Merge tag 'acpi-5.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull more ACPI updates from Rafael Wysocki:
 "These add support for a new ACPI device configuration object called
  _DSC, fix some issues including one recent regression, add two new
  items to quirk lists and clean up assorted pieces of code.

  Specifics:

   - Add support for new ACPI device configuration object called _DSC
     ("Deepest State for Configuration") to allow certain devices to be
     probed without changing their power states, document it and make
     two drivers use it (Sakari Ailus, Rajmohan Mani).

   - Fix device wakeup power reference counting broken recently by
     mistake (Rafael Wysocki).

   - Drop unused symbol and macros depending on it from acgcc.h (Rafael
     Wysocki).

   - Add HP ZHAN 66 Pro to the "no EC wakeup" quirk list (Binbin Zhou).

   - Add Xiaomi Mi Pad 2 to the backlight quirk list and drop an unused
     piece of data from all of the list entries (Hans de Goede).

   - Fix register read accesses handling in the Intel PMIC operation
     region driver (Hans de Goede).

   - Clean up static variables initialization in the EC driver
     (wangzhitong)"

* tag 'acpi-5.16-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Documentation: ACPI: Fix non-D0 probe _DSC object example
  ACPI: Drop ACPI_USE_BUILTIN_STDARG ifdef from acgcc.h
  ACPI: PM: Fix device wakeup power reference counting error
  ACPI: video: use platform backlight driver on Xiaomi Mi Pad 2
  ACPI: video: Drop dmi_system_id.ident settings from video_detect_dmi_table[]
  ACPI: PMIC: Fix intel_pmic_regs_handler() read accesses
  ACPI: EC: Remove initialization of static variables to false
  ACPI: EC: Use ec_no_wakeup on HP ZHAN 66 Pro
  at24: Support probing while in non-zero ACPI D state
  media: i2c: imx319: Support device probe in non-zero ACPI D state
  ACPI: Add a convenience function to tell a device is in D0 state
  Documentation: ACPI: Document _DSC object usage for enum power state
  i2c: Allow an ACPI driver to manage the device's power state during probe
  ACPI: scan: Obtain device's desired enumeration power state

1 files changed, 27 insertions, 18 deletions

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 305ffad131a2..49ab656e8a96 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -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)