Re: [PATCH v4 2/2] mtd: spi-nor: add a stateless method to support memory size above 128Mib

[Cyrille Pitchen]

Le 04/01/2017 Ã 14:33, Marek Vasut a Ãcrit :
> On 01/04/2017 01:20 PM, Cyrille Pitchen wrote:
>> This patch provides an alternative mean to support memory above 16MiB
>> (128Mib) by replacing 3byte address op codes by their associated 4byte
>> address versions.
>>
>> Using the dedicated 4byte address op codes doesn't change the internal
>> state of the SPI NOR memory as opposed to using other means such as
>> updating a Base Address Register (BAR) and sending command to enter/leave
>> the 4byte mode.
>>
>> Hence when a CPU reset occurs, early bootloaders don't need to be aware
>> of BAR value or 4byte mode being enabled: they can still access the first
>> 16MiB of the SPI NOR memory using the regular 3byte address op codes.
>>
>> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxx>
>> Tested-by: Vignesh R <vigneshr@xxxxxx>
> 
> Acked-by: Marek Vasut <marek.vasut@xxxxxxxxx>
> 

Thanks!

The series has been applied to git://github.com/spi-nor/linux.git

>> ---
>>  drivers/mtd/spi-nor/spi-nor.c | 101 +++++++++++++++++++++++++++++++++---------
>>  1 file changed, 80 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
>> index 9bb8f91fa42e..499a68d2bf8c 100644
>> --- a/drivers/mtd/spi-nor/spi-nor.c
>> +++ b/drivers/mtd/spi-nor/spi-nor.c
>> @@ -81,6 +81,10 @@ struct flash_info {
>>  					 * because it has the same value as
>>  					 * ATMEL flashes)
>>  					*/
>> +#define SPI_NOR_4B_OPCODES	BIT(11)	/*
>> +					 * Use dedicated 4byte address op codes
>> +					 * to support memory size above 128Mib.
>> +					 */
>>  };
>>  
>>  #define JEDEC_MFR(info)	((info)->id[0])
>> @@ -194,6 +198,78 @@ static inline struct spi_nor *mtd_to_spi_nor(struct mtd_info *mtd)
>>  	return mtd->priv;
>>  }
>>  
>> +
>> +static u8 spi_nor_convert_opcode(u8 opcode, const u8 table[][2], size_t size)
>> +{
>> +	size_t i;
>> +
>> +	for (i = 0; i < size; i++)
>> +		if (table[i][0] == opcode)
>> +			return table[i][1];
>> +
>> +	/* No conversion found, keep input op code. */
>> +	return opcode;
>> +}
>> +
>> +static inline u8 spi_nor_convert_3to4_read(u8 opcode)
>> +{
>> +	static const u8 spi_nor_3to4_read[][2] = {
>> +		{ SPINOR_OP_READ,	SPINOR_OP_READ_4B },
>> +		{ SPINOR_OP_READ_FAST,	SPINOR_OP_READ_FAST_4B },
>> +		{ SPINOR_OP_READ_1_1_2,	SPINOR_OP_READ_1_1_2_4B },
>> +		{ SPINOR_OP_READ_1_2_2,	SPINOR_OP_READ_1_2_2_4B },
>> +		{ SPINOR_OP_READ_1_1_4,	SPINOR_OP_READ_1_1_4_4B },
>> +		{ SPINOR_OP_READ_1_4_4,	SPINOR_OP_READ_1_4_4_4B },
>> +	};
>> +
>> +	return spi_nor_convert_opcode(opcode, spi_nor_3to4_read,
>> +				      ARRAY_SIZE(spi_nor_3to4_read));
>> +}
>> +
>> +static inline u8 spi_nor_convert_3to4_program(u8 opcode)
>> +{
>> +	static const u8 spi_nor_3to4_program[][2] = {
>> +		{ SPINOR_OP_PP,		SPINOR_OP_PP_4B },
>> +		{ SPINOR_OP_PP_1_1_4,	SPINOR_OP_PP_1_1_4_4B },
>> +		{ SPINOR_OP_PP_1_4_4,	SPINOR_OP_PP_1_4_4_4B },
>> +	};
>> +
>> +	return spi_nor_convert_opcode(opcode, spi_nor_3to4_program,
>> +				      ARRAY_SIZE(spi_nor_3to4_program));
>> +}
>> +
>> +static inline u8 spi_nor_convert_3to4_erase(u8 opcode)
>> +{
>> +	static const u8 spi_nor_3to4_erase[][2] = {
>> +		{ SPINOR_OP_BE_4K,	SPINOR_OP_BE_4K_4B },
>> +		{ SPINOR_OP_BE_32K,	SPINOR_OP_BE_32K_4B },
>> +		{ SPINOR_OP_SE,		SPINOR_OP_SE_4B },
>> +	};
>> +
>> +	return spi_nor_convert_opcode(opcode, spi_nor_3to4_erase,
>> +				      ARRAY_SIZE(spi_nor_3to4_erase));
>> +}
>> +
>> +static void spi_nor_set_4byte_opcodes(struct spi_nor *nor,
>> +				      const struct flash_info *info)
>> +{
>> +	/* Do some manufacturer fixups first */
>> +	switch (JEDEC_MFR(info)) {
>> +	case SNOR_MFR_SPANSION:
>> +		/* No small sector erase for 4-byte command set */
>> +		nor->erase_opcode = SPINOR_OP_SE;
>> +		nor->mtd.erasesize = info->sector_size;
>> +		break;
>> +
>> +	default:
>> +		break;
>> +	}
>> +
>> +	nor->read_opcode = spi_nor_convert_3to4_read(nor->read_opcode);
>> +	nor->program_opcode = spi_nor_convert_3to4_program(nor->program_opcode);
>> +	nor->erase_opcode = spi_nor_convert_3to4_erase(nor->erase_opcode);
>> +}
>> +
>>  /* Enable/disable 4-byte addressing mode. */
>>  static inline int set_4byte(struct spi_nor *nor, const struct flash_info *info,
>>  			    int enable)
>> @@ -1621,27 +1697,10 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, enum read_mode mode)
>>  	else if (mtd->size > 0x1000000) {
>>  		/* enable 4-byte addressing if the device exceeds 16MiB */
>>  		nor->addr_width = 4;
>> -		if (JEDEC_MFR(info) == SNOR_MFR_SPANSION) {
>> -			/* Dedicated 4-byte command set */
>> -			switch (nor->flash_read) {
>> -			case SPI_NOR_QUAD:
>> -				nor->read_opcode = SPINOR_OP_READ_1_1_4_4B;
>> -				break;
>> -			case SPI_NOR_DUAL:
>> -				nor->read_opcode = SPINOR_OP_READ_1_1_2_4B;
>> -				break;
>> -			case SPI_NOR_FAST:
>> -				nor->read_opcode = SPINOR_OP_READ_FAST_4B;
>> -				break;
>> -			case SPI_NOR_NORMAL:
>> -				nor->read_opcode = SPINOR_OP_READ_4B;
>> -				break;
>> -			}
>> -			nor->program_opcode = SPINOR_OP_PP_4B;
>> -			/* No small sector erase for 4-byte command set */
>> -			nor->erase_opcode = SPINOR_OP_SE_4B;
>> -			mtd->erasesize = info->sector_size;
>> -		} else
>> +		if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
>> +		    info->flags & SPI_NOR_4B_OPCODES)
>> +			spi_nor_set_4byte_opcodes(nor, info);
>> +		else
>>  			set_4byte(nor, info, 1);
>>  	} else {
>>  		nor->addr_width = 3;
>>
> 
>