9 files changed, 455 insertions, 153 deletions

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index aba8facecce8..111afbe8de03 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -31,21 +31,6 @@ config HID
 
           If unsure, say Y.
 
-config HID_DEBUG
-        bool "HID debugging support"
-        default y
-        depends on HID
-        ---help---
-        This option lets the HID layer output diagnostics about its internal
-        state, resolve HID usages, dump HID fields, etc. Individual HID drivers
-        use this debugging facility to output information about individual HID
-        devices, etc.
-
-        This feature is useful for those who are either debugging the HID parser
-        or any HID hardware device.
-
-        If unsure, say Y.
-
 config HIDRAW
         bool "/dev/hidraw raw HID device support"
         depends on HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 9b9271d6527a..0de2dff5542c 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -3,9 +3,12 @@
 #
 hid-objs                        := hid-core.o hid-input.o
 
+ifdef CONFIG_DEBUG_FS
+        hid-objs                += hid-debug.o
+endif
+
 obj-$(CONFIG_HID)               += hid.o
 
-hid-$(CONFIG_HID_DEBUG)         += hid-debug.o
 hid-$(CONFIG_HIDRAW)            += hidraw.o
 
 hid-logitech-objs               := hid-lg.o
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 48567d8fe358..342b7d36d7bb 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -44,12 +44,10 @@
 #define DRIVER_DESC "HID core driver"
 #define DRIVER_LICENSE "GPL"
 
-#ifdef CONFIG_HID_DEBUG
 int hid_debug = 0;
 module_param_named(debug, hid_debug, int, 0600);
-MODULE_PARM_DESC(debug, "HID debugging (0=off, 1=probing info, 2=continuous data dumping)");
+MODULE_PARM_DESC(debug, "toggle HID debugging messages");
 EXPORT_SYMBOL_GPL(hid_debug);
-#endif
 
 /*
  * Register a new report for a device.
@@ -861,7 +859,7 @@ static void hid_process_event(struct hid_device *hid, struct hid_field *field,
         struct hid_driver *hdrv = hid->driver;
         int ret;
 
-        hid_dump_input(usage, value);
+        hid_dump_input(hid, usage, value);
 
         if (hdrv && hdrv->event && hid_match_usage(hid, usage)) {
                 ret = hdrv->event(hid, field, usage, value);
@@ -983,11 +981,10 @@ int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
 {
         unsigned size = field->report_size;
 
-        hid_dump_input(field->usage + offset, value);
+        hid_dump_input(field->report->device, field->usage + offset, value);
 
         if (offset >= field->report_count) {
                 dbg_hid("offset (%d) exceeds report_count (%d)\n", offset, field->report_count);
-                hid_dump_field(field, 8);
                 return -1;
         }
         if (field->logical_minimum < 0) {
@@ -1078,6 +1075,7 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
         struct hid_report_enum *report_enum;
         struct hid_driver *hdrv;
         struct hid_report *report;
+        char *buf;
         unsigned int i;
         int ret;
 
@@ -1091,18 +1089,38 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
                 return -1;
         }
 
-        dbg_hid("report (size %u) (%snumbered)\n", size, report_enum->numbered ? "" : "un");
+        buf = kmalloc(sizeof(char) * HID_DEBUG_BUFSIZE,
+                        interrupt ? GFP_ATOMIC : GFP_KERNEL);
+
+        if (!buf) {
+                report = hid_get_report(report_enum, data);
+                goto nomem;
+        }
+
+        snprintf(buf, HID_DEBUG_BUFSIZE - 1,
+                        "\nreport (size %u) (%snumbered)\n", size, report_enum->numbered ? "" : "un");
+        hid_debug_event(hid, buf);
 
         report = hid_get_report(report_enum, data);
-        if (!report)
+        if (!report) {
+                kfree(buf);
                 return -1;
+        }
 
