Re: [PATCH v3 4/5] mtd: rawnand: qcom: Add support for read, write, erase exec_ops

Md Sadre Alam
2023-06-14T15:20:37Z

On 6/8/2023 7:33 PM, Miquel Raynal wrote:
> Hi Md,
>
> quic_mdalam@quicinc.com wrote on Wed, 31 May 2023 18:19:52 +0530:
>
>> This change will add exec_ops support for READ, WRITE, and ERASE
>> command.
>>
>> Co-developed-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Signed-off-by: Sricharan Ramabadhran <quic_srichara@quicinc.com>
>> Signed-off-by: Md Sadre Alam <quic_mdalam@quicinc.com>
>> ---
>> Change in [v3]
>>
>> * Removed chip->cont_read.ongoing flag.
>>
>> * Removed pre_command from erase_etype_exec_ops.
>>
>> Change in [v2]
>>
>> * Missed to post Cover-letter, so posting v2 patch with cover-letter.
>>
>> Change in [v1]
>>
>> * Added initial support for exec_ops.
>>
>> drivers/mtd/nand/raw/qcom_nandc.c | 97 +++++++++++++++++++++++++++++--
>> 1 file changed, 93 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
>> index b4823b72fe73..7dc769f9e797 100644
>> --- a/drivers/mtd/nand/raw/qcom_nandc.c
>> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
>> @@ -1546,8 +1546,7 @@ static void pre_command(struct qcom_nand_host *host, int command)
>>
>> clear_read_regs(nandc);
>>
>> - if (command == NAND_CMD_ERASE1)
>> - clear_bam_transaction(nandc);
>> + clear_bam_transaction(nandc);
>> }
>>
>> /*
>> @@ -1764,7 +1763,7 @@ qcom_nandc_read_cw_raw(struct mtd_info *mtd, struct nand_chip *chip,
>> int ret, reg_off = FLASH_BUF_ACC, read_loc = 0;
>> int raw_cw = cw;
>>
>> - nand_read_page_op(chip, page, 0, NULL, 0);
>> + nand_read_page_op(chip, page, 0, data_buf, mtd->writesize);
>> host->use_ecc = false;
>>
>> if (nandc->props->qpic_v2)
>> @@ -2181,14 +2180,23 @@ static void qcom_nandc_codeword_fixup(struct qcom_nand_host *host, int page)
>> static int qcom_nandc_read_page(struct nand_chip *chip, uint8_t *buf,
>> int oob_required, int page)
>> {
>> + struct mtd_info *mtd = nand_to_mtd(chip);
>> struct qcom_nand_host *host = to_qcom_nand_host(chip);
>> struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> + struct nand_ecc_ctrl *ecc = &chip->ecc;
>> u8 *data_buf, *oob_buf = NULL;
>>
>> if (host->nr_boot_partitions)
>> qcom_nandc_codeword_fixup(host, page);
>>
>> - nand_read_page_op(chip, page, 0, NULL, 0);
>> + nand_read_page_op(chip, page, 0, buf, mtd->writesize);
>> + nandc->buf_count = 0;
>> + nandc->buf_start = 0;
>> + host->use_ecc = true;
>> + clear_read_regs(nandc);
>> + set_address(host, 0, page);
>> + update_rw_regs(host, ecc->steps, true, 0);
>> +
>> data_buf = buf;
>> oob_buf = oob_required ? chip->oob_poi : NULL;
>>
>> @@ -2258,6 +2266,9 @@ static int qcom_nandc_write_page(struct nand_chip *chip, const uint8_t *buf,
>>
>> nand_prog_page_begin_op(chip, page, 0, NULL, 0);
>>
>> + set_address(host, 0, page);
>> + nandc->buf_count = 0;
>> + nandc->buf_start = 0;
>> clear_read_regs(nandc);
>> clear_bam_transaction(nandc);
>>
>> @@ -3274,6 +3285,67 @@ static int qcom_param_page_type_exec(struct nand_chip *chip, const struct nand_
>> return ret;
>> }
>>
>> +static int qcom_erase_cmd_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
>> +{
>> + struct qcom_nand_host *host = to_qcom_nand_host(chip);
>> + struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
>> + struct qcom_op q_op;
>> + int ret = 0;
>> +
>> + qcom_parse_instructions(chip, subop, &q_op);
>> +
>> + q_op.cmd_reg |= PAGE_ACC | LAST_PAGE;
>> +
>> + nandc->buf_count = 0;
>> + nandc->buf_start = 0;
>> + host->use_ecc = false;
>> + clear_read_regs(nandc);
>> + clear_bam_transaction(nandc);
>> +
>> + nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
>> + nandc_set_reg(chip, NAND_ADDR0, q_op.addr1_reg);
>> + nandc_set_reg(chip, NAND_ADDR1, q_op.addr2_reg);
>> + nandc_set_reg(chip, NAND_DEV0_CFG0,
>> + host->cfg0_raw & ~(7 << CW_PER_PAGE));
>> + nandc_set_reg(chip, NAND_DEV0_CFG1, host->cfg1_raw);
>> + nandc_set_reg(chip, NAND_EXEC_CMD, 1);
>> +
>> + write_reg_dma(nandc, NAND_FLASH_CMD, 3, NAND_BAM_NEXT_SGL);
>> + write_reg_dma(nandc, NAND_DEV0_CFG0, 2, NAND_BAM_NEXT_SGL);
>> + write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
>> +
>> + ret = submit_descs(nandc);
>> + if (ret) {
>> + dev_err(nandc->dev, "failure in sbumitting erase descriptor\n");
>
> :)

