[PATCH v2 3/4] ACPI / scan: Recognize Apple SPI and I2C slaves

[Lukas Wunner <lukas@xxxxxxxxx>]

SPI and I2C slaves are enumerated by their respective parents rather
than the ACPI core.  They are recognized by presence of _CRS resources,
which however are missing on Macs.  Check for presence of device
properties instead.

Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Federico Lorenzi <florenzi@xxxxxxxxx>
Reported-and-tested-by: Ronald Tschalär <ronald@xxxxxxxxxxxxx>
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
---
Changes v1 -> v2:
- Newly inserted patch in v2 to fix an enumeration issue. (Ronald)

 drivers/acpi/scan.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index d4ff2cd1f738..c565e74bd2dd 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1444,6 +1444,12 @@ static bool acpi_is_spi_i2c_slave(struct acpi_device *device)
 	struct list_head resource_list;
 	bool is_spi_i2c_slave = false;
 
+	/* Macs use device properties in lieu of _CRS resources */
+	if (IS_ENABLED(CONFIG_X86) && dmi_match(DMI_SYS_VENDOR, "Apple Inc.") &&
+	    (device_property_present(&device->dev, "spiSclkPeriod") ||
+	     device_property_present(&device->dev, "i2cAddress")))
+		return true;
+
 	INIT_LIST_HEAD(&resource_list);
 	acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
 			       &is_spi_i2c_slave);
-- 
2.11.0

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