Re: [PATCH] mtd: rawnand: qcom: update last code word register

From: Manivannan Sadhasivam
Date: Thu Dec 31 2020 - 05:54:23 EST

On Thu, Dec 17, 2020 at 07:32:56PM +0530, Md Sadre Alam wrote:
> From QPIC version 2.0 onwards new register got added to
> read last codeword. This change will update the same.
>
> For first three code word READ_LOCATION_n register will be
> use.For last code wrod READ_LOCATION_LAST_CW_n register will be
> use.
>
> Signed-off-by: Md Sadre Alam <mdalam@xxxxxxxxxxxxxx>
> ---
> drivers/mtd/nand/raw/qcom_nandc.c | 79 +++++++++++++++++++++++++++++++++------
> 1 file changed, 67 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index 667e4bf..eaef51d 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -48,6 +48,10 @@
> #define NAND_READ_LOCATION_1 0xf24
> #define NAND_READ_LOCATION_2 0xf28
> #define NAND_READ_LOCATION_3 0xf2c
> +#define NAND_READ_LOCATION_LAST_CW_0 0xf40
> +#define NAND_READ_LOCATION_LAST_CW_1 0xf44
> +#define NAND_READ_LOCATION_LAST_CW_2 0xf48
> +#define NAND_READ_LOCATION_LAST_CW_3 0xf4c

Please keep the alignment as before.

>
> /* dummy register offsets, used by write_reg_dma */
> #define NAND_DEV_CMD1_RESTORE 0xdead
> @@ -187,6 +191,12 @@ nandc_set_reg(nandc, NAND_READ_LOCATION_##reg, \
> ((size) << READ_LOCATION_SIZE) | \
> ((is_last) << READ_LOCATION_LAST))
>
> +#define nandc_set_read_loc_last(nandc, reg, offset, size, is_last) \
> +nandc_set_reg(nandc, NAND_READ_LOCATION_LAST_CW_##reg, \
> + ((offset) << READ_LOCATION_OFFSET) | \
> + ((size) << READ_LOCATION_SIZE) | \
> + ((is_last) << READ_LOCATION_LAST))
> +
> /*
> * Returns the actual register address for all NAND_DEV_ registers
> * (i.e. NAND_DEV_CMD0, NAND_DEV_CMD1, NAND_DEV_CMD2 and NAND_DEV_CMD_VLD)
> @@ -316,6 +326,10 @@ struct nandc_regs {
> __le32 read_location1;
> __le32 read_location2;
> __le32 read_location3;
> + __le32 read_location_last0;
> + __le32 read_location_last1;
> + __le32 read_location_last2;
> + __le32 read_location_last3;
>
> __le32 erased_cw_detect_cfg_clr;
> __le32 erased_cw_detect_cfg_set;
> @@ -644,6 +658,14 @@ static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset)
> return &regs->read_location2;
> case NAND_READ_LOCATION_3:
> return &regs->read_location3;
> + case NAND_READ_LOCATION_LAST_CW_0:
> + return &regs->read_location_last0;
> + case NAND_READ_LOCATION_LAST_CW_1:
> + return &regs->read_location_last1;
> + case NAND_READ_LOCATION_LAST_CW_2:
> + return &regs->read_location_last2;
> + case NAND_READ_LOCATION_LAST_CW_3:
> + return &regs->read_location_last3;
> default:
> return NULL;
> }
> @@ -719,9 +741,13 @@ static void update_rw_regs(struct qcom_nand_host *host, int num_cw, bool read)
> nandc_set_reg(nandc, NAND_READ_STATUS, host->clrreadstatus);
> nandc_set_reg(nandc, NAND_EXEC_CMD, 1);
>
> - if (read)
> + if (read) {
> + if (nandc->props->qpic_v2)
> + nandc_set_read_loc_last(nandc, 0, 0, host->use_ecc ?
> + host->cw_data : host->cw_size, 1);

Forgot to add else? Otherwise both NAND_READ_LOCATION_n and NAND_READ_LOCATION_LAST_CW_n
will be used.

