pinctrl: at91-pio4: add PM stuff

Allow GPIOs to be configured as wakeup sources. When going to suspend,
disable all GPIO irqs excepting the one configured as wakeup sources.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c
index 6aff632aaa46bc275dbbcf284170b686df29dd07..5e2189f17fe17565e5367e8230b17b2fc85b90a4 100644 (file)
--- a/drivers/pinctrl/pinctrl-at91-pio4.c
+++ b/drivers/pinctrl/pinctrl-at91-pio4.c
@@ -16,6 +16,7 @@
 
 #include <linux/clk.h>
 #include <linux/gpio.h>
+#include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -122,6 +123,8 @@ struct atmel_pioctrl {
        struct gpio_chip        *gpio_chip;
        struct irq_domain       *irq_domain;
        int                     *irqs;
+       unsigned                *pm_wakeup_sources;
+       unsigned                *pm_suspend_backup;
        struct device           *dev;
        struct device_node      *node;
 };
@@ -214,12 +217,35 @@ static void atmel_gpio_irq_unmask(struct irq_data *d)
                         BIT(pin->line));
 }
 
+#ifdef CONFIG_PM_SLEEP
+
+static int atmel_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+       struct atmel_pioctrl *atmel_pioctrl = irq_data_get_irq_chip_data(d);
+       int bank = ATMEL_PIO_BANK(d->hwirq);
+       int line = ATMEL_PIO_LINE(d->hwirq);
+
+       /* The gpio controller has one interrupt line per bank. */
+       irq_set_irq_wake(atmel_pioctrl->irqs[bank], on);
+
+       if (on)
+               atmel_pioctrl->pm_wakeup_sources[bank] |= BIT(line);
+       else
+               atmel_pioctrl->pm_wakeup_sources[bank] &= ~(BIT(line));
+
+       return 0;
+}
+#else
+#define atmel_gpio_irq_set_wake NULL
+#endif /* CONFIG_PM_SLEEP */
+
 static struct irq_chip atmel_gpio_irq_chip = {
        .name           = "GPIO",
        .irq_ack        = atmel_gpio_irq_ack,
        .irq_mask       = atmel_gpio_irq_mask,
        .irq_unmask     = atmel_gpio_irq_unmask,
        .irq_set_type   = atmel_gpio_irq_set_type,
+       .irq_set_wake   = atmel_gpio_irq_set_wake,
 };
 
 static void atmel_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
@@ -792,6 +818,43 @@ static struct pinctrl_desc atmel_pinctrl_desc = {
        .pmxops         = &atmel_pmxops,
 };
 
+static int atmel_pctrl_suspend(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
+       int i;
+
+       /*
+        * For each bank, save IMR to restore it later and disable all GPIO
+        * interrupts excepting the ones marked as wakeup sources.
+        */
+       for (i = 0; i < atmel_pioctrl->nbanks; i++) {
+               atmel_pioctrl->pm_suspend_backup[i] =
+                       atmel_gpio_read(atmel_pioctrl, i, ATMEL_PIO_IMR);
+               atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IDR,
+                                ~atmel_pioctrl->pm_wakeup_sources[i]);
+       }
+
+       return 0;
+}
+
+static int atmel_pctrl_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct atmel_pioctrl *atmel_pioctrl = platform_get_drvdata(pdev);
+       int i;
+
+       for (i = 0; i < atmel_pioctrl->nbanks; i++)
+               atmel_gpio_write(atmel_pioctrl, i, ATMEL_PIO_IER,
+                                atmel_pioctrl->pm_suspend_backup[i]);
+
+       return 0;
+}
+
+static const struct dev_pm_ops atmel_pctrl_pm_ops = {
+       SET_SYSTEM_SLEEP_PM_OPS(atmel_pctrl_suspend, atmel_pctrl_resume)
+};
+
 /*
  * The number of banks can be different from a SoC to another one.
  * We can have up to 16 banks.
@@ -908,6 +971,18 @@ static int atmel_pinctrl_probe(struct platform_device *pdev)
        atmel_pioctrl->gpio_chip->dev = dev;
        atmel_pioctrl->gpio_chip->names = atmel_pioctrl->group_names;
 
+       atmel_pioctrl->pm_wakeup_sources = devm_kzalloc(dev,
+                       sizeof(*atmel_pioctrl->pm_wakeup_sources)
+                       * atmel_pioctrl->nbanks, GFP_KERNEL);
+       if (!atmel_pioctrl->pm_wakeup_sources)
+               return -ENOMEM;
+
+       atmel_pioctrl->pm_suspend_backup = devm_kzalloc(dev,
+                       sizeof(*atmel_pioctrl->pm_suspend_backup)
+                       * atmel_pioctrl->nbanks, GFP_KERNEL);
+       if (!atmel_pioctrl->pm_suspend_backup)
+               return -ENOMEM;
+
        atmel_pioctrl->irqs = devm_kzalloc(dev, sizeof(*atmel_pioctrl->irqs)
                        * atmel_pioctrl->nbanks, GFP_KERNEL);
        if (!atmel_pioctrl->irqs)
@@ -1006,6 +1081,7 @@ static struct platform_driver atmel_pinctrl_driver = {
        .driver = {
                .name = "pinctrl-at91-pio4",
                .of_match_table = atmel_pctrl_of_match,
+               .pm = &atmel_pctrl_pm_ops,
        },
        .probe = atmel_pinctrl_probe,
        .remove = atmel_pinctrl_remove,