[U-Boot] [PATCH v6 08/12] sf: Discover read dummy_cycles

[Sourav Poddar <sourav.poddar@ti.com>]

On Monday 06 January 2014 03:48 PM, Jagan Teki wrote:
> Hi Sourav,
>
> On Mon, Jan 6, 2014 at 12:34 PM, Sourav Poddar<sourav.poddar@ti.com>  wrote:
>> On Saturday 04 January 2014 08:34 PM, Jagannadha Sutradharudu Teki wrote:
>>> Discovered the read dummy_cycles based on the configured
>>> read command.
>>>
>>> Signed-off-by: Jagannadha Sutradharudu Teki<jaganna@xilinx.com>
>>> ---
>>>    drivers/mtd/spi/sf_internal.h |  2 ++
>>>    drivers/mtd/spi/sf_ops.c      | 10 ++++++----
>>>    drivers/mtd/spi/sf_probe.c    | 12 ++++++++++++
>>>    include/spi_flash.h           |  2 ++
>>>    4 files changed, 22 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
>>> index 7be0292..a9f5a81 100644
>>> --- a/drivers/mtd/spi/sf_internal.h
>>> +++ b/drivers/mtd/spi/sf_internal.h
>>> @@ -10,6 +10,8 @@
>>>    #ifndef _SF_INTERNAL_H_
>>>    #define _SF_INTERNAL_H_
>>>
>>> +#define SPI_FLASH_3B_ADDR_LEN          3
>>> +#define SPI_FLASH_CMD_LEN              (1 + SPI_FLASH_3B_ADDR_LEN)
>>>    #define SPI_FLASH_16MB_BOUN           0x1000000
>>>
>>>    /* CFI Manufacture ID's */
>>> diff --git a/drivers/mtd/spi/sf_ops.c b/drivers/mtd/spi/sf_ops.c
>>> index 827f719..dda75b1 100644
>>> --- a/drivers/mtd/spi/sf_ops.c
>>> +++ b/drivers/mtd/spi/sf_ops.c
>>> @@ -9,6 +9,7 @@
>>>     */
>>>
>>>    #include<common.h>
>>> +#include<malloc.h>
>>>    #include<spi.h>
>>>    #include<spi_flash.h>
>>>    #include<watchdog.h>
>>> @@ -216,7 +217,7 @@ int spi_flash_write_common(struct spi_flash *flash,
>>> const u8 *cmd,
>>>    int spi_flash_cmd_erase_ops(struct spi_flash *flash, u32 offset, size_t
>>> len)
>>>    {
>>>          u32 erase_size;
>>> -       u8 cmd[4];
>>> +       u8 cmd[SPI_FLASH_CMD_LEN];
>>>          int ret = -1;
>>>
>>>          erase_size = flash->erase_size;
>>> @@ -255,7 +256,7 @@ int spi_flash_cmd_write_ops(struct spi_flash *flash,
>>> u32 offset,
>>>    {
>>>          unsigned long byte_addr, page_size;
>>>          size_t chunk_len, actual;
>>> -       u8 cmd[4];
>>> +       u8 cmd[SPI_FLASH_CMD_LEN];
>>>          int ret = -1;
>>>
>>>          page_size = flash->page_size;
>>> @@ -317,7 +318,7 @@ int spi_flash_read_common(struct spi_flash *flash,
>>> const u8 *cmd,
>>>    int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
>>>                  size_t len, void *data)
>>>    {
>>> -       u8 cmd[5], bank_sel = 0;
>>> +       u8 *cmd, bank_sel = 0;
>>>          u32 remain_len, read_len;
>>>          int ret = -1;
>>>
>>> @@ -335,8 +336,9 @@ int spi_flash_cmd_read_ops(struct spi_flash *flash,
>>> u32 offset,
>>>                  return 0;
>>>          }
>>>
>>> +       cmd = malloc(SPI_FLASH_CMD_LEN + flash->dummy_cycles);
>>> +       memset(cmd, 0, SPI_FLASH_CMD_LEN + flash->dummy_cycles);
>>>          cmd[0] = flash->read_cmd;
>>> -       cmd[4] = 0x00;
>>>
>>>          while (len) {
>>>    #ifdef CONFIG_SPI_FLASH_BAR
>>> diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
>>> index a049e72..b070adc 100644
>>> --- a/drivers/mtd/spi/sf_probe.c
>>> +++ b/drivers/mtd/spi/sf_probe.c
>>> @@ -140,6 +140,18 @@ static struct spi_flash
>>> *spi_flash_validate_params(struct spi_slave *spi,
>>>                  }
>>>          }
>>>
>>> +       /* Read dummy cycles */
>>> +       switch (flash->read_cmd) {
>>> +       case CMD_READ_QUAD_IO_FAST:
>>> +               flash->dummy_cycles = 2;
>>> +               break;
>>> +       case CMD_READ_ARRAY_SLOW:
>>> +               flash->dummy_cycles = 0;
>>> +               break;
>>> +       default:
>>> +               flash->dummy_cycles = 1;
>>> +       }
>>> +
>> what about dummy cycles for dual i/o(0xbb), it has 4 clock bit dummy
>> cycles(macronix), so
>> by your code you keep it to 1(8 bit) dummy cycle. ?
> Yes- Actually i miss used the names here.
> These are dummy_byte_count
>
> Ex: Except fast reads (array, dual and quad fast)
> dummy_byte_count = dummy_cycles * no.of lines
> dual i/o (4 dummy_cycles) - 4 * 2 = 1 dummy_byte
> quad i/o (4 dummy_cycles) - 4 * 4 = 2 dummy_byte
>
is this calculation documented in any of the flash sheet?
> fast, dual and quad fast have 8 dummy_cycles means 1 byte dummy the
> reason why I am not including
> no.of lines here is irrespective of fast(1 line), dual(2 lines) and
> quad(4 lines) only data can travel among the difference lines
> but the cmd,inst, dummy can travel only on single line. this can be
> opposite in i/o commands.
>
> Hope you understand - I just said based on my knowledge.
> I will change the dummy_cycles into dummy_bytes - nevertheless everything same.
>