Its spelling mistake. Will fix this in next patch V4.

>
>> + free_descs(nandc);
>> + goto err_out;
>> + }
>> + free_descs(nandc);
>> +
>> + ret = qcom_wait_rdy_poll(chip, q_op.rdy_timeout_ms);
>> + if (ret)
>> + goto err_out;
>> +
>> +err_out:
>> + return ret;
>> +}
>> +
>> +static int qcom_data_read_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
>> +{
>> + /* currently read_exec_op() return 0 , and all the read operation handle in
>> + * actual API itself
>> + */
>> + return 0;
>
> Mmmh, I don't think this is gonna work. I don't understand what you're
> doing here. What is "actual API itself"? What is "read_exec_op"? I
> doubt I am going to like what all this means. Please don't make any
> assumptions on what could come next. The core asks you to do something,
> just do it. If you can't then the parsing will fail. If the core has a
> fallback it's fine. If the core does not, we can discuss it. But please
> don't do any guesses like that, this is *exactly* why we introduced
> exec_op in the first place: you have access to the whole operation, so
> please handle it correctly.

Thanks, When Initailly I was started exec_op() implementation I thought
that nand_read_page_op() will fail, so that I added the dummy
qcom_data_read_type_exec() and qcom_data_write_type_exec() APIs for read/write.
But as you said in above comment , we have to follow whatever core ask. So I
removed these APIs and tested read/write working fine. So now these
dummy APIs not at all needed.I think I misunderstood. I will keep
nand_read_page_op() API in original state nand_read_page_op(chip, page, 0, NULL, 0);
Also removed the pattern for read_page() and write_page() since its not at all
needed.

Will fix these all in patch V4.

>
>> +}
>> +
>> +static int qcom_data_write_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
>> +{
>> + /* currently write_exec_op() return 0, and all the write operation handle in
>> + * actual API itself
>> + */
>> + return 0;
>> +}
>> +
>> static const struct nand_op_parser qcom_op_parser = NAND_OP_PARSER(
>> NAND_OP_PARSER_PATTERN(
>> qcom_misc_cmd_type_exec,
>> @@ -3294,6 +3366,23 @@ static const struct nand_op_parser qcom_op_parser = NAND_OP_PARSER(
>> NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
>> NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
>> NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 512)),
>> + NAND_OP_PARSER_PATTERN(
>> + qcom_erase_cmd_type_exec,
>> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
>> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
>> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
>> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
>> + NAND_OP_PARSER_PATTERN(
>> + qcom_data_read_type_exec,
>> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
>> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, MAX_ADDRESS_CYCLE),
>> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
>> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
>> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
>> + NAND_OP_PARSER_PATTERN(
>> + qcom_data_write_type_exec,
>> + NAND_OP_PARSER_PAT_CMD_ELEM(true),
>> + NAND_OP_PARSER_PAT_ADDR_ELEM(true, MAX_ADDRESS_CYCLE)),
>> );
>>
>> static int qcom_check_op(struct nand_chip *chip,
>
>
> Thanks,
> Miquèl