On 03/09/15 01:20, Ivan T. Ivanov wrote:
> Hi Stephen,
>
>> On Mar 6, 2015, at 8:34 PM, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote:
>> On 03/06/15 07:26, Ivan T. Ivanov wrote:
>>> Ensure that driver is owner of the GPIO's used for CS signals.
>> Why? What happens if we don’t?
> We can have wrong DT configuration, which could reconfigure
> GPIO’s without any warning or error.
Ouch. That sounds bad. Can you please add this information to the commit
text?
>
>>> Signed-off-by: Ivan T. Ivanov <iivanov@xxxxxxxxxx>
>>> ---
>>> drivers/spi/spi-qup.c | 17 ++++++++++++++++-
>>> 1 file changed, 16 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c
>>> index 2b2c359..a07ba46 100644
>>> --- a/drivers/spi/spi-qup.c
>>> +++ b/drivers/spi/spi-qup.c
>>> @@ -14,11 +14,13 @@
>>> #include <linux/clk.h>
>>> #include <linux/delay.h>
>>> #include <linux/err.h>
>>> +#include <linux/gpio.h>
>>> #include <linux/interrupt.h>
>>> #include <linux/io.h>
>>> #include <linux/list.h>
>>> #include <linux/module.h>
>>> #include <linux/of.h>
>>> +#include <linux/of_gpio.h>
>>> #include <linux/platform_device.h>
>>> #include <linux/pm_runtime.h>
>>> #include <linux/spi/spi.h>
>>> @@ -499,7 +501,7 @@ static int spi_qup_probe(struct platform_device *pdev)
>>> struct device *dev;
>>> void __iomem *base;
>>> u32 max_freq, iomode, num_cs;
>>> - int ret, irq, size;
>>> + int ret, irq, size, cs, cs_gpio;
>>>
>>> dev = &pdev->dev;
>>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> @@ -556,6 +558,19 @@ static int spi_qup_probe(struct platform_device *pdev)
>>> else
>>> master->num_chipselect = num_cs;
>>>
>>> + for (cs = 0; cs < master->num_chipselect; cs++) {
>>> + cs_gpio = of_get_named_gpio(dev->of_node, "cs-gpios", cs);
>>> +
>>> + if (!gpio_is_valid(cs_gpio))
>>> + continue;
>>> +
>>> + ret = devm_gpio_request(&pdev->dev, cs_gpio, "spi-qup-cs");
>>> + if (ret) {
>>> + dev_err(&pdev->dev, "can't get cs gpios\n");
>>> + goto error;
>>> + }
>>> + }
>>> +
>>> master->bus_num = pdev->id;
>> Is this related to [1]? In that case I was just relying on DT/pinctrl to
>> properly request the gpios.
> But the DT/pinctrl did not request GPIO’s, it just configure them.
> For some reason we are ending without any pinctrl_map of type
> PIN_MAP_TYPE_MUX_GROUP, which is used for pin reservation.
>
Ah ok. I seem to be misremembering the details.
Can you please use the gpiod interfaces here (devm_gpiod_get_index)?
That's more modern. Also, don't print any error because -EPROBE_DEFER
may come out and because __gpiod_get_index() already prints an error on
failure at the debug level.
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