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?
>
> Signed-off-by: Ivan T. Ivanov <iiva...@mm-sol.com>
> ---
> 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.
[1] https://lkml.org/lkml/2014/5/27/784
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