From: Stefan Eichenberger <[email protected]>
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 in suspend mode. This increases the overall power consumption. In
order to turn off the controller when the system goes into suspend mode,
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 v1:
- Rename the property and change the description (Krzysztof, Linus,
Dmitry, Conor)
Stefan Eichenberger (2):
dt-bindings: input: atmel,maxtouch: add poweroff-sleep property
Input: atmel_mxt_ts - support poweroff in suspend
.../bindings/input/atmel,maxtouch.yaml | 6 ++
drivers/input/touchscreen/atmel_mxt_ts.c | 72 ++++++++++++++-----
2 files changed, 61 insertions(+), 17 deletions(-)
--
2.40.1
From: Stefan Eichenberger <[email protected]>
Add a new device tree property to indicate that the device should be
powered off in suspend mode. We have a shared regulator that powers the
display, a USB hub and some other peripherals. The maXTouch controller
doesn't normally disable the regulator in suspend mode, so our extra
peripherals stay powered on. This is not desirable as it consumes more
power. With this patch we add the option to disable the regulator in
suspend mode for the maXTouch and accept the longer initialisation time.
Signed-off-by: Stefan Eichenberger <[email protected]>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 72 ++++++++++++++++++------
1 file changed, 55 insertions(+), 17 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 20094b9899f0..3f7f58f1c930 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;
@@ -2799,15 +2800,18 @@ 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");
- }
+ /* 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(dev, "No touch object detected\n");
+ }
- mxt_debug_init(data);
+ mxt_debug_init(data);
+ }
return 0;
}
@@ -3328,6 +3332,8 @@ static int mxt_probe(struct i2c_client *client)
msleep(MXT_RESET_INVALID_CHG);
}
+ 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.
@@ -3390,12 +3396,21 @@ static int mxt_suspend(struct device *dev)
if (!input_dev)
return 0;
- mutex_lock(&input_dev->mutex);
+ if (!device_may_wakeup(dev) && data->poweroff_sleep) {
+ if (data->reset_gpio)
+ gpiod_set_value(data->reset_gpio, 1);
- if (input_device_enabled(input_dev))
- mxt_stop(data);
+ regulator_bulk_disable(ARRAY_SIZE(data->regulators),
+ data->regulators);
+ data->T44_address = 0;
+ } else {
+ mutex_lock(&input_dev->mutex);
+
+ if (input_device_enabled(input_dev))
+ mxt_stop(data);
- mutex_unlock(&input_dev->mutex);
+ mutex_unlock(&input_dev->mutex);
+ }
disable_irq(data->irq);
@@ -3411,14 +3426,37 @@ static int mxt_resume(struct device *dev)
if (!input_dev)
return 0;
- enable_irq(data->irq);
+ if (!device_may_wakeup(dev) && data->poweroff_sleep) {
+ int ret;
- mutex_lock(&input_dev->mutex);
+ ret = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
+ data->regulators);
+ if (ret) {
+ dev_err(dev, "failed to enable regulators: %d\n",
+ ret);
+ return ret;
+ }
+ msleep(MXT_BACKUP_TIME);
- if (input_device_enabled(input_dev))
- mxt_start(data);
+ 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);
+ }
- mutex_unlock(&input_dev->mutex);
+ /* This also enables the irq again */
+ mxt_initialize(data);
+ } else {
+ enable_irq(data->irq);
+
+ mutex_lock(&input_dev->mutex);
+
+ if (input_device_enabled(input_dev))
+ mxt_start(data);
+
+ mutex_unlock(&input_dev->mutex);
+ }
return 0;
}
--
2.40.1