[PATCH 3/4] gpio: loongson1: Add DT support

[Keguang Zhang <keguang.zhang@gmail.com>]

This patch adds DT support for Loongson-1 GPIO driver,
including the following changes.
- Add the of_match_table
- Parse the ngpios property
- Parse the alias id

Signed-off-by: Keguang Zhang <keguang.zhang@gmail.com>
---
 drivers/gpio/gpio-loongson1.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpio-loongson1.c b/drivers/gpio/gpio-loongson1.c
index b950bcfd78ce..92ad31f61bf0 100644
--- a/drivers/gpio/gpio-loongson1.c
+++ b/drivers/gpio/gpio-loongson1.c
@@ -48,7 +48,10 @@ static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
 static int ls1x_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct device_node *dn = pdev->dev.of_node;
 	struct ls1x_gpio_chip *ls1x_gc;
+	unsigned int ngpios;
+	int id;
 	int ret;
 
 	ls1x_gc = devm_kzalloc(dev, sizeof(*ls1x_gc), GFP_KERNEL);
@@ -59,34 +62,56 @@ static int ls1x_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(ls1x_gc->reg_base))
 		return PTR_ERR(ls1x_gc->reg_base);
 
+	if (of_property_read_u32(dn, "ngpios", &ngpios)) {
+		dev_err(dev, "Missing ngpios OF property\n");
+		return -ENODEV;
+	}
+
+	id = of_alias_get_id(dn, "gpio");
+	if (id < 0) {
+		dev_err(dev, "Couldn't get OF id\n");
+		return id;
+	}
+
 	ret = bgpio_init(&ls1x_gc->gc, dev, 4, ls1x_gc->reg_base + GPIO_DATA,
 			 ls1x_gc->reg_base + GPIO_OUTPUT, NULL,
 			 NULL, ls1x_gc->reg_base + GPIO_DIR, 0);
 	if (ret)
 		goto err;
 
+	ls1x_gc->gc.label = dev_name(&pdev->dev);
+	ls1x_gc->gc.ngpio = ngpios;
 	ls1x_gc->gc.owner = THIS_MODULE;
+	ls1x_gc->gc.parent = dev;
+	ls1x_gc->gc.base = pdev->id * BITS_PER_LONG;
 	ls1x_gc->gc.request = ls1x_gpio_request;
 	ls1x_gc->gc.free = ls1x_gpio_free;
-	ls1x_gc->gc.base = pdev->id * 32;
 
 	ret = devm_gpiochip_add_data(dev, &ls1x_gc->gc, ls1x_gc);
 	if (ret)
 		goto err;
 
 	platform_set_drvdata(pdev, ls1x_gc);
-	dev_info(dev, "Loongson1 GPIO driver registered\n");
+
+	dev_info(dev, "GPIO controller %d registered with %d pins\n", id,
+		 ngpios);
 
 	return 0;
 err:
-	dev_err(dev, "failed to register GPIO device\n");
+	dev_err(dev, "failed to register GPIO controller\n");
 	return ret;
 }
 
+static const struct of_device_id ls1x_gpio_dt_ids[] = {
+	{ .compatible = "loongson,ls1x-gpio", },
+	{ /* sentinel */ }
+};
+
 static struct platform_driver ls1x_gpio_driver = {
 	.probe	= ls1x_gpio_probe,
 	.driver	= {
 		.name	= "ls1x-gpio",
+		.of_match_table = ls1x_gpio_dt_ids,
 	},
 };
 
-- 
2.34.1