[PATCH 0/3] Enable the front camera on the Dell Latitude 7320 Detachable

[PATCH 0/3] Enable the front camera on the Dell Latitude 7320 Detachable

[Sahan Nissanka]

This series enables the user-facing 5MP camera on the Dell Latitude 7320
Detachable, which has never worked on Linux. Two open reports ask for it:
intel/ipu6-drivers issues #24 (2022) and #402 (2025), the latter blocked
waiting for "OV5678 sensor specifications (clock rates, power requirements)".

Those specifications turned out not to be needed. ACPI describes the front
sensor as OVTI5678 and no driver has ever claimed that id. The part reports
chip id 0x005675 at register 0x300a, and the values ov5675.c is sensitive to
were read from the machine's ACPI SSDB before the sensor was ever powered and
both agree - 2 CSI-2 data lanes and a 19.2 MHz external clock. The advertised
5MP also matches the driver's native 2592x1944. So no new sensor driver and no
new register tables are required to make it stream.

One caveat, set out in full in 2/3: this part is not a plain Bayer sensor. It
carries a 4x4 RGB-IR colour filter array, one pixel in four being infrared.
That is confirmed from Intel's own Windows IPU6 configuration for this exact
module, from measurements on the sensor at full resolution, and from the
module's tuning data, which agree with each other. The SGRBG10 that ov5675
declares is therefore inaccurate, and colour is wrong in a way white balance
cannot correct.

That cannot be fixed in this series: the V4L2 ABI has no RGB-IR media bus
code at all, and ox05b1s already carries the same inaccuracy for an RGB-IR
sensor of the same class and resolution. I intend to propose RGB-IR media bus
codes separately. Until such support exists, this series takes hardware that
does not work at all to hardware that works with imperfect colour, which
seemed worth having in the meantime. I am happy to hold 2/3 if maintainers
would rather not add the id before the format can be described honestly.

That leaves three small pieces:

  1/3 gives the TPS68470 PMIC board data, without which the sensors are not
      even enumerated - they declare an ACPI _DEP on the control logic, so no
      i2c client is created until it probes.
  2/3 adds the OVTI5678 id to ov5675.
  3/3 adds the ipu-bridge entry so a software node is created for it.

The patches touch two subsystems: 1/3 is platform-driver-x86, 2/3 and 3/3 are
media. They are independent of each other in build terms, but none of them
does anything useful alone, so they are sent together for context. Happy to
split them if maintainers prefer.

Tested on a Dell Latitude 7320 Detachable, BIOS 1.48.0, kernel 7.0.0. With
all three applied:

  intel-ipu6 0000:00:05.0: Found supported sensor OVTI5678:00
  intel-ipu6 0000:00:05.0: Found supported sensor OVTI8856:00
  intel-ipu6 0000:00:05.0: Connected 2 cameras
  ov5675 1-0036: ... appears in the media graph

and libcamera captures 2584x1944 at 29.95 fps.

The rear OVTI8856 sensor shares the same PMIC. Its rails are described by the
same board data, but its reset/powerdown GPIO assignment is not yet known, so
it is deliberately left out here.

Sahan Nissanka (3):
  platform/x86: int3472: Add TPS68470 board data for Dell 7320
    Detachable
  media: i2c: ov5675: Add OVTI5678 ACPI id
  media: ipu-bridge: Add sensor configuration for OV5675 (OVTI5678)

 drivers/media/i2c/ov5675.c                    | 11 ++
 drivers/media/pci/intel/ipu-bridge.c          |  2 +
 .../x86/intel/int3472/tps68470_board_data.c   | 92 +++++++++++++++++++
 3 files changed, 105 insertions(+)

-- 
2.53.0

[PATCH 1/3] platform/x86: int3472: Add TPS68470 board data for Dell 7320 Detachable

[Sahan Nissanka]

The Dell Latitude 7320 Detachable has two MIPI cameras behind an Intel
IPU6, both powered by a TPS68470 PMIC. Without board data the PMIC
driver fails:

  int3472-tps68470 i2c-INT3472:07: error -ENODEV: No board-data found
  for this model

and because the sensors declare an ACPI _DEP on the control logic they
are never enumerated at all - no i2c client is created for either of
them, so nothing can bind them.

