Re: [PATCH 3/7] mtd: spi_nor: Rework quad_enable()

[Tudor.Ambarus]

On 08/01/2019 09:29 AM, Boris Brezillon wrote:
> External E-Mail
> 
> 
> On Wed, 31 Jul 2019 09:03:31 +0000
> <Tudor.Ambarus@xxxxxxxxxxxxx> wrote:
> 
>> From: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
>>
>> The goal is to move the quad_enable manufacturer specific init in the
>> nor->manufacturer->fixups->default_init()
>>
>> The legacy/core quad_enable() implementation is spansion_quad_enable(),
>> select this method by default.
>>
>> Set specific manufacturer fixups->default_init() hooks to overwrite
>> the default quad_enable() implementation when needed.
>>
>> Get rid of the spi_nor_flash_parameter int (*quad_enable)() pointer to
>> function, as we always choose to overwrite the nor->quad_enable,
>> if needed.
>>
>> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 103 +++++++++++++++++++++++-------------------
>>  1 file changed, 57 insertions(+), 46 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index 94aba5ce1462..a906c36260c8 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -101,8 +101,6 @@ struct spi_nor_flash_parameter {
>>  	struct spi_nor_hwcaps		hwcaps;
>>  	struct spi_nor_read_command	reads[SNOR_CMD_READ_MAX];
>>  	struct spi_nor_pp_command	page_programs[SNOR_CMD_PP_MAX];
>> -
>> -	int (*quad_enable)(struct spi_nor *nor);
>>  };
>>  
>>  struct sfdp_parameter_header {
>> @@ -2275,7 +2273,7 @@ static void gd25q256_default_init(struct spi_nor *nor,
>>  	 * indicate the quad_enable method for this case, we need
>>  	 * set it in the default_init fixup hook.
>>  	 */
>> -	params->quad_enable = macronix_quad_enable;
>> +	nor->quad_enable = macronix_quad_enable;
>>  }
>>  
>>  static struct spi_nor_fixups gd25q256_fixups = {
>> @@ -3618,24 +3616,24 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor,
>>  	/* Quad Enable Requirements. */
>>  	switch (bfpt.dwords[BFPT_DWORD(15)] & BFPT_DWORD15_QER_MASK) {
>>  	case BFPT_DWORD15_QER_NONE:
>> -		params->quad_enable = NULL;
>> +		nor->quad_enable = NULL;
>>  		break;
>>  
>>  	case BFPT_DWORD15_QER_SR2_BIT1_BUGGY:
>>  	case BFPT_DWORD15_QER_SR2_BIT1_NO_RD:
>> -		params->quad_enable = spansion_no_read_cr_quad_enable;
>> +		nor->quad_enable = spansion_no_read_cr_quad_enable;
>>  		break;
>>  
>>  	case BFPT_DWORD15_QER_SR1_BIT6:
>> -		params->quad_enable = macronix_quad_enable;
>> +		nor->quad_enable = macronix_quad_enable;
>>  		break;
>>  
>>  	case BFPT_DWORD15_QER_SR2_BIT7:
>> -		params->quad_enable = sr2_bit7_quad_enable;
>> +		nor->quad_enable = sr2_bit7_quad_enable;
>>  		break;
>>  
>>  	case BFPT_DWORD15_QER_SR2_BIT1:
>> -		params->quad_enable = spansion_read_cr_quad_enable;
>> +		nor->quad_enable = spansion_read_cr_quad_enable;
>>  		break;
>>  
>>  	default:
>> @@ -4286,10 +4284,41 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
>>  	return err;
>>  }
>>  
>> +static void macronix_set_default_init(struct spi_nor *nor)
>> +{
>> +	nor->quad_enable = macronix_quad_enable;
>> +}
>> +
>> +static void st_micron_set_default_init(struct spi_nor *nor)
>> +{
>> +	nor->quad_enable = NULL;
>> +}
>> +
>> +static void spi_nor_mfr_init_params(struct spi_nor *nor,
>> +				    struct spi_nor_flash_parameter *params)
> 
> So now we have spi_nor_mfr_init_params() and
> spi_nor_manufacturer_init_params(), that's a bit confusing. Can't we
> just inline the below code in the spi_nor_manufacturer_init_params()
> func? I guess this func will be removed anyway, so maybe it's not
> such a big deal.
> 

Will do. spi_nor_mfr_init_params() would have been removed anyway when moving
the manufacturer specific code out of the core. I chose separate function to
underline that these selects are done solely based on JEDEC_MFR, while the
default_init() sets data that can't be deduced from JEDEC_MFR. But might be
confusing, so will remove it.

> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
> 
>> +{
>> +	switch (JEDEC_MFR(nor->info)) {
>> +	case SNOR_MFR_MACRONIX:
>> +		macronix_set_default_init(nor);
>> +		break;
>> +
>> +	case SNOR_MFR_ST:
>> +	case SNOR_MFR_MICRON:
>> +		st_micron_set_default_init(nor);
>> +		break;
>> +
>> +	default:
>> +		break;
>> +	}
>> +}
>> +
>>  static void
>>  spi_nor_manufacturer_init_params(struct spi_nor *nor,
>>  				 struct spi_nor_flash_parameter *params)
>>  {
>> +	/* Init flash parameters based on MFR */
>> +	spi_nor_mfr_init_params(nor, params);
>> +
>>  	if (nor->info->fixups && nor->info->fixups->default_init)
>>  		return nor->info->fixups->default_init(nor, params);
>>  }
>> @@ -4369,25 +4398,6 @@ static int spi_nor_init_params(struct spi_nor *nor,
>>  			       SPINOR_OP_SE);
>>  	spi_nor_init_uniform_erase_map(map, erase_mask, params->size);
>>  
>> -	/* Select the procedure to set the Quad Enable bit. */
>> -	if (params->hwcaps.mask & (SNOR_HWCAPS_READ_QUAD |
>> -				   SNOR_HWCAPS_PP_QUAD)) {
>> -		switch (JEDEC_MFR(info)) {
>> -		case SNOR_MFR_MACRONIX:
>> -			params->quad_enable = macronix_quad_enable;
>> -			break;
>> -
>> -		case SNOR_MFR_ST:
>> -		case SNOR_MFR_MICRON:
>> -			break;
>> -
>> -		default:
>> -			/* Kept only for backward compatibility purpose. */
>> -			params->quad_enable = spansion_quad_enable;
>> -			break;
>> -		}
>> -	}
>> -
>>  	spi_nor_manufacturer_init_params(nor, params);
>>  
>>  	if ((info->flags & (SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)) &&
>> @@ -4569,7 +4579,6 @@ static int spi_nor_setup(struct spi_nor *nor,
>>  			 const struct spi_nor_hwcaps *hwcaps)
>>  {
>>  	u32 ignored_mask, shared_mask;
>> -	bool enable_quad_io;
>>  	int err;
>>  
>>  	/*
>> @@ -4617,21 +4626,23 @@ static int spi_nor_setup(struct spi_nor *nor,
>>  
>>  	/* Select the Sector Erase command. */
>>  	err = spi_nor_select_erase(nor, nor->info->sector_size);
>> -	if (err) {
>> +	if (err)
>>  		dev_err(nor->dev,
>>  			"can't select erase settings supported by both the SPI controller and memory.\n");
>> -		return err;
>> -	}
>>  
>> -	/* Enable Quad I/O if needed. */
>> -	enable_quad_io = (spi_nor_get_protocol_width(nor->read_proto) == 4 ||
>> -			  spi_nor_get_protocol_width(nor->write_proto) == 4);
>> -	if (enable_quad_io && params->quad_enable)
>> -		nor->quad_enable = params->quad_enable;
>> -	else
>> -		nor->quad_enable = NULL;
>> +	return err;
>> +}
>>  
>> -	return 0;
>> +static int spi_nor_quad_enable(struct spi_nor *nor)
>> +{
>> +	if (!nor->quad_enable)
>> +		return 0;
>> +
>> +	if (!(spi_nor_get_protocol_width(nor->read_proto) == 4 ||
>> +	      spi_nor_get_protocol_width(nor->write_proto) == 4))
>> +		return 0;
>> +
>> +	return nor->quad_enable(nor);
>>  }
>>  
>>  static int spi_nor_init(struct spi_nor *nor)
>> @@ -4650,12 +4661,10 @@ static int spi_nor_init(struct spi_nor *nor)
>>  		}
>>  	}
>>  
>> -	if (nor->quad_enable) {
>> -		err = nor->quad_enable(nor);
>> -		if (err) {
>> -			dev_err(nor->dev, "quad mode not supported\n");
>> -			return err;
>> -		}
>> +	err = spi_nor_quad_enable(nor);
>> +	if (err) {
>> +		dev_err(nor->dev, "quad mode not supported\n");
>> +		return err;
>>  	}
>>  
>>  	if (nor->addr_width == 4 && !(nor->flags & SNOR_F_4B_OPCODES)) {
>> @@ -4782,6 +4791,9 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>>  	    nor->info->flags & SPI_NOR_HAS_LOCK)
>>  		nor->clear_sr_bp = spi_nor_clear_sr_bp;
>>  
>> +	/* Kept only for backward compatibility purpose. */
>> +	nor->quad_enable = spansion_quad_enable;
>> +
>>  	/* Parse the Serial Flash Discoverable Parameters table. */
>>  	ret = spi_nor_init_params(nor, &params);
>>  	if (ret)
>> @@ -4858,7 +4870,6 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
>>  	 * - select op codes for (Fast) Read, Page Program and Sector Erase.
>>  	 * - set the number of dummy cycles (mode cycles + wait states).
>>  	 * - set the SPI protocols for register and memory accesses.
>> -	 * - set the Quad Enable bit if needed (required by SPI x-y-4 protos).
>>  	 */
>>  	ret = spi_nor_setup(nor, &params, hwcaps);
>>  	if (ret)
> 
> 
>