Re: [PATCH 3/3] mtd: rawnand: qcom: Add support for page scope read

mdalam
2021-09-28T12:21:22Z

On 2021-09-15 15:27, Md Sadre Alam wrote:
> QPIC V2.0 onwards QPIC controller support enhanced read mode
> like page scope read and multi page read.
>
> In QPIC V1, SW is needed to write EXEC_CMD register for each
> Code word and collect any Status related to that CW before
> issueing EXEC_CMD for next CW.
>
> Page scope command is truly a page mode command where SW is
> required to issue EXEC_CMD only once for a page. Controller
> HW takes care of Codeword specific details and automatically
> returns status associated with each CW to BAM pipe, dedicated
> for status deposition.
>
> With this command, SW now can issue one read command for a page
> and upon receiving completion interrupt, can process status,
> that have already been deposited in memory through status BAM pipe.
>
> Signed-off-by: Md Sadre Alam <mdalam@codeaurora.org>
> ---
> drivers/mtd/nand/raw/qcom_nandc.c | 77
> ++++++++++++++++++++++++++++++++++++---
> 1 file changed, 71 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c
> b/drivers/mtd/nand/raw/qcom_nandc.c
> index 07448c4..257dec7e 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -157,6 +157,10 @@
> #define OP_FETCH_ID 0xb
> #define OP_RESET_DEVICE 0xd
>
> +/* Auto status val and mask */
> +#define AUTO_STS_VAL 0x000B000B
> +#define PAGE_SCOPE_READ BIT(23)
> +
> /* Default Value for NAND_DEV_CMD_VLD */
> #define NAND_DEV_CMD_VLD_VAL (READ_START_VLD | WRITE_START_VLD | \
> ERASE_START_VLD | SEQ_READ_START_VLD)
> @@ -336,6 +340,8 @@ struct nandc_regs {
>
> __le32 erased_cw_detect_cfg_clr;
> __le32 erased_cw_detect_cfg_set;
> +
> + __le32 auto_sts_en;
> };
>
> /*
> @@ -421,6 +427,9 @@ struct qcom_nand_controller {
>
> u32 cmd1, vld;
> const struct qcom_nandc_props *props;
> +
> + __le32 *status_buf;
> + int sts_buf_size;
> };
>
> /*
> @@ -487,6 +496,7 @@ struct qcom_nandc_props {
> bool is_bam;
> bool is_qpic;
> bool qpic_v2;
> + bool page_scope;
> u32 dev_cmd_reg_start;
> };
>
> @@ -656,6 +666,8 @@ static __le32 *offset_to_nandc_reg(struct
> nandc_regs *regs, int offset)
> return &regs->cfg1;
> case NAND_DEV0_ECC_CFG:
> return &regs->ecc_bch_cfg;
> + case NAND_AUTO_STATUS_EN:
> + return &regs->auto_sts_en;
> case NAND_READ_STATUS:
> return &regs->clrreadstatus;
> case NAND_DEV_CMD1:
> @@ -756,10 +768,13 @@ static void update_rw_regs(struct qcom_nand_host
> *host, int num_cw, bool read, i
> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>
> if (read) {
> - if (host->use_ecc)
> + if (host->use_ecc) {
> cmd = OP_PAGE_READ_WITH_ECC | PAGE_ACC | LAST_PAGE;
> - else
> + if (nandc->props->qpic_v2 && nandc->props->page_scope)
> + cmd |= PAGE_SCOPE_READ;
> + } else {
> cmd = OP_PAGE_READ | PAGE_ACC | LAST_PAGE;
> + }
> } else {
> cmd = OP_PROGRAM_PAGE | PAGE_ACC | LAST_PAGE;
> }
> @@ -788,6 +803,9 @@ static void update_rw_regs(struct qcom_nand_host
> *host, int num_cw, bool read, i
> nandc_set_reg(chip, NAND_READ_STATUS, host->clrreadstatus);
> nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>
> + if (nandc->props->qpic_v2 && nandc->props->page_scope)
> + nandc_set_reg(chip, NAND_AUTO_STATUS_EN, AUTO_STS_VAL);
> +
> if (read)
> nandc_set_read_loc(chip, cw, 0, 0, host->use_ecc ?
> host->cw_data : host->cw_size, 1);
> @@ -1040,6 +1058,26 @@ static int prep_adm_dma_desc(struct
> qcom_nand_controller *nandc, bool read,
> }
>
> /*
> + * read_status_data_dma: prepares a DMA descriptor to transfer status
> from the
