diff mbox series

[v3,1/3] Input: atmel_mxt_ts: Add support for optional regulators.

Message ID 1533050291-11502-2-git-send-email-pawel.mikolaj.chmiel@gmail.com (mailing list archive)
State New, archived
Headers show
Series Input: atmel_mxt_ts: Add support for optional regulators | expand

Commit Message

Paweł Chmiel July 31, 2018, 3:18 p.m. UTC 
This patch adds optional regulators, which can be used to power
up touchscreen. After enabling regulators, we need to wait 150msec.
This value is taken from official driver.

It was tested on Samsung Galaxy i9000 (based on Samsung S5PV210 SOC).

Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
---
Changes from v2:
  - Move code enabling regulators into separate method,
    to make code more readable.

Changes from v1:
  - Enable regulators only if reset_gpio is present.
  - Switch from devm_regulator_get_optional to devm_regulator_get
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 65 +++++++++++++++++++++++++++++---
 1 file changed, 59 insertions(+), 6 deletions(-)

Comments

George G. Davis Aug. 22, 2018, 6:06 p.m. UTC | #1 
Hello Paweł,


I would suggest dropping sentence punctuation in the patch subject line:

Input: atmel_mxt_ts: Add support for optional regulators.

More below...

On Tue, Jul 31, 2018 at 05:18:09PM +0200, Paweł Chmiel wrote:
> This patch adds optional regulators, which can be used to power
> up touchscreen. After enabling regulators, we need to wait 150msec.
> This value is taken from official driver.
> 
> It was tested on Samsung Galaxy i9000 (based on Samsung S5PV210 SOC).
> 
> Signed-off-by: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
> ---
> Changes from v2:
>   - Move code enabling regulators into separate method,
>     to make code more readable.
> 
> Changes from v1:
>   - Enable regulators only if reset_gpio is present.
>   - Switch from devm_regulator_get_optional to devm_regulator_get
> ---
>  drivers/input/touchscreen/atmel_mxt_ts.c | 65 +++++++++++++++++++++++++++++---
>  1 file changed, 59 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index 54fe190fd4bc..2cd7f6db6ba9 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -27,6 +27,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/of.h>
>  #include <linux/property.h>
> +#include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/property.h>
> @@ -194,10 +195,10 @@ enum t100_type {
>  
>  /* Delay times */
>  #define MXT_BACKUP_TIME		50	/* msec */
> -#define MXT_RESET_GPIO_TIME	20	/* msec */
>  #define MXT_RESET_INVALID_CHG	100	/* msec */
>  #define MXT_RESET_TIME		200	/* msec */
>  #define MXT_RESET_TIMEOUT	3000	/* msec */
> +#define MXT_REGULATOR_DELAY	150	/* msec */
>  #define MXT_CRC_TIMEOUT		1000	/* msec */
>  #define MXT_FW_RESET_TIME	3000	/* msec */
>  #define MXT_FW_CHG_TIMEOUT	300	/* msec */
> @@ -310,6 +311,8 @@ struct mxt_data {
>  	struct t7_config t7_cfg;
>  	struct mxt_dbg dbg;
>  	struct gpio_desc *reset_gpio;
> +	struct regulator *vdd_reg;
> +	struct regulator *avdd_reg;
>  
>  	/* Cached parameters from object table */
>  	u16 T5_address;
> @@ -3016,6 +3019,38 @@ static const struct dmi_system_id chromebook_T9_suspend_dmi[] = {
>  	{ }
>  };
>  
> +static int mxt_regulator_enable(struct mxt_data *data)
> +{
> +	int error;
> +
> +	if (data->reset_gpio) {
> +		error = regulator_enable(data->vdd_reg);
> +		if (error) {
> +			dev_err(&data->client->dev, "Failed to enable vdd regulator: %d\n",
> +				error);
> +			return error;
> +		}
> +
> +		error = regulator_enable(data->avdd_reg);
> +		if (error) {
> +			dev_err(&data->client->dev, "Failed to enable avdd regulator: %d\n",
> +				error);
> +			return error;
> +		}
> +
> +		/*
> +		 * According to maXTouch power sequencing specification, RESET line

Please fix the following checkpatch issue:

drivers/input/touchscreen/atmel_mxt_ts.c:3065: WARNING:LONG_LINE_COMMENT: line over 80 characters

Thanks!

