Our hardware has a shared regulator that powers various peripherals such
as the display, touch, USB hub, etc. Since the Maxtouch controller
doesn't currently allow it to be turned off, this regulator has to stay
on when not used. This increases the overall power consumption. In order
to turn off the controller when the system does not use it, this series
adds a device tree property to the maxtouch driver that allows the
controller to be turned off completely and ensurs that it can resume
from the power off state.
Changes since v3:
- Move the power on part to mxt_start and the power off part to
mxt_stop. This allows to turn the touch controller off even when not
in use and not only when being suspended (Dmitry)
Changes since v2:
- Add Reviewed-by tags from Linus and Krzysztof to the dt-bindings patch
Changes since v1:
- Rename the property and change the description (Krzysztof, Linus,
Dmitry, Conor)
Stefan Eichenberger (4):
Input: atmel_mxt_ts - add power off and power on functions
Input: atmel_mxt_ts - move calls to register the input device to
separate function
dt-bindings: input: atmel,maxtouch: add poweroff-sleep property
Input: atmel_mxt_ts - add support for poweroff-sleep
.../bindings/input/atmel,maxtouch.yaml | 6 +
drivers/input/touchscreen/atmel_mxt_ts.c | 162 +++++++++++++-----
2 files changed, 124 insertions(+), 44 deletions(-)
--
2.40.1
From: Stefan Eichenberger <[email protected]>
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 <[email protected]>
---
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);
}
static int mxt_suspend(struct device *dev)
--
2.40.1
From: Stefan Eichenberger <[email protected]>
The calls to register the input device are moved to a separate function
so that we can call it without having to confiugre the device. This is
necessary if we want to power on the device only when it is opened.
Signed-off-by: Stefan Eichenberger <[email protected]>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 34 +++++++++++++++++-------
1 file changed, 25 insertions(+), 9 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 52867ce3b9b6..7c807d1f1f9b 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -2277,6 +2277,28 @@ static void mxt_config_cb(const struct firmware *cfg, void *ctx)
release_firmware(cfg);
}
+static void mxt_debug_init(struct mxt_data *data);
+
+static int mxt_device_register(struct mxt_data *data)
+{
+ int error;
+
+ /* If input device is not already registered */
+ if (!data->input_dev) {
+ if (data->multitouch) {
+ error = mxt_initialize_input_device(data);
+ if (error)
+ return error;
+ } else {
+ dev_warn(&data->client->dev, "No touch object detected\n");
+ }
+
+ mxt_debug_init(data);
+ }
+
+ return 0;
+}
+
static int mxt_initialize(struct mxt_data *data)
{
struct i2c_client *client = data->client;
@@ -2831,15 +2853,9 @@ 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");
- }
-
- mxt_debug_init(data);
+ error = mxt_device_register(data);
+ if (error)
+ return error;
return 0;
}
--
2.40.1
From: Stefan Eichenberger <[email protected]>
Add a new property to indicate that the device should power off rather
than use deep sleep. Deep sleep is a feature of the controller that
expects the controller to remain powered in suspend. However, if a
display shares its regulator with the touch controller, we may want to
do a power off so that the display and touch controller do not use any
power.
Signed-off-by: Stefan Eichenberger <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>
---
Documentation/devicetree/bindings/input/atmel,maxtouch.yaml | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.yaml b/Documentation/devicetree/bindings/input/atmel,maxtouch.yaml
index c40799355ed7..8de5f539b30e 100644
--- a/Documentation/devicetree/bindings/input/atmel,maxtouch.yaml
+++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.yaml
@@ -87,6 +87,12 @@ properties:
- 2 # ATMEL_MXT_WAKEUP_GPIO
default: 0
+ atmel,poweroff-sleep:
+ description: |
+ Instead of using the deep sleep feature of the maXTouch controller,
+ poweroff the regulators.
