platform/x86: int3472/discrete: Get the polarity from the _DSM entry

According to:
https://github.com/intel/ipu6-drivers/blob/master/patch/int3472-support-independent-clock-and-LED-gpios-5.17%2B.patch

Bits 31-24 of the _DSM pin entry integer value codes the active-value,
that is the actual physical signal (0 or 1) which needs to be output on
the pin to turn the sensor chip on (to make it active).

So if bits 31-24 are 0 for a reset pin, then the actual value of the reset
pin needs to be 0 to take the chip out of reset. IOW in this case the reset
signal is active-high rather then the default active-low.

And if bits 31-24 are 0 for a clk-en pin then the actual value of the clk
pin needs to be 0 to enable the clk. So in this case the clk-en signal
is active-low rather then the default active-high.

IOW if bits 31-24 are 0 for a pin, then the default polarity of the pin
is inverted.

Add a check for this and also propagate this new polarity to the clock
registration.

Signed-off-by: Hans de Goede <[email protected]>
Reviewed-by: Sakari Ailus <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c
index b7752c2b798d..96963e30ab6c 100644
--- a/drivers/platform/x86/intel/int3472/discrete.c
+++ b/drivers/platform/x86/intel/int3472/discrete.c
@@ -220,11 +220,11 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
 	struct int3472_discrete_device *int3472 = data;
 	struct acpi_resource_gpio *agpio;
 	union acpi_object *obj;
+	u8 active_value, type;
 	const char *err_msg;
 	const char *func;
 	u32 polarity;
 	int ret;
-	u8 type;
 
 	if (!acpi_gpio_get_io_resource(ares, &agpio))
 		return 1;
@@ -248,6 +248,15 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
 
 	int3472_get_func_and_polarity(type, &func, &polarity);
 
+	/* If bits 31-24 of the _DSM entry are all 0 then the signal is inverted */
+	active_value = obj->integer.value >> 24;
+	if (!active_value)
+		polarity ^= GPIO_ACTIVE_LOW;
+
+	dev_dbg(int3472->dev, "%s %s pin %d active-%s\n", func,
+		agpio->resource_source.string_ptr, agpio->pin_table[0],
+		(polarity == GPIO_ACTIVE_HIGH) ? "high" : "low");
+
 	switch (type) {
 	case INT3472_GPIO_TYPE_RESET:
 	case INT3472_GPIO_TYPE_POWERDOWN:
@@ -257,7 +266,7 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares,
 
 		break;
 	case INT3472_GPIO_TYPE_CLK_ENABLE:
-		ret = skl_int3472_register_clock(int3472, agpio);
+		ret = skl_int3472_register_clock(int3472, agpio, polarity);
 		if (ret)
 			err_msg = "Failed to register clock\n";