--
Regards,
George

> +		 * must be kept low until some time after regulators come up to
> +		 * voltage
> +		 */
> +		msleep(MXT_REGULATOR_DELAY);
> +		gpiod_set_value(data->reset_gpio, 1);
> +		msleep(MXT_RESET_INVALID_CHG);
> +	}
> +
> +	return 0;
> +}
> +
>  static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  {
>  	struct mxt_data *data;
> @@ -3076,6 +3111,22 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  		return error;
>  	}
>  
> +	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
> +	if (IS_ERR(data->vdd_reg)) {
> +		error = PTR_ERR(data->vdd_reg);
> +		dev_err(&client->dev, "Failed to get vdd regulator: %d\n",
> +			error);
> +		return error;
> +	}
> +
> +	data->avdd_reg = devm_regulator_get(&client->dev, "avdd");
> +	if (IS_ERR(data->avdd_reg)) {
> +		error = PTR_ERR(data->avdd_reg);
> +		dev_err(&client->dev, "Failed to get avdd regulator: %d\n",
> +			error);
> +		return error;
> +	}
> +
>  	error = devm_request_threaded_irq(&client->dev, client->irq,
>  					  NULL, mxt_interrupt, IRQF_ONESHOT,
>  					  client->name, data);
> @@ -3086,11 +3137,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  
>  	disable_irq(client->irq);
>  
> -	if (data->reset_gpio) {
> -		msleep(MXT_RESET_GPIO_TIME);
> -		gpiod_set_value(data->reset_gpio, 1);
> -		msleep(MXT_RESET_INVALID_CHG);
> -	}
> +	error = mxt_regulator_enable(data);
> +	if (error)
> +		return error;
>  
>  	error = mxt_initialize(data);
>  	if (error)
> @@ -3116,6 +3165,10 @@ static int mxt_remove(struct i2c_client *client)
>  	struct mxt_data *data = i2c_get_clientdata(client);
>  
>  	disable_irq(data->irq);
> +	if (data->reset_gpio) {
> +		regulator_disable(data->avdd_reg);
> +		regulator_disable(data->vdd_reg);
> +	}
>  	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
>  	mxt_free_input_device(data);
>  	mxt_free_object_table(data);
> -- 
> 2.7.4
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff mbox series

Patch

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 54fe190fd4bc..2cd7f6db6ba9 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -27,6 +27,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/property.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 #include <linux/gpio/consumer.h>
 #include <linux/property.h>
@@ -194,10 +195,10 @@  enum t100_type {
 
 /* Delay times */
 #define MXT_BACKUP_TIME		50	/* msec */
-#define MXT_RESET_GPIO_TIME	20	/* msec */
 #define MXT_RESET_INVALID_CHG	100	/* msec */
 #define MXT_RESET_TIME		200	/* msec */
 #define MXT_RESET_TIMEOUT	3000	/* msec */
+#define MXT_REGULATOR_DELAY	150	/* msec */
 #define MXT_CRC_TIMEOUT		1000	/* msec */
 #define MXT_FW_RESET_TIME	3000	/* msec */
 #define MXT_FW_CHG_TIMEOUT	300	/* msec */
@@ -310,6 +311,8 @@  struct mxt_data {
 	struct t7_config t7_cfg;
 	struct mxt_dbg dbg;
 	struct gpio_desc *reset_gpio;
+	struct regulator *vdd_reg;
+	struct regulator *avdd_reg;
 
 	/* Cached parameters from object table */
 	u16 T5_address;
@@ -3016,6 +3019,38 @@  static const struct dmi_system_id chromebook_T9_suspend_dmi[] = {
 	{ }
 };
 
+static int mxt_regulator_enable(struct mxt_data *data)
+{
+	int error;
+
+	if (data->reset_gpio) {
+		error = regulator_enable(data->vdd_reg);
+		if (error) {
+			dev_err(&data->client->dev, "Failed to enable vdd regulator: %d\n",
+				error);
+			return error;
+		}
+
+		error = regulator_enable(data->avdd_reg);
+		if (error) {
+			dev_err(&data->client->dev, "Failed to enable avdd regulator: %d\n",
+				error);
+			return error;
+		}
+
+		/*
+		 * According to maXTouch power sequencing specification, RESET line
+		 * must be kept low until some time after regulators come up to
+		 * voltage
+		 */
+		msleep(MXT_REGULATOR_DELAY);
+		gpiod_set_value(data->reset_gpio, 1);
+		msleep(MXT_RESET_INVALID_CHG);
+	}
+
+	return 0;
+}
+
 static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	struct mxt_data *data;
@@ -3076,6 +3111,22 @@  static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return error;
 	}
 
+	data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
+	if (IS_ERR(data->vdd_reg)) {
+		error = PTR_ERR(data->vdd_reg);
+		dev_err(&client->dev, "Failed to get vdd regulator: %d\n",
+			error);
+		return error;
+	}
+
+	data->avdd_reg = devm_regulator_get(&client->dev, "avdd");
+	if (IS_ERR(data->avdd_reg)) {
+		error = PTR_ERR(data->avdd_reg);
+		dev_err(&client->dev, "Failed to get avdd regulator: %d\n",
+			error);
+		return error;
+	}
+
 	error = devm_request_threaded_irq(&client->dev, client->irq,
 					  NULL, mxt_interrupt, IRQF_ONESHOT,
 					  client->name, data);
@@ -3086,11 +3137,9 @@  static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 
 	disable_irq(client->irq);
 
-	if (data->reset_gpio) {
-		msleep(MXT_RESET_GPIO_TIME);
-		gpiod_set_value(data->reset_gpio, 1);
-		msleep(MXT_RESET_INVALID_CHG);
-	}
+	error = mxt_regulator_enable(data);
+	if (error)
+		return error;
 
 	error = mxt_initialize(data);
 	if (error)
@@ -3116,6 +3165,10 @@  static int mxt_remove(struct i2c_client *client)
 	struct mxt_data *data = i2c_get_clientdata(client);
 
 	disable_irq(data->irq);
+	if (data->reset_gpio) {
+		regulator_disable(data->avdd_reg);
+		regulator_disable(data->vdd_reg);
+	}
 	sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
 	mxt_free_input_device(data);
 	mxt_free_object_table(data);