[U-Boot] [PATCH V2] spi: mxs: Configure chipselect after block reset

Jagan Teki jagannadh.teki at gmail.com
Tue Aug 27 16:12:39 CEST 2013


On 27-08-2013 15:04, Marek Vasut wrote:
> Dear Jagan Teki,
>
>> Hi
>>
>> On Tue, Aug 27, 2013 at 2:51 PM, Marek Vasut <marex at denx.de> wrote:
>>> Dear Jagan Teki,
>>>
>>>> Hi,
>>>>
>>>> On Tue, Aug 27, 2013 at 2:35 PM, Marek Vasut <marex at denx.de> wrote:
>>>>> Dear Stefano Babic,
>>>>>
>>>>>> On 26/08/2013 17:45, Marek Vasut wrote:
>>>>>>> The chipselect must be written into the CTRL0 register after the
>>>>>>> SSP block is reset, otherwise the block will always use ChipSelect
>>>>>>> #0.
>>>>>>>
>>>>>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>>>>>> Cc: Fabio Estevam <fabio.estevam at freescale.com>
>>>>>>> Cc: Jagannadha Sutradharudu Teki <jagannadh.teki at gmail.com>
>>>>>>> Cc: Otavio Salvador <otavio at ossystems.com.br>
>>>>>>> Cc: Stefano Babic <sbabic at denx.de>
>>>>>>> ---
>>>>>>>
>>>>>>>   drivers/spi/mxs_spi.c |   12 +++---------
>>>>>>>   1 file changed, 3 insertions(+), 9 deletions(-)
>>>>>>>
>>>>>>> V2: Clean up a warning that "ssp_regs" are not used
>>>>>>>
>>>>>>> diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
>>>>>>> index 3cf7142..2b9f395 100644
>>>>>>> --- a/drivers/spi/mxs_spi.c
>>>>>>> +++ b/drivers/spi/mxs_spi.c
>>>>>>> @@ -56,8 +56,6 @@ struct spi_slave *spi_setup_slave(unsigned int
>>>>>>> bus, unsigned int cs,
>>>>>>>
>>>>>>>                                unsigned int max_hz, unsigned int
>>>>>>>                                mode)
>>>>>>>
>>>>>>>   {
>>>>>>>
>>>>>>>      struct mxs_spi_slave *mxs_slave;
>>>>>>>
>>>>>>> -   struct mxs_ssp_regs *ssp_regs;
>>>>>>> -   int reg;
>>>>>>>
>>>>>>>      if (!spi_cs_is_valid(bus, cs)) {
>>>>>>>
>>>>>>>              printf("mxs_spi: invalid bus %d / chip select %d\n",
>>>>>>>              bus, cs);
>>>>>>>
>>>>>>> @@ -74,13 +72,7 @@ struct spi_slave *spi_setup_slave(unsigned int
>>>>>>> bus, unsigned int cs,
>>>>>>>
>>>>>>>      mxs_slave->max_khz = max_hz / 1000;
>>>>>>>      mxs_slave->mode = mode;
>>>>>>>      mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
>>>>>>>
>>>>>>> -   ssp_regs = mxs_slave->regs;
>>>>>>>
>>>>>>> -   reg = readl(&ssp_regs->hw_ssp_ctrl0);
>>>>>>> -   reg &= ~(MXS_SSP_CHIPSELECT_MASK);
>>>>>>> -   reg |= cs << MXS_SSP_CHIPSELECT_SHIFT;
>>>>>>> -
>>>>>>> -   writel(reg, &ssp_regs->hw_ssp_ctrl0);
>>>>>>>
>>>>>>>      return &mxs_slave->slave;
>>>>>>>
>>>>>>>   err_init:
>>>>>>> @@ -102,7 +94,9 @@ int spi_claim_bus(struct spi_slave *slave)
>>>>>>>
>>>>>>>      mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
>>>>>>>
>>>>>>> -   writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
>>>>>>> +   writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
>>>>>>> +          SSP_CTRL0_BUS_WIDTH_ONE_BIT,
>>>>>>> +          &ssp_regs->hw_ssp_ctrl0);
>>>>>>>
>>>>>>>      reg = SSP_CTRL1_SSP_MODE_SPI |
>>>>>>>      SSP_CTRL1_WORD_LENGTH_EIGHT_BITS; reg |= (mxs_slave->mode &
>>>>>>>      SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
>>>>>>
>>>>>> Acked-by: Stefano Babic <sbabic at denx.de>
>>>>>
>>>>> Can we push this via IMX tree ?
>>>>
>>>> I have a simple concern about commit head msg.
>>>> spi: mxs:
>>>> spi: mxs_spi:
>>>>
>>>> I preferred the second one as rest are follow the same, just for
>>>> unification. Please send the v2, if your OK. then I will push it on my
>>>> tree.
>>>
>>> Can you fix that before pushing? I am fine either way.
>>
>> OK, sure I will do that.
>
> Thanks a lot!
>
> Best regards,
> Marek Vasut
>

Applied to u-boot-spi/master

--
Thanks,
Jagan.


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