patches/6.19: int3472: map Surface Pro 7+ ov8865 DVDD supply pin - #2241

What

This PR adds an entry to int3472_gpio_map[] in patches/6.19/0013-cameras.patch to map the Surface Pro 7+ rear camera's (ov8865 / INT347A:00) digital power supply pin (0xaf, declared in DSDT as type 0x08) to INT3472_GPIO_TYPE_HANDSHAKE with supply name dvdd.

With this mapping, the rear camera on the Surface Pro 7+ powers up and streams reliably (1280x720 @ ~30 fps and 3264x2448 RAW @ 15 fps).

Why

On the Surface Pro 7+, the ACPI INT3472:01 device declares the rear sensor's digital supply as GPIO type 0x08 on pin 0xaf.

1. Mainline status: In mainline kernel discrete.c, type 0x08 has no case statement and falls through to unknown, so no regulator is ever registered.
2. Current linux-surface status: In this tree's 0013-cameras.patch, type 0x08 was tentatively mapped to the supply name pwr1. Because no sensor driver requests pwr1, the resulting regulator stays disabled (users=0) and the sensor never receives digital power:

ov8865 i2c-INT347A:00: supply dvdd not found, using dummy regulator
int3472-discrete INT3472:01: GPIO type 0x08 detected on pin 0xaf
int3472-discrete INT3472:01:   con_id=pwr1, flags=0x0
ov8865 i2c-INT347A:00: failed to perform sw reset
ov8865 i2c-INT347A:00: Error -121 runtime-resuming sensor, cannot instantiate VCM

3. Previous RFC approach ([RFC] cameras: ov8865: enable optional pwr1 supply on Surface Pro 7+ #2201): PR [RFC] cameras: ov8865: enable optional pwr1 supply on Surface Pro 7+ #2201 proposed adding an optional pwr1 supply request into ov8865.c. However, pwr1 is an out-of-tree name specific to 0013-cameras.patch and cannot be upstreamed to mainline.

Solution

The pin is the sensor's DVDD rail. Mapping the firmware's type 0x08 to INT3472_GPIO_TYPE_HANDSHAKE (which provides dvdd) keyed on the sensor HID INT347A in int3472_gpio_map[] solves the problem cleanly:

	{	/* Surface Pro 7+ declares the ov8865 dvdd pin as type 0x08 */
		.hid = "INT347A",
		.type_from = 0x08,
		.type_to = INT3472_GPIO_TYPE_HANDSHAKE,
		.con_id = "dvdd",
		.enable_time_us = GPIO_REGULATOR_ENABLE_TIME,
	},

Advantages:

• No changes to ov8865.c: The driver continues requesting standard dvdd.
• Precedent: Follows the existing mapping architecture used for OVTI08F4 in discrete.c.
• Targeted: Keyed specifically on HID INT347A, so Pro 9 (OVTI5693 / OVTID858) remains untouched.
• Mainline clean: Can be sent directly upstream to platform-driver-x86.

Verification

Tested on Microsoft Surface Pro 7+ (Intel Tiger Lake IPU6 8086:9a19, Fedora 44, kernel 6.19.8-3.surface.fc43, libcamera 0.7.1):

• ov8865 i2c-INT347A:00: Instantiated dw9719 VCM
• Stream capture: 1280x720 @ 30 fps (30/30 frames) and 3264x2448 RAW @ 15 fps (10/10 frames).
• Software reset and runtime-PM errors completely resolved.

Refs

• Supersedes / solves the root cause discussed in [RFC] cameras: ov8865: enable optional pwr1 supply on Surface Pro 7+ #2201
• Resolves rear camera issue on SP7+ reported in Surface Pro 7+ Cameras not working #1702