Add board data for the front sensor, which ACPI describes as OVTI5678.
The GPIO and rail assignments are the same as on the Dell 7212 and the
Dell 5290 2-in-1: reset on tps68470-gpio 3, powerdown on 4, and
VSIO/AUX1/AUX2 feeding avdd/dvdd/dovdd. This was confirmed on the
hardware - with these settings the sensor powers up and acknowledges on
i2c, and with the conventional ANA/CORE/VSIO mapping it does not. The
CLDB buffer read from this machine also carries C0W4=3, agreeing with
reset on GPIO 3.

The rails that have no consumers are wired as on the Dell 7212, so reuse
those regulator_init_data rather than duplicating them.

Note the control logic here enumerates as INT3472:07, not :05 as on the
other Dell models in this file. The board data lookup matches on DMI and
device name, so this has to be exact.

The rear OVTI8856 sensor shares this PMIC but its GPIO assignment is not
yet known, so it is left out for now.

Signed-off-by: Sahan Nissanka <adee.sahan@gmail.com>
---
 .../x86/intel/int3472/tps68470_board_data.c   | 92 +++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/drivers/platform/x86/intel/int3472/tps68470_board_data.c b/drivers/platform/x86/intel/int3472/tps68470_board_data.c
index 71357a0..f32a884 100644
--- a/drivers/platform/x86/intel/int3472/tps68470_board_data.c
+++ b/drivers/platform/x86/intel/int3472/tps68470_board_data.c
@@ -232,6 +232,69 @@ static const struct tps68470_regulator_platform_data dell_7212_tps68470_pdata =
 	},
 };
 
+/* Settings for Dell Latitude 7320 Detachable */
+
+static struct regulator_consumer_supply ovti5678_vsio_consumer_supplies[] = {
+	REGULATOR_SUPPLY("avdd", "i2c-OVTI5678:00"),
+};
+
+static struct regulator_consumer_supply ovti5678_aux1_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dvdd", "i2c-OVTI5678:00"),
+};
+
+static struct regulator_consumer_supply ovti5678_aux2_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dovdd", "i2c-OVTI5678:00"),
+};
+
+static const struct regulator_init_data dell_7320_tps68470_vsio_reg_init_data = {
+	.constraints = {
+		.min_uV = 1800600,
+		.max_uV = 1800600,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(ovti5678_vsio_consumer_supplies),
+	.consumer_supplies = ovti5678_vsio_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_7320_tps68470_aux1_reg_init_data = {
+	.constraints = {
+		.min_uV = 1213200,
+		.max_uV = 1213200,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(ovti5678_aux1_consumer_supplies),
+	.consumer_supplies = ovti5678_aux1_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_7320_tps68470_aux2_reg_init_data = {
+	.constraints = {
+		.min_uV = 1800600,
+		.max_uV = 1800600,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(ovti5678_aux2_consumer_supplies),
+	.consumer_supplies = ovti5678_aux2_consumer_supplies,
+};
+
+/*
+ * The rails without consumers are wired the same way as on the Dell 7212, so
+ * reuse those init_data rather than duplicating them.
+ */
+static const struct tps68470_regulator_platform_data dell_7320_tps68470_pdata = {
+	.reg_init_data = {
+		[TPS68470_CORE] = &dell_7212_tps68470_core_reg_init_data,
+		[TPS68470_ANA]  = &dell_7212_tps68470_ana_reg_init_data,
+		[TPS68470_VCM]  = &dell_7212_tps68470_vcm_reg_init_data,
+		[TPS68470_VIO]  = &dell_7212_tps68470_vio_reg_init_data,
+		[TPS68470_VSIO] = &dell_7320_tps68470_vsio_reg_init_data,
+		[TPS68470_AUX1] = &dell_7320_tps68470_aux1_reg_init_data,
+		[TPS68470_AUX2] = &dell_7320_tps68470_aux2_reg_init_data,
+	},
+};
+
 static struct gpiod_lookup_table surface_go_int347a_gpios = {
 	.dev_id = "i2c-INT347A:00",
 	.table = {
@@ -258,6 +321,15 @@ static struct gpiod_lookup_table dell_7212_int3479_gpios = {
 	}
 };
 
