[PATCH v2] platform/x86: int3472: map the ov7251 power enable GPIO to "vdda"

["D. Manresa" <dmanresa@gmail.com>]

On IPU6 designs carrying an OV7251 IR sensor (ACPI HID INT347E) the INT3472
describes the sensor's single gated rail as a power-enable GPIO, which the
driver registers as a regulator with con_id "avdd". The ov7251 driver and its
DT bindings name the sensor supplies vdda, vddd and vdddo, so the lookup finds
nothing, the rail is never enabled, and probe fails on the first I2C access:

  int3472-discrete INT3472:02: avdd  \_SB.GPI0 pin 131 active-high
  ov7251 i2c-INT347E:00: supply vdda not found, using dummy regulator
  ov7251 i2c-INT347E:00: probe with driver ov7251 failed with error -121

Map the power-enable GPIO to con_id "vdda" for INT347E, the same way the
existing entries map it to "vdd" for the mt9m114 and to "vana" for the imx471.
The sensor's other two supplies keep falling back to the dummy regulator,
which is correct here: the firmware gates a single rail.

The table already has an INT347E entry mapping the reset GPIO to "enable",
added when the ov7251 was brought up on these machines; this is the same class
of firmware-vs-binding name mismatch for the remaining pin.

Tested on a Microsoft Surface Pro 7+ (Tiger Lake, IPU6): with this change the
IR sensor probes, the illuminator strobes, and the camera streams 640x480 at
30 fps through libcamera. The same failure was reproduced independently on a
second Pro 7+ running stock firmware and a distro kernel, with no out-of-tree
code, in [1].

Developed with the assistance of an AI tool (Claude) and verified on hardware.

Link: https://github.com/linux-surface/linux-surface/issues/1702 [1]
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: D. Manresa <dmanresa@gmail.com>
---
v2: no code changes. v1 never reached the lists (a mail tooling error on
my side dropped the Cc headers); resent with platform-driver-x86 on Cc as
Hans requested, with his Reviewed-by collected.

diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index 6c729fc..157345e 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -143,6 +143,11 @@ static const char * const power_enable_hids_enable[] = {
 	NULL
 };
 
+static const char * const power_enable_hids_vdda[] = {
+	"INT347E", /* ov7251 */
+	NULL
+};
+
 /**
  * struct int3472_gpio_map - Map GPIOs to whatever is expected by the
  * sensor driver (as in DT bindings)
@@ -185,6 +190,13 @@ static const struct int3472_gpio_map int3472_gpio_map[] = {
 		.con_id = "dvdd",
 		.enable_time_us = 45 * USEC_PER_MSEC,
 	},
+	{	/* Sensors which expect "vdda" as con_id for power enable */
+		.hids = power_enable_hids_vdda,
+		.type_from = INT3472_GPIO_TYPE_POWER_ENABLE,
+		.type_to = INT3472_GPIO_TYPE_POWER_ENABLE,
+		.con_id = "vdda",
+		.enable_time_us = GPIO_REGULATOR_ENABLE_TIME,
+	},
 	{	/* Sensors which expect "vana" as con_id for power enable */
 		.hids = power_enable_hids_vana,
 		.type_from = INT3472_GPIO_TYPE_POWER_ENABLE,
-- 
2.43.0