Add debugfs entries for device activity trigger. Three entries are
created under /sys/kernel/debug/ledtrig-dev when the driver gets
loaded. These are:
devices - cat'ing will produce a list of currently registered devices
in <major>:<minor> format, a line for each device.
register - echo'ing <major>:<minor> will create a trigger for this
device
trigger - echo'ing <major>:<minor> will fire a trigger for this device
Signed-off-by: Maciek Borzecki <maciek.borze...@gmail.com>
---
drivers/leds/trigger/ledtrig-device.c | 113 +++++++++++++++++++++++++++++++++-
1 file changed, 111 insertions(+), 2 deletions(-)
diff --git a/drivers/leds/trigger/ledtrig-device.c
b/drivers/leds/trigger/ledtrig-device.c
index
dbb8d7d2b4a0258149c581a040c416d412d9ceeb..6814db5e34d76974ae095d2e1c8f1f2e23dea79e
100644
--- a/drivers/leds/trigger/ledtrig-device.c
+++ b/drivers/leds/trigger/ledtrig-device.c
@@ -16,15 +16,18 @@
#include <linux/list.h>
#include <linux/rwsem.h>
#include <linux/kdev_t.h>
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
#define BLINK_DELAY 30
static unsigned long blink_delay = BLINK_DELAY;
static DECLARE_RWSEM(devs_list_lock);
static LIST_HEAD(devs_list);
+static struct dentry *debug_root;
#define MAX_NAME_LEN 20
-
struct ledtrig_dev_data {
char name[MAX_NAME_LEN];
dev_t dev;
@@ -114,8 +117,11 @@ void ledtrig_dev_add(dev_t dev)
/* register with led triggers */
led_trigger_register_simple(new_dev_trig->name,
&new_dev_trig->trig);
- else
+ else {
+ pr_warn("device %u:%u already registered\n",
+ MAJOR(dev), MINOR(dev));
kfree(new_dev_trig);
+ }
}
EXPORT_SYMBOL(ledtrig_dev_add);
@@ -167,13 +173,116 @@ static void ledtrig_dev_remove_all(void)
up_write(&devs_list_lock);
}
+static int ledtrig_dev_devices_show(struct seq_file *s, void *unused)
+{
+ struct ledtrig_dev_data *dev_trig;
+
+ down_read(&devs_list_lock);
+ list_for_each_entry(dev_trig, &devs_list, node) {
+ seq_printf(s, "%u:%u\n", MAJOR(dev_trig->dev),
+ MINOR(dev_trig->dev));
+ }
+ up_read(&devs_list_lock);
+ return 0;
+}
+
+static int ledtrig_dev_devices_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, ledtrig_dev_devices_show,
+ &inode->i_private);
+}
+
+static const struct file_operations debug_devices_ops = {
+ .owner = THIS_MODULE,
+ .open = ledtrig_dev_devices_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release
+};
+
+static int get_dev_from_user(const char __user *buf, size_t size,
+ dev_t *dev)
+{
+ unsigned int major;
+ unsigned int minor;
+ int ret;
+
+ WARN_ON(dev == NULL);
+ if (dev == NULL)
+ return -EINVAL;
+
+ ret = sscanf(buf, "%u:%u", &major, &minor);
+ if (ret < 2)
+ return -EINVAL;
+
+ *dev = MKDEV(major, minor);
+ return 0;
+}
+
+static ssize_t ledtrig_dev_register_write(struct file *filp,
+ const char __user *buf,
+ size_t size, loff_t *off)
+{
+ dev_t dev;
+ int ret;
+
+ ret = get_dev_from_user(buf, size, &dev);
+ if (ret < 0)
+ return ret;
+
+ pr_debug("got device %u:%u\n", MAJOR(dev), MINOR(dev));
+ ledtrig_dev_add(dev);
+
+ return size;
+}
+
+static const struct file_operations debug_register_ops = {
+ .owner = THIS_MODULE,
+ .write = ledtrig_dev_register_write,
+};
+
+static ssize_t ledtrig_dev_trigger_write(struct file *filp,
+ const char __user *buf,
+ size_t size, loff_t *off)
+{
+ dev_t dev;
+ int ret;
+
+ ret = get_dev_from_user(buf, size, &dev);
+ if (ret < 0)
+ return ret;
+
+ pr_debug("trigger device %u:%u\n", MAJOR(dev), MINOR(dev));
+ ledtrig_dev_activity(dev);
+
+ return size;
+}
+
+static const struct file_operations debug_trigger_ops = {
+ .owner = THIS_MODULE,
+ .write = ledtrig_dev_trigger_write,
+};
+
static int __init ledtrig_dev_init(void)
{
+ debug_root = debugfs_create_dir("ledtrig-dev", NULL);
+
+ if (debug_root) {
+ debugfs_create_file("devices", 0444, debug_root, NULL,
+ &debug_devices_ops);
+ debugfs_create_file("register", 0200, debug_root, NULL,
+ &debug_register_ops);
+ debugfs_create_file("trigger", 0200, debug_root, NULL,
+ &debug_trigger_ops);
+ }
+
return 0;
}
static void __exit ledtrig_dev_exit(void)
{
+ debugfs_remove_recursive(debug_root);
+
ledtrig_dev_remove_all();
}
--
2.5.3
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