> nandc_set_read_loc(nandc, 0, 0, host->use_ecc ?
> host->cw_data : host->cw_size, 1);
> + }
> }
>
> /*
> @@ -1096,9 +1122,13 @@ static void config_nand_page_read(struct qcom_nand_controller *nandc)
> static void
> config_nand_cw_read(struct qcom_nand_controller *nandc, bool use_ecc)
> {
> - if (nandc->props->is_bam)
> + if (nandc->props->is_bam) {
> + if (nandc->props->qpic_v2)
> + write_reg_dma(nandc, NAND_READ_LOCATION_LAST_CW_0,
> + 4, NAND_BAM_NEXT_SGL);
> write_reg_dma(nandc, NAND_READ_LOCATION_0, 4,
> NAND_BAM_NEXT_SGL);

Don't you need to modify the number of registers to write? It can't be 4 all the
time if NAND_READ_LOCATION_LAST_CW_0 is used.

> + }
>
> write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> @@ -1633,16 +1663,28 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
> }
>
> if (nandc->props->is_bam) {
> - nandc_set_read_loc(nandc, 0, read_loc, data_size1, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, read_loc, data_size1, 0);
> + else
> + nandc_set_read_loc(nandc, 0, read_loc, data_size1, 0);

IIUC nandc_set_read_loc_last() is only needed to read the last codeword which is
handled by the last command in this function:

nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);

> read_loc += data_size1;
>
> - nandc_set_read_loc(nandc, 1, read_loc, oob_size1, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 1, read_loc, oob_size1, 0);
> + else
> + nandc_set_read_loc(nandc, 1, read_loc, oob_size1, 0);
> read_loc += oob_size1;
>
> - nandc_set_read_loc(nandc, 2, read_loc, data_size2, 0);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 2, read_loc, data_size2, 0);
> + else
> + nandc_set_read_loc(nandc, 2, read_loc, data_size2, 0);
> read_loc += data_size2;
>
> - nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
> + if (nandc->props->qpic_v2 && cw == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 3, read_loc, oob_size2, 0);
> + else
> + nandc_set_read_loc(nandc, 3, read_loc, oob_size2, 1);
> }
>
> config_nand_cw_read(nandc, false);
> @@ -1873,14 +1915,27 @@ static int read_page_ecc(struct qcom_nand_host *host, u8 *data_buf,
>
> if (nandc->props->is_bam) {
> if (data_buf && oob_buf) {
> - nandc_set_read_loc(nandc, 0, 0, data_size, 0);
> - nandc_set_read_loc(nandc, 1, data_size,
> - oob_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1)) {
> + nandc_set_read_loc_last(nandc, 0, 0, data_size, 0);

Why do you need this? Can't you use nandc_set_read_loc()? Same for below cases.

Thanks,
Mani

> + nandc_set_read_loc_last(nandc, 1, data_size,
> + oob_size, 1);
> + } else {
> + nandc_set_read_loc(nandc, 0, 0, data_size, 0);
> + nandc_set_read_loc(nandc, 1, data_size,
> + oob_size, 1);
> + }
> } else if (data_buf) {
> - nandc_set_read_loc(nandc, 0, 0, data_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, 0, data_size, 1);
> + else
> + nandc_set_read_loc(nandc, 0, 0, data_size, 1);
> } else {
> - nandc_set_read_loc(nandc, 0, data_size,
> - oob_size, 1);
> + if (nandc->props->qpic_v2 && i == (ecc->steps - 1))
> + nandc_set_read_loc_last(nandc, 0, data_size,
> + oob_size, 1);
> + else
> + nandc_set_read_loc(nandc, 0, data_size,
> + oob_size, 1);
> }
> }
>
> --
> 2.7.4
>