[U-Boot] [RFC PATCH v2] sf: support chips using 4-byte addressing
Vignesh R
vigneshr at ti.com
Thu Oct 20 06:35:12 CEST 2016
On Wednesday 19 October 2016 05:20 PM, Siva Durga Prasad Paladugu wrote:
> Hi Chris,
>
>> -----Original Message-----
>> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Chris
>> Packham
>> Sent: Wednesday, October 19, 2016 2:06 PM
>> To: u-boot at lists.denx.de
>> Cc: Jagan Teki <jteki at openedev.com>; Chris Packham
>> <judge.packham at gmail.com>
>> Subject: [U-Boot] [RFC PATCH v2] sf: support chips using 4-byte addressing
>>
>> SPI chips with >16MB capacity use 4-byte addressing to allow accessing
>> beyond 16MB. When the size of the SPI flash exceeds 16MB switch to using 4
>> byte addressing.
>
> Not all spi controllers support 4-byte addressing and hence its better not to decide
> just using spi flash device size but consider capability of driver also into account.
Also not all SPI devices >16MB support 4 byte addressing, some flash
devices just using BAR register to support > 4byte addressing
Please look at the series posted by Cyrille Pitchen on linux-mtd to see
how kernel is planning to support 4 byte addressing opcodes:
http://lists-archives.com/linux-kernel/28675410-mtd-spi-nor-parse-sfdp-tables-to-setup-q-spi-memories.html
>
> Thanks,
> Siva
>
>>
>> Signed-off-by: Chris Packham <judge.packham at gmail.com>
>>
>> ---
>>
>> Changes in v2:
>> - automatically detect when 4 byte addressing is needed. This is similar
>> to how the linux kernel does the same detection
>>
>> drivers/mtd/spi/sf_internal.h | 4 ++--
>> drivers/mtd/spi/spi_flash.c | 32 ++++++++++++++++++++++----------
>> include/spi_flash.h | 2 ++
>> 3 files changed, 26 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
>> index cde4cfbf2e32..db4532849145 100644
>> --- a/drivers/mtd/spi/sf_internal.h
>> +++ b/drivers/mtd/spi/sf_internal.h
>> @@ -25,8 +25,8 @@ enum spi_nor_option_flags {
>> SNOR_F_USE_FSR = BIT(1),
>> };
>>
>> -#define SPI_FLASH_3B_ADDR_LEN 3
>> -#define SPI_FLASH_CMD_LEN (1 + SPI_FLASH_3B_ADDR_LEN)
>> +#define SPI_FLASE_MAX_ADDR_WIDTH 4
>> +#define SPI_FLASH_CMD_LEN (1 + SPI_FLASE_MAX_ADDR_WIDTH)
>> #define SPI_FLASH_16MB_BOUN 0x1000000
>>
>> /* CFI Manufacture ID's */
>> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c index
>> 7f6e9ae23ea8..a3efaa129231 100644
>> --- a/drivers/mtd/spi/spi_flash.c
>> +++ b/drivers/mtd/spi/spi_flash.c
>> @@ -22,12 +22,19 @@
>>
>> DECLARE_GLOBAL_DATA_PTR;
>>
>> -static void spi_flash_addr(u32 addr, u8 *cmd)
>> +static void spi_flash_addr(u32 addr, u8 *cmd, u8 addr_width)
>> {
>> /* cmd[0] is actual command */
>> - cmd[1] = addr >> 16;
>> - cmd[2] = addr >> 8;
>> - cmd[3] = addr >> 0;
>> + if (addr_width == 4) {
>> + cmd[1] = addr >> 24;
>> + cmd[2] = addr >> 16;
>> + cmd[3] = addr >> 8;
>> + cmd[4] = addr;
>> + } else {
>> + cmd[1] = addr >> 16;
>> + cmd[2] = addr >> 8;
>> + cmd[3] = addr >> 0;
>> + }
>> }
>>