         /* dump the report */
-        dbg_hid("report %d (size %u) = ", report->id, size);
-        for (i = 0; i < size; i++)
-                dbg_hid_line(" %02x", data[i]);
-        dbg_hid_line("\n");
+        snprintf(buf, HID_DEBUG_BUFSIZE - 1,
+                        "report %d (size %u) = ", report->id, size);
+        hid_debug_event(hid, buf);
+        for (i = 0; i < size; i++) {
+                snprintf(buf, HID_DEBUG_BUFSIZE - 1,
+                                " %02x", data[i]);
+                hid_debug_event(hid, buf);
+        }
+        hid_debug_event(hid, "\n");
 
+        kfree(buf);
+
+nomem:
         if (hdrv && hdrv->raw_event && hid_match_report(hid, report)) {
                 ret = hdrv->raw_event(hid, report, data, size);
                 if (ret != 0)
@@ -1323,7 +1341,6 @@ static const struct hid_device_id hid_blacklist[] = {
         { HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0005) },
         { HID_USB_DEVICE(USB_VENDOR_ID_ZEROPLUS, 0x0030) },
 
-        { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE, 0x030c) },
         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_PRESENTER_8K_BT) },
         { }
 };
@@ -1730,6 +1747,8 @@ int hid_add_device(struct hid_device *hdev)
         if (!ret)
                 hdev->status |= HID_STAT_ADDED;
 
+        hid_debug_register(hdev, dev_name(&hdev->dev));
+
         return ret;
 }
 EXPORT_SYMBOL_GPL(hid_add_device);
@@ -1766,6 +1785,9 @@ struct hid_device *hid_allocate_device(void)
         for (i = 0; i < HID_REPORT_TYPES; i++)
                 INIT_LIST_HEAD(&hdev->report_enum[i].report_list);
 
+        init_waitqueue_head(&hdev->debug_wait);
+        INIT_LIST_HEAD(&hdev->debug_list);
+
         return hdev;
 err:
         put_device(&hdev->dev);
@@ -1777,6 +1799,7 @@ static void hid_remove_device(struct hid_device *hdev)
 {
         if (hdev->status & HID_STAT_ADDED) {
                 device_del(&hdev->dev);
+                hid_debug_unregister(hdev);
                 hdev->status &= ~HID_STAT_ADDED;
         }
 }
@@ -1852,6 +1875,10 @@ static int __init hid_init(void)
 {
         int ret;
 
+        if (hid_debug)
+                printk(KERN_WARNING "HID: hid_debug is now used solely for parser and driver debugging.\n"
+                                "HID: debugfs is now used for inspecting the device (report descriptor, reports)\n");
+
         ret = bus_register(&hid_bus_type);
         if (ret) {
                 printk(KERN_ERR "HID: can't register hid bus\n");
@@ -1862,6 +1889,8 @@ static int __init hid_init(void)
         if (ret)
                 goto err_bus;
 
+        hid_debug_init();
+
         return 0;
 err_bus:
         bus_unregister(&hid_bus_type);
@@ -1871,6 +1900,7 @@ err:
 
 static void __exit hid_exit(void)
 {
+        hid_debug_exit();
         hidraw_exit();
         bus_unregister(&hid_bus_type);
 }
diff --git a/drivers/hid/hid-debug.c b/drivers/hid/hid-debug.c
index 04359ed64b87..6abd0369aedb 100644
--- a/drivers/hid/hid-debug.c
+++ b/drivers/hid/hid-debug.c
@@ -1,9 +1,9 @@
 /*
  *  (c) 1999 Andreas Gal                <gal@cs.uni-magdeburg.de>
  *  (c) 2000-2001 Vojtech Pavlik        <vojtech@ucw.cz>
- *  (c) 2007 Jiri Kosina
+ *  (c) 2007-2009 Jiri Kosina
  *
- *  Some debug stuff for the HID parser.
+ *  HID debugging support
  */
 
