[PATCH] spi: pxa2xx: Only claim CS GPIOs when the slave device is created

[Andy Shevchenko]

On Sun, Jul 9, 2017 at 12:30 PM, Jan Kiszka <jan.kiszka at web.de> wrote:
> On 2017-07-08 23:48, Andy Shevchenko wrote:
>> On Sat, Jul 8, 2017 at 11:41 AM, Jan Kiszka <jan.kiszka at web.de> wrote:
>>> From: Jan Kiszka <jan.kiszka at siemens.com>
>>>
>>> Avoid hogging chip select GPIOs just because they are listed for the
>>> master. They might be mulitplexed and, if no slave device is attached,
>>> used for different purposes. Moreover, this strategy avoids having to
>>> allocate a cs_gpiods structure.
>>>
>>> Tested on the IOT2000 where the second SPI bus is connected to an
>>> Arduino-compatible connector and multiplexed between SPI, GPIO and PWM
>>> usage.
>>
>> Can we first switch the driver to use GPIO descriptors instead of
>> plain integers?
>
> -ENOPARSE

In code you are trying to modify there is a mix of plain integers and
GPIO descriptors (and two APIs).
Can we just convert it to use GPIO descriptors API?

>
>>
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
>>> ---
>>>  drivers/spi/spi-pxa2xx.c | 59 +++++++++++++++++-------------------------------
>>>  1 file changed, 21 insertions(+), 38 deletions(-)
>>>
>>> diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
>>> index 38d053682892..be991266a6ce 100644
>>> --- a/drivers/spi/spi-pxa2xx.c
>>> +++ b/drivers/spi/spi-pxa2xx.c
>>> @@ -1213,21 +1213,33 @@ static int setup_cs(struct spi_device *spi, struct chip_data *chip,
>>>                     struct pxa2xx_spi_chip *chip_info)
>>>  {
>>>         struct driver_data *drv_data = spi_master_get_devdata(spi->master);
>>> +       struct device *pdev = &drv_data->pdev->dev;
>>> +       struct gpio_desc *gpiod;
>>>         int err = 0;
>>> +       int count;
>>>
>>>         if (chip == NULL)
>>>                 return 0;
>>>
>>> -       if (drv_data->cs_gpiods) {
>>> -               struct gpio_desc *gpiod;
>>> +       count = gpiod_count(pdev, "cs");
>>> +       if (count > 0) {
>>> +               if (spi->chip_select >= count)
>>> +                       return -EINVAL;
>>> +
>>> +               gpiod = gpiod_get_index(pdev, "cs", spi->chip_select,
>>> +                                       GPIOD_OUT_HIGH);
>>> +               if (IS_ERR(gpiod)) {
>>> +                       /* Means use native chip select */
>>> +                       if (PTR_ERR(gpiod) == -ENOENT)
>>> +                               return 0;
>>>
>>> -               gpiod = drv_data->cs_gpiods[spi->chip_select];
>>> -               if (gpiod) {
>>> -                       chip->gpio_cs = desc_to_gpio(gpiod);
>>> -                       chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
>>> -                       gpiod_set_value(gpiod, chip->gpio_cs_inverted);
>>> +                       return PTR_ERR(gpiod);
>>>                 }
>>>
>>> +               chip->gpio_cs = desc_to_gpio(gpiod);
>>> +               chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
>>> +               gpiod_set_value(gpiod, chip->gpio_cs_inverted);
>>> +
>>>                 return 0;
>>>         }
>>>
>>> @@ -1415,8 +1427,7 @@ static void cleanup(struct spi_device *spi)
>>>         if (!chip)
>>>                 return;
>>>
>>> -       if (drv_data->ssp_type != CE4100_SSP && !drv_data->cs_gpiods &&
>>> -           gpio_is_valid(chip->gpio_cs))
>>> +       if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs))
>>>                 gpio_free(chip->gpio_cs);
>>>
>>>         kfree(chip);
>>> @@ -1752,38 +1763,10 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
>>>         master->num_chipselect = platform_info->num_chipselect;
>>>
>>>         count = gpiod_count(&pdev->dev, "cs");
>>> -       if (count > 0) {
>>> -               int i;
>>> -
>>> +       if (count > 0)
>>>                 master->num_chipselect = max_t(int, count,
>>>                         master->num_chipselect);
>>>
>>> -               drv_data->cs_gpiods = devm_kcalloc(&pdev->dev,
>>> -                       master->num_chipselect, sizeof(struct gpio_desc *),
>>> -                       GFP_KERNEL);
>>> -               if (!drv_data->cs_gpiods) {
>>> -                       status = -ENOMEM;
>>> -                       goto out_error_clock_enabled;
>>> -               }
>>> -
>>> -               for (i = 0; i < master->num_chipselect; i++) {
>>> -                       struct gpio_desc *gpiod;
>>> -
>>> -                       gpiod = devm_gpiod_get_index(dev, "cs", i,
>>> -                                                    GPIOD_OUT_HIGH);
>>> -                       if (IS_ERR(gpiod)) {
>>> -                               /* Means use native chip select */
>>> -                               if (PTR_ERR(gpiod) == -ENOENT)
>>> -                                       continue;
>>> -
>>> -                               status = (int)PTR_ERR(gpiod);
>>> -                               goto out_error_clock_enabled;
>>> -                       } else {
>>> -                               drv_data->cs_gpiods[i] = gpiod;
>>> -                       }
>>> -               }
>>> -       }
>>> -
>>>         tasklet_init(&drv_data->pump_transfers, pump_transfers,
>>>                      (unsigned long)drv_data);
>>>
>>> --
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>>
>>
>>
>
>



-- 
With Best Regards,
Andy Shevchenko