gpio/pca953x: Deprecate meaningless device-tree bindings

The property 'polarity' is handled by the GPIO core, and the 'gpio-base'
should be assigned automatically. It is meaningless in the device-tree,
since GPIO's are identified by the "chip-name"/offset pair.
This way, the whole pca953x_get_alt_pdata() can hopefully soon go away.
We still need to check whether we really want GPIO-interrupt functionality
by simply looking if the I2C node has an interrupts property defined, since
this property is not used for anything else.

Signed-off-by: David Jander <[e-mail]>
Signed-off-by: Grant Likely <[e-mail]>

drivers/gpio/gpio-pca953x.c

···
 #include <linux/slab.h>
 #ifdef CONFIG_OF_GPIO
 #include <linux/of_platform.h>
-#include <linux/of_gpio.h>
 #endif
 
 #define PCA953X_INPUT		0
···
 #ifdef CONFIG_OF_GPIO
 /*
  * Translate OpenFirmware node properties into platform_data
+ * WARNING: This is DEPRECATED and will be removed eventually!
  */
 void
 pca953x_get_alt_pdata(struct i2c_client *client, int *gpio_base, int *invert)
···
 
 	*gpio_base = -1;
 	val = of_get_property(node, "linux,gpio-base", &size);
+	WARN(val, "%s: device-tree property 'linux,gpio-base' is deprecated!", __func__);
 	if (val) {
 		if (size != sizeof(*val))
 			dev_warn(&client->dev, "%s: wrong linux,gpio-base\n",
···
 	}
 
 	val = of_get_property(node, "polarity", NULL);
+	WARN(val, "%s: device-tree property 'polarity' is deprecated!", __func__);
 	if (val)
 		*invert = *val;
 }
···
 {
 	struct pca953x_platform_data *pdata;
 	struct pca953x_chip *chip;
-	int irq_base=-1, invert=0;
+	int irq_base=0, invert=0;
 	int ret = 0;
 
 	chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
···
 		chip->names = pdata->names;
 	} else {
 		pca953x_get_alt_pdata(client, &chip->gpio_start, &invert);
+#ifdef CONFIG_OF_GPIO
+		/* If I2C node has no interrupts property, disable GPIO interrupts */
+		if (of_find_property(client->dev.of_node, "interrupts", NULL) == NULL)
+			irq_base = -1;
+#endif
 	}
 
 	chip->client = client;