iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Input: atmel_mxt_ts - support regulator supplies

Browse Source 
This adds the code for the Atmel touchscreens such as mXT224 to obtain
power regulators for the supply voltages AVDD and VDD. On mobile phones
such as Samsung GT-I8190 (Golden) this is needed to explicitly bring power
online.

We just enable the regulators at probe() and disable them at remove()
or in the error path for now.

As regulators are naturally stubbed if not available, this should have no
impact on existing systems.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20201104153032.1387747-3-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Linus Walleij 2020-11-09 18:02:50 -08:00 committed by Dmitry Torokhov
parent 04f1842a8d
commit c6c7465089
1 changed files with 36 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
drivers/input/touchscreen/atmel_mxt_ts.c
View File

@ -24,6 +24,7 @@
#include <linux/of.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/regulator/consumer.h>
#include <linux/gpio/consumer.h>
#include <asm/unaligned.h>
#include <media/v4l2-device.h>
@ -309,6 +310,7 @@ struct mxt_data {
u8 multitouch;
struct t7_config t7_cfg;
struct mxt_dbg dbg;
struct regulator_bulk_data regulators[2];
struct gpio_desc *reset_gpio;
bool use_retrigen_workaround;
@ -3134,6 +3136,21 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
if (error)
return error;
/*
* VDDA is the analog voltage supply 2.57..3.47 V
* VDD is the digital voltage supply 1.71..3.47 V
*/
data->regulators[0].supply = "vdda";
data->regulators[1].supply = "vdd";
error = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(data->regulators),
data->regulators);
if (error) {
if (error != -EPROBE_DEFER)
dev_err(&client->dev, "Failed to get regulators %d\n",
error);
return error;
}
/* Request the RESET line as asserted so we go into reset */
data->reset_gpio = devm_gpiod_get_optional(&client->dev,
"reset", GPIOD_OUT_HIGH);
@ -3153,6 +3170,19 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
disable_irq(client->irq);
error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
data->regulators);
if (error) {
dev_err(&client->dev, "failed to enable regulators: %d\n",
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);
@ -3162,7 +3192,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
error = mxt_initialize(data);
if (error)
return error;
goto err_disable_regulators;
error = sysfs_create_group(&client->dev.kobj, &mxt_attr_group);
if (error) {
@ -3176,6 +3206,9 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
err_free_object:
mxt_free_input_device(data);
mxt_free_object_table(data);
err_disable_regulators:
regulator_bulk_disable(ARRAY_SIZE(data->regulators),
data->regulators);
return error;
}
@ -3187,6 +3220,8 @@ static int 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);
return 0;
}