Re: [PATCH v2 2/5] mtd: rawnand: qcom: Add support for reset, readid, status exec_op

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Md,

quic_mdalam@quicinc.com wrote on Thu, 11 May 2023 19:00:14 +0530:

> This change will add exec_ops support for RESET , READ_ID, STATUS
> 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 [v2]
> 
> * Missed to post Cover-letter, so posting v2 patch with cover-letter
> 
>  drivers/mtd/nand/raw/qcom_nandc.c | 166 +++++++++++++++++++++++++++++-
>  1 file changed, 163 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
> index dae460e2aa0b..d2f2a8971907 100644
> --- a/drivers/mtd/nand/raw/qcom_nandc.c
> +++ b/drivers/mtd/nand/raw/qcom_nandc.c
> @@ -384,6 +384,9 @@ struct nandc_regs {
>   * @reg_read_pos:		marker for data read in reg_read_buf
>   *
>   * @cmd1/vld:			some fixed controller register values
> + *
> + * @exec_opwrite:		flag to select correct number of code word
> + *				while reading status
>   */
>  struct qcom_nand_controller {
>  	struct device *dev;
> @@ -434,6 +437,7 @@ struct qcom_nand_controller {
>  	int reg_read_pos;
>  
>  	u32 cmd1, vld;
> +	bool exec_opwrite;
>  };
>  
>  /*
> @@ -2920,6 +2924,8 @@ static int qcom_op_cmd_mapping(struct qcom_nand_controller *nandc, u8 cmd,
>  		break;
>  	case NAND_CMD_PAGEPROG:
>  		ret = OP_PROGRAM_PAGE;
> +		q_op->flag = NAND_CMD_PAGEPROG;

Just use the instruction value?

> +		nandc->exec_opwrite = true;
>  		break;
>  	default:
>  		break;
> @@ -2982,10 +2988,95 @@ static void qcom_parse_instructions(struct nand_chip *chip,
>  	}
>  }
>  
> +static void qcom_delay_ns(unsigned int ns)
> +{
> +	if (!ns)
> +		return;
> +
> +	if (ns < 10000)
> +		ndelay(ns);
> +	else
> +		udelay(DIV_ROUND_UP(ns, 1000));
> +}
> +
> +static int qcom_wait_rdy_poll(struct nand_chip *chip, unsigned int time_ms)
> +{
> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +	unsigned long start = jiffies + msecs_to_jiffies(time_ms);
> +	u32 flash;
> +
> +	nandc_read_buffer_sync(nandc, true);
> +
> +	do {
> +		flash = le32_to_cpu(nandc->reg_read_buf[0]);
> +		if (flash & FS_READY_BSY_N)
> +			return 0;
> +		cpu_relax();
> +	} while (time_after(start, jiffies));
> +
> +	dev_err(nandc->dev, "Timeout waiting for device to be ready:0x%08x\n", flash);
> +
> +	return -ETIMEDOUT;
> +}
> +
>  static int qcom_read_status_exec(struct nand_chip *chip,
>  				 const struct nand_subop *subop)
>  {
> -	return 0;
> +	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;
> +	struct qcom_op q_op;
> +	const struct nand_op_instr *instr = NULL;
> +	unsigned int op_id = 0;
> +	unsigned int len = 0;
> +	int ret = 0, num_cw = 1, i;
> +	u32 flash_status;
> +
> +	host->status = NAND_STATUS_READY | NAND_STATUS_WP;
> +
> +	qcom_parse_instructions(chip, subop, &q_op);
> +
> +	if (nandc->exec_opwrite) {

I definitely don't understand this flag at all.

> +		num_cw = ecc->steps;
> +		nandc->exec_opwrite = false;
> +	}
> +
> +	pre_command(host, NAND_CMD_STATUS);
> +
> +	nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
> +	nandc_set_reg(chip, NAND_EXEC_CMD, 1);
> +
> +	write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> +	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +
> +	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +
> +	ret = submit_descs(nandc);
> +	if (ret)
> +		dev_err(nandc->dev, "failure in sbumitting status descriptor\n");
> +
> +	free_descs(nandc);
> +
> +	nandc_read_buffer_sync(nandc, true);
> +	for (i = 0; i < num_cw; i++) {
> +		flash_status = le32_to_cpu(nandc->reg_read_buf[i]);
> +
> +	if (flash_status & FS_MPU_ERR)
> +		host->status &= ~NAND_STATUS_WP;
> +
> +	if (flash_status & FS_OP_ERR || (i == (num_cw - 1) &&
> +					 (flash_status & FS_DEVICE_STS_ERR)))
> +		host->status |= NAND_STATUS_FAIL;

If there is a failure detected, error out (everywhere).