+static struct gpiod_lookup_table dell_7320_ovti5678_gpios = {
+	.dev_id = "i2c-OVTI5678:00",
+	.table = {
+		GPIO_LOOKUP("tps68470-gpio", 3, "reset", GPIO_ACTIVE_LOW),
+		GPIO_LOOKUP("tps68470-gpio", 4, "powerdown", GPIO_ACTIVE_LOW),
+		{ }
+	}
+};
+
 static const struct int3472_tps68470_board_data surface_go_tps68470_board_data = {
 	.dev_name = "i2c-INT3472:05",
 	.tps68470_regulator_pdata = &surface_go_tps68470_pdata,
@@ -287,6 +359,19 @@ static const struct int3472_tps68470_board_data dell_7212_tps68470_board_data =
 	},
 };
 
+/*
+ * The control logic on the Latitude 7320 Detachable enumerates as INT3472:07,
+ * not :05 as on the other Dell models here.
+ */
+static const struct int3472_tps68470_board_data dell_7320_tps68470_board_data = {
+	.dev_name = "i2c-INT3472:07",
+	.tps68470_regulator_pdata = &dell_7320_tps68470_pdata,
+	.n_gpiod_lookups = 1,
+	.tps68470_gpio_lookup_tables = {
+		&dell_7320_ovti5678_gpios,
+	},
+};
+
 static const struct dmi_system_id int3472_tps68470_board_data_table[] = {
 	{
 		.matches = {
@@ -316,6 +401,13 @@ static const struct dmi_system_id int3472_tps68470_board_data_table[] = {
 		},
 		.driver_data = (void *)&dell_7212_tps68470_board_data,
 	},
+	{
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_EXACT_MATCH(DMI_PRODUCT_NAME, "Latitude 7320 Detachable"),
+		},
+		.driver_data = (void *)&dell_7320_tps68470_board_data,
+	},
 	{ }
 };
 
-- 
2.53.0

[PATCH 2/3] media: i2c: ov5675: Add OVTI5678 ACPI id

[Sahan Nissanka]

The front camera of the Dell Latitude 7320 Detachable is described in
ACPI as OVTI5678, and no driver has ever claimed that id. It reports
chip id 0x005675 at register 0x300a, which is what
ov5675_identify_module() expects, and it streams with this driver
unmodified:

  ov5675 i2c-OVTI5678:00: chip id at 0x300a reads 0x005675
    reg 0x300a = 0x00  reg 0x300b = 0x56  reg 0x300c = 0x75

The two other values this driver is sensitive to were read from the
machine's ACPI SSDB before the sensor was ever powered, and both agree:
L0NL = 2 data lanes (OV5675_DATA_LANES) and L0CK = 19200000 Hz
(OV5675_XVCLK_19_2). Native resolution matches at 2592x1944.

With this id added the sensor binds and streams: libcamera lists it and
capture runs at 2584x1944, 29.95 fps.

This part is not a plain Bayer sensor, however, and the format this
driver declares for it is inaccurate. It carries a 4x4 RGB-IR colour
filter array, one pixel in four being infrared:

    G I G I
    R G B G
    G I G I
    B G R G

Confirmed three ways. Intel's Windows IPU6 configuration for this exact
module - matched by ACPI _DDN, so not a near relative - declares
bayer_order="GIGI_RGBG_GIGI_BGRG" and sensor_type="RGB_IR". Measured on
the sensor at full resolution, positions a 2x2 model treats as a single
channel differ by 18% while the four infrared positions agree to 0.4%.
And the module's Intel tuning data carries a 4x4 channel index map that
agrees with both.