 /*
@@ -26,9 +26,17 @@
  * Vojtech Pavlik, Simunkova 1594, Prague 8, 182 00 Czech Republic
  */
 
+#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>
 
+static struct dentry *hid_debug_root;
+
 struct hid_usage_entry {
         unsigned  page;
         unsigned  usage;
@@ -339,72 +347,120 @@ static const struct hid_usage_entry hid_usage_table[] = {
   { 0, 0, NULL }
 };
 
-static void resolv_usage_page(unsigned page) {
+/* 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) {
-                        printk("%s", p->description);
-                        return;
+                        if (!f) {
+                                snprintf(buf, HID_DEBUG_BUFSIZE, "%s",
+                                                p->description);
+                                return buf;
+                        }
+                        else {
+                                seq_printf(f, "%s", p->description);
+                                return NULL;
+                        }
                 }
-        printk("%04x", page);
+        if (!f)
+                snprintf(buf, HID_DEBUG_BUFSIZE, "%04x", page);
+        else
+                seq_printf(f, "%04x", page);
+        return buf;
 }
 
-void hid_resolv_usage(unsigned usage) {
+char *hid_resolv_usage(unsigned usage, struct seq_file *f) {
         const struct hid_usage_entry *p;
+        char *buf = NULL;
+        int len = 0;
+
+        buf = resolv_usage_page(usage >> 16, f);
+        if (IS_ERR(buf)) {
+                printk(KERN_ERR "error allocating HID debug buffer\n");
+                return NULL;
+        }
 
-        if (!hid_debug)
-                return;
 
-        resolv_usage_page(usage >> 16);
-        printk(".");
+        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)) {
-                                        printk("%s", p->description);
-                                        return;
+                                        if (!f)
+                                                snprintf(buf + len,
+                                                        max(0,HID_DEBUG_BUFSIZE - len - 1),
+                                                        "%s", p->description);
+                                        else
+                                                seq_printf(f,
+                                                        "%s",
+                                                        p->description);
+                                        return buf;
                                 }
                         break;
                 }
-        printk("%04x", usage & 0xffff);
+        if (!f)
+                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);
 
-static void tab(int n) {
-        printk(KERN_DEBUG "%*s", n, "");
+static void tab(int n, struct seq_file *f) {
+        seq_printf(f, "%*s", n, "");
 }
 
-void hid_dump_field(struct hid_field *field, int n) {
+void hid_dump_field(struct hid_field *field, int n, struct seq_file *f) {
         int j;
 
-        if (!hid_debug)
-                return;
-
         if (field->physical) {
-                tab(n);
-                printk("Physical(");
-                hid_resolv_usage(field->physical); printk(")\n");
+                tab(n, f);
+                seq_printf(f, "Physical(");
+                hid_resolv_usage(field->physical, f); seq_printf(f, ")\n");
         }
         if (field->logical) {
-                tab(n);
-                printk("Logical(");
-                hid_resolv_usage(field->logical); printk(")\n");
+                tab(n, f);
+                seq_printf(f, "Logical(");
+                hid_resolv_usage(field->logical, f); seq_printf(f, ")\n");
         }
-        tab(n); printk("Usage(%d)\n", field->maxusage);
+        tab(n, f); seq_printf(f, "Usage(%d)\n", field->maxusage);
         for (j = 0; j < field->maxusage; j++) {
-                tab(n+2); hid_resolv_usage(field->usage[j].hid); printk("\n");
+                tab(n+2, f); hid_resolv_usage(field->usage[j].hid, f); seq_printf(f, "\n");
         }
         if (field->logical_minimum != field->logical_maximum) {
-                tab(n); printk("Logical Minimum(%d)\n", field->logical_minimum);
-                tab(n); printk("Logical Maximum(%d)\n", field->logical_maximum);
+                tab(n, f); seq_printf(f, "Logical Minimum(%d)\n", field->logical_minimum);
+                tab(n, f); seq_printf(f, "Logical Maximum(%d)\n", field->logical_maximum);
         }
         if (field->physical_minimum != field->physical_maximum) {
-                tab(n); printk("Physical Minimum(%d)\n", field->physical_minimum);
-                tab(n); printk("Physical Maximum(%d)\n", field->physical_maximum);
+                tab(n, f); seq_printf(f, "Physical Minimum(%d)\n", field->physical_minimum);
+                tab(n, f); seq_printf(f, "Physical Maximum(%d)\n", field->physical_maximum);
         }
         if (field->unit_exponent) {
-                tab(n); printk("Unit Exponent(%d)\n", field->unit_exponent);
+                tab(n, f); seq_printf(f, "Unit Exponent(%d)\n", field->unit_exponent);
         }
         if (field->unit) {
                 static const char *systems[5] = { "None", "SI Linear", "SI Rotation", "English Linear", "English Rotation" };
@@ -425,77 +481,75 @@ void hid_dump_field(struct hid_field *field, int n) {
                 data >>= 4;
 
