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at24: Support probing while in non-zero ACPI D state 

In certain use cases (where the chip is part of a camera module, and the
camera module is wired together with a camera privacy LED), powering on
the device during probe is undesirable. Add support for the at24 to
execute probe while being in ACPI D state other than 0 (which means fully
powered on).

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Sakari Ailus 2021-10-18 15:17:29 +03:00 committed by Rafael J. Wysocki
parent 434aa74bd7
commit 1e96078e0a
1 changed files with 27 additions and 18 deletions
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45
drivers/misc/eeprom/at24.c
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@ -595,6 +595,7 @@ static int at24_probe(struct i2c_client *client)
bool i2c_fn_i2c, i2c_fn_block;
unsigned int i, num_addresses;
struct at24_data *at24;
bool full_power;
struct regmap *regmap;
bool writable;
u8 test_byte;
@ -747,14 +748,16 @@ static int at24_probe(struct i2c_client *client)
i2c_set_clientdata(client, at24);
err = regulator_enable(at24->vcc_reg);
if (err) {
dev_err(dev, "Failed to enable vcc regulator\n");
return err;
}
full_power = acpi_dev_state_d0(&client->dev);
if (full_power) {
err = regulator_enable(at24->vcc_reg);
if (err) {
dev_err(dev, "Failed to enable vcc regulator\n");
return err;
}
/* enable runtime pm */
pm_runtime_set_active(dev);
pm_runtime_set_active(dev);
}
pm_runtime_enable(dev);
at24->nvmem = devm_nvmem_register(dev, &nvmem_config);
@ -766,15 +769,18 @@ static int at24_probe(struct i2c_client *client)
}
/*
* Perform a one-byte test read to verify that the
* chip is functional.
* Perform a one-byte test read to verify that the chip is functional,
* unless powering on the device is to be avoided during probe (i.e.
* it's powered off right now).
*/
err = at24_read(at24, 0, &test_byte, 1);
if (err) {
pm_runtime_disable(dev);
if (!pm_runtime_status_suspended(dev))
regulator_disable(at24->vcc_reg);
return -ENODEV;
if (full_power) {
err = at24_read(at24, 0, &test_byte, 1);
if (err) {
pm_runtime_disable(dev);
if (!pm_runtime_status_suspended(dev))
regulator_disable(at24->vcc_reg);
return -ENODEV;
}
}
pm_runtime_idle(dev);
@ -794,9 +800,11 @@ static int at24_remove(struct i2c_client *client)
struct at24_data *at24 = i2c_get_clientdata(client);
pm_runtime_disable(&client->dev);
if (!pm_runtime_status_suspended(&client->dev))
regulator_disable(at24->vcc_reg);
pm_runtime_set_suspended(&client->dev);
if (acpi_dev_state_d0(&client->dev)) {
if (!pm_runtime_status_suspended(&client->dev))
regulator_disable(at24->vcc_reg);
pm_runtime_set_suspended(&client->dev);
}
return 0;
}
@ -833,6 +841,7 @@ static struct i2c_driver at24_driver = {
.probe_new = at24_probe,
.remove = at24_remove,
.id_table = at24_ids,
.flags = I2C_DRV_ACPI_WAIVE_D0_PROBE,
};
static int __init at24_init(void)