>> static int read_sr(struct spi_flash *flash, u8 *rs) @@ -357,12 +364,13 @@
>> int spi_flash_cmd_erase_ops(struct spi_flash *flash, u32 offset, size_t len)
>> if (ret < 0)
>> return ret;
>> #endif
>> - spi_flash_addr(erase_addr, cmd);
>> + spi_flash_addr(erase_addr, cmd, flash->addr_width);
>>
>> debug("SF: erase %2x %2x %2x %2x (%x)\n", cmd[0], cmd[1],
>> cmd[2], cmd[3], erase_addr);
>>
>> - ret = spi_flash_write_common(flash, cmd, sizeof(cmd), NULL,
>> 0);
>> + ret = spi_flash_write_common(flash, cmd, flash->addr_width
>> + 1,
>> + NULL, 0);
>> if (ret < 0) {
>> debug("SF: erase failed\n");
>> break;
>> @@ -415,12 +423,12 @@ int spi_flash_cmd_write_ops(struct spi_flash
>> *flash, u32 offset,
>> chunk_len = min(chunk_len,
>> (size_t)spi->max_write_size);
>>
>> - spi_flash_addr(write_addr, cmd);
>> + spi_flash_addr(write_addr, cmd, flash->addr_width);
>>
>> debug("SF: 0x%p => cmd = { 0x%02x 0x%02x%02x%02x }
>> chunk_len = %zu\n",
>> buf + actual, cmd[0], cmd[1], cmd[2], cmd[3], chunk_len);
>>
>> - ret = spi_flash_write_common(flash, cmd, sizeof(cmd),
>> + ret = spi_flash_write_common(flash, cmd, flash->addr_width
>> + 1,
>> buf + actual, chunk_len);
>> if (ret < 0) {
>> debug("SF: write failed\n");
>> @@ -492,7 +500,7 @@ int spi_flash_cmd_read_ops(struct spi_flash *flash,
>> u32 offset,
>> return 0;
>> }
>>
>> - cmdsz = SPI_FLASH_CMD_LEN + flash->dummy_byte;
>> + cmdsz = flash->addr_width + 1 + flash->dummy_byte;
>> cmd = calloc(1, cmdsz);
>> if (!cmd) {
>> debug("SF: Failed to allocate cmd\n"); @@ -520,7 +528,7 @@
>> int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
>> else
>> read_len = remain_len;
>>
>> - spi_flash_addr(read_addr, cmd);
>> + spi_flash_addr(read_addr, cmd, flash->addr_width);
>>
>> ret = spi_flash_read_common(flash, cmd, cmdsz, data,
>> read_len);
>> if (ret < 0) {
>> @@ -1154,6 +1162,10 @@ int spi_flash_scan(struct spi_flash *flash)
>> if (flash->dual_flash & SF_DUAL_STACKED_FLASH)
>> flash->size <<= 1;
>> #endif
>> + if (flash->size > SPI_FLASH_16MB_BOUN)
>> + flash->addr_width = 4;
>> + else
>> + flash->addr_width = 3;
>>
>> #ifdef CONFIG_SPI_FLASH_USE_4K_SECTORS
>> /* Compute erase sector and command */ diff --git
>> a/include/spi_flash.h b/include/spi_flash.h index
>> be2fe3f84cb9..c65bf22aee8b 100644
>> --- a/include/spi_flash.h
>> +++ b/include/spi_flash.h
>> @@ -39,6 +39,7 @@ struct spi_slave;
>> * @flags: Indication of spi flash flags
>> * @size: Total flash size
>> * @page_size: Write (page) size
>> + * @addr_width: number of address bytes
>> * @sector_size: Sector size
>> * @erase_size: Erase size
>> * @bank_read_cmd: Bank read cmd
>> @@ -72,6 +73,7 @@ struct spi_flash {
>>
>> u32 size;
>> u32 page_size;
>> + u8 addr_width;
>> u32 sector_size;
>> u32 erase_size;
>> #ifdef CONFIG_SPI_FLASH_BAR
>> --
>> 2.10.0.479.g7c56b16
>>
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--
Regards
Vignesh
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