[PATCH v4 1/2] media: i2c: ov8856 : remove ACPI node bypass mechanism

On Intel platforms the sensor is enumerated via ACPI, and an INT3472
"discrete" companion device (the power-logic-control driver under
drivers/platform/x86/intel/int3472) registers the sensor's
reset/powerdown GPIOs and the regulator supply. These resources are
therefore discoverable and usable through the standard gpiod/regulator
lookups at probe time.

However, the driver guarded both the GPIO/regulator acquisition in
ov8856_get_hwcfg() and the whole power-on/off sequence with
is_acpi_node() and skipped them on ACPI. As a result the sensor was
never powered or reset by the driver, and probe failed when reading the
chip ID in ov8856_identify_module().

Remove the is_acpi_node() checks so the GPIO/regulator resources are
acquired and the full power sequence runs regardless of the firmware
interface. The driver now behaves consistently across DT and ACPI
platforms and initialises the hardware correctly.

Tested on Intel platforms with kernel 6.17 and 7.0.

Fixes: d2fa1134a48b ("media: i2c: ov8856: Use V4L2 legacy sensor clock helper")
Cc: [email protected]
Signed-off-by: Serin Yeh <[email protected]>
Reviewed-by: Bryan O'Donoghue <[email protected]>
---
 drivers/media/i2c/ov8856.c | 29 ++++++++++-------------------
 1 file changed, 10 insertions(+), 19 deletions(-)

diff --git a/drivers/media/i2c/ov8856.c b/drivers/media/i2c/ov8856.c
index 8bedb47cd7cf..9d2b0469a576 100644
--- a/drivers/media/i2c/ov8856.c
+++ b/drivers/media/i2c/ov8856.c
@@ -2082,9 +2082,6 @@ static int ov8856_power_on(struct device *dev)
 	struct ov8856 *ov8856 = to_ov8856(sd);
 	int ret;
 
-	if (is_acpi_node(dev_fwnode(dev)))
-		return 0;
-
 	ret = clk_prepare_enable(ov8856->xvclk);
 	if (ret < 0) {
 		dev_err(dev, "failed to enable xvclk\n");
@@ -2120,9 +2117,6 @@ static int ov8856_power_off(struct device *dev)
 	struct v4l2_subdev *sd = dev_get_drvdata(dev);
 	struct ov8856 *ov8856 = to_ov8856(sd);
 
-	if (is_acpi_node(dev_fwnode(dev)))
-		return 0;
-
 	gpiod_set_value_cansleep(ov8856->reset_gpio, 1);
 	regulator_bulk_disable(ARRAY_SIZE(ov8856_supply_names),
 			       ov8856->supplies);
@@ -2293,21 +2287,18 @@ static int ov8856_get_hwcfg(struct ov8856 *ov8856)
 		dev_warn(dev, "external clock rate %u is unsupported",
 			 xvclk_rate);
 
-	if (!is_acpi_node(fwnode)) {
-		ov8856->reset_gpio = devm_gpiod_get_optional(dev, "reset",
-							     GPIOD_OUT_LOW);
-		if (IS_ERR(ov8856->reset_gpio))
-			return PTR_ERR(ov8856->reset_gpio);
+	ov8856->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+						     GPIOD_OUT_LOW);
+	if (IS_ERR(ov8856->reset_gpio))
+		return PTR_ERR(ov8856->reset_gpio);
 
-		for (i = 0; i < ARRAY_SIZE(ov8856_supply_names); i++)
-			ov8856->supplies[i].supply = ov8856_supply_names[i];
+	for (i = 0; i < ARRAY_SIZE(ov8856_supply_names); i++)
+		ov8856->supplies[i].supply = ov8856_supply_names[i];
 
-		ret = devm_regulator_bulk_get(dev,
-					      ARRAY_SIZE(ov8856_supply_names),
-					      ov8856->supplies);
-		if (ret)
-			return ret;
-	}
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ov8856_supply_names),
+				      ov8856->supplies);
+	if (ret)
+		return ret;
 
 	ep = fwnode_graph_get_next_endpoint(fwnode, NULL);
 	if (!ep)
-- 
2.25.1