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Diffstat (limited to 'drivers/hid/hid-debug.c')
-rw-r--r--drivers/hid/hid-debug.c239
1 files changed, 220 insertions, 19 deletions
diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c
index 067e173aa3e..a331a1821e8 100644
--- a/drivers/hid/hid-debug.c
+++ b/drivers/hid/hid-debug.c
@@ -28,6 +28,10 @@
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+
#include <linux/hid.h>
#include <linux/hid-debug.h>
@@ -335,49 +339,86 @@ static const struct hid_usage_entry hid_usage_table[] = {
{ 0, 0, NULL }
};
-static void resolv_usage_page(unsigned page, struct seq_file *f) {
+/* Either output directly into simple seq_file, or (if f == NULL)
+ * allocate a separate buffer that will then be passed to the 'events'
+ * ringbuffer.
+ *
+ * This is because these functions can be called both for "one-shot"
+ * "rdesc" while resolving, or for blocking "events".
+ *
+ * This holds both for resolv_usage_page() and hid_resolv_usage().
+ */
+static char *resolv_usage_page(unsigned page, struct seq_file *f) {
const struct hid_usage_entry *p;
+ char *buf = NULL;
+
+ if (!f) {
+ buf = kzalloc(sizeof(char) * HID_DEBUG_BUFSIZE, GFP_ATOMIC);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+ }
for (p = hid_usage_table; p->description; p++)
if (p->page == page) {
- if (!f)
- printk("%s", p->description);
- else
+ if (!f) {
+ snprintf(buf, HID_DEBUG_BUFSIZE, "%s",
+ p->description);
+ return buf;
+ }
+ else {
seq_printf(f, "%s", p->description);
- return;
+ return NULL;
+ }
}
if (!f)
- printk("%04x", page);
+ snprintf(buf, HID_DEBUG_BUFSIZE, "%04x", page);
else
seq_printf(f, "%04x", page);
+ return buf;
}
-void hid_resolv_usage(unsigned usage, struct seq_file *f) {
+char *hid_resolv_usage(unsigned usage, struct seq_file *f) {
const struct hid_usage_entry *p;
+ char *buf = NULL;
+ int len = 0;
- resolv_usage_page(usage >> 16, f);
- if (!f)
- printk(".");
- else
+ buf = resolv_usage_page(usage >> 16, f);
+ if (IS_ERR(buf)) {
+ printk(KERN_ERR "error allocating HID debug buffer\n");
+ return NULL;
+ }
+
+
+ if (!f) {
+ len = strlen(buf);
+ snprintf(buf+len, max(0, HID_DEBUG_BUFSIZE - len), ".");
+ len++;
+ }
+ else {
seq_printf(f, ".");
+ }
for (p = hid_usage_table; p->description; p++)
if (p->page == (usage >> 16)) {
for(++p; p->description && p->usage != 0; p++)
if (p->usage == (usage & 0xffff)) {
if (!f)
- printk("%s", p->description);
+ snprintf(buf + len,
+ max(0,HID_DEBUG_BUFSIZE - len - 1),
+ "%s", p->description);
else
seq_printf(f,
"%s",
p->description);
- return;
+ return buf;
}
break;
}
if (!f)
- printk("%04x", usage & 0xffff);
+ snprintf(buf + len, max(0, HID_DEBUG_BUFSIZE - len - 1),
+ "%04x", usage & 0xffff);
else
seq_printf(f, "%04x", usage & 0xffff);
+ return buf;
}
EXPORT_SYMBOL_GPL(hid_resolv_usage);
@@ -508,13 +549,37 @@ void hid_dump_device(struct hid_device *device, struct seq_file *f)
}
EXPORT_SYMBOL_GPL(hid_dump_device);
-void hid_dump_input(struct hid_usage *usage, __s32 value) {
- if (hid_debug < 2)
+/* enqueue string to 'events' ring buffer */
+void hid_debug_event(struct hid_device *hdev, char *buf)
+{
+ int i;
+ struct hid_debug_list *list;
+
+ list_for_each_entry(list, &hdev->debug_list, node) {
+ for (i = 0; i <= strlen(buf); i++)
+ list->hid_debug_buf[(list->tail + i) % (HID_DEBUG_BUFSIZE - 1)] =
+ buf[i];
+ list->tail = (list->tail + i) % (HID_DEBUG_BUFSIZE - 1);
+ }
+}
+EXPORT_SYMBOL_GPL(hid_debug_event);
+
+void hid_dump_input(struct hid_device *hdev, struct hid_usage *usage, __s32 value)
+{
+ char *buf;
+ int len;
+
+ buf = hid_resolv_usage(usage->hid, NULL);
+ if (!buf)
return;
+ len = strlen(buf);
+ snprintf(buf + len, HID_DEBUG_BUFSIZE - len - 1, " = %d\n", value);
+
+ hid_debug_event(hdev, buf);
+
+ kfree(buf);
+ wake_up_interruptible(&hdev->debug_wait);
- printk(KERN_DEBUG "hid-debug: input ");
- hid_resolv_usage(usage->hid, NULL);
- printk(" = %d\n", value);
}
EXPORT_SYMBOL_GPL(hid_dump_input);
@@ -808,6 +873,7 @@ void hid_dump_input_mapping(struct hid_device *hid, struct seq_file *f)
