i2c: Check for ACPI resource conflicts

Check for ACPI resource conflicts in i2c bus drivers. I've included
all recent SMBus master drivers for PC hardware.

I've voluntarily left out:
* Drivers that don't run on PCs: they can't conflict with ACPI.
* Bit-banged bus device drivers: it's very unlikely that ACPI would
  deal with such buses.

Signed-off-by: Jean Delvare <jdelvare@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-isch.c b/drivers/i2c/busses/i2c-isch.c
index 8d648911a7f5..b9c01aa90036 100644
--- a/drivers/i2c/busses/i2c-isch.c
+++ b/drivers/i2c/busses/i2c-isch.c
@@ -35,6 +35,7 @@
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/acpi.h>
 
 /* SCH SMBus address offsets */
 #define SMBHSTCNT       (0 + sch_smba)
@@ -279,6 +280,8 @@ static int __devinit sch_probe(struct pci_dev *dev,
                 dev_err(&dev->dev, "SMBus base address uninitialized!\n");
                 return -ENODEV;
         }
+        if (acpi_check_region(sch_smba, SMBIOSIZE, sch_driver.name))
+                return -EBUSY;
         if (!request_region(sch_smba, SMBIOSIZE, sch_driver.name)) {
                 dev_err(&dev->dev, "SMBus region 0x%x already in use!\n",
                         sch_smba);