diff mbox series

[v3,6/9] platform/x86: int3472: Avoid GPIO regulator spikes

Message ID 20250416124037.90508-7-hdegoede@redhat.com
State Superseded
Headers show
Series platform/x86: int3472: Add handshake pin support | expand

Commit Message

Hans de Goede April 16, 2025, 12:40 p.m. UTC 
Avoid the GPIO controlling the avdd regulator being driven low or high
for a very short time leading to spikes by adding an enable delay of 2 ms
and a minimum off to on delay of also 2 ms.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v3:
- Add a comment to the defines int3472/common.h explaining where the 2 ms
  comes from
---
 .../platform/x86/intel/int3472/clk_and_regulator.c  |  7 ++++---
 drivers/platform/x86/intel/int3472/common.h         | 13 ++++++++++++-
 drivers/platform/x86/intel/int3472/discrete.c       |  4 +++-
 3 files changed, 19 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/platform/x86/intel/int3472/clk_and_regulator.c b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
index a08b953b597a..b4af17e8dcaf 100644
--- a/drivers/platform/x86/intel/int3472/clk_and_regulator.c
+++ b/drivers/platform/x86/intel/int3472/clk_and_regulator.c
@@ -187,6 +187,7 @@  void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472)
 
 int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
 				   struct gpio_desc *gpio,
+				   unsigned int enable_time,
 				   const char *supply_name,
 				   const char *second_sensor)
 {
@@ -224,9 +225,9 @@  int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
 	snprintf(regulator->regulator_name, sizeof(regulator->regulator_name), "%s-%s",
 		 acpi_dev_name(int3472->adev), supply_name);
 
-	int3472->regulator.rdesc = INT3472_REGULATOR(
-						int3472->regulator.regulator_name,
-						&int3472_gpio_regulator_ops);
+	regulator->rdesc = INT3472_REGULATOR(regulator->regulator_name,
+					     &int3472_gpio_regulator_ops,
+					     enable_time, GPIO_REGULATOR_OFF_ON_DELAY);
 
 	cfg.dev = &int3472->adev->dev;
 	cfg.init_data = &init_data;
diff --git a/drivers/platform/x86/intel/int3472/common.h b/drivers/platform/x86/intel/int3472/common.h
index b750a309ee16..c3b28424af6e 100644
--- a/drivers/platform/x86/intel/int3472/common.h
+++ b/drivers/platform/x86/intel/int3472/common.h
@@ -32,17 +32,27 @@ 
 #define GPIO_REGULATOR_NAME_LENGTH				(12 + GPIO_SUPPPLY_NAME_LENGTH)
 /* lower- and upper-case mapping */
 #define GPIO_REGULATOR_SUPPLY_MAP_COUNT				2
+/*
+ * Ensure the GPIO is driven low/high for at least 2 ms before changing.
+ *
+ * 2 ms has been chosen because it is the minimum time ovXXXX sensors need to
+ * have their reset line driven logical high to properly register a reset.
+ */
+#define GPIO_REGULATOR_ENABLE_TIME				(2 * USEC_PER_MSEC)
+#define GPIO_REGULATOR_OFF_ON_DELAY				(2 * USEC_PER_MSEC)
 
 #define INT3472_LED_MAX_NAME_LEN				32
 
 #define CIO2_SENSOR_SSDB_MCLKSPEED_OFFSET			86
 
-#define INT3472_REGULATOR(_name, _ops)				\
+#define INT3472_REGULATOR(_name, _ops, _enable_time, _off_on_delay) \
 	(const struct regulator_desc) {				\
 		.name = _name,					\
 		.type = REGULATOR_VOLTAGE,			\
 		.ops = _ops,					\
 		.owner = THIS_MODULE,				\
+		.enable_time = _enable_time,			\
+		.off_on_delay = _off_on_delay,			\
 	}
 
 #define to_int3472_clk(hw)					\
@@ -134,6 +144,7 @@  void skl_int3472_unregister_clock(struct int3472_discrete_device *int3472);
 
 int skl_int3472_register_regulator(struct int3472_discrete_device *int3472,
 				   struct gpio_desc *gpio,
+				   unsigned int enable_time,
 				   const char *supply_name,
 				   const char *second_sensor);
 void skl_int3472_unregister_regulator(struct int3472_discrete_device *int3472);
diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index f6dae82739e5..a2db4fae0e6d 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -311,7 +311,9 @@  static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
 
 			break;
 		case INT3472_GPIO_TYPE_POWER_ENABLE:
-			ret = skl_int3472_register_regulator(int3472, gpio, con_id,
+			ret = skl_int3472_register_regulator(int3472, gpio,
+							     GPIO_REGULATOR_ENABLE_TIME,
+							     con_id,
 							     int3472->quirks.avdd_second_sensor);
 			if (ret)
 				err_msg = "Failed to map regulator to sensor\n";