Re: [PATCH v2 2/2] gpio: zynq: Implement irq_pm_(get|put)

From: Grygorii Strashko
Date: Mon Nov 09 2015 - 10:00:55 EST


Hi Soren,

On 11/04/2015 10:16 PM, Soren Brinkmann wrote:
> The driver uses runtime PM to leverage low power techniques. For
> use-cases using GPIO as interrupt the device needs to be in an
> appropriate state.
>
> Reported-by: John Linn <linnj@xxxxxxxxxx>
> Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>

I've one question here. As I know, there is one code path when
GPIO HW can be accessed before request_irq() during OF boot:

irq_create_of_mapping()
- irq_create_fwspec_mapping()
- irq_set_irq_type()

How do you handle this situation? :(

> ---
> v2:
> - declare callbacks static
> ---
> drivers/gpio/gpio-zynq.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpio/gpio-zynq.c b/drivers/gpio/gpio-zynq.c
> index 8abeacac5885..98197f778694 100644
> --- a/drivers/gpio/gpio-zynq.c
> +++ b/drivers/gpio/gpio-zynq.c
> @@ -471,6 +471,22 @@ static int zynq_gpio_set_wake(struct irq_data *data, unsigned int on)
> return 0;
> }
>
> +static int zynq_gpio_irq_pm_get(struct irq_data *data)
> +{
> + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(data);
> + struct device *dev = gpio->chip.dev;
> +
> + return pm_runtime_get_sync(dev);
> +}
> +
> +static void zynq_gpio_irq_pm_put(struct irq_data *data)
> +{
> + struct zynq_gpio *gpio = irq_data_get_irq_chip_data(data);
> + struct device *dev = gpio->chip.dev;
> +
> + pm_runtime_put(dev);
> +}
> +
> /* irq chip descriptor */
> static struct irq_chip zynq_gpio_level_irqchip = {
> .name = DRIVER_NAME,
> @@ -480,6 +496,8 @@ static struct irq_chip zynq_gpio_level_irqchip = {
> .irq_unmask = zynq_gpio_irq_unmask,
> .irq_set_type = zynq_gpio_set_irq_type,
> .irq_set_wake = zynq_gpio_set_wake,
> + .irq_pm_get = zynq_gpio_irq_pm_get,
> + .irq_pm_put = zynq_gpio_irq_pm_put,
> .flags = IRQCHIP_EOI_THREADED | IRQCHIP_EOI_IF_HANDLED |
> IRQCHIP_MASK_ON_SUSPEND,
> };
> @@ -492,6 +510,8 @@ static struct irq_chip zynq_gpio_edge_irqchip = {
> .irq_unmask = zynq_gpio_irq_unmask,
> .irq_set_type = zynq_gpio_set_irq_type,
> .irq_set_wake = zynq_gpio_set_wake,
> + .irq_pm_get = zynq_gpio_irq_pm_get,
> + .irq_pm_put = zynq_gpio_irq_pm_put,
> .flags = IRQCHIP_MASK_ON_SUSPEND,
> };
>
>


--
regards,
-grygorii
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