For all the commands that go through chip->cmdfunc, can we move
clear_bam_transaction() calls to pre_command()?

Thanks,
Archit

> /*
> * NAND_CMD_PARAM is called before we know much about the FLASH chip
> * in use. we configure the controller to perform a raw read of 512
> @@ -993,6 +1139,8 @@ static int erase_block(struct qcom_nand_host *host, int page_addr)
> struct nand_chip *chip = &host->chip;
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> + clear_bam_transaction(nandc);
> +
> nandc_set_reg(nandc, NAND_FLASH_CMD,
> BLOCK_ERASE | PAGE_ACC | LAST_PAGE);
> nandc_set_reg(nandc, NAND_ADDR0, page_addr);
> @@ -1025,10 +1173,13 @@ static int read_id(struct qcom_nand_host *host, int column)
> if (column == -1)
> return 0;
>
> + clear_bam_transaction(nandc);
> +
> nandc_set_reg(nandc, NAND_FLASH_CMD, FETCH_ID);
> nandc_set_reg(nandc, NAND_ADDR0, column);
> nandc_set_reg(nandc, NAND_ADDR1, 0);
> - nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
> + nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT,
> + nandc->dma_bam_enabled ? 0 : DM_EN);
> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>
> write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
> @@ -1045,6 +1196,8 @@ static int reset(struct qcom_nand_host *host)
> struct nand_chip *chip = &host->chip;
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> + clear_bam_transaction(nandc);
> +
> nandc_set_reg(nandc, NAND_FLASH_CMD, RESET_DEVICE);
> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>
> @@ -1561,6 +1714,7 @@ static int qcom_nandc_read_page(struct mtd_info *mtd, struct nand_chip *chip,
> data_buf = buf;
> oob_buf = oob_required ? chip->oob_poi : NULL;
>
> + clear_bam_transaction(nandc);
> ret = read_page_ecc(host, data_buf, oob_buf);
> if (ret) {
> dev_err(nandc->dev, "failure to read page\n");
> @@ -1585,6 +1739,8 @@ static int qcom_nandc_read_page_raw(struct mtd_info *mtd,
> oob_buf = chip->oob_poi;
>
> host->use_ecc = false;
> +
> + clear_bam_transaction(nandc);
> update_rw_regs(host, ecc->steps, true);
>
> for (i = 0; i < ecc->steps; i++) {
> @@ -1641,6 +1797,7 @@ static int qcom_nandc_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> int ret;
>
> clear_read_regs(nandc);
> + clear_bam_transaction(nandc);
>
> host->use_ecc = true;
> set_address(host, 0, page);
> @@ -1664,6 +1821,7 @@ static int qcom_nandc_write_page(struct mtd_info *mtd, struct nand_chip *chip,
> int i, ret;
>
> clear_read_regs(nandc);
> + clear_bam_transaction(nandc);
>
> data_buf = (u8 *)buf;
> oob_buf = chip->oob_poi;
> @@ -1729,6 +1887,7 @@ static int qcom_nandc_write_page_raw(struct mtd_info *mtd,
> int i, ret;
>
> clear_read_regs(nandc);
> + clear_bam_transaction(nandc);
>
> data_buf = (u8 *)buf;
> oob_buf = chip->oob_poi;
> @@ -1803,6 +1962,7 @@ static int qcom_nandc_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
>
> host->use_ecc = true;
>
> + clear_bam_transaction(nandc);
> ret = copy_last_cw(host, page);
> if (ret)
> return ret;
> @@ -1860,6 +2020,7 @@ static int qcom_nandc_block_bad(struct mtd_info *mtd, loff_t ofs)
> */
> host->use_ecc = false;
>
> + clear_bam_transaction(nandc);
> ret = copy_last_cw(host, page);
> if (ret)
> goto err;
> @@ -1890,6 +2051,7 @@ static int qcom_nandc_block_markbad(struct mtd_info *mtd, loff_t ofs)
> int page, ret, status = 0;
>
> clear_read_regs(nandc);
> + clear_bam_transaction(nandc);
>
> /*
> * to mark the BBM as bad, we flash the entire last codeword with 0s.
> @@ -2396,11 +2558,18 @@ static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc)
> /* one time setup of a few nand controller registers */
> static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
> {
> + u32 nand_ctrl;
> +
> /* kill onenand */
> nandc_write(nandc, SFLASHC_BURST_CFG, 0);
>
> - /* enable ADM DMA */
> - nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
> + /* enable ADM or BAM DMA */
> + if (!nandc->dma_bam_enabled) {
> + nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN);
> + } else {
> + nand_ctrl = nandc_read(nandc, NAND_CTRL);
> + nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN);
> + }
>
> /* save the original values of these registers */
> nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
> @@ -2592,6 +2761,7 @@ static int qcom_nandc_probe(struct platform_device *pdev)
> if (IS_ERR(nandc->base))
> return PTR_ERR(nandc->base);
>
> + nandc->base_phys = res->start;
> nandc->base_dma = phys_to_dma(dev, (phys_addr_t)res->start);
>
> nandc->core_clk = devm_clk_get(dev, "core");
>

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

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