[U-Boot] [PATH v3 1/2] sf: Add status register reading support

[Jagan Teki]

Hi Simon,

On Fri, Jan 11, 2013 at 9:29 PM, Simon Glass <sjg at chromium.org> wrote:
> Hi Jagan,
>
> On Fri, Jan 11, 2013 at 7:51 AM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>> Hi Simon,
>>
>> On Fri, Jan 11, 2013 at 7:52 AM, Simon Glass <sjg at chromium.org> wrote:
>>> Hi Jagannadha
>>>
>>> On Thu, Jan 3, 2013 at 6:51 AM, Jagannadha Sutradharudu Teki
>>> <jagannadh.teki at gmail.com> wrote:
>>>> This patch provides support to read a flash status register.
>>>>
>>>> Status register contains a control bits used to verify
>>>> the progress of flash program and erase operations.
>>>>
>>>> User need to get the data through spi_flash_cmd_read_status()
>>>> based on their usage.
>>>
>>> Do you have a console command for this, and the control register also?
>>
>> There is no sf command for status register read.
>>
>> Usage is based on the user code, see how I am using this function on
>> Quad Enable bit setting.
>> http://patchwork.ozlabs.org/patch/207454/
>>
>> Please tell me if you still unclear.
>
> Yes, but do you think such a command might be useful? Or is it better
> to have commands for each individual feature? I am thinking of locking
> of part of the flash and anything else that the status register
> provides

I don't think so.

The status and config registers read and write functionalities are
used based on the usage level
in flash programming (flash reads/writes). so these special features
are valid in those cases.

User can use these features by calling a respective register function
calls with respective their need.

Thanks,
Jagan.

>
> Regards,
> Simon
>
>>
>> Thanks,
>> Jagan.
>>
>>>
>>> Regards,
>>> Simon
>>>
>>>>
>>>> Signed-off-by: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
>>>> ---
>>>> Changes in v3:
>>>>         improved coding style
>>>>
>>>>  drivers/mtd/spi/spi_flash.c          |    8 ++++++++
>>>>  drivers/mtd/spi/spi_flash_internal.h |    3 +++
>>>>  2 files changed, 11 insertions(+), 0 deletions(-)
>>>>
>>>> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
>>>> index 9e8939c..0f05b91 100644
>>>> --- a/drivers/mtd/spi/spi_flash.c
>>>> +++ b/drivers/mtd/spi/spi_flash.c
>>>> @@ -264,6 +264,14 @@ int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr)
>>>>         return 0;
>>>>  }
>>>>
>>>> +int spi_flash_cmd_read_status(struct spi_flash *flash, void *data)
>>>> +{
>>>> +       u8 cmd;
>>>> +
>>>> +       cmd = CMD_READ_STATUS;
>>>> +       return spi_flash_read_common(flash, &cmd, sizeof(cmd), (void *)data, 1);
>>>> +}
>>>> +
>>>>  /*
>>>>   * The following table holds all device probe functions
>>>>   *
>>>> diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
>>>> index 141cfa8..8232595 100644
>>>> --- a/drivers/mtd/spi/spi_flash_internal.h
>>>> +++ b/drivers/mtd/spi/spi_flash_internal.h
>>>> @@ -77,6 +77,9 @@ static inline int spi_flash_cmd_write_disable(struct spi_flash *flash)
>>>>  /* Program the status register. */
>>>>  int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr);
>>>>
>>>> +/* Read the status register */
>>>> +int spi_flash_cmd_read_status(struct spi_flash *flash, void *data);
>>>> +
>>>>  /*
>>>>   * Same as spi_flash_cmd_read() except it also claims/releases the SPI
>>>>   * bus. Used as common part of the ->read() operation.
>>>> --
>>>> 1.7.0.4
>>>>
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