Re: [PATCH v2 3/5] drivers: pinctrl: msm: enable PDC interrupt only during suspend

From: Matthias Kaehlcke
Date: Mon Aug 27 2018 - 18:57:28 EST


Hi Lina,

On Fri, Aug 24, 2018 at 02:01:55PM -0600, Lina Iyer wrote:
> During suspend the system may power down some of the system rails. As a
> result, the TLMM hw block may not be operational anymore and wakeup
> capable GPIOs will not be detected. The PDC however will be operational
> and the GPIOs that are routed to the PDC as IRQs can wake the system up.
>
> To avoid being interrupted twice (for TLMM and once for PDC IRQ) when a
> GPIO trips, use TLMM for active and switch to PDC for suspend. When
> entering suspend, disable the TLMM wakeup interrupt and instead enable
> the PDC IRQ and revert upon resume.
>
> Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Fix PDC IRQ max port, 126 is the max supported in h/w
> - Use PDC hwirq in bitmap, linux numbers could be large
> - Setup DISABLE_UNLAZY for both TLMM and PDC IRQs
> ---
> drivers/pinctrl/qcom/pinctrl-msm.c | 70 +++++++++++++++++++++++++++++-
> drivers/pinctrl/qcom/pinctrl-msm.h | 3 ++
> 2 files changed, 72 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
> index b675ea56a4ff..a880cefbd248 100644
> --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> @@ -37,6 +37,7 @@
> #include "../pinctrl-utils.h"
>
> #define MAX_NR_GPIO 300
> +#define MAX_PDC_HWIRQ 126
> #define PS_HOLD_OFFSET 0x820
>
> /**
> @@ -51,6 +52,7 @@
> * @enabled_irqs: Bitmap of currently enabled irqs.
> * @dual_edge_irqs: Bitmap of irqs that need sw emulated dual edge
> * detection.
> + * @pdc_hwirqs: Bitmap of wakeup capable irqs.
> * @soc; Reference to soc_data of platform specific data.
> * @regs: Base address for the TLMM register map.
> */
> @@ -68,11 +70,15 @@ struct msm_pinctrl {
>
> DECLARE_BITMAP(dual_edge_irqs, MAX_NR_GPIO);
> DECLARE_BITMAP(enabled_irqs, MAX_NR_GPIO);
> + DECLARE_BITMAP(pdc_hwirqs, MAX_PDC_HWIRQ);
>
> const struct msm_pinctrl_soc_data *soc;
> void __iomem *regs;
> + struct irq_domain *pdc_irq_domain;
> };
>
> +static bool in_suspend;
> +
> static int msm_get_groups_count(struct pinctrl_dev *pctldev)
> {
> struct msm_pinctrl *pctrl = pinctrl_dev_get_drvdata(pctldev);
> @@ -787,8 +793,13 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
>
> raw_spin_lock_irqsave(&pctrl->lock, flags);
>
> - if (pdc_irqd)
> + if (pdc_irqd && !in_suspend) {
> irq_set_irq_wake(pdc_irqd->irq, on);
> + if (on)
> + set_bit(pdc_irqd->hwirq, pctrl->pdc_hwirqs);
> + else
> + clear_bit(pdc_irqd->hwirq, pctrl->pdc_hwirqs);
> + }
>
> irq_set_irq_wake(pctrl->irq, on);
>
> @@ -919,7 +930,12 @@ static int msm_gpio_pdc_pin_request(struct irq_data *d)
> }
>
> irq_set_handler_data(d->irq, irq_get_irq_data(irq));
> + irq_set_handler_data(irq, d);
> + irq_set_status_flags(irq, IRQ_DISABLE_UNLAZY);
> + irq_set_status_flags(d->irq, IRQ_DISABLE_UNLAZY);
> disable_irq(irq);
> + if (!pctrl->pdc_irq_domain)
> + pctrl->pdc_irq_domain = irq_get_irq_data(irq)->domain;
>
> return 0;
> }
> @@ -1069,6 +1085,58 @@ static void msm_pinctrl_setup_pm_reset(struct msm_pinctrl *pctrl)
> }
> }
>
> +int __maybe_unused msm_pinctrl_suspend_late(struct device *dev)
> +{
> + struct msm_pinctrl *pctrl = dev_get_drvdata(dev);
> + struct irq_data *irqd;
> + unsigned int irq;
> + int i;
> +
> + in_suspend = true;
> + for_each_set_bit(i, pctrl->pdc_hwirqs, MAX_PDC_HWIRQ) {
> + irq = irq_find_mapping(pctrl->pdc_irq_domain, i);
> + irqd = irq_get_handler_data(irq);
> + /*
> + * We don't know if the TLMM will be functional
> + * or not, during the suspend. If its functional,
> + * we do not want duplicate interrupts from PDC.
> + * Hence disable the GPIO IRQ and enable PDC IRQ.
> + */
> + if (irqd_is_wakeup_set(irqd)) {
> + disable_irq_wake(irqd->irq);
> + disable_irq(irqd->irq);
> + enable_irq(irq);
> + }

Would it make sense to limit this to edge triggered interrupts since
the interrupt handler does nothing for level triggered ones?

Cheers

Matthias