[PATCH v4 1/2] dt-bindings: input: gpio-keys: Allow optional dedicated wakeirq

[PATCH v4 1/2] dt-bindings: input: gpio-keys: Allow optional dedicated wakeirq

[Tony Lindgren]

Allow configuring an optional dedicated wakeirq for gpio-keys that
some SoCs have.

Let's use the common interrupt naming "irq" and "wakeup" that we already
have in use for some drivers and subsystems like i2c framework.

Note that the gpio-keys interrupt property is optional. If only a gpio
property is specified, the driver tries to translate the gpio into an
interrupt.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

No changes since v3

Changes since v2:
- Fix indentation as noted by Rob's bot

- Add Reviewed-by from Rob

Changes since v1:

- Run make dt_binding_check on the binding

- Add better checks for interrupt-names as suggested by Rob, it is
  now required if two interrupts are configured

- Add more decription entries

- Add a new example for key-wakeup

 .../devicetree/bindings/input/gpio-keys.yaml  | 41 ++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/input/gpio-keys.yaml b/Documentation/devicetree/bindings/input/gpio-keys.yaml
--- a/Documentation/devicetree/bindings/input/gpio-keys.yaml
+++ b/Documentation/devicetree/bindings/input/gpio-keys.yaml
@@ -31,7 +31,23 @@ patternProperties:
         maxItems: 1
 
       interrupts:
-        maxItems: 1
+        oneOf:
+          - items:
+              - description: Optional key interrupt or wakeup interrupt
+          - items:
+              - description: Key interrupt
+              - description: Wakeup interrupt
+
+      interrupt-names:
+        description:
+          Optional interrupt names, can be used to specify a separate dedicated
+          wake-up interrupt in addition to the gpio irq
+        oneOf:
+          - items:
+              - enum: [ irq, wakeup ]
+          - items:
+              - const: irq
+              - const: wakeup
 
       label:
         description: Descriptive name of the key.
@@ -97,6 +113,20 @@ patternProperties:
       - required:
           - gpios
 
+    allOf:
+      - if:
+          properties:
+            interrupts:
+              minItems: 2
+          required:
+            - interrupts
+        then:
+          properties:
+            interrupt-names:
+              minItems: 2
+          required:
+            - interrupt-names
+
     dependencies:
       wakeup-event-action: [ wakeup-source ]
       linux,input-value: [ gpios ]
@@ -137,6 +167,15 @@ examples:
             linux,code = <108>;
             interrupts = <1 IRQ_TYPE_EDGE_FALLING>;
         };
+
+        key-wakeup {
+            label = "GPIO Key WAKEUP";
+            linux,code = <143>;
+            interrupts-extended = <&intc 2 IRQ_TYPE_EDGE_FALLING>,
+                                  <&intc_wakeup 0 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "irq", "wakeup";
+            wakeup-source;
+        };
     };
 
 ...
-- 
2.42.1

[PATCH v4 2/2] Input: gpio-keys - Add system suspend support for dedicated wakeirqs

[Tony Lindgren]

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@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

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

Re: [PATCH v4 2/2] Input: gpio-keys - Add system suspend support for dedicated wakeirqs

[Dmitry Torokhov]

Hi Tony,

On Fri, Nov 24, 2023 at 10:32:41AM +0200, Tony Lindgren wrote:
> +	/*
> +	 * 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);

Why _nosync() here and below? Is there any harm in sing the normal
variant?

Thanks.

-- 
Dmitry

Re: [PATCH v4 2/2] Input: gpio-keys - Add system suspend support for dedicated wakeirqs

[Tony Lindgren]

* Dmitry Torokhov <dmitry.torokhov@gmail.com> [231125 04:50]:
> Hi Tony,
> 
> On Fri, Nov 24, 2023 at 10:32:41AM +0200, Tony Lindgren wrote:
> > +	/*
> > +	 * 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);
> 
> Why _nosync() here and below? Is there any harm in sing the normal
> variant?

Well they are enabled the same time anyways for a while, so I see no
harm using the normal variant here. Will post updated patches after
some testing.

Regards,

Tony