+ type: boolean
+
wakeup-source:
type: boolean
--
2.40.1
From: Stefan Eichenberger <[email protected]>
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 <[email protected]>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 71 +++++++++++++++++++-----
1 file changed, 57 insertions(+), 14 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 7c807d1f1f9b..f92808be3f5b 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -317,6 +317,7 @@ struct mxt_data {
struct gpio_desc *reset_gpio;
struct gpio_desc *wake_gpio;
bool use_retrigen_workaround;
+ bool poweroff_sleep;
/* Cached parameters from object table */
u16 T5_address;
@@ -2277,6 +2278,19 @@ static void mxt_config_cb(const struct firmware *cfg, void *ctx)
release_firmware(cfg);
}
+static int mxt_initialize_after_resume(struct mxt_data *data)
+{
+ const struct firmware *fw;
+
+ mxt_acquire_irq(data);
+
+ firmware_request_nowarn(&fw, MXT_CFG_NAME, &data->client->dev);
+
+ mxt_config_cb(fw, data);
+
+ return 0;
+}
+
static void mxt_debug_init(struct mxt_data *data);
static int mxt_device_register(struct mxt_data *data)
@@ -2341,17 +2355,23 @@ static int mxt_initialize(struct mxt_data *data)
if (error)
return error;
- error = mxt_acquire_irq(data);
- if (error)
- return error;
+ if (data->poweroff_sleep) {
+ error = mxt_device_register(data);
+ if (error)
+ return error;
+ } else {
+ error = mxt_acquire_irq(data);
+ if (error)
+ return error;
- error = request_firmware_nowait(THIS_MODULE, true, MXT_CFG_NAME,
- &client->dev, GFP_KERNEL, data,
- mxt_config_cb);
- if (error) {
- dev_err(&client->dev, "Failed to invoke firmware loader: %d\n",
- error);
- return error;
+ error = request_firmware_nowait(THIS_MODULE, true, MXT_CFG_NAME,
+ &client->dev, GFP_KERNEL, data,
+ mxt_config_cb);
+ if (error) {
+ dev_err(&client->dev, "Failed to invoke firmware loader: %d\n",
+ error);
+ return error;
+ }
}
return 0;
@@ -3089,6 +3109,9 @@ static ssize_t mxt_update_fw_store(struct device *dev,
struct mxt_data *data = dev_get_drvdata(dev);
int error;
+ if (data->poweroff_sleep && !data->in_bootloader)
+ mxt_power_on(data);
+
error = mxt_load_fw(dev, MXT_FW_NAME);
if (error) {
dev_err(dev, "The firmware update failed(%d)\n", error);
@@ -3101,6 +3124,9 @@ static ssize_t mxt_update_fw_store(struct device *dev,
return error;
}
+ if (data->poweroff_sleep && !data->in_bootloader)
+ mxt_power_off(data);
+
return count;
}
@@ -3123,7 +3149,12 @@ 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->poweroff_sleep) {
+ mxt_power_on(data);
+ mxt_initialize_after_resume(data);
+ } else {
+ mxt_wakeup_toggle(data->client, true, false);
+ }
switch (data->suspend_mode) {
case MXT_SUSPEND_T9_CTRL:
@@ -3160,7 +3191,12 @@ static void mxt_stop(struct mxt_data *data)
break;
}
- mxt_wakeup_toggle(data->client, false, false);
+ if (data->poweroff_sleep) {
+ 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)
@@ -3357,6 +3393,8 @@ static int mxt_probe(struct i2c_client *client)
if (error)
return error;
+ data->poweroff_sleep = device_property_read_bool(&client->dev,
+ "atmel,poweroff-sleep");
/*
* Controllers like mXT1386 have a dedicated WAKE line that could be
* connected to a GPIO or to I2C SCL pin, or permanently asserted low.
@@ -3387,6 +3425,9 @@ static int mxt_probe(struct i2c_client *client)
goto err_free_object;
}
+ if (data->poweroff_sleep && !data->in_bootloader)
+ mxt_power_off(data);
+
return 0;
err_free_object:
@@ -3406,7 +3447,8 @@ 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->poweroff_sleep)
+ mxt_power_off(data);
}
static int mxt_suspend(struct device *dev)
@@ -3439,7 +3481,8 @@ static int mxt_resume(struct device *dev)
if (!input_dev)
return 0;
- enable_irq(data->irq);
+ if (!data->poweroff_sleep)
+ enable_irq(data->irq);
mutex_lock(&input_dev->mutex);
--
2.40.1
> Our hardware has a shared regulator that powers various peripherals such
> as the display, touch, USB hub, etc. Since the Maxtouch controller
> doesn't currently allow it to be turned off, this regulator has to stay
> on when not used. This increases the overall power consumption. In order
> to turn off the controller when the system does not use it, this series
> adds a device tree property to the maxtouch driver that allows the
> controller to be turned off completely and ensurs that it can resume
> from the power off state.
>
> Changes since v3:
> - Move the power on part to mxt_start and the power off part to
> mxt_stop. This allows to turn the touch controller off even when not
> in use and not only when being suspended (Dmitry)
>
> Changes since v2:
> - Add Reviewed-by tags from Linus and Krzysztof to the dt-bindings patch
>
> Changes since v1:
> - Rename the property and change the description (Krzysztof, Linus,
> Dmitry, Conor)
>
> Stefan Eichenberger (4):
> Input: atmel_mxt_ts - add power off and power on functions
> Input: atmel_mxt_ts - move calls to register the input device to
> separate function
> dt-bindings: input: atmel,maxtouch: add poweroff-sleep property
> Input: atmel_mxt_ts - add support for poweroff-sleep
>
> .../bindings/input/atmel,maxtouch.yaml | 6 +
> drivers/input/touchscreen/atmel_mxt_ts.c | 162 +++++++++++++-----
> 2 files changed, 124 insertions(+), 44 deletions(-)
>
> --
> 2.40.1
>
Reviewed-by: Joao Paulo Goncalves <[email protected]>
Regards,
Joao Paulo