gpio: pl061: add DT binding support

This adds devicetree binding support to the ARM pl061 driver removing the
platform_data dependency. When DT binding is used, the gpio numbering is
assigned dynamically. For now, interrupts are not supported with DT until
irqdomains learn dynamic irq assignment.

Rather than add another case of -1, updating the driver to use NO_IRQ.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpio-pl061.c

@@ -118,7 +118,7 @@ static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
 {
 	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
 
-	if (chip->irq_base == (unsigned) -1)
+	if (chip->irq_base == NO_IRQ)
 		return -EINVAL;
 
 	return chip->irq_base + offset;
@@ -246,6 +246,18 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
 	if (chip == NULL)
 		return -ENOMEM;
 
+	pdata = dev->dev.platform_data;
+	if (pdata) {
+		chip->gc.base = pdata->gpio_base;
+		chip->irq_base = pdata->irq_base;
+	} else if (dev->dev.of_node) {
+		chip->gc.base = -1;
+		chip->irq_base = NO_IRQ;
+	} else {
+		ret = -ENODEV;
+		goto free_mem;
+	}
+
 	if (!request_mem_region(dev->res.start,
 				resource_size(&dev->res), "pl061")) {
 		ret = -EBUSY;
@@ -267,14 +279,11 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
 	chip->gc.get = pl061_get_value;
 	chip->gc.set = pl061_set_value;
 	chip->gc.to_irq = pl061_to_irq;
-	chip->gc.base = pdata->gpio_base;
 	chip->gc.ngpio = PL061_GPIO_NR;
 	chip->gc.label = dev_name(&dev->dev);
 	chip->gc.dev = &dev->dev;
 	chip->gc.owner = THIS_MODULE;
 
-	chip->irq_base = pdata->irq_base;
-
 	ret = gpiochip_add(&chip->gc);
 	if (ret)
 		goto iounmap;
@@ -283,7 +292,7 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
 	 * irq_chip support
 	 */
 
-	if (chip->irq_base == (unsigned) -1)
+	if (chip->irq_base == NO_IRQ)
 		return 0;
 
 	writeb(0, chip->base + GPIOIE); /* disable irqs */
@@ -307,11 +316,13 @@ static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
 	list_add(&chip->list, chip_list);
 
 	for (i = 0; i < PL061_GPIO_NR; i++) {
-		if (pdata->directions & (1 << i))
-			pl061_direction_output(&chip->gc, i,
-					pdata->values & (1 << i));
-		else
-			pl061_direction_input(&chip->gc, i);
+		if (pdata) {
+			if (pdata->directions & (1 << i))
+				pl061_direction_output(&chip->gc, i,
+						pdata->values & (1 << i));
+			else
+				pl061_direction_input(&chip->gc, i);
+		}
 
 		irq_set_chip_and_handler(i + chip->irq_base, &pl061_irqchip,
 					 handle_simple_irq);

include/linux/amba/pl061.h

@@ -7,8 +7,7 @@ struct pl061_platform_data {
 	unsigned	gpio_base;
 
 	/* number of the first IRQ.
-	 * If the IRQ functionality in not desired this must be set to
-	 * (unsigned) -1.
+	 * If the IRQ functionality in not desired this must be set to NO_IRQ.
 	 */
 	unsigned	irq_base;