[U-Boot] [PATCH v3 05/16] spi: Add support for dual and quad mode

[Mugunthan V N <mugunthanvnm@ti.com>]

On Sunday 06 December 2015 08:13 PM, Jagan Teki wrote:
> On 6 December 2015 at 11:33, Mugunthan V N <mugunthanvnm@ti.com> wrote:
>> On Thursday 03 December 2015 09:37 PM, Jagan Teki wrote:
>>> On 19 November 2015 at 12:35, Mugunthan V N <mugunthanvnm@ti.com> wrote:
>>>> spi bus can support dual and quad wire data transfers for tx and
>>>> rx. So defining dual and quad modes for both tx and rx. Also add
>>>> support to parse bus width used for spi tx and rx transfers.
>>>>
>>>> Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
>>>> Reviewed-by: Simon Glass <sjg@chromium.org>
>>>> Reviewed-by: Tom Rini <trini@konsulko.com>
>>>> ---
>>>>  drivers/spi/spi-uclass.c | 33 +++++++++++++++++++++++++++++++++
>>>>  include/spi.h            |  4 ++++
>>>>  2 files changed, 37 insertions(+)
>>>>
>>>> diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c
>>>> index 58388ef..62d8da7 100644
>>>> --- a/drivers/spi/spi-uclass.c
>>>> +++ b/drivers/spi/spi-uclass.c
>>>> @@ -349,6 +349,7 @@ int spi_slave_ofdata_to_platdata(const void *blob, int node,
>>>>                                  struct dm_spi_slave_platdata *plat)
>>>>  {
>>>>         int mode = 0;
>>>> +       int value;
>>>>
>>>>         plat->cs = fdtdec_get_int(blob, node, "reg", -1);
>>>>         plat->max_hz = fdtdec_get_int(blob, node, "spi-max-frequency", 0);
>>>> @@ -360,6 +361,38 @@ int spi_slave_ofdata_to_platdata(const void *blob, int node,
>>>>                 mode |= SPI_CS_HIGH;
>>>>         if (fdtdec_get_bool(blob, node, "spi-half-duplex"))
>>>>                 mode |= SPI_PREAMBLE;
>>>> +
>>>> +       /* Device DUAL/QUAD mode */
>>>> +       value = fdtdec_get_uint(blob, node, "spi-tx-bus-width", 1);
>>>> +       switch (value) {
>>>> +       case 1:
>>>> +               break;
>>>> +       case 2:
>>>> +               mode |= SPI_TX_DUAL;
>>>> +               break;
>>>> +       case 4:
>>>> +               mode |= SPI_TX_QUAD;
>>>> +               break;
>>>> +       default:
>>>> +               error("spi-tx-bus-width %d not supported\n", value);
>>>> +               break;
>>>> +       }
>>>> +
>>>> +       value = fdtdec_get_uint(blob, node, "spi-rx-bus-width", 1);
>>>> +       switch (value) {
>>>> +       case 1:
>>>> +               break;
>>>> +       case 2:
>>>> +               mode |= SPI_RX_DUAL;
>>>> +               break;
>>>> +       case 4:
>>>> +               mode |= SPI_RX_QUAD;
>>>> +               break;
>>>> +       default:
>>>> +               error("spi-rx-bus-width %d not supported\n", value);
>>>> +               break;
>>>> +       }
>>>> +
>>>
>>> I think these are similar to SPI TX/RX operation modes in spi.h and I
>>> understand this is similar approach as with Linux but before this we
>>> need to do many changes on u-boot as well.
>>
>> I agree that op_mode_rx/op_mode_tx can be used. I just tried to follow
>> Linux way of implementation to have consistency between Linux and
> 
> Agreed but the way these mode or flags handling in Linux vs u-boot is different.
> 
>> U-Boot. If you feel that using op_mode_(rx/tx) will be the best
>> approach, I can repost the series with the changes.
> 
> If this is a dependent patch wrt series pls- do otherwise bypass this
> with your series now once we handle these mode/flags with Linux way
> will add till now will mark it as "Under review" on patchwork.
> 

08/16 patch is dependent on this patch where the mode is used to select
dual/quad mode. I will respin 05 (this patch) and 08 patch as a
follow-up patch.

Regards
Mugunthan V N