Some SoCs have a separate dedicated wake-up interrupt controller that can
be used to wake up the system from deeper idle states. We already support
configuring a separate interrupt for a gpio-keys button to be used with a
gpio line. However, we are lacking support system suspend for cases where
a separate interrupt needs to be used in deeper sleep modes.
Because of it's nature, gpio-keys does not know about the runtime PM state
of the button gpios, and may have several gpio buttons configured for each
gpio-keys device instance. Implementing runtime PM support for gpio-keys
does not help, and we cannot use drivers/base/power/wakeirq.c support. We
need to implement custom wakeirq support for gpio-keys.
For handling a dedicated wakeirq for system suspend, we enable and disable
it with gpio_keys_enable_wakeup() and gpio_keys_disable_wakeup() that we
already use based on device_may_wakeup().
Some systems may have a dedicated wakeirq that can also be used as the
main interrupt, this is already working for gpio-keys. Let's add some
wakeirq related comments while at it as the usage with a gpio line and
separate interrupt line may not be obvious.
Tested-by: Dhruva Gole <d-gole@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
No changes from v1
---
drivers/input/keyboard/gpio_keys.c | 69 ++++++++++++++++++++++++++++--
include/linux/gpio_keys.h | 2 +
2 files changed, 67 insertions(+), 4 deletions(-)
diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -45,7 +45,9 @@ struct gpio_button_data {
unsigned int software_debounce; /* in msecs, for GPIO-driven buttons */
unsigned int irq;
+ unsigned int wakeirq;
unsigned int wakeup_trigger_type;
+
spinlock_t lock;
bool disabled;
bool key_pressed;
@@ -511,6 +513,7 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
struct gpio_button_data *bdata = &ddata->data[idx];
irq_handler_t isr;
unsigned long irqflags;
+ const char *wakedesc;
int irq;
int error;
@@ -575,6 +578,14 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
!gpiod_cansleep(bdata->gpiod);
}
+ /*
+ * If an interrupt was specified, use it instead of the gpio
+ * interrupt and use the gpio for reading the state. A separate
+ * interrupt may be used as the main button interrupt for
+ * runtime PM to detect events also in deeper idle states. If a
+ * dedicated wakeirq is used for system suspend only, see below
+ * for bdata->wakeirq setup.
+ */
if (button->irq) {
bdata->irq = button->irq;
} else {
@@ -672,6 +683,36 @@ static int gpio_keys_setup_key(struct platform_device *pdev,
return error;
}
+ if (!button->wakeirq)
+ return 0;
+
+ /* Use :wakeup suffix like drivers/base/power/wakeirq.c does */
+ wakedesc = devm_kasprintf(dev, GFP_KERNEL, "%s:wakeup", desc);
+ if (!wakedesc)
+ return -ENOMEM;
+
+ bdata->wakeirq = button->wakeirq;
+ irqflags |= IRQF_NO_SUSPEND;
+
+ /*
+ * Wakeirq shares the handler with the main interrupt, it's only
+ * active during system suspend. See gpio_keys_button_enable_wakeup()
+ * and gpio_keys_button_disable_wakeup().
+ */
+ error = devm_request_any_context_irq(dev, bdata->wakeirq, isr,
+ irqflags, wakedesc, bdata);
+ if (error < 0) {
+ dev_err(dev, "Unable to claim wakeirq %d; error %d\n",
+ bdata->irq, error);
+ return error;
+ }
+
+ /*
+ * Disable wakeirq until suspend. IRQF_NO_AUTOEN won't work if
+ * IRQF_SHARED was set based on !button->can_disable.
+ */
+ disable_irq_nosync(bdata->wakeirq);
+
return 0;
}
@@ -728,7 +769,7 @@ gpio_keys_get_devtree_pdata(struct device *dev)
struct gpio_keys_platform_data *pdata;
struct gpio_keys_button *button;
struct fwnode_handle *child;
- int nbuttons;
+ int nbuttons, irq;
nbuttons = device_get_child_node_count(dev);
if (nbuttons == 0)
@@ -750,9 +791,19 @@ gpio_keys_get_devtree_pdata(struct device *dev)
device_property_read_string(dev, "label", &pdata->name);
device_for_each_child_node(dev, child) {
- if (is_of_node(child))
- button->irq =
- irq_of_parse_and_map(to_of_node(child), 0);
+ if (is_of_node(child)) {
+ irq = of_irq_get_byname(to_of_node(child), "irq");
+ if (irq > 0)
+ button->irq = irq;
+
+ irq = of_irq_get_byname(to_of_node(child), "wakeup");
+ if (irq > 0)
+ button->wakeirq = irq;
+
+ if (!button->irq && !button->wakeirq)
+ button->irq =
+ irq_of_parse_and_map(to_of_node(child), 0);
+ }
if (fwnode_property_read_u32(child, "linux,code",
&button->code)) {
@@ -921,6 +972,11 @@ gpio_keys_button_enable_wakeup(struct gpio_button_data *bdata)
}
}
+ if (bdata->wakeirq) {
+ enable_irq(bdata->wakeirq);
+ disable_irq_nosync(bdata->irq);
+ }
+
return 0;
}
@@ -929,6 +985,11 @@ gpio_keys_button_disable_wakeup(struct gpio_button_data *bdata)
{
int error;
+ if (bdata->wakeirq) {
+ enable_irq(bdata->irq);
+ disable_irq_nosync(bdata->wakeirq);
+ }
+
/*
* The trigger type is always both edges for gpio-based keys and we do
* not support changing wakeup trigger for interrupt-based keys.
diff --git a/include/linux/gpio_keys.h b/include/linux/gpio_keys.h
--- a/include/linux/gpio_keys.h
+++ b/include/linux/gpio_keys.h
@@ -21,6 +21,7 @@ struct device;
* disable button via sysfs
* @value: axis value for %EV_ABS
* @irq: Irq number in case of interrupt keys
+ * @wakeirq: Optional dedicated wake-up interrupt
*/
struct gpio_keys_button {
unsigned int code;
@@ -34,6 +35,7 @@ struct gpio_keys_button {
bool can_disable;
int value;
unsigned int irq;
+ unsigned int wakeirq;
};
/**
--
2.42.1