                 if(sys > 4) {
-                        tab(n); printk("Unit(Invalid)\n");
+                        tab(n, f); seq_printf(f, "Unit(Invalid)\n");
                 }
                 else {
                         int earlier_unit = 0;
 
-                        tab(n); printk("Unit(%s : ", systems[sys]);
+                        tab(n, f); seq_printf(f, "Unit(%s : ", systems[sys]);
 
                         for (i=1 ; i<sizeof(__u32)*2 ; i++) {
                                 char nibble = data & 0xf;
                                 data >>= 4;
                                 if (nibble != 0) {
                                         if(earlier_unit++ > 0)
-                                                printk("*");
-                                        printk("%s", units[sys][i]);
+                                                seq_printf(f, "*");
+                                        seq_printf(f, "%s", units[sys][i]);
                                         if(nibble != 1) {
                                                 /* This is a _signed_ nibble(!) */
 
                                                 int val = nibble & 0x7;
                                                 if(nibble & 0x08)
                                                         val = -((0x7 & ~val) +1);
-                                                printk("^%d", val);
+                                                seq_printf(f, "^%d", val);
                                         }
                                 }
                         }
-                        printk(")\n");
+                        seq_printf(f, ")\n");
                 }
         }
-        tab(n); printk("Report Size(%u)\n", field->report_size);
-        tab(n); printk("Report Count(%u)\n", field->report_count);
-        tab(n); printk("Report Offset(%u)\n", field->report_offset);
+        tab(n, f); seq_printf(f, "Report Size(%u)\n", field->report_size);
+        tab(n, f); seq_printf(f, "Report Count(%u)\n", field->report_count);
+        tab(n, f); seq_printf(f, "Report Offset(%u)\n", field->report_offset);
 
-        tab(n); printk("Flags( ");
+        tab(n, f); seq_printf(f, "Flags( ");
         j = field->flags;
-        printk("%s", HID_MAIN_ITEM_CONSTANT & j ? "Constant " : "");
-        printk("%s", HID_MAIN_ITEM_VARIABLE & j ? "Variable " : "Array ");
-        printk("%s", HID_MAIN_ITEM_RELATIVE & j ? "Relative " : "Absolute ");
-        printk("%s", HID_MAIN_ITEM_WRAP & j ? "Wrap " : "");
-        printk("%s", HID_MAIN_ITEM_NONLINEAR & j ? "NonLinear " : "");
-        printk("%s", HID_MAIN_ITEM_NO_PREFERRED & j ? "NoPreferredState " : "");
-        printk("%s", HID_MAIN_ITEM_NULL_STATE & j ? "NullState " : "");
-        printk("%s", HID_MAIN_ITEM_VOLATILE & j ? "Volatile " : "");
-        printk("%s", HID_MAIN_ITEM_BUFFERED_BYTE & j ? "BufferedByte " : "");
-        printk(")\n");
+        seq_printf(f, "%s", HID_MAIN_ITEM_CONSTANT & j ? "Constant " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_VARIABLE & j ? "Variable " : "Array ");
+        seq_printf(f, "%s", HID_MAIN_ITEM_RELATIVE & j ? "Relative " : "Absolute ");
+        seq_printf(f, "%s", HID_MAIN_ITEM_WRAP & j ? "Wrap " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_NONLINEAR & j ? "NonLinear " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_NO_PREFERRED & j ? "NoPreferredState " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_NULL_STATE & j ? "NullState " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_VOLATILE & j ? "Volatile " : "");
+        seq_printf(f, "%s", HID_MAIN_ITEM_BUFFERED_BYTE & j ? "BufferedByte " : "");
+        seq_printf(f, ")\n");
 }
 EXPORT_SYMBOL_GPL(hid_dump_field);
 
