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authorDustin Byford <dustin@cumulusnetworks.com>2015-10-23 21:27:07 +0200
committerWolfram Sang <wsa@the-dreams.de>2015-10-25 15:49:46 +0100
commit8eb5c87a92c065aaca39ac3e841b07906a4959a2 (patch)
tree326cf581c599660996c4ddb59a5ffc6898ad0ebd /drivers/i2c/busses/i2c-designware-pcidrv.c
parentacpi: add acpi_preset_companion() stub (diff)
downloadlinux-8eb5c87a92c065aaca39ac3e841b07906a4959a2.tar.xz
linux-8eb5c87a92c065aaca39ac3e841b07906a4959a2.zip
i2c: add ACPI support for I2C mux ports
Although I2C mux devices are easily enumerated using ACPI (_HID/_CID or device property compatible string match), enumerating I2C client devices connected through an I2C mux needs a little extra work. This change implements a method for describing an I2C device hierarchy that includes mux devices by using an ACPI Device() for each mux channel along with an _ADR to set the channel number for the device. See Documentation/acpi/i2c-muxes.txt for a simple example. To make this work the ismt, i801, and designware pci/platform devs now share an ACPI companion with their I2C adapter dev similar to how it's done in OF. This is done on the assumption that power management functions will not be called directly on the I2C dev that is sharing the ACPI node. Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-pcidrv.c')
-rw-r--r--drivers/i2c/busses/i2c-designware-pcidrv.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 169be1e26241..1543d35d228d 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -35,6 +35,7 @@
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/pm_runtime.h>
+#include <linux/acpi.h>
#include "i2c-designware-core.h"
#define DRIVER_NAME "i2c-designware-pci"
@@ -244,6 +245,7 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
adap = &dev->adapter;
adap->owner = THIS_MODULE;
adap->class = 0;
+ ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
adap->nr = controller->bus_num;
r = i2c_dw_probe(dev);