i2c: Make I2C ID tables non-mandatory for DT'ed devices

Currently the I2C framework insists on devices supplying an I2C ID
table.  Many of the devices which do so unnecessarily adding quite a
few wasted lines to kernel code.  This patch allows drivers a means
to 'not' supply the aforementioned table and match on DT match tables
instead.

Acked-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Tested-by: Kieran Bingham <kieran@bingham.xyz>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Kieran Bingham <kieran@bingham.xyz>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 2151d0b..a97f7a0 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -697,7 +697,7 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
 
 
        /* Attempt an OF style match */
-       if (of_driver_match_device(dev, drv))
+       if (i2c_of_match_device(drv->of_match_table, client))
                return 1;
 
        /* Then ACPI style match */
@@ -923,7 +923,15 @@ static int i2c_device_probe(struct device *dev)
        }
 
        driver = to_i2c_driver(dev->driver);
-       if (!driver->probe || !driver->id_table)
+       if (!driver->probe)
+               return -EINVAL;
+
+       /*
+        * An I2C ID table is not mandatory, if and only if, a suitable Device
+        * Tree match table entry is supplied for the probing device.
+        */
+       if (!driver->id_table &&
+           !i2c_of_match_device(dev->driver->of_match_table, client))
                return -ENODEV;
 
        if (client->flags & I2C_CLIENT_WAKE) {