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

[Jagan Teki <jteki@openedev.com>]

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.

thanks!
-- 
Jagan.