The Dell Latitude 5285 2-in-1 has two cameras connected through a TPS68470
PMIC/clock/GPIO hub:

  Front: OV5670 (ACPI INT3479) on I2C4
  Back:  OV8858 (ACPI INT3477) on I2C2, daisy-chained behind TPS68470
         S_I2C port (controlled by reg 0x43 S_I2C_CTL)

GPIO mapping (TPS68470):
  INT3479 (OV5670): GPIO3 = reset, GPIO4 = powerdown (both active-low)
  INT3477 (OV8858): GPIO9 = s_resetn, GPIO7 = s_enable (both active-low)
    GPIO9 and GPIO7 are the TPS68470 secondary-port GPIOs (SGPO reg 0x22
    bits 2 and 0), not regular GPDO outputs.

Regulator mapping:
  CORE  -> dvdd  / INT3477
  ANA   -> avdd  / INT3477
  VIO   -> dovdd / INT3477
  VSIO  -> avdd  / INT3479 and vsio / INT3477 (always_on: keeps S_I2C_CTL
           non-zero from boot so OV8858 is reachable on I2C2 at any time)
  AUX1  -> dvdd  / INT3479
  AUX2  -> dovdd / INT3479

Marking VSIO always_on ensures the TPS68470 S_I2C passthrough is active
from the moment the PMIC driver probes, eliminating a timing dependency
between TPS68470 and ov8858 probe ordering.

Signed-off-by: Thierry Chatard <tchatard@gmail.com>
---
 .../x86/intel/int3472/tps68470_board_data.c   | 163 ++++++++++++++++++
 1 file changed, 163 insertions(+)

diff --git a/drivers/platform/x86/intel/int3472/tps68470_board_data.c b/drivers/platform/x86/intel/int3472/tps68470_board_data.c
index 71357a036..a5b469dcb 100644
--- a/drivers/platform/x86/intel/int3472/tps68470_board_data.c
+++ b/drivers/platform/x86/intel/int3472/tps68470_board_data.c
@@ -287,6 +287,162 @@ static const struct int3472_tps68470_board_data dell_7212_tps68470_board_data =
 	},
 };
 
