[PATCH v4 2/2] Input: gpio-keys - support wakeup pinctrl state on suspend

[Kendall Willis <k-willis@ti.com>]

GPIO can be used as a wakeup source for TI K3 AM62 devices during
suspend to RAM states. The GPIO controller is powered off in these
states, so a wakeup enable flag must be set on the GPIO pin in the
pinctrl in order to allow wakeup.

If the device is wakeup enabled, select the wakeup pinctrl state on
suspend and restore the default pinctrl state on resume.

Signed-off-by: Kendall Willis <k-willis@ti.com>
---
 drivers/input/keyboard/gpio_keys.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/input/keyboard/gpio_keys.c b/drivers/input/keyboard/gpio_keys.c
index 129fc4212a5ed126496b331ce626682d441c53bf..8d3409c6de1ea87ccc118b2d6ba9ffc313caa027 100644
--- a/drivers/input/keyboard/gpio_keys.c
+++ b/drivers/input/keyboard/gpio_keys.c
@@ -28,6 +28,7 @@
 #include <linux/of.h>
 #include <linux/of_irq.h>
 #include <linux/spinlock.h>
+#include <linux/pinctrl/consumer.h>
 #include <dt-bindings/input/gpio-keys.h>
 
 struct gpio_button_data {
@@ -60,6 +61,8 @@ struct gpio_keys_drvdata {
 	struct input_dev *input;
 	struct mutex disable_lock;
 	unsigned short *keymap;
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *pinctrl_wakeup;
 	struct gpio_button_data data[];
 };
 
@@ -884,6 +887,17 @@ static int gpio_keys_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, ddata);
 	input_set_drvdata(input, ddata);
 
+	ddata->pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR(ddata->pinctrl)) {
+		error = PTR_ERR(ddata->pinctrl);
+		ddata->pinctrl = NULL;
+
+		if (error != -ENODEV)
+			return dev_err_probe(dev, error, "Failed to get pinctrl\n");
+	} else if (ddata->pinctrl) {
+		ddata->pinctrl_wakeup = pinctrl_lookup_state(ddata->pinctrl, "wakeup");
+	}
+
 	input->name = pdata->name ? : pdev->name;
 	input->phys = "gpio-keys/input0";
 	input->dev.parent = dev;
@@ -1010,6 +1024,12 @@ gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 	int error;
 	int i;
 
+	if (!IS_ERR_OR_NULL(ddata->pinctrl_wakeup)) {
+		error = pinctrl_select_state(ddata->pinctrl, ddata->pinctrl_wakeup);
+		if (error)
+			return error;
+	}
+
 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		bdata = &ddata->data[i];
 		if (bdata->button->wakeup) {
@@ -1023,6 +1043,9 @@ gpio_keys_enable_wakeup(struct gpio_keys_drvdata *ddata)
 	return 0;
 
 err_out:
+	if (!IS_ERR_OR_NULL(ddata->pinctrl_wakeup))
+		pinctrl_pm_select_default_state(ddata->input->dev.parent);
+
 	while (i--) {
 		bdata = &ddata->data[i];
 		if (bdata->button->wakeup)
@@ -1039,6 +1062,9 @@ gpio_keys_disable_wakeup(struct gpio_keys_drvdata *ddata)
 	struct gpio_button_data *bdata;
 	int i;
 
+	if (!IS_ERR_OR_NULL(ddata->pinctrl_wakeup))
+		pinctrl_pm_select_default_state(ddata->input->dev.parent);
+
 	for (i = 0; i < ddata->pdata->nbuttons; i++) {
 		bdata = &ddata->data[i];
 		bdata->suspended = false;

-- 
2.34.1