Autodetect backlight

1 files changed, 39 insertions, 62 deletions

diff --git a/blinker.c b/blinker.c
index dbfaa68..36d80f2 100644
--- a/blinker.c
+++ b/blinker.c
@@ -3,25 +3,21 @@
  *   -- by Jason A. Donenfeld --
  *         Jason@zx2c4.com
  * 
- * This creates three files in proc:
+ * This creates two files in proc:
  * 
  *     /proc/blinker/trigger_port
- *     /proc/blinker/backlight_file
  *     /proc/blinker/delay_ms
  * 
  * When the system attempts to make a connection to localhost using the port
- * specified in trigger_port, backlight_file is used to blink the backlight
- * for delay_ms milliseconds.
+ * specified in trigger_port, the backlight blinks over delay_ms milliseconds.
  * 
  * This occurs regardless of whether or not there exists anything listening
  * on trigger_port.
  * 
  * # cd /proc/blinker/
  * # ls
- * backlight_file  delay_ms  trigger_port
+ * delay_ms  trigger_port
  * # echo 9184 > trigger_port 
- * # cat backlight_file 
- * /sys/class/backlight/s5p_bl/brightness
  * # cat delay_ms 
  * 100
  * # cat trigger_port 
@@ -29,14 +25,11 @@
  * # nc localhost 9184
  * ZX2C4-Laptop [127.0.0.1] 9184 (?) : Connection refused
  * # dmesg | tail -n 4
- * [  910.109435] blinker: connected to the magic port 9184
- * [  910.109466] blinker: read backlight level of 8
- * [  910.110363] blinker: set backlight to 0
- * [  910.212381] blinker: restored backlight
  * 
- * Development note:
- *     Though this is intended to work on Android/ARM, presently it is only
- *     implemented on x86. Work in progress.
+ * [  184.003146] blinker: connected to the magic port 9184
+ * [  184.003176] blinker: read backlight sony level of 8
+ * [  184.004086] blinker: set backlight sony to 0
+ * [  184.105603] blinker: restored backlight sony
  *
  */
 
@@ -54,7 +47,6 @@
 
 #define PROC_BLINKER	"blinker"
 #define PROC_PORT	"trigger_port"
-#define PROC_FILE	"backlight_file"
 #define PROC_DELAY	"delay_ms"
 #define MAX_LENGTH	512
 
@@ -65,9 +57,8 @@ MODULE_DESCRIPTION("Android Screen Blinker");
 extern struct proto_ops inet_stream_ops;
 extern void msleep_interruptible(unsigned long msecs);
 
-static struct proc_dir_entry *proc_blinker, *proc_port, *proc_file, *proc_delay;
+static struct proc_dir_entry *proc_blinker, *proc_port, *proc_delay;
 static unsigned int trigger_port, delay_ms;
-static unsigned char backlight_file[MAX_LENGTH];
 
 static void disable_page_protection(void)
 {
@@ -91,50 +82,62 @@ static void enable_page_protection(void)
 	}
 #endif
 }
-
-void blink(void)
+static int blink_entry(void *__buf, const char *name, int namelen, loff_t dir_offset, u64 ino, unsigned int d_type)
 {
 	struct file *filp;
-	struct cred *creds;
-	mm_segment_t oldfs;
 	unsigned long long offset;
 	char buf[MAX_LENGTH];
-	unsigned long previous_backlight;
 	
-	creds = prepare_creds();
-	commit_creds(prepare_kernel_cred(NULL));
+	if (dir_offset < 2)
+		return 0;
 	
-	oldfs = get_fs();
-	set_fs(get_ds());
+	snprintf(buf, MAX_LENGTH, "/sys/class/backlight/%s/brightness", name);
 	
-	filp = filp_open(backlight_file, O_RDWR, 0);
+	filp = filp_open(buf, O_RDWR, 0);
 	if(IS_ERR(filp))
 		goto error;
 	offset = 0;
+	memset(buf, 0, MAX_LENGTH);
 	vfs_read(filp, buf, MAX_LENGTH - 1, &offset);
-	buf[MAX_LENGTH - 1] = 0;
-	sscanf(buf, "%lu", &previous_backlight);
-	printk(KERN_INFO "blinker: read backlight level of %lu", previous_backlight);
+	printk(KERN_INFO "blinker: read backlight %s level of %s", name, buf);
 	
 	offset = 0;
 	vfs_write(filp, "0\n", 2, &offset);
 	generic_file_fsync(filp, 0, 2, 0);
-	printk(KERN_INFO "blinker: set backlight to 0\n");
+	printk(KERN_INFO "blinker: set backlight %s to 0\n", name);
 	
 	msleep_interruptible(delay_ms);
 	
