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[PATCH v4 4/5] ACPI / scan: Recognize Apple SPI and I2C slaves

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  [PATCH v4 4/5] ACPI / scan: Recognize Apple SPI and I2C slaves Lukas Wunner <lukas@wunner.de> - 2017-08-01 14:20 +0200
    Re: [PATCH v4 4/5] ACPI / scan: Recognize Apple SPI and I2C slaves Mika Westerberg <mika.westerberg@linux.intel.com> - 2017-08-01 15:40 +0200

#1700950 — [PATCH v4 4/5] 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.

Cc: Federico Lorenzi <florenzi@gmail.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-and-tested-by: Ronald Tschalär <ronald@innovation.ch>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
---
 drivers/acpi/scan.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 943536c9a2a8..71a067c412a1 100644
--- 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);
-- 
2.11.0

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#1701047

On Tue, Aug 01, 2017 at 02:10:41PM +0200, Lukas Wunner wrote:
> 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: Federico Lorenzi <florenzi@gmail.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>

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