mfd: max8998: Add support for Device Tree

This patch adds Device Tree support to max8998 driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 65 insertions, 2 deletions

diff --git a/drivers/mfd/max8998.c b/drivers/mfd/max8998.c
index d7218cc90945..21af51a499f4 100644
--- a/drivers/mfd/max8998.c
+++ b/drivers/mfd/max8998.c
@@ -20,12 +20,15 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include <linux/err.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
 #include <linux/pm_runtime.h>
 #include <linux/mutex.h>
 #include <linux/mfd/core.h>
@@ -128,6 +131,56 @@ int max8998_update_reg(struct i2c_client *i2c, u8 reg, u8 val, u8 mask)
 }
 EXPORT_SYMBOL(max8998_update_reg);
 
+#ifdef CONFIG_OF
+static struct of_device_id max8998_dt_match[] = {
+        { .compatible = "maxim,max8998", .data = (void *)TYPE_MAX8998 },
+        { .compatible = "national,lp3974", .data = (void *)TYPE_LP3974 },
+        { .compatible = "ti,lp3974", .data = (void *)TYPE_LP3974 },
+        {},
+};
+MODULE_DEVICE_TABLE(of, max8998_dt_match);
+#endif
+
+/*
+ * Only the common platform data elements for max8998 are parsed here from the
+ * device tree. Other sub-modules of max8998 such as pmic, rtc and others have
+ * to parse their own platform data elements from device tree.
+ *
+ * The max8998 platform data structure is instantiated here and the drivers for
+ * the sub-modules need not instantiate another instance while parsing their
+ * platform data.
+ */
+static struct max8998_platform_data *max8998_i2c_parse_dt_pdata(
+                                                        struct device *dev)
+{
+        struct max8998_platform_data *pd;
+
+        pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+        if (!pd)
+                return ERR_PTR(-ENOMEM);
+
+        pd->ono = irq_of_parse_and_map(dev->of_node, 1);
+
+        /*
+         * ToDo: the 'wakeup' member in the platform data is more of a linux
+         * specfic information. Hence, there is no binding for that yet and
+         * not parsed here.
+         */
+        return pd;
+}
+
+static inline int max8998_i2c_get_driver_data(struct i2c_client *i2c,
+                                                const struct i2c_device_id *id)
+{
+        if (IS_ENABLED(CONFIG_OF) && i2c->dev.of_node) {
+                const struct of_device_id *match;
+                match = of_match_node(max8998_dt_match, i2c->dev.of_node);
+                return (int)match->data;
+        }
+
+        return (int)id->driver_data;
+}
+
 static int max8998_i2c_probe(struct i2c_client *i2c,
                             const struct i2c_device_id *id)
 {
@@ -139,11 +192,20 @@ static int max8998_i2c_probe(struct i2c_client *i2c,
         if (max8998 == NULL)
                 return -ENOMEM;
 
+        if (IS_ENABLED(CONFIG_OF) && i2c->dev.of_node) {
+                pdata = max8998_i2c_parse_dt_pdata(&i2c->dev);
+                if (IS_ERR(pdata)) {
+                        ret = PTR_ERR(pdata);
+                        goto err;
+                }
+        }
+
         i2c_set_clientdata(i2c, max8998);
         max8998->dev = &i2c->dev;
         max8998->i2c = i2c;
         max8998->irq = i2c->irq;
-        max8998->type = id->driver_data;
+        max8998->type = max8998_i2c_get_driver_data(i2c, id);
+        max8998->pdata = pdata;
         if (pdata) {
                 max8998->ono = pdata->ono;
                 max8998->irq_base = pdata->irq_base;
@@ -158,7 +220,7 @@ static int max8998_i2c_probe(struct i2c_client *i2c,
 
         pm_runtime_set_active(max8998->dev);
 
-        switch (id->driver_data) {
+        switch (max8998->type) {
         case TYPE_LP3974:
                 ret = mfd_add_devices(max8998->dev, -1,
                                       lp3974_devs, ARRAY_SIZE(lp3974_devs),
@@ -314,6 +376,7 @@ static struct i2c_driver max8998_i2c_driver = {
                    .name = "max8998",
                    .owner = THIS_MODULE,
                    .pm = &max8998_pm,
+                   .of_match_table = of_match_ptr(max8998_dt_match),
         },
         .probe = max8998_i2c_probe,
         .remove = max8998_i2c_remove,