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>

1 files changed, 70 insertions, 0 deletions

diff --git a/drivers/leds/leds-lt3593.c b/drivers/leds/leds-lt3593.c
index a096ee64cbbb..2e35a4a4c571 100644
--- 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),
         },
 };