diff mbox series

[v4,1/4] Input: atmel_mxt_ts - add power off and power on functions

Message ID 20240417090527.15357-2-eichest@gmail.com
State New
Headers show
Series Add a property to turn off the max touch controller if not used | expand

Commit Message

Stefan Eichenberger April 17, 2024, 9:05 a.m. UTC
From: Stefan Eichenberger <stefan.eichenberger@toradex.com>

Add a separate function for power off and power on instead of calling
regulator_bulk_enable and regulator_bulk_disable directly.

Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 59 +++++++++++++++---------
 1 file changed, 37 insertions(+), 22 deletions(-)

Comments

Dmitry Torokhov June 20, 2024, 3:37 p.m. UTC | #1
Hi Stefan,

On Wed, Apr 17, 2024 at 11:05:24AM +0200, Stefan Eichenberger wrote:
> From: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> 
> Add a separate function for power off and power on instead of calling
> regulator_bulk_enable and regulator_bulk_disable directly.
> 
> Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com>
> ---
>  drivers/input/touchscreen/atmel_mxt_ts.c | 59 +++++++++++++++---------
>  1 file changed, 37 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index 542a31448c8f..52867ce3b9b6 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -1307,6 +1307,38 @@ static int mxt_soft_reset(struct mxt_data *data)
>  	return 0;
>  }
>  
> +static int mxt_power_on(struct mxt_data *data)
> +{
> +	int error;
> +
> +	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> +				      data->regulators);
> +	if (error) {
> +		dev_err(&data->client->dev, "failed to enable regulators: %d\n",
> +			error);
> +		return error;
> +	}
> +
> +	msleep(MXT_BACKUP_TIME);
> +
> +	if (data->reset_gpio) {
> +		/* Wait a while and then de-assert the RESET GPIO line */
> +		msleep(MXT_RESET_GPIO_TIME);
> +		gpiod_set_value(data->reset_gpio, 0);
> +		msleep(MXT_RESET_INVALID_CHG);
> +	}
> +
> +	return 0;
> +}
> +
> +static void mxt_power_off(struct mxt_data *data)
> +{
> +	if (data->reset_gpio)
> +		gpiod_set_value(data->reset_gpio, 1);
> +
> +	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
> +}
> +
>  static void mxt_update_crc(struct mxt_data *data, u8 cmd, u8 value)
>  {
>  	/*
> @@ -3305,25 +3337,9 @@ static int mxt_probe(struct i2c_client *client)
>  		return error;
>  	}
>  
> -	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
> -				      data->regulators);
> -	if (error) {
> -		dev_err(&client->dev, "failed to enable regulators: %d\n",
> -			error);
> +	error = mxt_power_on(data);
> +	if (error)
>  		return error;
> -	}
> -	/*
> -	 * The device takes 40ms to come up after power-on according
> -	 * to the mXT224 datasheet, page 13.
> -	 */
> -	msleep(MXT_BACKUP_TIME);
> -
> -	if (data->reset_gpio) {
> -		/* Wait a while and then de-assert the RESET GPIO line */
> -		msleep(MXT_RESET_GPIO_TIME);
> -		gpiod_set_value(data->reset_gpio, 0);
> -		msleep(MXT_RESET_INVALID_CHG);
> -	}
>  
>  	/*
>  	 * Controllers like mXT1386 have a dedicated WAKE line that could be
> @@ -3361,8 +3377,8 @@ static int mxt_probe(struct i2c_client *client)
>  	mxt_free_input_device(data);
>  	mxt_free_object_table(data);
>  err_disable_regulators:
> -	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
> -			       data->regulators);
> +	mxt_power_off(data);
> +
>  	return error;
>  }
>  
> @@ -3374,8 +3390,7 @@ 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);
> -	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
> -			       data->regulators);
> +	mxt_power_off(data);

This change means that on unbind we will leave with GPIO line asserted.
Won't this potentially cause some current leakage? Why do we need to
have reset asserted here?

Thanks.
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 542a31448c8f..52867ce3b9b6 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -1307,6 +1307,38 @@  static int mxt_soft_reset(struct mxt_data *data)
 	return 0;
 }
 
+static int mxt_power_on(struct mxt_data *data)
+{
+	int error;
+
+	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
+				      data->regulators);
+	if (error) {
+		dev_err(&data->client->dev, "failed to enable regulators: %d\n",
+			error);
+		return error;
+	}
+
+	msleep(MXT_BACKUP_TIME);
+
+	if (data->reset_gpio) {
+		/* Wait a while and then de-assert the RESET GPIO line */
+		msleep(MXT_RESET_GPIO_TIME);
+		gpiod_set_value(data->reset_gpio, 0);
+		msleep(MXT_RESET_INVALID_CHG);
+	}
+
+	return 0;
+}
+
+static void mxt_power_off(struct mxt_data *data)
+{
+	if (data->reset_gpio)
+		gpiod_set_value(data->reset_gpio, 1);
+
+	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
+}
+
 static void mxt_update_crc(struct mxt_data *data, u8 cmd, u8 value)
 {
 	/*
@@ -3305,25 +3337,9 @@  static int mxt_probe(struct i2c_client *client)
 		return error;
 	}
 
-	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
-				      data->regulators);
-	if (error) {
-		dev_err(&client->dev, "failed to enable regulators: %d\n",
-			error);
+	error = mxt_power_on(data);
+	if (error)
 		return error;
-	}
-	/*
-	 * The device takes 40ms to come up after power-on according
-	 * to the mXT224 datasheet, page 13.
-	 */
-	msleep(MXT_BACKUP_TIME);
-
-	if (data->reset_gpio) {
-		/* Wait a while and then de-assert the RESET GPIO line */
-		msleep(MXT_RESET_GPIO_TIME);
-		gpiod_set_value(data->reset_gpio, 0);
-		msleep(MXT_RESET_INVALID_CHG);
-	}
 
 	/*
 	 * Controllers like mXT1386 have a dedicated WAKE line that could be
@@ -3361,8 +3377,8 @@  static int mxt_probe(struct i2c_client *client)
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);
 err_disable_regulators:
-	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
-			       data->regulators);
+	mxt_power_off(data);
+
 	return error;
 }
 
@@ -3374,8 +3390,7 @@  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);
-	regulator_bulk_disable(ARRAY_SIZE(data->regulators),
-			       data->regulators);
+	mxt_power_off(data);
 }
 
 static int mxt_suspend(struct device *dev)