}
+
static int hid_debug_rdesc_show(struct seq_file *f, void *p)
{
struct hid_device *hdev = f->private;
@@ -831,6 +897,126 @@ static int hid_debug_rdesc_open(struct inode *inode, struct file *file)
return single_open(file, hid_debug_rdesc_show, inode->i_private);
}
+static int hid_debug_events_open(struct inode *inode, struct file *file)
+{
+ int err = 0;
+ struct hid_debug_list *list;
+
+ if (!(list = kzalloc(sizeof(struct hid_debug_list), GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (!(list->hid_debug_buf = kzalloc(sizeof(char) * HID_DEBUG_BUFSIZE, GFP_KERNEL))) {
+ err = -ENOMEM;
+ goto out;
+ }
+ list->hdev = (struct hid_device *) inode->i_private;
+ file->private_data = list;
+ mutex_init(&list->read_mutex);
+
+ list_add_tail(&list->node, &list->hdev->debug_list);
+
+out:
+ return err;
+}
+
+static ssize_t hid_debug_events_read(struct file *file, char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct hid_debug_list *list = file->private_data;
+ int ret = 0, len;
+ DECLARE_WAITQUEUE(wait, current);
+
+ while (ret == 0) {
+ mutex_lock(&list->read_mutex);
+ if (list->head == list->tail) {
+ add_wait_queue(&list->hdev->debug_wait, &wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ while (list->head == list->tail) {
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ break;
+ }
+ if (signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ break;
+ }
+
+ if (!list->hdev || !list->hdev->debug) {
+ ret = -EIO;
+ break;
+ }
+
+ /* allow O_NONBLOCK from other threads */
+ mutex_unlock(&list->read_mutex);
+ schedule();
+ mutex_lock(&list->read_mutex);
+ set_current_state(TASK_INTERRUPTIBLE);
+ }
+
+ set_current_state(TASK_RUNNING);
+ remove_wait_queue(&list->hdev->debug_wait, &wait);
+ }
+
+ if (ret)
+ goto out;
+
+ /* pass the ringbuffer contents to userspace */
+copy_rest:
+ if (list->tail == list->head)
+ goto out;
+ if (list->tail > list->head) {
+ len = list->tail - list->head;
+
+ if (copy_to_user(buffer + ret, &list->hid_debug_buf[list->head], len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret += len;
+ list->head += len;
+ } else {
+ len = HID_DEBUG_BUFSIZE - list->head;
+
+ if (copy_to_user(buffer, &list->hid_debug_buf[list->head], len)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ list->head = 0;
+ ret += len;
+ goto copy_rest;
+ }
+
+ }
+out:
+ mutex_unlock(&list->read_mutex);
+ return ret;
+}
+
+static unsigned int hid_debug_events_poll(struct file *file, poll_table *wait)
+{
+ struct hid_debug_list *list = file->private_data;
+
+ poll_wait(file, &list->hdev->debug_wait, wait);
+ if (list->head != list->tail)
+ return POLLIN | POLLRDNORM;
+ if (!list->hdev->debug)
+ return POLLERR | POLLHUP;
+ return 0;
+}
+
+static int hid_debug_events_release(struct inode *inode, struct file *file)
+{
+ struct hid_debug_list *list = file->private_data;
+
+ list_del(&list->node);
+ kfree(list->hid_debug_buf);
+ kfree(list);
+
+ return 0;
+}
+
static const struct file_operations hid_debug_rdesc_fops = {
.open = hid_debug_rdesc_open,
.read = seq_read,
@@ -838,16 +1024,31 @@ static const struct file_operations hid_debug_rdesc_fops = {
.release = single_release,
};
+static const struct file_operations hid_debug_events_fops = {
+ .owner = THIS_MODULE,
+ .open = hid_debug_events_open,
+ .read = hid_debug_events_read,
+ .poll = hid_debug_events_poll,
+ .release = hid_debug_events_release,
+};
+
+
void hid_debug_register(struct hid_device *hdev, const char *name)
{
hdev->debug_dir = debugfs_create_dir(name, hid_debug_root);
hdev->debug_rdesc = debugfs_create_file("rdesc", 0400,
hdev->debug_dir, hdev, &hid_debug_rdesc_fops);
+ hdev->debug_events = debugfs_create_file("events", 0400,
+ hdev->debug_dir, hdev, &hid_debug_events_fops);
+ hdev->debug = 1;
}
void hid_debug_unregister(struct hid_device *hdev)
{
+ hdev->debug = 0;
+ wake_up_interruptible(&hdev->debug_wait);
debugfs_remove(hdev->debug_rdesc);
+ debugfs_remove(hdev->debug_events);
debugfs_remove(hdev->debug_dir);
}