+/*
+ * Handlers for alternative sources of platform_data
+ */
+#ifdef CONFIG_OF_GPIO
+/*
+ * Translate OpenFirmware node properties into platform_data
+ */
+static struct pca953x_platform_data *
+pca953x_get_alt_pdata(struct i2c_client *client)
+{
+ struct pca953x_platform_data *pdata;
+ struct device_node *node;
+ const uint16_t *val;
+
+ node = dev_archdata_get_node(&client->dev.archdata);
+ if (node == NULL)
+ return NULL;
+
+ pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL);
+ if (pdata == NULL) {
+ dev_err(&client->dev, "Unable to allocate platform_data\n");
+ return NULL;
+ }
+
+ pdata->gpio_base = -1;
+ val = of_get_property(node, "linux,gpio-base", NULL);
+ if (val) {
+ if (*val < 0)
+ dev_warn(&client->dev,
+ "invalid gpio-base in device tree\n");
+ else
+ pdata->gpio_base = *val;
+ }
+
+ val = of_get_property(node, "polarity", NULL);
+ if (val)
+ pdata->invert = *val;
+
+ return pdata;
+}
+#else
+static struct pca953x_platform_data *
+pca953x_get_alt_pdata(struct i2c_client *client)
+{
+ return NULL;
+}
+#endif
+