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

[Sourav Poddar]

On Monday 06 January 2014 04:00 PM, Jagan Teki wrote:
> On Mon, Jan 6, 2014 at 3:51 PM, Sourav Poddar<sourav.poddar at ti.com>  wrote:
>> 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 at 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 at 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?
> I haven't see the exact calculation but ie. how the I/O operation usually works.
> quad read - cmd, 3byte_inst, 1 dummy_byte(8 dummy_cycles) goes on
> single line and data goes in 4 lines
> quad i/o - except cmd(1 lines) remaining goes in 4 lines.
>
Ok, got the point.
>>> 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.
>>>