max17042_battery: Make it possible to instantiate driver from DT

Allow both device tree (preferred) and platform data-based driver
instantiation.

Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>

diff --git a/Documentation/devicetree/bindings/power_supply/max17042_battery.txt b/Documentation/devicetree/bindings/power_supply/max17042_battery.txt
new file mode 100644 (file)
index 0000000..5bc9b68
--- /dev/null
+++ b/Documentation/devicetree/bindings/power_supply/max17042_battery.txt
@@ -0,0 +1,18 @@
+max17042_battery
+~~~~~~~~~~~~~~~~
+
+Required properties :
+ - compatible : "maxim,max17042"
+
+Optional properties :
+ - maxim,rsns-microohm : Resistance of rsns resistor in micro Ohms
+                         (datasheet-recommended value is 10000).
+   Defining this property enables current-sense functionality.
+
+Example:
+
+       battery-charger@36 {
+               compatible = "maxim,max17042";
+               reg = <0x36>;
+               maxim,rsns-microohm = <10000>;
+       };

diff --git a/drivers/power/max17042_battery.c b/drivers/power/max17042_battery.c
index 872e9b4..e36763a 100644 (file)
--- a/drivers/power/max17042_battery.c
+++ b/drivers/power/max17042_battery.c
@@ -31,6 +31,7 @@
 #include <linux/mod_devicetable.h>
 #include <linux/power_supply.h>
 #include <linux/power/max17042_battery.h>
+#include <linux/of.h>
 
 /* Status register bits */
 #define STATUS_POR_BIT         (1 << 1)
@@ -608,6 +609,40 @@ static void max17042_init_worker(struct work_struct *work)
        chip->init_complete = 1;
 }
 
+#ifdef CONFIG_OF
+static struct max17042_platform_data *
+max17042_get_pdata(struct device *dev)
+{
+       struct device_node *np = dev->of_node;
+       u32 prop;
+       struct max17042_platform_data *pdata;
+
+       if (!np)
+               return dev->platform_data;
+
+       pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+       if (!pdata)
+               return NULL;
+
+       /*
+        * Require current sense resistor value to be specified for
+        * current-sense functionality to be enabled at all.
+        */
+       if (of_property_read_u32(np, "maxim,rsns-microohm", &prop) == 0) {
+               pdata->r_sns = prop;
+               pdata->enable_current_sense = true;
+       }
+
+       return pdata;
+}
+#else
+static struct max17042_platform_data *
+max17042_get_pdata(struct device *dev)
+{
+       return dev->platform_data;
+}
+#endif
+
 static int __devinit max17042_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -624,7 +659,11 @@ static int __devinit max17042_probe(struct i2c_client *client,
                return -ENOMEM;
 
        chip->client = client;
-       chip->pdata = client->dev.platform_data;
+       chip->pdata = max17042_get_pdata(&client->dev);
+       if (!chip->pdata) {
+               dev_err(&client->dev, "no platform data provided\n");
+               return -EINVAL;
+       }
 
        i2c_set_clientdata(client, chip);
 
@@ -689,6 +728,14 @@ static int __devexit max17042_remove(struct i2c_client *client)
        return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id max17042_dt_match[] = {
+       { .compatible = "maxim,max17042" },
+       { },
+};
+MODULE_DEVICE_TABLE(of, max17042_dt_match);
+#endif
+
 static const struct i2c_device_id max17042_id[] = {
        { "max17042", 0 },
        { }
@@ -698,6 +745,7 @@ MODULE_DEVICE_TABLE(i2c, max17042_id);
 static struct i2c_driver max17042_i2c_driver = {
        .driver = {
                .name   = "max17042",
+               .of_match_table = of_match_ptr(max17042_dt_match),
        },
        .probe          = max17042_probe,
        .remove         = __devexit_p(max17042_remove),