Re: [PATCH 08/12] drivers: pinctrl: msm: setup GPIO chip in hierarchy

[Stephen Boyd]

Quoting Lina Iyer (2019-11-14 10:35:17)
> Some GPIOs are marked as wakeup capable and are routed to another
> interrupt controller that is an always-domain and can detect interrupts
> even most of the SoC is powered off. The wakeup interrupt controller

even when?

> wakes up the GIC and replays the interrupt at the GIC.
> 
> Setup the TLMM irqchip in hierarchy with the wakeup interrupt controller
> and ensure the wakeup GPIOs are handled correctly.
> 
> Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>

Is it Co-developed-by for Maulik?

> Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>

Some minor comments. Shouldn't be hard to fix and resend quickly I hope.

> diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
> index 763da0b..c245686 100644
> --- a/drivers/pinctrl/qcom/pinctrl-msm.c
> +++ b/drivers/pinctrl/qcom/pinctrl-msm.c
> @@ -44,6 +46,7 @@
>   * @enabled_irqs:   Bitmap of currently enabled irqs.
>   * @dual_edge_irqs: Bitmap of irqs that need sw emulated dual edge
>   *                  detection.
> + * @skip_wake_irqs: Skip IRQs that are handled by wakeup interrupt contrroller

s/contrroller/controller/

>   * @soc;            Reference to soc_data of platform specific data.
>   * @regs:           Base addresses for the TLMM tiles.
>   */
> @@ -778,10 +794,37 @@ static void msm_gpio_irq_clear_unmask(struct irq_data *d, bool status_clear)
>  
>  static void msm_gpio_irq_enable(struct irq_data *d)
>  {
> +       /*
> +        * Clear the interrupt that may be pending before we enable
> +        * the line.
> +        * This is especially a problem with the GPIOs routed to the
> +        * PDC. These GPIOs are direct-connect interrupts to the GIC.
> +        * Disabling the interrupt line at the PDC does not prevent
> +        * the interrupt from being latched at the GIC. The state at
> +        * GIC needs to be cleared before enabling.
> +        */
> +       if (d->parent_data) {
> +               irq_chip_set_parent_state(d, IRQCHIP_STATE_PENDING, 0);
> +               irq_chip_enable_parent(d);
> +       }
>  
>         msm_gpio_irq_clear_unmask(d, true);
>  }
>  
> +static void msm_gpio_irq_disable(struct irq_data *d)
> +{
> +       struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
> +       struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
> +
> +       if (d->parent_data)
> +               irq_chip_disable_parent(d);
> +
> +       if (test_bit(d->hwirq, pctrl->skip_wake_irqs))
> +               return;
> +
> +       msm_gpio_irq_mask(d);

Why not

	if (!test_bit(...)
		msm_gpio_irq_mask(d);

> +}
> +
>  static void msm_gpio_irq_unmask(struct irq_data *d)
>  {
>         msm_gpio_irq_clear_unmask(d, false);
> @@ -912,6 +964,15 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
>         struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
>         unsigned long flags;
>  
> +       if (d->parent_data)
> +               irq_chip_set_wake_parent(d, on);
> +
> +       /*
> +        * While they may not wake up when the TLMM is powered off,
> +        * some GPIOs would like to wakeup the system from suspend
> +        * when TLMM is powered on. To allow that, enable the GPIO
> +        * summary line to be wakeup capable at GIC.
> +        */

Can this comment go above the irq_set_irq_wake() line below instead of
this spinlock?

>         raw_spin_lock_irqsave(&pctrl->lock, flags);
>  
>         irq_set_irq_wake(pctrl->irq, on);
> @@ -990,6 +1051,30 @@ static void msm_gpio_irq_handler(struct irq_desc *desc)
>         chained_irq_exit(chip, desc);
>  }
>  
> +static int msm_gpio_wakeirq(struct gpio_chip *gc,
> +                           unsigned int child,
> +                           unsigned int child_type,
> +                           unsigned int *parent,
> +                           unsigned int *parent_type)
> +{
> +       struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
> +       const struct msm_gpio_wakeirq_map *map;
> +       int i;
> +
> +       *parent = GPIO_NO_WAKE_IRQ;
> +       *parent_type = IRQ_TYPE_EDGE_RISING;
> +
> +       for (i = 0; i < pctrl->soc->nwakeirq_map; i++) {
> +               map = &pctrl->soc->wakeirq_map[i];
> +               if (map->gpio == child) {
> +                       *parent = map->wakeirq;
> +                       break;
> +               }
> +       }
> +
> +       return 0;

Shouldn't we return -EINVAL if we can't translate the gpio irq to the
parent domain? I would expect to see return -EINVAL here and the above
if condition to return 0 instead of break.

