Le 08/11/2016 à 18:49, Alexandre Belloni a écrit :
> On 08/11/2016 at 18:48:52 +0100, Nicolas Ferre wrote :
>> Use the managed gpio CS pin request so that we avoid having trouble
>> in the cleanup code.
>> In fact, if module was configured with DT, cleanup code released
>> invalid pin. Since resource wasn't freed, module cannot be reinserted.
>>
>> This require to extract the gpio request call from the "setup" function
>> and call it in the appropriate probe function.
>>
>> Reported-by: Alexander Morozov <li...@meltdown.ru>
>> Signed-off-by: Nicolas Ferre <nicolas.fe...@atmel.com>
>
> I think that's fine but I still have that item on my todo list
> (discussion in july 2014 with Mark):
>
> ---
>>> Mark: maybe it would make sense to do devm_gpio_request_one() in
>>> of_spi_register_master(), after of_get_named_gpio.
>
>> You need to transition all the drivers doing things manually but yes.
>> As I keep saying all the GPIO handling needs to be completely
>> refactored.
> ---
Would make sense indeed as we are currently doing the same node scanning
twice...
But this patch actually fixes an issue with module unloading/re-loading
and freeing of a wrong gpio. So I do think that we shouldn't hold its
adoption while thinking about this enhancement...
Regards,
>> ---
>> v2: fix devm_gpio_request location: the setup code for device was not proper
>> location. Move it to the probe function and add needed DT routines to
>> handle all CS gpio specified.
>>
>> drivers/spi/spi-atmel.c | 50
>> ++++++++++++++++++++++++++++++++++++++-----------
>> 1 file changed, 39 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
>> index 32683a13dd60..a60925614480 100644
>> --- a/drivers/spi/spi-atmel.c
>> +++ b/drivers/spi/spi-atmel.c
>> @@ -24,6 +24,7 @@
>>
>> #include <linux/io.h>
>> #include <linux/gpio.h>
>> +#include <linux/of_gpio.h>
>> #include <linux/pinctrl/consumer.h>
>> #include <linux/pm_runtime.h>
>>
>> @@ -1204,7 +1205,6 @@ static int atmel_spi_setup(struct spi_device *spi)
>> u32 csr;
>> unsigned int bits = spi->bits_per_word;
>> unsigned int npcs_pin;
>> - int ret;
>>
>> as = spi_master_get_devdata(spi->master);
>>
>> @@ -1247,16 +1247,9 @@ static int atmel_spi_setup(struct spi_device *spi)
>> if (!asd)
>> return -ENOMEM;
>>
>> - if (as->use_cs_gpios) {
>> - ret = gpio_request(npcs_pin, dev_name(&spi->dev));
>> - if (ret) {
>> - kfree(asd);
>> - return ret;
>> - }
>> -
>> + if (as->use_cs_gpios)
>> gpio_direction_output(npcs_pin,
>> !(spi->mode & SPI_CS_HIGH));
>> - }
>>
>> asd->npcs_pin = npcs_pin;
>> spi->controller_state = asd;
>> @@ -1471,13 +1464,11 @@ static int atmel_spi_transfer_one_message(struct
>> spi_master *master,
>> static void atmel_spi_cleanup(struct spi_device *spi)
>> {
>> struct atmel_spi_device *asd = spi->controller_state;
>> - unsigned gpio = (unsigned long) spi->controller_data;
>>
>> if (!asd)
>> return;
>>
>> spi->controller_state = NULL;
>> - gpio_free(gpio);
>> kfree(asd);
>> }
>>
>> @@ -1499,6 +1490,39 @@ static void atmel_get_caps(struct atmel_spi *as)
>> }
>>
>>
>> /*-------------------------------------------------------------------------*/
>> +static int atmel_spi_gpio_cs(struct platform_device *pdev)
>> +{
>> + struct spi_master *master = platform_get_drvdata(pdev);
>> + struct atmel_spi *as = spi_master_get_devdata(master);
>> + struct device_node *np = master->dev.of_node;
>> + int i;
>> + int ret = 0;
>> + int nb = 0;
>> +
>> + if (!as->use_cs_gpios)
>> + return 0;
>> +
>> + if (!np)
>> + return 0;
>> +
>> + nb = of_gpio_named_count(np, "cs-gpios");
>> + for (i = 0; i < nb; i++) {
>> + int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
>> + "cs-gpios", i);
>> +
>> + if (cs_gpio == -EPROBE_DEFER)
>> + return cs_gpio;
>> +
>> + if (gpio_is_valid(cs_gpio)) {
>> + ret = devm_gpio_request(&pdev->dev, cs_gpio,
>> + dev_name(&pdev->dev));
>> + if (ret)
>> + return ret;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>>
>> static int atmel_spi_probe(struct platform_device *pdev)
>> {
>> @@ -1577,6 +1601,10 @@ static int atmel_spi_probe(struct platform_device
>> *pdev)
>> master->num_chipselect = 4;
>> }
>>
>> + ret = atmel_spi_gpio_cs(pdev);
>> + if (ret)
>> + goto out_unmap_regs;
>> +
>> as->use_dma = false;
>> as->use_pdc = false;
>> if (as->caps.has_dma_support) {
>> --
>> 2.9.0
>>
>
--
Nicolas Ferre
