Commit 1e96078e authored by Sakari Ailus's avatar Sakari Ailus Committed by Rafael J. Wysocki
Browse files

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: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: default avatarTomasz Figa <tfiga@chromium.org>
Acked-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 434aa74b

drivers/misc/eeprom/at24.c

+27 −18
Original line number Diff line number Diff line
@@ -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);



	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_enable(dev);



	at24->nvmem = devm_nvmem_register(dev, &nvmem_config);
@@ -766,9 +769,11 @@ 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).

	 */

	if (full_power) {

		err = at24_read(at24, 0, &test_byte, 1);

		if (err) {

			pm_runtime_disable(dev);
@@ -776,6 +781,7 @@ static int at24_probe(struct i2c_client *client) 
				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 (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)