Created
October 5, 2013 23:19
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Hack to control the keyboard backlight level on a Thinkpad Lenovo X1 Carbon Touch
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/* gcc -o tmp `pkg-config --libs --cflags glib-2.0` tmp.c | |
* | |
* # modprobe ec_sys | |
* | |
* # watch -n 0.1 hexdump -C /sys/kernel/debug/ec/ec0/io | |
* | |
* 00000000 a7 05 a0 e2 00 86 05 00 00 00 47 00 00 03 00 10 |..........G.....| | |
* 00000000 a7 05 a0 e2 00 86 05 00 00 00 47 00 00 43 00 10 |..........G..C..| | |
* 00000000 a7 05 a0 e2 00 86 05 00 00 00 47 00 00 83 00 10 |..........G.....| | |
* | |
* # ./tmp 0 | |
* # ./tmp 1 | |
* # ./tmp 2 | |
* | |
*/ | |
#include <glib.h> | |
#include <sys/stat.h> | |
#include <fcntl.h> | |
#include <errno.h> | |
char levels[] = { | |
0x03, | |
0x43, | |
0x83 | |
}; | |
static void | |
usage (char **argv) | |
{ | |
g_print ("%s [level]\n", argv[0]); | |
g_print ("Where level is between 1 and 3\n"); | |
} | |
int main (int argc, char **argv) | |
{ | |
int fd; | |
int level; | |
if (argc < 2) { | |
usage (argv); | |
return 1; | |
} | |
level = atoi(argv[1]); | |
if (level < 0 || level > 3) { | |
usage (argv); | |
return 1; | |
} | |
fd = open ("/sys/kernel/debug/ec/ec0/io", O_RDWR); | |
if (fd < 0) { | |
g_print ("open: %s\n", g_strerror (errno)); | |
return 1; | |
} | |
if (lseek (fd, 0xd, SEEK_CUR) < 0) { | |
g_print ("seek: %s\n", g_strerror (errno)); | |
return 1; | |
} | |
if (write (fd, &levels[level], 1) < 0) { | |
g_print ("write: %s\n", g_strerror (errno)); | |
return 1; | |
} | |
return 0; | |
} |
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Can someone tell me how to set this up on X1 Ubuntu 20 so that backlight is persistent? Not sure what steps to take so if someone can write step by step guide.