[PATCH] platform/x86: int3472: add HP Spectre handshake delay

[James Alexander <opensource@inspiredexperts.com>]

The OVTI08F4 sensor on an HP Spectre x360 14-eu0xxx failed to read its
chip ID with error -121 when the existing 45 ms handshake delay was used.
Increasing the delay to 150 ms allowed the sensor to probe.

Keep the existing delay for other OVTI08F4 systems. Add a reusable
handshake-delay field to the discrete-device quirks and set it only for the
affected HP Spectre family through DMI matching.

Compile-tested against Linux base fd923b32d761. Hardware-tested with the
full patch set across 25 consecutive reboots on the affected laptop running
Ubuntu 7.0.0-29-generic; the sensor probed successfully on every boot.

Signed-off-by: James Alexander <opensource@inspiredexperts.com>
---
diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index 115bb3757..80efeb452 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -193,6 +193,9 @@ static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3
 			      GPIO_ACTIVE_LOW : GPIO_ACTIVE_HIGH;
 		*con_id = int3472_gpio_map[i].con_id;
 		*enable_time_us = int3472_gpio_map[i].enable_time_us;
+		if (int3472_gpio_map[i].type_to == INT3472_GPIO_TYPE_HANDSHAKE &&
+		    int3472->quirks.handshake_enable_time_us)
+			*enable_time_us = int3472->quirks.handshake_enable_time_us;
 		return;
 	}
 
diff --git a/drivers/platform/x86/intel/int3472/discrete_quirks.c b/drivers/platform/x86/intel/int3472/discrete_quirks.c
index 552869ef9..d31f7c764 100644
--- a/drivers/platform/x86/intel/int3472/discrete_quirks.c
+++ b/drivers/platform/x86/intel/int3472/discrete_quirks.c
@@ -8,6 +8,10 @@ static const struct int3472_discrete_quirks lenovo_miix_510_quirks = {
 	.avdd_second_sensor = "i2c-OVTI2680:00",
 };
 
+static const struct int3472_discrete_quirks hp_spectre_14_eu0xxx_quirks = {
+	.handshake_enable_time_us = 150 * USEC_PER_MSEC,
+};
+
 const struct dmi_system_id skl_int3472_discrete_quirks[] = {
 	{
 		/* Lenovo Miix 510-12IKB */
@@ -17,5 +21,14 @@ const struct dmi_system_id skl_int3472_discrete_quirks[] = {
 		},
 		.driver_data = (void *)&lenovo_miix_510_quirks,
 	},
+	{
+		/* HP Spectre x360 2-in-1 Laptop 14-eu0xxx */
+		.matches = {
+			DMI_EXACT_MATCH(DMI_SYS_VENDOR, "HP"),
+			DMI_EXACT_MATCH(DMI_PRODUCT_NAME,
+					"HP Spectre x360 2-in-1 Laptop 14-eu0xxx"),
+		},
+		.driver_data = (void *)&hp_spectre_14_eu0xxx_quirks,
+	},
 	{ }
 };
diff --git a/include/linux/platform_data/x86/int3472.h b/include/linux/platform_data/x86/int3472.h
index a73841dfa..797694aa8 100644
--- a/include/linux/platform_data/x86/int3472.h
+++ b/include/linux/platform_data/x86/int3472.h
@@ -96,6 +96,8 @@ struct int3472_cldb {
 struct int3472_discrete_quirks {
 	/* For models where AVDD GPIO is shared between sensors */
 	const char *avdd_second_sensor;
+	/* Override the default delay for handshake GPIO regulators */
+	unsigned int handshake_enable_time_us;
 };
 
 struct int3472_gpio_regulator {
-- 
2.46.0