From ba5ff4b54633a3f049823d384c3eaeb7a1997f39 Mon Sep 17 00:00:00 2001
From: Andy Spencer <andy753421@gmail.com>
Date: Thu, 20 Sep 2018 20:38:42 +0000
Subject: [PATCH 1/1] Add initial hwkeys program.

---
 .gitignore |   4 ++
 hwkeys.c   | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 makefile   |  14 +++++++
 3 files changed, 123 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 hwkeys.c
 create mode 100644 makefile

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5a9e4e9
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+*~
+*.o
+*.swp
+hwkeys
diff --git a/hwkeys.c b/hwkeys.c
new file mode 100644
index 0000000..9807081
--- /dev/null
+++ b/hwkeys.c
@@ -0,0 +1,105 @@
+#include <math.h>
+#include <stdio.h>
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/input.h>
+
+static void screenlight(int up)
+{
+	static const char *path = "/sys/class/backlight/gmux_backlight/brightness";
+	static int    prev, next, tmp;
+	static double val;
+	static FILE  *fd;
+
+	// Open brightness file
+	if (fd == NULL)
+		fd = fopen(path, "r+");
+	if (fd == NULL) {
+		printf("error opening file\n");
+		return;
+	}
+
+	// Reset if someone else changed the value
+	fseek(fd, 0, SEEK_SET);
+	fscanf(fd, "%d", &tmp);
+	if (tmp != prev)
+		val = pow(tmp/1024.0, 1/10.0);
+	//if (tmp != prev)
+	//	printf("convert: %d -> %d -> %f\n",
+	//			prev, tmp, val);
+
+	// Update the current value
+	val += 0.01 * (up?1:-1);
+	if (val < 0) val = 0;
+	if (val > 1) val = 1;
+
+	// Write it back to the file
+	next = pow(val, 10) * 1024;
+	if (next == prev)
+		next += (up?1:-1);
+	else
+		prev = next;
+
+	//printf("saving:  %d\n", next);
+	fprintf(fd, "%d", next);
+	fflush(fd);
+}
+
+static void keylight(int up)
+{
+	//static const char *path = "/sys/class/leds/smc::kbd_backlight/brightness";
+}
+
+int main(int argc, char **argv)
+{
+	struct input_event ev;
+	int fd, len, debug=0;
+
+	//if ((fd = open("/dev/input/event4", O_RDONLY)) < 0) {
+	//if ((fd = open("/dev/input/event6", O_RDONLY)) < 0) {
+	if ((fd = open("/dev/input/event10", O_RDONLY)) < 0) {
+		printf("Error\n");
+		return 0;
+	}
+
+	while ((len = read(fd, &ev, sizeof(ev)))) {
+		if (len != sizeof(ev)) {
+			printf("Error\n");
+			sleep(1);
+			continue;
+		}
+
+		if (debug) {
+			printf("%ld.%06lu: type=%04hx code=%04hx val=%08x\n",
+					ev.time.tv_sec,
+					ev.time.tv_usec,
+					ev.type, ev.code, ev.value);
+			fflush(stdout);
+		}
+
+		if (ev.type != EV_KEY)
+			continue;
+		if (ev.value == 0) // key up
+			continue;
+
+		switch (ev.code) {
+			case KEY_BRIGHTNESSDOWN:
+				screenlight(0);
+				break;
+			case KEY_BRIGHTNESSUP:
+				screenlight(1);
+				break;
+			case KEY_KBDILLUMDOWN:
+				keylight(0);
+				break;
+			case KEY_KBDILLUMUP:
+				keylight(1);
+				break;
+		}
+		fflush(stdout);
+	}
+	return 0;
+}
diff --git a/makefile b/makefile
new file mode 100644
index 0000000..b72730c
--- /dev/null
+++ b/makefile
@@ -0,0 +1,14 @@
+CC      ?= gcc
+CFLAGS  ?= -Wall -g
+LDFLAGS ?= -lm
+
+run: hwkeys
+	./hwkeys
+
+all: hwkeys
+
+hwkeys: hwkeys.o
+	$(CC) $(CFLAGS) -o $@ $+ $(LDFLAGS)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c -o $@ $+
-- 
2.43.2