[PATCH v6 3/3] Input: atmel_mxt_ts - add support for poweroff-sleep

[Stefan Eichenberger]

From: Stefan Eichenberger <stefan.eichenberger at toradex.com>

Add support for poweroff-sleep to the Atmel maXTouch driver. This allows
us to power off the input device entirely and only power it on when it
is opened. This will also automatically power it off when we suspend the
system.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger at toradex.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 82 ++++++++++++++++++++----
 1 file changed, 70 insertions(+), 12 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 9416de53bf9af..46ed3dbf0c5ed 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -265,6 +265,7 @@ enum v4l_dbg_inputs {
 enum mxt_suspend_mode {
 	MXT_SUSPEND_DEEP_SLEEP	= 0,
 	MXT_SUSPEND_T9_CTRL	= 1,
+	MXT_SUSPEND_POWEROFF	= 2,
 };
 
 /* Config update context */
@@ -1311,6 +1312,10 @@ static int mxt_power_on(struct mxt_data *data)
 {
 	int error;
 
+	/* Make sure the device is in reset before enabling power */
+	if (data->reset_gpio)
+		gpiod_set_value_cansleep(data->reset_gpio, 1);
+
 	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
 				      data->regulators);
 	if (error) {
@@ -2270,8 +2275,38 @@ static int mxt_configure_objects(struct mxt_data *data,
 
 static void mxt_config_cb(const struct firmware *cfg, void *ctx)
 {
+	struct mxt_data *data = ctx;
+
 	mxt_configure_objects(ctx, cfg);
 	release_firmware(cfg);
+
+	if ((data->suspend_mode == MXT_SUSPEND_POWEROFF) && !data->in_bootloader) {
+		disable_irq(data->irq);
+		mxt_power_off(data);
+	}
+}
+
+static void mxt_initialize_after_resume(struct mxt_data *data)
+{
+	int error;
+
+	error = mxt_power_on(data);
+	if (error) {
+		dev_err(&data->client->dev, "Failed to power on device\n");
+		return;
+	}
+
+	error = mxt_acquire_irq(data);
+	if (error) {
+		dev_err(&data->client->dev, "Failed to acquire IRQ\n");
+		return;
+	}
+
+	error = mxt_configure_objects(data, NULL);
+	if (error) {
+		dev_err(&data->client->dev, "Failed to configure objects\n");
+		return;
+	}
 }
 
 static int mxt_initialize(struct mxt_data *data)
@@ -2828,15 +2863,18 @@ static int mxt_configure_objects(struct mxt_data *data,
 			dev_warn(dev, "Error %d updating config\n", error);
 	}
 
-	if (data->multitouch) {
-		error = mxt_initialize_input_device(data);
-		if (error)
-			return error;
-	} else {
-		dev_warn(dev, "No touch object detected\n");
-	}
+	/* Do not initialize and register input device twice */
+	if (!data->input_dev) {
+		if (data->multitouch) {
+			error = mxt_initialize_input_device(data);
+			if (error)
+				return error;
+		} else {
+			dev_warn(dev, "No touch object detected\n");
+		}
 
-	mxt_debug_init(data);
+		mxt_debug_init(data);
+	}
 
 	return 0;
 }
@@ -3070,6 +3108,12 @@ static ssize_t mxt_update_fw_store(struct device *dev,
 	struct mxt_data *data = dev_get_drvdata(dev);
 	int error;
 
+	if ((data->suspend_mode == MXT_SUSPEND_POWEROFF) && !data->in_bootloader) {
+		error = mxt_power_on(data);
+		if (error)
+			return error;
+	}
+
 	error = mxt_load_fw(dev, MXT_FW_NAME);
 	if (error) {
 		dev_err(dev, "The firmware update failed(%d)\n", error);
@@ -3104,7 +3148,10 @@ static const struct attribute_group mxt_attr_group = {
 
 static void mxt_start(struct mxt_data *data)
 {
-	mxt_wakeup_toggle(data->client, true, false);
+	if (data->suspend_mode == MXT_SUSPEND_POWEROFF)
+		mxt_initialize_after_resume(data);
+	else
+		mxt_wakeup_toggle(data->client, true, false);
 
 	switch (data->suspend_mode) {
 	case MXT_SUSPEND_T9_CTRL:
@@ -3116,6 +3163,7 @@ static void mxt_start(struct mxt_data *data)
 				MXT_TOUCH_MULTI_T9, MXT_T9_CTRL, 0x83);
 		break;
 
+	case MXT_SUSPEND_POWEROFF:
 	case MXT_SUSPEND_DEEP_SLEEP:
 	default:
 		mxt_set_t7_power_cfg(data, MXT_POWER_CFG_RUN);
@@ -3141,7 +3189,12 @@ static void mxt_stop(struct mxt_data *data)
 		break;
 	}
 
-	mxt_wakeup_toggle(data->client, false, false);
+	if (data->suspend_mode == MXT_SUSPEND_POWEROFF) {
+		disable_irq(data->irq);
+		mxt_power_off(data);
+	} else {
+		mxt_wakeup_toggle(data->client, false, false);
+	}
 }
 
 static int mxt_input_open(struct input_dev *dev)
@@ -3338,6 +3391,9 @@ static int mxt_probe(struct i2c_client *client)
 	if (error)
 		return error;
 
+	if (device_property_read_bool(&client->dev, "atmel,poweroff-sleep"))
+		data->suspend_mode = MXT_SUSPEND_POWEROFF;
+
 	/*
 	 * Controllers like mXT1386 have a dedicated WAKE line that could be
 	 * connected to a GPIO or to I2C SCL pin, or permanently asserted low.
@@ -3387,7 +3443,8 @@ static void mxt_remove(struct i2c_client *client)
 	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
-	mxt_power_off(data);
+	if (!(data->suspend_mode == MXT_SUSPEND_POWEROFF))
+		mxt_power_off(data);
 }
 
 static int mxt_suspend(struct device *dev)
@@ -3420,7 +3477,8 @@ static int mxt_resume(struct device *dev)
 	if (!input_dev)
 		return 0;
 
-	enable_irq(data->irq);
+	if (!(data->suspend_mode == MXT_SUSPEND_POWEROFF))
+		enable_irq(data->irq);
 
 	mutex_lock(&input_dev->mutex);
 
-- 
2.43.0