leds: lt3593: Add device tree probing glue

The binding details are described in an earlier commit that adds the
documentation.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>

diff --git a/drivers/leds/leds-lt3593.c b/drivers/leds/leds-lt3593.c
index a096ee6..2e35a4a 100644 (file)
--- a/drivers/leds/leds-lt3593.c
+++ b/drivers/leds/leds-lt3593.c
@@ -24,8 +24,11 @@
 #include <linux/gpio/consumer.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/of.h>
+#include <uapi/linux/uleds.h>
 
 struct lt3593_led_data {
+       char name[LED_MAX_NAME_SIZE];
        struct led_classdev cdev;
        struct gpio_desc *gpiod;
 };
@@ -120,22 +123,89 @@ static int lt3593_led_probe(struct platform_device *pdev)
 {
        struct device *dev = &pdev->dev;
        struct lt3593_led_data *led_data;
+       struct fwnode_handle *child;
+       int ret, state = LEDS_GPIO_DEFSTATE_OFF;
+       enum gpiod_flags flags = GPIOD_OUT_LOW;
+       const char *tmp;
 
        if (dev_get_platdata(dev)) {
                led_data = lt3593_led_probe_pdata(dev);
                if (IS_ERR(led_data))
                        return PTR_ERR(led_data);
+
+               goto out;
        }
 
+       if (!dev->of_node)
+               return -ENODEV;
+
+       led_data = devm_kzalloc(dev, sizeof(*led_data), GFP_KERNEL);
+       if (!led_data)
+               return -ENOMEM;
+
+       if (device_get_child_node_count(dev) != 1) {
+               dev_err(dev, "Device must have exactly one LED sub-node.");
+               return -EINVAL;
+       }
+
+       led_data->gpiod = devm_gpiod_get(dev, "lltc,ctrl", 0);
+       if (IS_ERR(led_data->gpiod))
+               return PTR_ERR(led_data->gpiod);
+
+       child = device_get_next_child_node(dev, NULL);
+
+       ret = fwnode_property_read_string(child, "label", &tmp);
+       if (ret < 0)
+               snprintf(led_data->name, sizeof(led_data->name),
+                        "lt3593::");
+       else
+               snprintf(led_data->name, sizeof(led_data->name),
+                        "lt3593:%s", tmp);
+
+       fwnode_property_read_string(child, "linux,default-trigger",
+                                   &led_data->cdev.default_trigger);
+
+       if (!fwnode_property_read_string(child, "default-state", &tmp)) {
+               if (!strcmp(tmp, "keep")) {
+                       state = LEDS_GPIO_DEFSTATE_KEEP;
+                       flags = GPIOD_ASIS;
+               } else if (!strcmp(tmp, "on")) {
+                       state = LEDS_GPIO_DEFSTATE_ON;
+                       flags = GPIOD_OUT_HIGH;
+               }
+       }
+
+       led_data->cdev.name = led_data->name;
+       led_data->cdev.brightness_set_blocking = lt3593_led_set;
+       led_data->cdev.brightness = state ? LED_FULL : LED_OFF;
+
+       ret = devm_led_classdev_register(dev, &led_data->cdev);
+       if (ret < 0) {
+               fwnode_handle_put(child);
+               return ret;
+       }
+
+       led_data->cdev.dev->of_node = dev->of_node;
+
+out:
        platform_set_drvdata(pdev, led_data);
 
        return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id of_lt3593_leds_match[] = {
+       { .compatible = "lltc,lt3593", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, of_lt3593_leds_match);
+#endif
+
 static struct platform_driver lt3593_led_driver = {
        .probe          = lt3593_led_probe,
        .driver         = {
                .name   = "leds-lt3593",
+               .of_match_table = of_match_ptr(of_lt3593_leds_match),
        },
 };