Input: gpio-keys - add support for wakeup event action

Add support for specifying event actions to trigger wakeup when using
the gpio-keys input device as a wakeup source.

This would allow the device to configure when to wakeup the system. For
example a gpio-keys input device for pen insert, may only want to wakeup
the system when ejecting the pen.

Suggested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 131 insertions, 14 deletions

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 87e613dc33b8..052e37675086 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -30,6 +30,7 @@
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/spinlock.h>
+#include <dt-bindings/input/gpio-keys.h>
 
 struct gpio_button_data {
         const struct gpio_keys_button *button;
@@ -45,6 +46,7 @@ struct gpio_button_data {
         unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
 
         unsigned int irq;
+        unsigned int wakeup_trigger_type;
         spinlock_t lock;
         bool disabled;
         bool key_pressed;
@@ -540,6 +542,8 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
         }
 
         if (bdata->gpiod) {
+                bool active_low = gpiod_is_active_low(bdata->gpiod);
+
                 if (button->debounce_interval) {
                         error = gpiod_set_debounce(bdata->gpiod,
                                         button->debounce_interval * 1000);
@@ -568,6 +572,24 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
                 isr = gpio_keys_gpio_isr;
                 irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
 
+                switch (button->wakeup_event_action) {
+                case EV_ACT_ASSERTED:
+                        bdata->wakeup_trigger_type = active_low ?
+                                IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
+                        break;
+                case EV_ACT_DEASSERTED:
+                        bdata->wakeup_trigger_type = active_low ?
+                                IRQ_TYPE_EDGE_RISING : IRQ_TYPE_EDGE_FALLING;
+                        break;
+                case EV_ACT_ANY:
+                        /* fall through */
+                default:
+                        /*
+                         * For other cases, we are OK letting suspend/resume
+                         * not reconfigure the trigger type.
+                         */
+                        break;
+                }
         } else {
                 if (!button->irq) {
                         dev_err(dev, "Found button without gpio or irq\n");
@@ -586,6 +608,11 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
 
                 isr = gpio_keys_irq_isr;
                 irqflags = 0;
+
+                /*
+                 * For IRQ buttons, there is no interrupt for release.
+                 * So we don't need to reconfigure the trigger type for wakeup.
+                 */
         }
 
         bdata->code = &ddata->keymap[idx];
@@ -718,6 +745,9 @@ gpio_keys_get_devtree_pdata(struct device *dev)
                         /* legacy name */
                         fwnode_property_read_bool(child, "gpio-key,wakeup");
 
+                fwnode_property_read_u32(child, "wakeup-event-action",
+                                         &button->wakeup_event_action);
+
                 button->can_disable =
                         fwnode_property_read_bool(child, "linux,can-disable");
 
@@ -845,19 +875,112 @@ static int gpio_keys_probe(struct platform_device *pdev)
         return 0;
 }
 
+static int __maybe_unused
+gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
+{
+        int error;
+
+        error = enable_irq_wake(bdata->irq);
+        if (error) {
+                dev_err(bdata->input->dev.parent,
+                        "failed to configure IRQ %d as wakeup source: %d\n",
+                        bdata->irq, error);
+                return error;
+        }
+
+        if (bdata->wakeup_trigger_type) {
+                error = irq_set_irq_type(bdata->irq,
+                                         bdata->wakeup_trigger_type);
+                if (error) {
+                        dev_err(bdata->input->dev.parent,
+                                "failed to set wakeup trigger %08x for IRQ %d: %d\n",
+                                bdata->wakeup_trigger_type, bdata->irq, error);
+                        disable_irq_wake(bdata->irq);
+                        return error;
+                }
+        }
+
+        return 0;
+}
+
+static void __maybe_unused
+gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
+{
+        int error;
+
+        /*
+         * The trigger type is always both edges for gpio-based keys and we do
+         * not support changing wakeup trigger for interrupt-based keys.
+         */
+        if (bdata->wakeup_trigger_type) {
+                error = irq_set_irq_type(bdata->irq, IRQ_TYPE_EDGE_BOTH);
+                if (error)
+                        dev_warn(bdata->input->dev.parent,
+                                 "failed to restore interrupt trigger for IRQ %d: %d\n",
+                                 bdata->irq, error);
+        }
+
+        error = disable_irq_wake(bdata->irq);
+        if (error)
+                dev_warn(bdata->input->dev.parent,
+                         "failed to disable IRQ %d as wake source: %d\n",
+                         bdata->irq, error);
+}
+
+static int __maybe_unused
+gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
+{
+        struct gpio_button_data *bdata;
+        int error;
+        int i;
+
+        for (i = 0; i < ddata->pdata->nbuttons; i++) {
+                bdata = &ddata->data[i];
+                if (bdata->button->wakeup) {
+                        error = gpio_keys_button_enable_wakeup(bdata);
+                        if (error)
+                                goto err_out;
+                }
+                bdata->suspended = true;
+        }
+
+        return 0;
+
+err_out:
+        while (i--) {
+                bdata = &ddata->data[i];
+                if (bdata->button->wakeup)
+                        gpio_keys_button_disable_wakeup(bdata);
+                bdata->suspended = false;
+        }
+
+        return error;
+}
+
+static void __maybe_unused
+gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
+{
+        struct gpio_button_data *bdata;
+        int i;
+
+        for (i = 0; i < ddata->pdata->nbuttons; i++) {
+                bdata = &ddata->data[i];
+                bdata->suspended = false;
+                if (irqd_is_wakeup_set(irq_get_irq_data(bdata->irq)))
+                        gpio_keys_button_disable_wakeup(bdata);
+        }
+}
+
 static int __maybe_unused gpio_keys_suspend(struct device *dev)
 {
         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
         struct input_dev *input = ddata->input;
-        int i;
+        int error;
 
         if (device_may_wakeup(dev)) {
-                for (i = 0; i < ddata->pdata->nbuttons; i++) {
-                        struct gpio_button_data *bdata = &ddata->data[i];
-                        if (bdata->button->wakeup)
-                                enable_irq_wake(bdata->irq);
-                        bdata->suspended = true;
-                }
+                error = gpio_keys_enable_wakeup(ddata);
+                if (error)
+                        return error;
         } else {
                 mutex_lock(&input->mutex);
                 if (input->users)
@@ -873,15 +996,9 @@ static int __maybe_unused gpio_keys_resume(struct device *dev)
         struct gpio_keys_drvdata *ddata = dev_get_drvdata(dev);
         struct input_dev *input = ddata->input;
         int error = 0;
-        int i;
 
         if (device_may_wakeup(dev)) {
-                for (i = 0; i < ddata->pdata->nbuttons; i++) {
-                        struct gpio_button_data *bdata = &ddata->data[i];
-                        if (bdata->button->wakeup)
-                                disable_irq_wake(bdata->irq);
-                        bdata->suspended = false;
-                }
+                gpio_keys_disable_wakeup(ddata);
         } else {
                 mutex_lock(&input->mutex);
                 if (input->users)