-void hid_dump_device(struct hid_device *device) {
+void hid_dump_device(struct hid_device *device, struct seq_file *f)
+{
         struct hid_report_enum *report_enum;
         struct hid_report *report;
         struct list_head *list;
         unsigned i,k;
         static const char *table[] = {"INPUT", "OUTPUT", "FEATURE"};
 
-        if (!hid_debug)
-                return;
-
         for (i = 0; i < HID_REPORT_TYPES; i++) {
                 report_enum = device->report_enum + i;
                 list = report_enum->report_list.next;
                 while (list != &report_enum->report_list) {
                         report = (struct hid_report *) list;
-                        tab(2);
-                        printk("%s", table[i]);
+                        tab(2, f);
+                        seq_printf(f, "%s", table[i]);
                         if (report->id)
-                                printk("(%d)", report->id);
-                        printk("[%s]", table[report->type]);
-                        printk("\n");
+                                seq_printf(f, "(%d)", report->id);
+                        seq_printf(f, "[%s]", table[report->type]);
+                        seq_printf(f, "\n");
                         for (k = 0; k < report->maxfield; k++) {
-                                tab(4);
-                                printk("Field(%d)\n", k);
-                                hid_dump_field(report->field[k], 6);
+                                tab(4, f);
+                                seq_printf(f, "Field(%d)\n", k);
+                                hid_dump_field(report->field[k], 6, f);
                         }
                         list = list->next;
                 }
@@ -503,13 +557,37 @@ void hid_dump_device(struct hid_device *device) {
 }
 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);
-        printk(" = %d\n", value);
 }
 EXPORT_SYMBOL_GPL(hid_dump_input);
 
@@ -786,12 +864,221 @@ static const char **names[EV_MAX + 1] = {
         [EV_SND] = sounds,                      [EV_REP] = repeats,
 };
 
-void hid_resolv_event(__u8 type, __u16 code) {
+void hid_resolv_event(__u8 type, __u16 code, struct seq_file *f) {
 
