dm: led: Add a new 'led' command

When driver model is used for LEDs, provide a command to allow LED access.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ziping Chen <techping.chan@gmail.com>

cmd/Kconfig

@@ -667,6 +667,15 @@ config CMD_CACHE
 	help
 	  Enable the "icache" and "dcache" commands
 
+config CMD_LED
+	bool "led"
+	default y if LED
+	help
+	  Enable the 'led' command which allows for control of LEDs supported
+	  by the board. The LEDs can be listed with 'led list' and controlled
+	  with led on/off/togle/blink. Any LED drivers can be controlled with
+	  this command, e.g. led_gpio.
+
 config CMD_TIME
 	bool "time"
 	help

cmd/Makefile

@@ -79,6 +79,7 @@ obj-$(CONFIG_CMD_JFFS2) += jffs2.o
 obj-$(CONFIG_CMD_CRAMFS) += cramfs.o
 obj-$(CONFIG_CMD_LDRINFO) += ldrinfo.o
 obj-$(CONFIG_LED_STATUS_CMD) += legacy_led.o
+obj-$(CONFIG_CMD_LED) += led.o
 obj-$(CONFIG_CMD_LICENSE) += license.o
 obj-y += load.o
 obj-$(CONFIG_LOGBUFFER) += log.o

cmd/led.c

+/*
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <dm.h>
+#include <led.h>
+#include <dm/uclass-internal.h>
+
+#define LED_TOGGLE LEDST_COUNT
+
+static const char *const state_label[] = {
+	[LEDST_OFF]	= "off",
+	[LEDST_ON]	= "on",
+	[LEDST_TOGGLE]	= "toggle",
+#ifdef CONFIG_LED_BLINK
+	[LEDST_BLINK]	= "blink",
+#endif
+};
+
+enum led_state_t get_led_cmd(char *var)
+{
+	int i;
+
+	for (i = 0; i < LEDST_COUNT; i++) {
+		if (!strncmp(var, state_label[i], strlen(var)))
+			return i;
+	}
+
+	return -1;
+}
+
+static int show_led_state(struct udevice *dev)
+{
+	int ret;
+
+	ret = led_get_state(dev);
+	if (ret >= LEDST_COUNT)
+		ret = -EINVAL;
+	if (ret >= 0)
+		printf("%s\n", state_label[ret]);
+
+	return ret;
+}
+
+static int list_leds(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	for (uclass_find_first_device(UCLASS_LED, &dev);
+	     dev;
+	     uclass_find_next_device(&dev)) {
+		struct led_uc_plat *plat = dev_get_uclass_platdata(dev);
+
+		if (!plat->label)
+			continue;
+		printf("%-15s ", plat->label);
+		if (device_active(dev)) {
+			ret = show_led_state(dev);
+			if (ret < 0)
+				printf("Error %d\n", ret);
+		} else {
+			printf("<inactive>\n");
+		}
+	}
+
+	return 0;
+}
+
+int do_led(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	enum led_state_t cmd;
+	const char *led_label;
+	struct udevice *dev;
+#ifdef CONFIG_LED_BLINK
+	int freq_ms = 0;
+#endif
+	int ret;
+
+	/* Validate arguments */
+	if (argc < 2)
+		return CMD_RET_USAGE;
+	led_label = argv[1];
+	if (*led_label == 'l')
+		return list_leds();
+
+	cmd = argc > 2 ? get_led_cmd(argv[2]) : LEDST_COUNT;
+	if (cmd < 0)
+		return CMD_RET_USAGE;
+#ifdef CONFIG_LED_BLINK
+	if (cmd == LEDST_BLINK) {
+		if (argc < 4)
+			return CMD_RET_USAGE;
+		freq_ms = simple_strtoul(argv[3], NULL, 10);
+	}
+#endif
+	ret = led_get_by_label(led_label, &dev);
+	if (ret) {
+		printf("LED '%s' not found (err=%d)\n", led_label, ret);
+		return CMD_RET_FAILURE;
+	}
+	switch (cmd) {
+	case LEDST_OFF:
+	case LEDST_ON:
+	case LEDST_TOGGLE:
+		ret = led_set_state(dev, cmd);
+		break;
+#ifdef CONFIG_LED_BLINK
+	case LEDST_BLINK:
+		ret = led_set_period(dev, freq_ms);
+		if (!ret)
+			ret = led_set_state(dev, LEDST_BLINK);
+		break;
+#endif
+	case LEDST_COUNT:
+		printf("LED '%s': ", led_label);
+		ret = show_led_state(dev);
+		break;
+	}
+	if (ret < 0) {
+		printf("LED '%s' operation failed (err=%d)\n", led_label, ret);
+		return CMD_RET_FAILURE;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_LED_BLINK
+#define BLINK "|blink [blink-freq in ms]"
+#else
+#define BLINK ""
+#endif
+
+U_BOOT_CMD(
+	led, 4, 1, do_led,
+	"manage LEDs",
+	"<led_label> on|off|toggle" BLINK "\tChange LED state\n"
+	"led [<led_label>\tGet LED state\n"
+	"led list\t\tshow a list of LEDs"
+);