-	snprintf(buf, MAX_LENGTH, "%lu\n", previous_backlight);
 	offset = 0;
 	vfs_write(filp, buf, MAX_LENGTH, &offset);
-	printk(KERN_INFO "blinker: restored backlight\n");
+	printk(KERN_INFO "blinker: restored backlight %s\n", name);
 	
+	goto out;
+error:
+	printk(KERN_ERR "blinker: could not open %s\n", buf);
+out:
 	filp_close(filp, NULL);
+	return 0;
+}
+void blink(void)
+{
+	struct file *filp;
+	struct cred *creds;
+	mm_segment_t oldfs;
 	
-	goto out;
+	creds = prepare_creds();
+	commit_creds(prepare_kernel_cred(NULL));
+	
+	oldfs = get_fs();
+	set_fs(get_ds());
 	
+	filp = filp_open("/sys/class/backlight/", O_RDONLY | O_DIRECTORY, 0);
+	if(IS_ERR(filp))
+		goto error;
+	vfs_readdir(filp, blink_entry, NULL);	
+	
+	filp_close(filp, NULL);
 error:
-	printk(KERN_ERR "blinker: could not work with %s, error %ld\n", backlight_file, PTR_ERR(filp));
-out:
 	set_fs(oldfs);
 	commit_creds(creds);
 }
@@ -167,27 +170,6 @@ int port_read(char *page, char **start, off_t off, int count, int *eof, void *da
 	printk(KERN_INFO "blinker: called get_port\n");
 	return snprintf(page, MAX_LENGTH, "%u\n", trigger_port);
 }
-int file_write(struct file *file, const char __user *ubuf, unsigned long count, void *data)
-{
-	char buf[MAX_LENGTH];
-	char *line;
-	printk(KERN_INFO "blinker: called set_file\n");
-	if (count > MAX_LENGTH - 1)
-		count = MAX_LENGTH - 1;
-	if (copy_from_user(&buf, ubuf, count))
-		return -EFAULT;
-	buf[count + 1] = 0;
-	line = strchr(buf, '\n');
-	if (line)
-		*line = 0;
-	memcpy(backlight_file, buf, sizeof(backlight_file));
-	return count;
-}
-int file_read(char *page, char **start, off_t off, int count, int *eof, void *data)
-{
-	printk(KERN_INFO "blinker: called get_file\n");
-	return snprintf(page, MAX_LENGTH, "%s\n", backlight_file);
-}
 int delay_write(struct file *file, const char __user *ubuf, unsigned long count, void *data)
 {
 	char buf[MAX_LENGTH];
@@ -213,9 +195,6 @@ static int init(void)
 	proc_port = create_proc_entry(PROC_PORT, 0600, proc_blinker);
 	proc_port->read_proc = port_read;
 	proc_port->write_proc = port_write;
-	proc_file = create_proc_entry(PROC_FILE, 0600, proc_blinker);
-	proc_file->read_proc = file_read;
-	proc_file->write_proc = file_write;
 	proc_delay = create_proc_entry(PROC_DELAY, 0600, proc_blinker);
 	proc_delay->read_proc = delay_read;
 	proc_delay->write_proc = delay_write;
@@ -229,7 +208,6 @@ static int init(void)
 
 	trigger_port = 9191;
 	delay_ms = 100;
-	strcpy(backlight_file, "/sys/class/backlight/s5p_bl/brightness");
 
 	return 0;
 }
@@ -241,7 +219,6 @@ static void exit(void)
 	printk(KERN_INFO "blinker: unremapped inet_stream_ops.connect\n");
 
 	remove_proc_entry(PROC_PORT, proc_blinker);
-	remove_proc_entry(PROC_FILE, proc_blinker);
 	remove_proc_entry(PROC_DELAY, proc_blinker);
 	remove_proc_entry(PROC_BLINKER, NULL);
 	printk(KERN_INFO "blinker: removed /proc/blinker/\n");