iio:ak8975 Add support for gpios DT property

Add support for parsing 'gpios' property when initializing
from oftree.
This patch adds also the binding documentation file.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 9 insertions, 3 deletions

diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index af6c320a534e..d75cc23e8ae7 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -29,6 +29,7 @@
 #include <linux/delay.h>
 
 #include <linux/gpio.h>
+#include <linux/of_gpio.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -384,10 +385,15 @@ static int ak8975_probe(struct i2c_client *client,
         int err;
 
         /* Grab and set up the supplied GPIO. */
-        if (client->dev.platform_data == NULL)
-                eoc_gpio = -1;
-        else
+        if (client->dev.platform_data)
                 eoc_gpio = *(int *)(client->dev.platform_data);
+        else if (client->dev.of_node)
+                eoc_gpio = of_get_gpio(client->dev.of_node, 0);
+        else
+                eoc_gpio = -1;
+
+        if (eoc_gpio == -EPROBE_DEFER)
+                return -EPROBE_DEFER;
 
         /* We may not have a GPIO based IRQ to scan, that is fine, we will
            poll if so */