-        if (!hid_debug)
-                return;
-
-        printk("%s.%s", events[type] ? events[type] : "?",
+        seq_printf(f, "%s.%s", events[type] ? events[type] : "?",
                 names[type] ? (names[type][code] ? names[type][code] : "?") : "?");
 }
-EXPORT_SYMBOL_GPL(hid_resolv_event);
+
+void hid_dump_input_mapping(struct hid_device *hid, struct seq_file *f)
+{
+        int i, j, k;
+        struct hid_report *report;
+        struct hid_usage *usage;
+
+        for (k = HID_INPUT_REPORT; k <= HID_OUTPUT_REPORT; k++) {
+                list_for_each_entry(report, &hid->report_enum[k].report_list, list) {
+                        for (i = 0; i < report->maxfield; i++) {
+                                for ( j = 0; j < report->field[i]->maxusage; j++) {
+                                        usage = report->field[i]->usage + j;
+                                        hid_resolv_usage(usage->hid, f);
+                                        seq_printf(f, " ---> ");
+                                        hid_resolv_event(usage->type, usage->code, f);
+                                        seq_printf(f, "\n");
+                                }
+                        }
+                }
+        }
+
+}
+
+
+static int hid_debug_rdesc_show(struct seq_file *f, void *p)
+{
+        struct hid_device *hdev = f->private;
+        int i;
+
+        /* dump HID report descriptor */
+        for (i = 0; i < hdev->rsize; i++)
+                seq_printf(f, "%02x ", hdev->rdesc[i]);
+        seq_printf(f, "\n\n");
+
+        /* dump parsed data and input mappings */
+        hid_dump_device(hdev, f);
+        seq_printf(f, "\n");
+        hid_dump_input_mapping(hdev, f);
+
+        return 0;
+}
+
+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;
+                kfree(list);
+                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,
+        .llseek         = seq_lseek,
+        .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);
+}
+
+void hid_debug_init(void)
+{
+        hid_debug_root = debugfs_create_dir("hid", NULL);
+}
+
+void hid_debug_exit(void)
+{
+        debugfs_remove_recursive(hid_debug_root);
+}
+
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 7f183b7147e1..5862b0f3b55d 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -159,17 +159,12 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 
         field->hidinput = hidinput;
 
-        dbg_hid("Mapping: ");
-        hid_resolv_usage(usage->hid);
-        dbg_hid_line(" ---> ");
-
         if (field->flags & HID_MAIN_ITEM_CONSTANT)
                 goto ignore;
 
         /* only LED usages are supported in output fields */
         if (field->report_type == HID_OUTPUT_REPORT &&
                         (usage->hid & HID_USAGE_PAGE) != HID_UP_LED) {
-                dbg_hid_line(" [non-LED output field] ");
                 goto ignore;
         }
 
@@ -561,15 +556,9 @@ mapped:
                 set_bit(MSC_SCAN, input->mscbit);
         }
 
-        hid_resolv_event(usage->type, usage->code);
-
-        dbg_hid_line("\n");
-
-        return;
-
 ignore:
-        dbg_hid_line("IGNORED\n");
         return;
+
 }
 
 void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct hid_usage *usage, __s32 value)
diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 25f38a5af269..1b0e07a67d6d 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -4,8 +4,8 @@
  *  Copyright (c) 1999 Andreas Gal
  *  Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz>
  *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc
- *  Copyright (c) 2006-2008 Jiri Kosina
  *  Copyright (c) 2007-2008 Oliver Neukum
+ *  Copyright (c) 2006-2009 Jiri Kosina
  */
 
 /*
@@ -886,11 +886,6 @@ static int usbhid_parse(struct hid_device *hid)
                 goto err;
         }
 
-        dbg_hid("report descriptor (size %u, read %d) = ", rsize, n);
-        for (n = 0; n < rsize; n++)
-                dbg_hid_line(" %02x", (unsigned char) rdesc[n]);
-        dbg_hid_line("\n");
-
         ret = hid_parse_report(hid, rdesc, rsize);
         kfree(rdesc);
         if (ret) {
@@ -1004,7 +999,6 @@ static int usbhid_start(struct hid_device *hid)
         usbhid->urbctrl->transfer_flags |= (URB_NO_TRANSFER_DMA_MAP | URB_NO_SETUP_DMA_MAP);
 
         usbhid_init_reports(hid);
-        hid_dump_device(hid);
 
         set_bit(HID_STARTED, &usbhid->iofl);
 
diff --git a/drivers/hid/usbhid/hid-quirks.c b/drivers/hid/usbhid/hid-quirks.c
index d8f7423f363e..0d9045aa2c4b 100644
--- a/drivers/hid/usbhid/hid-quirks.c
+++ b/drivers/hid/usbhid/hid-quirks.c
@@ -201,7 +201,7 @@ int usbhid_quirks_init(char **quirks_param)
         u32 quirks;
         int n = 0, m;
 
