[alsa-devel] Need help with WM8960

[Timur Tabi]

Timur Tabi wrote:
> Also, how do I get the platform data to the codec driver?  Do I need to
> create some arch code that reads the device tree properties and parses
> them into a wm8960_data object, and then (somehow) injects that into the
> wm8960 driver?

So, I'm guessing that there is no magical way to inject platform data into
an OF-initialized driver.  What do you think about this patch:

@@ -1029,6 +1030,7 @@ static const struct regmap_config wm8960_regmap = {
 static __devinit int wm8960_i2c_probe(struct i2c_client *i2c,
                                      const struct i2c_device_id *id)
 {
+       struct device_node *np = i2c->dev.of_node;
        struct wm8960_data *pdata = dev_get_platdata(&i2c->dev);
        struct wm8960_priv *wm8960;
        int ret;
@@ -1038,6 +1040,31 @@ static __devinit int wm8960_i2c_probe(struct
i2c_client *i2c,
        if (wm8960 == NULL)
                return -ENOMEM;

+       /*
+        * Are we running on an OF platform?  If so, then parse the device
+        * tree node for properties and create the platform data object
+        * ourselves.
+        */
+       if (np && !pdata) {
+               const __be32 *iprop;
+               int len;
+
+               pdata = devm_kzalloc(&i2c->dev, sizeof(struct wm8960_data),
+                                    GFP_KERNEL);
+               if (!pdata)
+                       return -ENOMEM;
+
+               if (of_find_property(np, "wlf,capless", NULL))
+                       pdata->capless = true;
+
+               iprop = of_get_property(np, "wlf,discharge-resistance", &len);
+               if (iprop && len == sizeof(uint32_t))
+                       pdata->dres = be32_to_cpup(iprop);
+
+               if (of_find_property(np, "wlf,shared-lrclk", NULL))
+                       pdata->shared_lrclk = true;
+
+               i2c->dev.platform_data = pdata;
+       }
+
        wm8960->regmap = regmap_init_i2c(i2c, &wm8960_regmap);
        if (IS_ERR(wm8960->regmap))
                return PTR_ERR(wm8960->regmap);


-- 
Timur Tabi
Linux kernel developer at Freescale