iio: ak8975: Added ACPI enumeration

Added capability so that this device can be enumerated via ACPI.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 37 insertions, 3 deletions

diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c
index 0f1ca5303139..f5c1d41bf39f 100644
--- a/drivers/iio/magnetometer/ak8975.c
+++ b/drivers/iio/magnetometer/ak8975.c
@@ -31,6 +31,7 @@
 #include <linux/bitops.h>
 #include <linux/gpio.h>
 #include <linux/of_gpio.h>
+#include <linux/acpi.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
@@ -475,6 +476,27 @@ static const struct iio_info ak8975_info = {
         .driver_module = THIS_MODULE,
 };
 
+static const struct acpi_device_id ak_acpi_match[] = {
+        {"AK8975", AK8975},
+        {"AK8963", AK8963},
+        {"INVN6500", AK8963},
+        { },
+};
+MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
+
+static char *ak8975_match_acpi_device(struct device *dev,
+                                enum asahi_compass_chipset *chipset)
+{
+        const struct acpi_device_id *id;
+
+        id = acpi_match_device(dev->driver->acpi_match_table, dev);
+        if (!id)
+                return NULL;
+        *chipset = (int)id->driver_data;
+
+        return (char *)dev_name(dev);
+}
+
 static int ak8975_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
 {
@@ -482,6 +504,7 @@ static int ak8975_probe(struct i2c_client *client,
         struct iio_dev *indio_dev;
         int eoc_gpio;
         int err;
+        char *name = NULL;
 
         /* Grab and set up the supplied GPIO. */
         if (client->dev.platform_data)
@@ -519,8 +542,18 @@ static int ak8975_probe(struct i2c_client *client,
         data->eoc_gpio = eoc_gpio;
         data->eoc_irq = 0;
 
-        data->chipset = (enum asahi_compass_chipset)(id->driver_data);
-        dev_dbg(&client->dev, "Asahi compass chip %s\n", id->name);
+        /* id will be NULL when enumerated via ACPI */
+        if (id) {
+                data->chipset =
+                        (enum asahi_compass_chipset)(id->driver_data);
+                name = (char *) id->name;
+        } else if (ACPI_HANDLE(&client->dev))
+                name = ak8975_match_acpi_device(&client->dev, &data->chipset);
+        else {
+                err = -ENOSYS;
+                goto exit_free_iio;
+        }
+        dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
 
         /* Perform some basic start-of-day setup of the device. */
         err = ak8975_setup(client);
@@ -538,7 +571,7 @@ static int ak8975_probe(struct i2c_client *client,
         indio_dev->info = &ak8975_info;
         indio_dev->name = id->name;
         indio_dev->modes = INDIO_DIRECT_MODE;
-
+        indio_dev->name = name;
         err = iio_device_register(indio_dev);
         if (err < 0)
                 goto exit_free_iio;
@@ -593,6 +626,7 @@ static struct i2c_driver ak8975_driver = {
         .driver = {
                 .name   = "ak8975",
                 .of_match_table = ak8975_of_match,
+                .acpi_match_table = ACPI_PTR(ak_acpi_match),
         },
         .probe          = ak8975_probe,
         .remove         = ak8975_remove,