Read as the SGRBG10 declared here, the "blue" channel is pure infrared
and the "red" channel interleaves real red with real blue, so colour is
wrong in a way no white balance can correct.

This cannot be fixed in this driver: there is no RGB-IR media bus code
in the V4L2 ABI. Nor is it unique to this part - ox05b1s declares
SGRBG10 for an RGB-IR sensor of the same class and resolution. I intend
to propose RGB-IR media bus codes separately. Until such support
exists, this patch makes otherwise unusable hardware work, carrying the
same known inaccuracy as the existing RGB-IR sensor support.

One further note for anyone building on this: the sensor's binned
1296x972 mode averages infrared pixels together with colour ones, which
destroys the mosaic. Only the full resolution mode is meaningful for an
RGB-IR aware pipeline.

Signed-off-by: Sahan Nissanka <adee.sahan@gmail.com>
---
 drivers/media/i2c/ov5675.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
index ea26df3..99dbf53 100644
--- a/drivers/media/i2c/ov5675.c
+++ b/drivers/media/i2c/ov5675.c
@@ -1355,6 +1355,17 @@ static const struct dev_pm_ops ov5675_pm_ops = {
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id ov5675_acpi_ids[] = {
 	{"OVTI5675"},
+	/*
+	 * The front sensor of the Dell Latitude 7320 Detachable is described
+	 * as OVTI5678 in ACPI, but the part reports chip id 0x005675 and its
+	 * SSDB agrees with this driver on both other values that matter:
+	 * 2 CSI-2 data lanes and a 19.2 MHz external clock.
+	 *
+	 * Note this variant carries a 4x4 RGB-IR colour filter array, not the
+	 * 2x2 Bayer declared here, so colour is incorrect. There is currently
+	 * no RGB-IR media bus code to declare instead.
+	 */
+	{"OVTI5678"},
 	{}
 };
 
-- 
2.53.0

[PATCH 3/3] media: ipu-bridge: Add sensor configuration for OV5675 (OVTI5678)

[Sahan Nissanka]

The front camera of the Dell Latitude 7320 Detachable is an OV5675
described in ACPI as OVTI5678. Without an entry here ipu-bridge creates
no software node for it, so no fwnode endpoint exists and the sensor
cannot be connected to the IPU6 even once a driver binds it:

  intel-ipu6 0000:00:05.0: Found supported sensor OVTI8856:00
  intel-ipu6 0000:00:05.0: Connected 1 cameras

450 MHz is OV5675_LINK_FREQ_450MHZ, the only link frequency ov5675.c
supports, and matches the two data lanes the machine's SSDB reports.

With this entry both cameras are found and the front sensor appears in
the media graph:

  intel-ipu6 0000:00:05.0: Found supported sensor OVTI5678:00
  intel-ipu6 0000:00:05.0: Found supported sensor OVTI8856:00
  intel-ipu6 0000:00:05.0: Connected 2 cameras

Signed-off-by: Sahan Nissanka <adee.sahan@gmail.com>
---
 drivers/media/pci/intel/ipu-bridge.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/pci/intel/ipu-bridge.c b/drivers/media/pci/intel/ipu-bridge.c
index 9cebc6a..78fe1f7 100644
--- a/drivers/media/pci/intel/ipu-bridge.c
+++ b/drivers/media/pci/intel/ipu-bridge.c
@@ -101,6 +101,8 @@ static const struct ipu_sensor_config ipu_supported_sensors[] = {
 	IPU_SENSOR_CONFIG("OVTIDB10", 1, 560000000),
 	/* Omnivision OV2680 */
 	IPU_SENSOR_CONFIG("OVTI2680", 1, 331200000),
+	/* Omnivision OV5675, described as OVTI5678 in ACPI */
+	IPU_SENSOR_CONFIG("OVTI5678", 1, 450000000),
 	/* Omnivision OV8856 */
 	IPU_SENSOR_CONFIG("OVTI8856", 3, 180000000, 360000000, 720000000),
 	/* Sony IMX471 */
-- 
2.53.0