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

Florian Fainelli
2020-05-29T19:17:09Z

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;
+ 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;

--
2.17.1