led: add function naming option from linux

in linux we have the option to create the name of a led
optionally through the following properties:

- function
- color
- function-enumerator

This patch adds support for parsing this properties if there
is no label property.

The led name is created in led_post_bind() and we need some
storage place for it. Currently this patch prevents to use
malloc() instead it stores the name in new member :

        char name[LED_MAX_NAME_SIZE];

of struct led_uc_plat. While at it append led tests for the
new feature.

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>

arch/sandbox/dts/test.dts

@@ -13,6 +13,7 @@
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/gpio/sandbox-gpio.h>
 #include <dt-bindings/input/input.h>
+#include <dt-bindings/leds/common.h>
 #include <dt-bindings/pinctrl/sandbox-pinmux.h>
 #include <dt-bindings/mux/mux.h>
 
@@ -820,7 +821,7 @@
 			gpio-controller;
 			#gpio-cells = <1>;
 			gpio-bank-name = "a";
-			sandbox,gpio-count = <20>;
+			sandbox,gpio-count = <25>;
 			hog_input_active_low {
 				gpio-hog;
 				input;
@@ -1010,6 +1011,40 @@
 			/* label intentionally omitted */
 			default-state = "off";
 		};
+
+		led-20 {
+			gpios = <&gpio_a 20 0>;
+			/* label intentionally omitted */
+			function = LED_FUNCTION_STATUS;
+			color = <LED_COLOR_ID_RED>;
+			function-enumerator = <20>;
+		};
+
+		led-21 {
+			gpios = <&gpio_a 21 0>;
+			/* label intentionally omitted */
+			function = LED_FUNCTION_STATUS;
+			color = <LED_COLOR_ID_GREEN>;
+		};
+
+		led-22 {
+			gpios = <&gpio_a 22 0>;
+			/* label intentionally omitted */
+			function = LED_FUNCTION_STATUS;
+		};
+
+		led-23 {
+			gpios = <&gpio_a 23 0>;
+			/* label intentionally omitted */
+			color = <LED_COLOR_ID_GREEN>;
+		};
+
+		led-24 {
+			gpios = <&gpio_a 24 0>;
+			label = "sandbox:function";
+			function = LED_FUNCTION_STATUS;
+			color = <LED_COLOR_ID_GREEN>;
+		};
 	};
 
 	wdt-gpio-toggle {

drivers/led/led-uclass.c

@@ -13,6 +13,25 @@
 #include <dm/lists.h>
 #include <dm/root.h>
 #include <dm/uclass-internal.h>
+#include <dt-bindings/leds/common.h>
+
+static const char * const led_colors[LED_COLOR_ID_MAX] = {
+	[LED_COLOR_ID_WHITE] = "white",
+	[LED_COLOR_ID_RED] = "red",
+	[LED_COLOR_ID_GREEN] = "green",
+	[LED_COLOR_ID_BLUE] = "blue",
+	[LED_COLOR_ID_AMBER] = "amber",
+	[LED_COLOR_ID_VIOLET] = "violet",
+	[LED_COLOR_ID_YELLOW] = "yellow",
+	[LED_COLOR_ID_IR] = "ir",
+	[LED_COLOR_ID_MULTI] = "multicolor",
+	[LED_COLOR_ID_RGB] = "rgb",
+	[LED_COLOR_ID_PURPLE] = "purple",
+	[LED_COLOR_ID_ORANGE] = "orange",
+	[LED_COLOR_ID_PINK] = "pink",
+	[LED_COLOR_ID_CYAN] = "cyan",
+	[LED_COLOR_ID_LIME] = "lime",
+};
 
 int led_bind_generic(struct udevice *parent, const char *driver_name)
 {
@@ -232,11 +251,54 @@ int led_activity_blink(void)
 #endif
 #endif
 
-static const char *led_get_label(ofnode node)
+static const char *led_get_function_name(struct udevice *dev)
+{
+	struct led_uc_plat *uc_plat;
+	const char *func;
+	u32 color;
+	u32 enumerator;
+	int ret;
+	int cp;
+
+	if (!dev)
+		return NULL;
+
+	uc_plat = dev_get_uclass_plat(dev);
+	if (!uc_plat)
+		return NULL;
+
+	if (uc_plat->label)
+		return uc_plat->label;
+
+	/* Now try to detect function label name */
+	func = dev_read_string(dev, "function");
+	cp = dev_read_u32(dev, "color", &color);
+	if (cp == 0 || func) {
+		ret = dev_read_u32(dev, "function-enumerator", &enumerator);
+		if (!ret) {
+			snprintf(uc_plat->name, LED_MAX_NAME_SIZE,
+				 "%s:%s-%d",
+				 cp ? "" : led_colors[color],
+				 func ? func : "", enumerator);
+		} else {
+			snprintf(uc_plat->name, LED_MAX_NAME_SIZE,
+				 "%s:%s",
+				 cp ? "" : led_colors[color],
+				 func ? func : "");
+		}
+		uc_plat->label = uc_plat->name;
+	}
+
+	return uc_plat->label;
+}
+
+static const char *led_get_label(struct udevice *dev, ofnode node)
 {
 	const char *label;
 
 	label = ofnode_read_string(node, "label");
+	if (!label)
+		label = led_get_function_name(dev);
 	if (!label && !ofnode_read_string(node, "compatible"))
 		label = ofnode_get_name(node);
 
