[RFC PATCH 3/5] hw/misc/led: Add create_led_by_gpio_id() helper

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

Add create_led_by_gpio_id() to easily connect a LED to
a GPIO output.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
 include/hw/misc/led.h | 14 ++++++++++++++
 hw/misc/led.c         | 20 ++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/include/hw/misc/led.h b/include/hw/misc/led.h
index 427ca1418e..58393c16de 100644
--- a/include/hw/misc/led.h
+++ b/include/hw/misc/led.h
@@ -27,4 +27,18 @@ typedef struct LEDState {
     uint8_t reset_state; /* TODO [GPIO_ACTIVE_LOW, GPIO_ACTIVE_HIGH] */
 } LEDState;
 
+/**
+ * create_led_by_gpio_id: create and LED device
+ * @parent: the parent object
+ * @gpio_dev: device exporting GPIOs
+ * @gpio_id: GPIO ID of this LED
+ * @name: name of the LED
+ *
+ * This utility function creates a LED and connects it to a
+ * GPIO exported by another device.
+ */
+DeviceState *create_led_by_gpio_id(Object *parentobj,
+                                   DeviceState *gpio_dev, unsigned gpio_id,
+                                   const char *led_name);
+
 #endif /* HW_MISC_LED_H */
diff --git a/hw/misc/led.c b/hw/misc/led.c
index 233843f581..27882e2f9d 100644
--- a/hw/misc/led.c
+++ b/hw/misc/led.c
@@ -86,3 +86,23 @@ static void led_register_types(void)
 }
 
 type_init(led_register_types)
+
+DeviceState *create_led_by_gpio_id(Object *parentobj,
+                                   DeviceState *gpio_dev, unsigned gpio_id,
+                                   const char *led_name)
+{
+    DeviceState *dev;
+    char *name;
+
+    dev = qdev_create(NULL, TYPE_LED);
+    /* TODO set "reset_state" */
+    qdev_prop_set_string(dev, "name", led_name);
+    name = g_ascii_strdown(led_name, -1);
+    name = g_strdelimit(name, " #", '-');
+    object_property_add_child(parentobj, name, OBJECT(dev));
+    g_free(name);
+    qdev_init_nofail(dev);
+    qdev_connect_gpio_out(gpio_dev, gpio_id, qdev_get_gpio_in(dev, 0));
+
+    return dev;
+}
-- 
2.21.3