Re: [PATCH v4 13/20] mtd: nand: qcom: support for different DEV_CMD register offsets

[Archit Taneja <architt@codeaurora.org>]

On 08/11/2017 05:09 PM, Abhishek Sahu wrote:
> The FLASH_DEV_CMD registers starting offset is not same in
> different QPIC NAND controller versions. This patch adds
> the starting offset in NAND controller properties and uses
> the same for calculating the actual offset of these registers.
> 
> Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
> ---
>   drivers/mtd/nand/qcom_nandc.c | 22 ++++++++++++++++------
>   1 file changed, 16 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
> index 85fbe00..c0c140b 100644
> --- a/drivers/mtd/nand/qcom_nandc.c
> +++ b/drivers/mtd/nand/qcom_nandc.c
> @@ -193,6 +193,9 @@
>   	      ((size) << READ_LOCATION_SIZE) |			\
>   	      ((is_last) << READ_LOCATION_LAST))
>   
> +/* Returns the actual register address for NAND_FLASH_DEV_* */

There aren't any registers starting with NAND_FLASH_DEV_* in the registers
defined above, it might get confusing for someone who doesn't have access
to the HW docs. Could you explicitly mention in this comment all the register
names that are required to go through this translation, it should make things
more readable. With that:

Reviewed-by: Archit Taneja <architt@codeaurora.org>

Thanks,
Archit


> +#define nandc_dev_addr(nandc, reg) ((nandc)->props->flash_dev_offset + (reg))
> +
>   #define QPIC_PER_CW_CMD_SGL		32
>   #define QPIC_PER_CW_DATA_SGL		8
>   
> @@ -426,10 +429,12 @@ struct qcom_nand_host {
>    * among different NAND controllers.
>    * @ecc_modes - ecc mode for NAND
>    * @is_bam - whether NAND controller is using BAM
> + * @flash_dev_offset - NAND_FLASH_DEV_* registers start offset
>    */
>   struct qcom_nandc_props {
>   	u32 ecc_modes;
>   	bool is_bam;
> +	u32 flash_dev_offset;
>   };
>   
>   /* Frees the BAM transaction memory */
> @@ -844,6 +849,9 @@ static int read_reg_dma(struct qcom_nand_controller *nandc, int first,
>   	if (first == NAND_READ_ID || first == NAND_FLASH_STATUS)
>   		flow_control = true;
>   
> +	if (first == NAND_DEV_CMD_VLD || first == NAND_DEV_CMD1)
> +		first = nandc_dev_addr(nandc, first);
> +
>   	size = num_regs * sizeof(u32);
>   	vaddr = nandc->reg_read_buf + nandc->reg_read_pos;
>   	nandc->reg_read_pos += num_regs;
> @@ -881,11 +889,11 @@ static int write_reg_dma(struct qcom_nand_controller *nandc, int first,
>   	if (first == NAND_EXEC_CMD)
>   		flags |= NAND_BAM_NWD;
>   
> -	if (first == NAND_DEV_CMD1_RESTORE)
> -		first = NAND_DEV_CMD1;
> +	if (first == NAND_DEV_CMD1_RESTORE || first == NAND_DEV_CMD1)
> +		first = nandc_dev_addr(nandc, NAND_DEV_CMD1);
>   
> -	if (first == NAND_DEV_CMD_VLD_RESTORE)
> -		first = NAND_DEV_CMD_VLD;
> +	if (first == NAND_DEV_CMD_VLD_RESTORE || first == NAND_DEV_CMD_VLD)
> +		first = nandc_dev_addr(nandc, NAND_DEV_CMD_VLD);
>   
>   	size = num_regs * sizeof(u32);
>   
> @@ -2492,7 +2500,8 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
>   
>   	/* kill onenand */
>   	nandc_write(nandc, SFLASHC_BURST_CFG, 0);
> -	nandc_write(nandc, NAND_DEV_CMD_VLD, NAND_DEV_CMD_VLD_VAL);
> +	nandc_write(nandc, nandc_dev_addr(nandc, NAND_DEV_CMD_VLD),
> +		    NAND_DEV_CMD_VLD_VAL);
>   
>   	/* enable ADM or BAM DMA */
>   	if (nandc->props->is_bam) {
> @@ -2503,7 +2512,7 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
>   	}
>   
>   	/* save the original values of these registers */
> -	nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1);
> +	nandc->cmd1 = nandc_read(nandc, nandc_dev_addr(nandc, NAND_DEV_CMD1));
>   	nandc->vld = NAND_DEV_CMD_VLD_VAL;
>   
>   	return 0;
> @@ -2752,6 +2761,7 @@ static int qcom_nandc_remove(struct platform_device *pdev)
>   static const struct qcom_nandc_props ipq806x_nandc_props = {
>   	.ecc_modes = (ECC_RS_4BIT | ECC_BCH_8BIT),
>   	.is_bam = false,
> +	.flash_dev_offset = 0x0,
>   };
>   
>   /*
> 

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