> +}
> +
>  static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl)
>  {
>         if (pctrl->soc->reserved_gpios)
> @@ -1004,6 +1089,7 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
>         struct gpio_irq_chip *girq;
>         int ret;
>         unsigned ngpio = pctrl->soc->ngpios;
> +       struct device_node *np;
>  
>         if (WARN_ON(ngpio > MAX_NR_GPIO))
>                 return -EINVAL;
> @@ -1020,17 +1106,44 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
>  
>         pctrl->irq_chip.name = "msmgpio";
>         pctrl->irq_chip.irq_enable = msm_gpio_irq_enable;
> +       pctrl->irq_chip.irq_disable = msm_gpio_irq_disable;
>         pctrl->irq_chip.irq_mask = msm_gpio_irq_mask;
>         pctrl->irq_chip.irq_unmask = msm_gpio_irq_unmask;
>         pctrl->irq_chip.irq_ack = msm_gpio_irq_ack;
> +       pctrl->irq_chip.irq_eoi = irq_chip_eoi_parent;
>         pctrl->irq_chip.irq_set_type = msm_gpio_irq_set_type;
>         pctrl->irq_chip.irq_set_wake = msm_gpio_irq_set_wake;
>         pctrl->irq_chip.irq_request_resources = msm_gpio_irq_reqres;
>         pctrl->irq_chip.irq_release_resources = msm_gpio_irq_relres;
>  
> +       np = of_parse_phandle(pctrl->dev->of_node, "wakeup-parent", 0);
> +       if (np) {
> +               int i;
> +               bool skip;
> +               unsigned int gpio;

Can these be placed at the top of this function instead of buried
halfway down here?

> +
> +               chip->irq.parent_domain = irq_find_matching_host(np,
> +                                                DOMAIN_BUS_WAKEUP);
> +               of_node_put(np);
> +               if (!chip->irq.parent_domain)
> +                       return -EPROBE_DEFER;
> +               chip->irq.child_to_parent_hwirq = msm_gpio_wakeirq;
> +
> +               /*
> +                * Let's skip handling the GPIOs, if the parent irqchip
> +                * handling the direct connect IRQ of the GPIO.

is handling?

> +                */
> +               skip = irq_domain_qcom_handle_wakeup(chip->irq.parent_domain);
> +               for (i = 0; skip && i < pctrl->soc->nwakeirq_map; i++) {
> +                       gpio = pctrl->soc->wakeirq_map[i].gpio;
> +                       set_bit(gpio, pctrl->skip_wake_irqs);
> +               }
> +       }
> +
>         girq = &chip->irq;
>         girq->chip = &pctrl->irq_chip;
>         girq->parent_handler = msm_gpio_irq_handler;
> +       girq->fwnode = pctrl->dev->fwnode;
>         girq->num_parents = 1;
>         girq->parents = devm_kcalloc(pctrl->dev, 1, sizeof(*girq->parents),
>                                      GFP_KERNEL);
> diff --git a/drivers/pinctrl/qcom/pinctrl-msm.h b/drivers/pinctrl/qcom/pinctrl-msm.h
> index 48569cda8..1547020 100644
> --- a/drivers/pinctrl/qcom/pinctrl-msm.h
> +++ b/drivers/pinctrl/qcom/pinctrl-msm.h
> @@ -5,6 +5,8 @@
>  #ifndef __PINCTRL_MSM_H__
>  #define __PINCTRL_MSM_H__
>  
> +#include <linux/gpio/driver.h>

What is this include for?

> +
>  struct pinctrl_pin_desc;
>  
>  /**
> @@ -101,6 +113,8 @@ struct msm_pingroup {
>   * @ngroups:       The numbmer of entries in @groups.
>   * @ngpio:         The number of pingroups the driver should expose as GPIOs.
>   * @pull_no_keeper: The SoC does not support keeper bias.
> + * @wakeirq_map:    The map of wakeup capable GPIOs and the pin at PDC/MPM
> + * @nwakeirq_map:   The number of entries in @hierarchy_map

Is it 'number of entries in @wakeirq_map"?

>   */
>  struct msm_pinctrl_soc_data {
>         const struct pinctrl_pin_desc *pins;
> @@ -114,6 +128,8 @@ struct msm_pinctrl_soc_data {
>         const char *const *tiles;
>         unsigned int ntiles;
>         const int *reserved_gpios;
> +       const struct msm_gpio_wakeirq_map *wakeirq_map;
> +       unsigned int nwakeirq_map;
>  };
>  
>  extern const struct dev_pm_ops msm_pinctrl_dev_pm_ops;
> diff --git a/include/linux/soc/qcom/irq.h b/include/linux/soc/qcom/irq.h
> index 637c0bf..e01391c 100644
> --- a/include/linux/soc/qcom/irq.h
> +++ b/include/linux/soc/qcom/irq.h
> @@ -18,4 +18,17 @@
>  #define IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP                (IRQ_DOMAIN_FLAG_NONCORE << 0)
>  #define IRQ_DOMAIN_FLAG_QCOM_MPM_WAKEUP                (IRQ_DOMAIN_FLAG_NONCORE << 1)
>  
> +/**
> + * irq_domain_qcom_handle_wakeup: Return if the domain handles interrupt
> + *                                configuration
> + * @d: irq domain
> + *
> + * This QCOM specific irq domain call returns if the interrupt controller
> + * requires the interrupt be masked at the child interrupt controller.
> + */
> +static inline bool irq_domain_qcom_handle_wakeup(struct irq_domain *d)

could be const irq_domain here.

> +{
> +       return (d->flags & IRQ_DOMAIN_FLAG_QCOM_PDC_WAKEUP);
> +}
> +