led-trigger: Allow multiple led triggers of the same type

We used to have a static array of trigger types which, allows only one led
per trigger. While this is enough for panic and heartbeat, it falls short when
multiple leds are associated to the default-on trigger. The default-on trigger
is used to turn on a led statically from devicetree and may be used multiple
times.
This patch reworks the led triggers so that a trigger struct is allocated
dynamically when needed and put onto a list.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 131 insertions, 54 deletions

diff --git a/commands/trigger.c b/commands/trigger.c
index 2758ce74e8..0dd3b346fa 100644
--- a/commands/trigger.c
+++ b/commands/trigger.c
@@ -28,59 +28,62 @@
 #define LED_COMMAND_SHOW_INFO		2
 #define	LED_COMMAND_DISABLE_TRIGGER	3
 
-static char *trigger_names[] = {
-	[LED_TRIGGER_PANIC] = "panic",
-	[LED_TRIGGER_HEARTBEAT] = "heartbeat",
-	[LED_TRIGGER_NET_RX] = "net rx",
-	[LED_TRIGGER_NET_TX] = "net tx",
-	[LED_TRIGGER_NET_TXRX] = "net",
-	[LED_TRIGGER_DEFAULT_ON] = "default on",
-};
 
 static int do_trigger(int argc, char *argv[])
 {
-	struct led *led;
-	int i, opt, ret = 0;
+	struct led *led = NULL;
+	int opt, ret = 0;
 	int cmd = LED_COMMAND_SHOW_INFO;
-	unsigned long trigger = 0;
+	enum led_trigger trigger;
+	const char *led_name = NULL;
+	const char *trigger_name = NULL;
 
 	while((opt = getopt(argc, argv, "t:d:")) > 0) {
 		switch(opt) {
 		case 't':
-			trigger = simple_strtoul(optarg, NULL, 0);
+			trigger_name = optarg;
 			cmd = LED_COMMAND_SET_TRIGGER;
 			break;
 		case 'd':
-			trigger = simple_strtoul(optarg, NULL, 0);
+			led_name = optarg;
 			cmd = LED_COMMAND_DISABLE_TRIGGER;
 		}
 	}
 
+	if (optind < argc)
+		led = led_by_name_or_number(argv[optind]);
+
 	switch (cmd) {
 	case LED_COMMAND_SHOW_INFO:
-		for (i = 0; i < LED_TRIGGER_MAX; i++) {
-			int led = led_get_trigger(i);
-			printf("%d: %s", i, trigger_names[i]);
-			if (led >= 0)
-				printf(" (led %d)", led);
-			printf("\n");
-		}
+		led_triggers_show_info();
 		break;
 
 	case LED_COMMAND_DISABLE_TRIGGER:
-		ret = led_set_trigger(trigger, NULL);
+		led = led_by_name_or_number(led_name);
+		if (!led) {
+			printf("no such led: %s\n", led_name);
+			return 1;
+		}
+
+		led_trigger_disable(led);
 		break;
 
 	case LED_COMMAND_SET_TRIGGER:
 		if (argc - optind != 1)
 			return COMMAND_ERROR_USAGE;
-		led = led_by_name_or_number(argv[optind]);
 
+		led = led_by_name_or_number(argv[optind]);
 		if (!led) {
 			printf("no such led: %s\n", argv[optind]);
 			return 1;
 		}
 
+		trigger = trigger_by_name(trigger_name);
+		if (trigger == LED_TRIGGER_INVALID) {
+			printf("no such trigger: %s\n", trigger_name);
+			return 1;
+		}
+
 		ret = led_set_trigger(trigger, led);
 		break;
 	}
@@ -92,16 +95,17 @@ static int do_trigger(int argc, char *argv[])
 
