2018-07-31 15:19:33

by Paweł Chmiel

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Subject: [PATCH v3 0/3] Input: atmel_mxt_ts: Add support for optional regulators

This patch series adds optional regulator support to atmel_mxt_ts.
First patch adds regulators to driver.
Second patch ensures that device is ready for communication.
Third patch updates documentation.

Changes from v2:
- Add reviewed-by to one patch
- Move code for enabling regulators into separate method,
to make code more readable.
- Add wait code, to ensure that device is ready for communication.

Changes from v1:
- Enable regulators only if reset_gpio is present.
- Switch from devm_regulator_get_optional to devm_regulator_get.

Paweł Chmiel (3):
Input: atmel_mxt_ts: Add support for optional regulators.
Input: atmel_mxt_ts: Wait for device be ready for communication
Input: atmel_mxt_ts: Document optional voltage regulators

.../devicetree/bindings/input/atmel,maxtouch.txt | 8 +++
drivers/input/touchscreen/atmel_mxt_ts.c | 76 ++++++++++++++++++++--
2 files changed, 78 insertions(+), 6 deletions(-)

--
2.7.4



2018-07-31 15:19:33

by Paweł Chmiel

[permalink] [raw]
Subject: [PATCH v3 3/3] Input: atmel_mxt_ts: Document optional voltage regulators

Document new optional voltage regulators, which can be used
to power down/up touchscreen.

Signed-off-by: Paweł Chmiel <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
---
Changes from v1:
- Added reviewed-by
---
Documentation/devicetree/bindings/input/atmel,maxtouch.txt | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
index c88919480d37..17930ecadad3 100644
--- a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
+++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
@@ -31,6 +31,12 @@ Optional properties for main touchpad device:

- reset-gpios: GPIO specifier for the touchscreen's reset pin (active low)

+- avdd-supply: Analog power supply. It powers up the analog channel block
+ of the controller to detect the touches.
+
+- vdd-supply: Digital power supply. It powers up the digital block
+ of the controller to enable i2c communication.
+
Example:

touch@4b {
@@ -38,4 +44,6 @@ Example:
reg = <0x4b>;
interrupt-parent = <&gpio>;
interrupts = <TEGRA_GPIO(W, 3) IRQ_TYPE_LEVEL_LOW>;
+ avdd-supply = <&atsp_reg>;
+ vdd-supply = <&tsp_reg>;
};
--
2.7.4


2018-07-31 15:19:44

by Paweł Chmiel

[permalink] [raw]
Subject: [PATCH v3 2/3] Input: atmel_mxt_ts: Wait for device be ready for communication

According to documentation, device isn't ready for communication,
until firmware asserts the CHG line. Add missing wait for this.

Signed-off-by: Paweł Chmiel <[email protected]>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2cd7f6db6ba9..79e08916359f 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -202,6 +202,7 @@ enum t100_type {
#define MXT_CRC_TIMEOUT 1000 /* msec */
#define MXT_FW_RESET_TIME 3000 /* msec */
#define MXT_FW_CHG_TIMEOUT 300 /* msec */
+#define MXT_POWERON_DELAY 150 /* msec */

/* Command to unlock bootloader */
#define MXT_UNLOCK_CMD_MSB 0xaa
@@ -3046,6 +3047,16 @@ static int mxt_regulator_enable(struct mxt_data *data)
msleep(MXT_REGULATOR_DELAY);
gpiod_set_value(data->reset_gpio, 1);
msleep(MXT_RESET_INVALID_CHG);
+
+retry_wait:
+ reinit_completion(&data->bl_completion);
+ data->in_bootloader = true;
+ error = mxt_wait_for_completion(data, &data->bl_completion,
+ MXT_POWERON_DELAY);
+ if (error == -EINTR)
+ goto retry_wait;
+
+ data->in_bootloader = false;
}

return 0;
--
2.7.4


2018-07-31 15:20:10

by Paweł Chmiel

[permalink] [raw]
Subject: [PATCH v3 1/3] Input: atmel_mxt_ts: Add support for optional regulators.

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 <[email protected]>
---
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
+ * 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


2018-08-22 18:07:26

by George G. Davis

[permalink] [raw]
Subject: Re: [PATCH v3 1/3] Input: atmel_mxt_ts: Add support for optional regulators.

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 <[email protected]>
> ---
> 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
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

2018-08-22 18:09:44

by George G. Davis

[permalink] [raw]
Subject: Re: [PATCH v3 2/3] Input: atmel_mxt_ts: Wait for device be ready for communication

Hello Paweł,

On Tue, Jul 31, 2018 at 05:18:10PM +0200, Paweł Chmiel wrote:
> According to documentation, device isn't ready for communication,
> until firmware asserts the CHG line. Add missing wait for this.
>
> Signed-off-by: Paweł Chmiel <[email protected]>
> ---
> drivers/input/touchscreen/atmel_mxt_ts.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
> index 2cd7f6db6ba9..79e08916359f 100644
> --- a/drivers/input/touchscreen/atmel_mxt_ts.c
> +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
> @@ -202,6 +202,7 @@ enum t100_type {
> #define MXT_CRC_TIMEOUT 1000 /* msec */
> #define MXT_FW_RESET_TIME 3000 /* msec */
> #define MXT_FW_CHG_TIMEOUT 300 /* msec */
> +#define MXT_POWERON_DELAY 150 /* msec */
>
> /* Command to unlock bootloader */
> #define MXT_UNLOCK_CMD_MSB 0xaa
> @@ -3046,6 +3047,16 @@ static int mxt_regulator_enable(struct mxt_data *data)
> msleep(MXT_REGULATOR_DELAY);
> gpiod_set_value(data->reset_gpio, 1);
> msleep(MXT_RESET_INVALID_CHG);
> +
> +retry_wait:
> + reinit_completion(&data->bl_completion);
> + data->in_bootloader = true;
> + error = mxt_wait_for_completion(data, &data->bl_completion,
> + MXT_POWERON_DELAY);

Please fix the following checkpatch issues:

drivers/input/touchscreen/atmel_mxt_ts.c:3078: WARNING:LONG_LINE: line over 80 characters
drivers/input/touchscreen/atmel_mxt_ts.c:3078: CHECK:PARENTHESIS_ALIGNMENT: Alignment should match open parenthesis

Thanks!

--
Regards,
George

> + if (error == -EINTR)
> + goto retry_wait;
> +
> + data->in_bootloader = false;
> }
>
> return 0;
> --
> 2.7.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel