add LED control function

Command-line to turn LEDs on the board on or off.

Also, modified .gitignore to be emacs-friendly.

.gitignore

@@ -1,3 +1,4 @@
 /build
 *.swp
 *.swo
+*~

Makefile

@@ -16,6 +16,7 @@ SRC_C = \
 	cmd-reboot.c \
 	cmd-sleep.c \
 	cmd-spi.c \
+	cmd-led.c \
 	emi.c \
 	irq.c \
 	main.c \

cmd-led.c

@@ -0,0 +1,27 @@
+#include <string.h>
+#include "bionic.h"
+#include "memio.h"
+#include "printf.h"
+#include "serial.h"
+#include "fernvale-kbd.h"
+
+int cmd_led(int argc, char **argv)
+{
+	uint32_t state;
+
+	if (argc < 1) {
+		printf("Usage: led [1 = on, 0 = off]\n");
+		return -1;
+	}
+
+	state = _strtoul(argv[0], NULL, 0);
+
+	if( state ) {
+	  *((volatile uint32_t *) BIG_LED_ADDR) = BIG_LED_ON;
+	} else {
+	  *((volatile uint32_t *) BIG_LED_ADDR) = BIG_LED_OFF;
+	}
+
+	return 0;
+}
+

include/fernvale-kbd.h

@@ -0,0 +1,14 @@
+#ifndef __FV_KBD_H__
+#define __FV_KBD_H__
+
+/// The BIG_LED is a 60mA drive-capable open-drain switch
+/// it's useful for driving circuits such as an array of LEDs
+/// used to illuminate a keyboard, hence its inclusion in the
+/// keyboard section. However, on PCBs with no keyboard, it's
+/// simply a big LED driver.
+
+#define BIG_LED_ADDR  (0xA0700000 + 0x0C80)
+#define BIG_LED_ON    (0x3)
+#define BIG_LED_OFF   (0x0)
+
+#endif /* __FV_KBD_H__ */

main.c

@@ -339,6 +339,7 @@ extern int cmd_poke(int argc, char **argv);
 extern int cmd_spi(int argc, char **argv);
 extern int cmd_swi(int argc, char **argv);
 extern int cmd_reboot(int argc, char **argv);
+extern int cmd_led(int argc, char **argv);
 
 static const struct {
 	int (*func)(int argc, char **argv);
@@ -390,6 +391,11 @@ static const struct {
 		.name = "swi",
 		.help = "Generate software interrupt",
 	},
+	{
+		.func = cmd_led,
+		.name = "led",
+		.help = "Turn the on-board LED on or off",
+	},
 };
 
 int cmd_help(int argc, char **argv)