pinctrl: bcm2835: Add support for wake-up interrupts

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>
Link: https://lore.kernel.org/r/20200531001101.24945-5-f.fainelli@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/bcm/pinctrl-bcm2835.c b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
index 1b00d93..1d21129 100644 (file)
--- 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 <= 57)
+               irqgroup = 2;
+       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;