Re: [PATCH v2 4/4] pinctrl: bcm2835: Add support for wake-up interrupts

Stefan Wahren
2020-05-30T07:49:26Z

Hi Florian,

Am 29.05.20 um 21:15 schrieb Florian Fainelli:
> Leverage the IRQCHIP_MASK_ON_SUSPEND flag in order to avoid having to
> specifically treat the GPIO interrupts during suspend and resume, and
> simply implement an irq_set_wake() callback that is responsible for
> enabling the parent wake-up interrupt as a wake-up interrupt.
>
> To avoid allocating unnecessary resources for other chips, the wake-up
> interrupts are only initialized if we have a brcm,bcm7211-gpio
> compatibility string.
>
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> drivers/pinctrl/bcm/pinctrl-bcm2835.c | 76 ++++++++++++++++++++++++++-
> 1 file changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> index 1b00d93aa66e..1fbf067a3eed 100644
> --- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> +++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
> @@ -19,6 +19,7 @@
> #include <linux/irq.h>
> #include <linux/irqdesc.h>
> #include <linux/init.h>
> +#include <linux/interrupt.h>
> #include <linux/of_address.h>
> #include <linux/of.h>
> #include <linux/of_irq.h>
> @@ -76,6 +77,7 @@
> struct bcm2835_pinctrl {
> struct device *dev;
> void __iomem *base;
> + int *wake_irq;
>
> /* note: locking assumes each bank will have its own unsigned long */
> unsigned long enabled_irq_map[BCM2835_NUM_BANKS];
> @@ -435,6 +437,11 @@ static void bcm2835_gpio_irq_handler(struct irq_desc *desc)
> chained_irq_exit(host_chip, desc);
> }
>
> +static irqreturn_t bcm2835_gpio_wake_irq_handler(int irq, void *dev_id)
> +{
> + return IRQ_HANDLED;
> +}
> +
> static inline void __bcm2835_gpio_irq_config(struct bcm2835_pinctrl *pc,
> unsigned reg, unsigned offset, bool enable)
> {
> @@ -634,6 +641,34 @@ static void bcm2835_gpio_irq_ack(struct irq_data *data)
> bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
> }
>
> +static int bcm2835_gpio_irq_set_wake(struct irq_data *data, unsigned int on)
> +{
> + struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
> + struct bcm2835_pinctrl *pc = gpiochip_get_data(chip);
> + unsigned gpio = irqd_to_hwirq(data);
> + unsigned int irqgroup;
> + int ret = -EINVAL;
> +
> + if (!pc->wake_irq)
> + return ret;
> +
> + if (gpio <= 27)
> + irqgroup = 0;
> + else if (gpio >= 28 && gpio <= 45)
> + irqgroup = 1;
> + else if (gpio >= 46 && gpio <= 53)
> + irqgroup = 2;
in case the BCM7211 has 58 GPIOs, but the wake up interrupts are only
available for the first 54 this should deserve a comment.
> + else
> + return ret;
> +
> + if (on)
> + ret = enable_irq_wake(pc->wake_irq[irqgroup]);
> + else
> + ret = disable_irq_wake(pc->wake_irq[irqgroup]);
> +
> + return ret;
> +}
> +
> static struct irq_chip bcm2835_gpio_irq_chip = {
> .name = MODULE_NAME,
> .irq_enable = bcm2835_gpio_irq_enable,
> @@ -642,6 +677,8 @@ static struct irq_chip bcm2835_gpio_irq_chip = {
> .irq_ack = bcm2835_gpio_irq_ack,
> .irq_mask = bcm2835_gpio_irq_disable,
> .irq_unmask = bcm2835_gpio_irq_enable,
> + .irq_set_wake = bcm2835_gpio_irq_set_wake,
> + .flags = IRQCHIP_MASK_ON_SUSPEND,
> };
>
> static int bcm2835_pctl_get_groups_count(struct pinctrl_dev *pctldev)
> @@ -1154,6 +1191,7 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
> struct resource iomem;
> int err, i;
> const struct of_device_id *match;
> + int is_7211 = 0;
>
> BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_pins) != BCM2711_NUM_GPIOS);
> BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_groups) != BCM2711_NUM_GPIOS);
> @@ -1180,6 +1218,7 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
> return -EINVAL;
>
> pdata = match->data;
> + is_7211 = of_device_is_compatible(np, "brcm,bcm7211-gpio");
>
> pc->gpio_chip = *pdata->gpio_chip;
> pc->gpio_chip.parent = dev;
> @@ -1214,6 +1253,15 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
> GFP_KERNEL);
> if (!girq->parents)
> return -ENOMEM;
> +
> + if (is_7211) {
> + pc->wake_irq = devm_kcalloc(dev, BCM2835_NUM_IRQS,
> + sizeof(*pc->wake_irq),
> + GFP_KERNEL);
> + if (!pc->wake_irq)
> + return -ENOMEM;
> + }
> +
> /*
> * Use the same handler for all groups: this is necessary
> * since we use one gpiochip to cover all lines - the
> @@ -1221,8 +1269,34 @@ static int bcm2835_pinctrl_probe(struct platform_device *pdev)
> * bank that was firing the IRQ and look up the per-group
> * and bank data.
> */
> - for (i = 0; i < BCM2835_NUM_IRQS; i++)
> + for (i = 0; i < BCM2835_NUM_IRQS; i++) {
> + int len;
> + char *name;
> +
> girq->parents[i] = irq_of_parse_and_map(np, i);
> + if (!is_7211)
> + continue;
> +
> + /* Skip over the all banks interrupts */
> + pc->wake_irq[i] = irq_of_parse_and_map(np, i +
> + BCM2835_NUM_IRQS + 1);
> +
> + len = strlen(dev_name(pc->dev)) + 16;
> + name = devm_kzalloc(pc->dev, len, GFP_KERNEL);
> + if (!name)
> + return -ENOMEM;
> +
> + snprintf(name, len, "%s:bank%d", dev_name(pc->dev), i);
> +
> + /* These are optional interrupts */
> + err = devm_request_irq(dev, pc->wake_irq[i],
> + bcm2835_gpio_wake_irq_handler,
> + IRQF_SHARED, name, pc);
> + if (err)
> + dev_warn(dev, "unable to request wake IRQ %d\n",
> + pc->wake_irq[i]);
> + }
> +
> girq->default_type = IRQ_TYPE_NONE;
> girq->handler = handle_level_irq;
>