+/* Settings for Dell Latitude 5285 2-in-1 */
+
+static struct regulator_consumer_supply dell_5285_int3477_ana_consumer_supplies[] = {
+	REGULATOR_SUPPLY("avdd", "i2c-INT3477:00"),
+};
+
+static struct regulator_consumer_supply dell_5285_int3477_core_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dvdd", "i2c-INT3477:00"),
+};
+
+static struct regulator_consumer_supply dell_5285_int3477_vio_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dovdd", "i2c-INT3477:00"),
+};
+
+static struct regulator_consumer_supply dell_5285_int3479_vsio_consumer_supplies[] = {
+	REGULATOR_SUPPLY("avdd", "i2c-INT3479:00"),
+	/* S_I2C_CTL: must be enabled for OV8858 I2C daisy-chain access */
+	REGULATOR_SUPPLY("vsio", "i2c-INT3477:00"),
+};
+
+static struct regulator_consumer_supply dell_5285_int3479_aux1_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dvdd", "i2c-INT3479:00"),
+};
+
+static struct regulator_consumer_supply dell_5285_int3479_aux2_consumer_supplies[] = {
+	REGULATOR_SUPPLY("dovdd", "i2c-INT3479:00"),
+};
+
+static const struct regulator_init_data dell_5285_tps68470_core_reg_init_data = {
+	.constraints = {
+		.min_uV = 1200000,
+		.max_uV = 1200000,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(dell_5285_int3477_core_consumer_supplies),
+	.consumer_supplies = dell_5285_int3477_core_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_5285_tps68470_ana_reg_init_data = {
+	.constraints = {
+		.min_uV = 2815200,
+		.max_uV = 2815200,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(dell_5285_int3477_ana_consumer_supplies),
+	.consumer_supplies = dell_5285_int3477_ana_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_5285_tps68470_vcm_reg_init_data = {
+	.constraints = {
+		.min_uV = 2815200,
+		.max_uV = 2815200,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = 0,
+	.consumer_supplies = NULL,
+};
+
+static const struct regulator_init_data dell_5285_tps68470_vio_reg_init_data = {
+	.constraints = {
+		.min_uV = 1800600,
+		.max_uV = 1800600,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(dell_5285_int3477_vio_consumer_supplies),
+	.consumer_supplies = dell_5285_int3477_vio_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_5285_tps68470_vsio_reg_init_data = {
+	.constraints = {
+		.min_uV = 1800600,
+		.max_uV = 1800600,
+		.apply_uV = 1,
+		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+		/*
+		 * Keep S_I2C_CTL enabled from boot so OV8858 I2C daisy-chain
+		 * is accessible before ov8858 driver probes.
+		 */
+		.always_on = 1,
+	},
+	.num_consumer_supplies = ARRAY_SIZE(dell_5285_int3479_vsio_consumer_supplies),
+	.consumer_supplies = dell_5285_int3479_vsio_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_5285_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(dell_5285_int3479_aux1_consumer_supplies),
+	.consumer_supplies = dell_5285_int3479_aux1_consumer_supplies,
+};
+
+static const struct regulator_init_data dell_5285_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(dell_5285_int3479_aux2_consumer_supplies),
+	.consumer_supplies = dell_5285_int3479_aux2_consumer_supplies,
+};
+
+static const struct tps68470_regulator_platform_data dell_5285_tps68470_pdata = {
+	.reg_init_data = {
+		[TPS68470_CORE] = &dell_5285_tps68470_core_reg_init_data,
+		[TPS68470_ANA]  = &dell_5285_tps68470_ana_reg_init_data,
+		[TPS68470_VCM]  = &dell_5285_tps68470_vcm_reg_init_data,
+		[TPS68470_VIO]  = &dell_5285_tps68470_vio_reg_init_data,
+		[TPS68470_VSIO] = &dell_5285_tps68470_vsio_reg_init_data,
+		[TPS68470_AUX1] = &dell_5285_tps68470_aux1_reg_init_data,
+		[TPS68470_AUX2] = &dell_5285_tps68470_aux2_reg_init_data,
+	},
+};
+
+static struct gpiod_lookup_table dell_5285_int3477_gpios = {
+	.dev_id = "i2c-INT3477:00",
+	.table = {
+		/*
+		 * TPS68470 GPIO9 = s_resetn (secondary camera reset, active-low)
+		 * TPS68470 GPIO7 = s_enable (secondary camera enable/powerdown)
+		 * These logic outputs are specifically designed for secondary
+		 * camera control on the TPS68470. Matches Surface Go pattern.
+		 */
+		GPIO_LOOKUP("tps68470-gpio", 9, "reset", GPIO_ACTIVE_LOW),
+		GPIO_LOOKUP("tps68470-gpio", 7, "powerdown", GPIO_ACTIVE_LOW),
+		{ }
+	}
+};
+
+static struct gpiod_lookup_table dell_5285_int3479_gpios = {
+	.dev_id = "i2c-INT3479:00",
+	.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 dell_5285_tps68470_board_data = {
+	.dev_name = "i2c-INT3472:05",
+	.tps68470_regulator_pdata = &dell_5285_tps68470_pdata,
+	.n_gpiod_lookups = 2,
+	.tps68470_gpio_lookup_tables = {
+		&dell_5285_int3477_gpios,
+		&dell_5285_int3479_gpios,
+	},
+};
+
 static const struct dmi_system_id int3472_tps68470_board_data_table[] = {
 	{
 		.matches = {
@@ -316,6 +472,13 @@ 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 5285"),
+		},
+		.driver_data = (void *)&dell_5285_tps68470_board_data,
+	},
 	{ }
 };
 
-- 
2.51.0