 BAREBOX_CMD_HELP_START(trigger)
 BAREBOX_CMD_HELP_TEXT("Control a LED trigger. Without options assigned triggers are shown.")
+BAREBOX_CMD_HELP_TEXT("triggers are given with their name, LEDs are given with their name or number")
 BAREBOX_CMD_HELP_TEXT("")
 BAREBOX_CMD_HELP_TEXT("Options:")
-BAREBOX_CMD_HELP_OPT ("-t",  "set a trigger (needs LED argument)")
-BAREBOX_CMD_HELP_OPT ("-d",  "disable a trigger")
+BAREBOX_CMD_HELP_OPT ("-t <trigger> <led>",  "set a trigger")
+BAREBOX_CMD_HELP_OPT ("-d <led>",  "disable a trigger")
 BAREBOX_CMD_HELP_END
 
 BAREBOX_CMD_START(trigger)
 	.cmd		= do_trigger,
 	BAREBOX_CMD_DESC("handle LED triggers")
-	BAREBOX_CMD_OPTS("[-td] TRIGGER [LED]")
+	BAREBOX_CMD_OPTS("[-td] [LED]")
 	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
 	BAREBOX_CMD_HELP(cmd_trigger_help)
 BAREBOX_CMD_END
diff --git a/drivers/led/led-triggers.c b/drivers/led/led-triggers.c
index 6c05cc5bbf..76a1481e14 100644
--- a/drivers/led/led-triggers.c
+++ b/drivers/led/led-triggers.c
@@ -52,7 +52,7 @@ struct led_trigger_struct {
 	enum led_trigger trigger;
 };
 
-static struct led_trigger_struct triggers[LED_TRIGGER_MAX];
+static LIST_HEAD(led_triggers);
 
 /**
  * led_trigger - triggers a trigger
@@ -63,17 +63,53 @@ static struct led_trigger_struct triggers[LED_TRIGGER_MAX];
  */
 void led_trigger(enum led_trigger trigger, enum trigger_type type)
 {
+	struct led_trigger_struct *led_trigger;
+
 	if (trigger >= LED_TRIGGER_MAX)
 		return;
-	if (!triggers[trigger].led)
-		return;
 
-	if (type == TRIGGER_FLASH) {
-		led_flash(triggers[trigger].led, 200);
-		return;
+	list_for_each_entry(led_trigger, &led_triggers, list) {
+		if (led_trigger->trigger != trigger)
+			continue;
+
+		switch (type) {
+		case TRIGGER_FLASH:
+			led_flash(led_trigger->led, 200);
+			break;
+		case TRIGGER_ENABLE:
+			led_set(led_trigger->led, led_trigger->led->max_value);
+			break;
+		case TRIGGER_DISABLE:
+			led_set(led_trigger->led, 0);
+			break;
+		}
 	}
+}
+
+static struct led_trigger_struct *led_find_trigger(struct led *led)
+{
+	struct led_trigger_struct *led_trigger;
+
+	list_for_each_entry(led_trigger, &led_triggers, list)
+		if (led_trigger->led == led)
+			return led_trigger;
+
+	return NULL;
+}
 
-	led_set(triggers[trigger].led, type == TRIGGER_ENABLE ? triggers[trigger].led->max_value : 0);
+void led_trigger_disable(struct led *led)
+{
+	struct led_trigger_struct *led_trigger;
+
+	led_trigger = led_find_trigger(led);
+	if (!led_trigger)
+		return;
+
+	list_del(&led_trigger->list);
+
+	led_set(led, 0);
+
+	free(led_trigger);
 }
 
 /**
@@ -86,40 +122,73 @@ void led_trigger(enum led_trigger trigger, enum trigger_type type)
  */
 int led_set_trigger(enum led_trigger trigger, struct led *led)
 {
-	int i;
+	struct led_trigger_struct *led_trigger;
 
 	if (trigger >= LED_TRIGGER_MAX)
 		return -EINVAL;
 
-	if (led)
-		for (i = 0; i < LED_TRIGGER_MAX; i++)
-			if (triggers[i].led == led)
-				return -EBUSY;
+	led_trigger_disable(led);
 
