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SubjectRe: [PATCH] spi: pxa2xx: Only claim CS GPIOs when the slave device is created
On Sun, Jul 9, 2017 at 12:30 PM, Jan Kiszka <jan.kiszka@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@web.de> wrote:
>>> From: Jan Kiszka <jan.kiszka@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@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

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