ACPI / scan: Recognize Apple SPI and I2C slaves

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. Reported-and-tested-by: Ronald Tschalär <[email protected]> Signed-off-by: Lukas Wunner <[email protected]> Acked-by: Mika Westerberg <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>
torvalds · Aug 3, 2017 · ca9ef3a · ca9ef3a
1 parent 899596e
commit ca9ef3a
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
@@ -13,6 +13,7 @@
 #include <linux/dmi.h>
 #include <linux/nls.h>
 #include <linux/dma-mapping.h>
+#include <linux/platform_data/x86/apple.h>
 
 #include <asm/pgtable.h>
 
@@ -1452,6 +1453,12 @@ 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 (x86_apple_machine &&
+	    (fwnode_property_present(&device->fwnode, "spiSclkPeriod") ||
+	     fwnode_property_present(&device->fwnode, "i2cAddress")))
+		return true;
+
 	INIT_LIST_HEAD(&resource_list);
 	acpi_dev_get_resources(device, &resource_list, acpi_check_spi_i2c_slave,
 			       &is_spi_i2c_slave);