> +	}
> +
> +	flash_status = host->status;
> +
> +	instr = q_op.data_instr;
> +	op_id = q_op.data_instr_idx;
> +	len = nand_subop_get_data_len(subop, op_id);
> +	memcpy(instr->ctx.data.buf.in, &flash_status, len);
> +
> +	return ret;
>  }
>  
>  static int qcom_erase_cmd_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
> @@ -3000,12 +3091,81 @@ static int qcom_param_page_type_exec(struct nand_chip *chip,  const struct nand_
>  
>  static int qcom_read_id_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
>  {
> -	return 0;
> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +	struct qcom_nand_host *host = to_qcom_nand_host(chip);
> +	struct qcom_op q_op;
> +	const struct nand_op_instr *instr = NULL;
> +	unsigned int op_id = 0;
> +	unsigned int len = 0;
> +	int ret = 0;
> +
> +	qcom_parse_instructions(chip, subop, &q_op);
> +
> +	pre_command(host, NAND_CMD_READID);
> +
> +	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_FLASH_CHIP_SELECT,
> +		      nandc->props->is_bam ? 0 : DM_EN);
> +
> +	nandc_set_reg(chip, NAND_EXEC_CMD, 1);
> +
> +	write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL);
> +	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +
> +	read_reg_dma(nandc, NAND_READ_ID, 1, NAND_BAM_NEXT_SGL);
> +
> +	ret = submit_descs(nandc);
> +	if (ret)
> +		dev_err(nandc->dev, "failure in sbumitting read id descriptor\n");
> +
> +	free_descs(nandc);
> +
> +	instr = q_op.data_instr;
> +	op_id = q_op.data_instr_idx;
> +	len = nand_subop_get_data_len(subop, op_id);
> +
> +	nandc_read_buffer_sync(nandc, true);
> +	memcpy(instr->ctx.data.buf.in, nandc->reg_read_buf, len);
> +
> +	return ret;
>  }
>  
>  static int qcom_misc_cmd_type_exec(struct nand_chip *chip, const struct nand_subop *subop)
>  {
> -	return 0;
> +	struct qcom_nand_controller *nandc = get_qcom_nand_controller(chip);
> +	struct qcom_nand_host *host = to_qcom_nand_host(chip);
> +	struct qcom_op q_op;
> +	int ret = 0;
> +
> +	qcom_parse_instructions(chip, subop, &q_op);
> +
> +	if (q_op.flag == NAND_CMD_PAGEPROG)
> +		goto wait_rdy;
> +
> +	pre_command(host, NAND_CMD_RESET);

???

> +
> +	nandc_set_reg(chip, NAND_FLASH_CMD, q_op.cmd_reg);
> +	nandc_set_reg(chip, NAND_EXEC_CMD, 1);
> +
> +	write_reg_dma(nandc, NAND_FLASH_CMD, 1, NAND_BAM_NEXT_SGL);
> +	write_reg_dma(nandc, NAND_EXEC_CMD, 1, NAND_BAM_NEXT_SGL);
> +
> +	read_reg_dma(nandc, NAND_FLASH_STATUS, 1, NAND_BAM_NEXT_SGL);
> +
> +	ret = submit_descs(nandc);
> +	if (ret)
> +		dev_err(nandc->dev, "failure in sbumitting misc descriptor\n");

Typo                                             ^

Same above.

You should error out immediately when something wrong happens.

> +
> +	free_descs(nandc);
> +
> +wait_rdy:
> +	qcom_delay_ns(q_op.rdy_delay_ns);
> +
> +	ret = qcom_wait_rdy_poll(chip, q_op.rdy_timeout_ms);
> +
> +	return ret;
>  }
>  
>  static int qcom_data_read_type_exec(struct nand_chip *chip, const struct nand_subop *subop)


Thanks,
Miquèl