-	if (triggers[trigger].led && !led)
-		led_set(triggers[trigger].led, 0);
+	led_trigger = xzalloc(sizeof(*led_trigger));
 
-	triggers[trigger].led = led;
+	led_trigger->led = led;
+	led_trigger->trigger = trigger;
+	list_add_tail(&led_trigger->list, &led_triggers);
 
-	if (led && trigger == LED_TRIGGER_DEFAULT_ON)
-		led_set(triggers[trigger].led, triggers[trigger].led->max_value);
-	if (led && trigger == LED_TRIGGER_HEARTBEAT)
+	if (trigger == LED_TRIGGER_DEFAULT_ON)
+		led_set(led, led->max_value);
+	if (trigger == LED_TRIGGER_HEARTBEAT)
 		led_blink(led, 200, 1000);
 
 	return 0;
 }
 
+static char *trigger_names[] = {
+	[LED_TRIGGER_PANIC] = "panic",
+	[LED_TRIGGER_HEARTBEAT] = "heartbeat",
+	[LED_TRIGGER_NET_RX] = "net-rx",
+	[LED_TRIGGER_NET_TX] = "net-tx",
+	[LED_TRIGGER_NET_TXRX] = "net",
+	[LED_TRIGGER_DEFAULT_ON] = "default-on",
+};
+
+const char *trigger_name(enum led_trigger trigger)
+{
+	return trigger_names[trigger];
+}
+
+enum led_trigger trigger_by_name(const char *name)
+{
+	int i;
+
+	for (i = 0; i < LED_TRIGGER_MAX; i++)
+		if (!strcmp(name, trigger_names[i]))
+			return i;
+
+	return LED_TRIGGER_MAX;
+}
+
 /**
- * led_get_trigger - get the LED for a trigger
- * @param trigger	The trigger to set a LED for
- *
- * return the LED number of a trigger.
+ * led_triggers_show_info - Show information about all registered
+ * triggers
  */
-int led_get_trigger(enum led_trigger trigger)
+void led_triggers_show_info(void)
 {
-	if (trigger >= LED_TRIGGER_MAX)
-		return -EINVAL;
-	if (!triggers[trigger].led)
-		return -ENODEV;
-	return led_get_number(triggers[trigger].led);
+	struct led_trigger_struct *led_trigger;
+	int i;
+
+	for (i = 0; i < LED_TRIGGER_MAX; i++) {
+		printf("%s", trigger_name(i));
+
+		list_for_each_entry(led_trigger, &led_triggers, list) {
+			struct led *led = led_trigger->led;
+
+			if (led_trigger->trigger != i)
+				continue;
+
+			printf("\n  LED %d (%s)", led->num, led->name);
+		}
+
+		printf("\n");
+	}
 }
diff --git a/include/led.h b/include/led.h
index fb5c48b9e2..0ce857129d 100644
--- a/include/led.h
+++ b/include/led.h
@@ -49,6 +49,7 @@ enum led_trigger {
 	LED_TRIGGER_NET_TXRX,
 	LED_TRIGGER_DEFAULT_ON,
 	LED_TRIGGER_MAX,
+	LED_TRIGGER_INVALID = LED_TRIGGER_MAX,
 };
 
 enum trigger_type {
@@ -59,6 +60,7 @@ enum trigger_type {
 
 #ifdef CONFIG_LED_TRIGGERS
 int led_set_trigger(enum led_trigger trigger, struct led *led);
+void led_trigger_disable(struct led *led);
 void led_trigger(enum led_trigger trigger, enum trigger_type);
 #else
 static inline int led_set_trigger(enum led_trigger trigger, struct led *led)
@@ -71,7 +73,9 @@ static inline void led_trigger(enum led_trigger trigger, enum trigger_type type)
 }
 #endif
 
-int led_get_trigger(enum led_trigger trigger);
+void led_triggers_show_info(void);
+const char *trigger_name(enum led_trigger trigger);
+enum led_trigger trigger_by_name(const char *name);
 
 void led_of_parse_trigger(struct led *led, struct device_node *np);