> + * controller's status registers to buffer 'vaddr'
> + * @reg_off: offset within the controller's data buffer
> + * @vaddr: virtual address of the buffer we want to
> write to
> + * @size: DMA transaction size in bytes
> + * @flags: flags to control DMA descriptor preparation
> + */
> +static int read_status_data_dma(struct qcom_nand_controller *nandc,
> int reg_off,
> + const u8 *vaddr, int size, unsigned int flags)
> +{
> + struct bam_transaction *bam_txn = nandc->bam_txn;
> +
> + sg_set_buf(&bam_txn->sts_sgl[bam_txn->sts_sgl_pos],
> + vaddr, size);
> + bam_txn->sts_sgl_pos++;
> +
> + return 0;
> +}
> +
> +/*
> * read_reg_dma: prepares a descriptor to read a given number of
> * contiguous registers to the reg_read_buf pointer
> *
> @@ -1186,13 +1224,20 @@ config_nand_cw_read(struct nand_chip *chip,
> bool use_ecc, int cw)
> write_reg_dma(nandc, reg, 4, NAND_BAM_NEXT_SGL);
>
> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> - write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>
> if (use_ecc) {
> - read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
> - read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
> - NAND_BAM_NEXT_SGL);
> + if (nandc->props->qpic_v2 && nandc->props->page_scope) {
> + if (qcom_nandc_is_last_cw(ecc, cw))
> + write_reg_dma(nandc, NAND_EXEC_CMD, 1,
> + NAND_BAM_NEXT_SGL);
> + } else {
> + write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> + read_reg_dma(nandc, NAND_FLASH_STATUS, 2, 0);
> + read_reg_dma(nandc, NAND_ERASED_CW_DETECT_STATUS, 1,
> + NAND_BAM_NEXT_SGL);
> + }
> } else {
> + write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> }
> }
> @@ -1959,6 +2004,8 @@ static int read_page_ecc(struct qcom_nand_host
> *host, u8 *data_buf,
> struct nand_ecc_ctrl *ecc = &chip->ecc;
> u8 *data_buf_start = data_buf, *oob_buf_start = oob_buf;
> int i, ret;
> + __le32 *status_buf_start = nandc->status_buf;
> + __le32 *status_buf_cw = nandc->status_buf;
>
> config_nand_page_read(chip);
>
> @@ -1994,6 +2041,12 @@ static int read_page_ecc(struct qcom_nand_host
> *host, u8 *data_buf,
> read_data_dma(nandc, FLASH_BUF_ACC, data_buf,
> data_size, 0);
>
> + if (nandc->props->qpic_v2 && nandc->props->page_scope) {
> + read_status_data_dma(nandc, FLASH_BUF_ACC, (void *)status_buf_cw,
> + (nandc->sts_buf_size >> 2), 0);
> + status_buf_cw += (nandc->sts_buf_size >> 4);
> + }
> +
> /*
> * when ecc is enabled, the controller doesn't read the real
> * or dummy bad block markers in each chunk. To maintain a
> @@ -2025,6 +2078,9 @@ static int read_page_ecc(struct qcom_nand_host
> *host, u8 *data_buf,
> return ret;
> }
>
> + if (nandc->props->qpic_v2 && nandc->props->page_scope)
> + memmove(nandc->reg_read_buf, status_buf_start, nandc->sts_buf_size);
> +
> return parse_read_errors(host, data_buf_start, oob_buf_start, page);
> }
>
> @@ -3005,6 +3061,14 @@ static int
> qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
> }
> }
>
> + if (nandc->props->qpic_v2 && nandc->props->page_scope) {
> + nandc->sts_buf_size = mtd->writesize == SZ_2K ? 48 : 96;
> + nandc->status_buf = devm_kzalloc(nandc->dev, nandc->sts_buf_size,
> + GFP_KERNEL);
> + if (!nandc->status_buf)
> + return -ENOMEM;
> + }
> +
> ret = mtd_device_parse_register(mtd, probes, NULL, NULL, 0);
> if (ret)
> nand_cleanup(chip);
> @@ -3197,6 +3261,7 @@ static const struct qcom_nandc_props
> sdx55_nandc_props = {
> .is_bam = true,
> .is_qpic = true,
> .qpic_v2 = true,
> + .page_scope = true,
> .dev_cmd_reg_start = 0x7000,
> };

Ping! Please provide me some updates on this patch.