@@ -249,7 +311,7 @@ static int led_post_bind(struct udevice *dev)
 	const char *default_state;
 
 	if (!uc_plat->label)
-		uc_plat->label = led_get_label(dev_ofnode(dev));
+		uc_plat->label = led_get_label(dev, dev_ofnode(dev));
 
 	uc_plat->default_state = LEDST_COUNT;
 
@@ -314,14 +376,14 @@ static int led_init(struct uclass *uc)
 #ifdef CONFIG_LED_BOOT
 	ret = ofnode_options_get_by_phandle("boot-led", &led_node);
 	if (!ret)
-		priv->boot_led_label = led_get_label(led_node);
+		priv->boot_led_label = led_get_label(NULL, led_node);
 	priv->boot_led_period = ofnode_options_read_int("boot-led-period-ms", 250);
 #endif
 
 #ifdef CONFIG_LED_ACTIVITY
 	ret = ofnode_options_get_by_phandle("activity-led", &led_node);
 	if (!ret)
-		priv->activity_led_label = led_get_label(led_node);
+		priv->activity_led_label = led_get_label(NULL, led_node);
 	priv->activity_led_period = ofnode_options_read_int("activity-led-period-ms",
 							    250);
 #endif

include/led.h

@@ -53,6 +53,11 @@
 
 struct udevice;
 
+/*
+ * value imported from linux:include/linux/uapi/linux/uleds.h
+ */
+#define LED_MAX_NAME_SIZE      64
+
 enum led_state_t {
 	LEDST_OFF = 0,
 	LEDST_ON = 1,
@@ -86,6 +91,7 @@ struct led_sw_blink {
 struct led_uc_plat {
 	const char *label;
 	enum led_state_t default_state;
+	char name[LED_MAX_NAME_SIZE];
 #ifdef CONFIG_LED_SW_BLINK
 	struct led_sw_blink *sw_blink;
 #endif

test/dm/led.c

@@ -20,7 +20,12 @@ static int dm_test_led_base(struct unit_test_state *uts)
 	ut_assertok(uclass_get_device(UCLASS_LED, 1, &dev));
 	ut_assertok(uclass_get_device(UCLASS_LED, 2, &dev));
 	ut_assertok(uclass_get_device(UCLASS_LED, 3, &dev));
-	ut_asserteq(-ENODEV, uclass_get_device(UCLASS_LED, 4, &dev));
+	ut_assertok(uclass_get_device(UCLASS_LED, 4, &dev));
+	ut_assertok(uclass_get_device(UCLASS_LED, 5, &dev));
+	ut_assertok(uclass_get_device(UCLASS_LED, 6, &dev));
+	ut_assertok(uclass_get_device(UCLASS_LED, 7, &dev));
+	ut_assertok(uclass_get_device(UCLASS_LED, 8, &dev));
+	ut_asserteq(-ENODEV, uclass_get_device(UCLASS_LED, 9, &dev));
 
 	return 0;
 }
@@ -110,6 +115,21 @@ static int dm_test_led_label(struct unit_test_state *uts)
 
 	ut_asserteq(-ENODEV, led_get_by_label("sandbox:blue", &dev));
 
+	/* Test if function, color and function-enumerator naming works */
+	ut_assertok(led_get_by_label("red:status-20", &dev));
+
+	/* Test if function, color naming works */
+	ut_assertok(led_get_by_label("green:status", &dev));
+
+	/* Test if function, without color naming works */
+	ut_assertok(led_get_by_label(":status", &dev));
+
+	/* Test if color without function naming works */
+	ut_assertok(led_get_by_label("green:", &dev));
+
+	/* Test if function, color naming is ignored if label is found */
+	ut_assertok(led_get_by_label("sandbox:function", &dev));
+
 	return 0;
 }
 DM_TEST(dm_test_led_label, UTF_SCAN_PDATA | UTF_SCAN_FDT);

test/dm/ofnode.c

@@ -1599,7 +1599,7 @@ static int dm_test_ofnode_delete(struct unit_test_state *uts)
 	ut_assert(!ofnode_valid(node));
 	ut_assert(!ofnode_valid(ofnode_path("/leds/default_on")));
 
-	ut_asserteq(2, ofnode_get_child_count(ofnode_path("/leds")));
+	ut_asserteq(7, ofnode_get_child_count(ofnode_path("/leds")));
 
 	return 0;
 }