-        for (; quirks_param[n] && n < MAX_USBHID_BOOT_QUIRKS; n++) {
+        for (; n < MAX_USBHID_BOOT_QUIRKS && quirks_param[n]; n++) {
 
                 m = sscanf(quirks_param[n], "0x%hx:0x%hx:0x%x",
                                 &idVendor, &idProduct, &quirks);
diff --git a/include/linux/hid-debug.h b/include/linux/hid-debug.h
index 50d568ec178a..53744fa1c8b7 100644
--- a/include/linux/hid-debug.h
+++ b/include/linux/hid-debug.h
@@ -2,7 +2,7 @@
 #define __HID_DEBUG_H
 
 /*
- *  Copyright (c) 2007  Jiri Kosina
+ *  Copyright (c) 2007-2009     Jiri Kosina
  */
 
 /*
@@ -22,24 +22,44 @@
  *
  */
 
-#ifdef CONFIG_HID_DEBUG
+#define HID_DEBUG_BUFSIZE 512
 
-void hid_dump_input(struct hid_usage *, __s32);
-void hid_dump_device(struct hid_device *);
-void hid_dump_field(struct hid_field *, int);
-void hid_resolv_usage(unsigned);
-void hid_resolv_event(__u8, __u16);
+#ifdef CONFIG_DEBUG_FS
+
+void hid_dump_input(struct hid_device *, struct hid_usage *, __s32);
+void hid_dump_device(struct hid_device *, struct seq_file *);
+void hid_dump_field(struct hid_field *, int, struct seq_file *);
+char *hid_resolv_usage(unsigned, struct seq_file *);
+void hid_debug_register(struct hid_device *, const char *);
+void hid_debug_unregister(struct hid_device *);
+void hid_debug_init(void);
+void hid_debug_exit(void);
+void hid_debug_event(struct hid_device *, char *);
 
-#else
 
-#define hid_dump_input(a,b)     do { } while (0)
-#define hid_dump_device(c)      do { } while (0)
-#define hid_dump_field(a,b)     do { } while (0)
-#define hid_resolv_usage(a)         do { } while (0)
-#define hid_resolv_event(a,b)       do { } while (0)
+struct hid_debug_list {
+        char *hid_debug_buf;
+        int head;
+        int tail;
+        struct fasync_struct *fasync;
+        struct hid_device *hdev;
+        struct list_head node;
+        struct mutex read_mutex;
+};
 
-#endif /* CONFIG_HID_DEBUG */
+#else
 
+#define hid_dump_input(a,b,c)           do { } while (0)
+#define hid_dump_device(a,b)            do { } while (0)
+#define hid_dump_field(a,b,c)           do { } while (0)
+#define hid_resolv_usage(a,b)           do { } while (0)
+#define hid_debug_register(a, b)        do { } while (0)
+#define hid_debug_unregister(a)         do { } while (0)
+#define hid_debug_init()                do { } while (0)
+#define hid_debug_exit()                do { } while (0)
+#define hid_debug_event(a,b)            do { } while (0)
+
+#endif
 
 #endif
 
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 53489fd4d700..a0ebdace7baa 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -500,6 +500,14 @@ struct hid_device {							/* device report descriptor */
 
         /* handler for raw output data, used by hidraw */
         int (*hid_output_raw_report) (struct hid_device *, __u8 *, size_t);
+
+        /* debugging support via debugfs */
+        unsigned short debug;
+        struct dentry *debug_dir;
+        struct dentry *debug_rdesc;
+        struct dentry *debug_events;
+        struct list_head debug_list;
+        wait_queue_head_t debug_wait;
 };
 
 static inline void *hid_get_drvdata(struct hid_device *hdev)
@@ -657,9 +665,7 @@ struct hid_ll_driver {
 
 /* HID core API */
 
-#ifdef CONFIG_HID_DEBUG
 extern int hid_debug;
-#endif
 
 extern int hid_add_device(struct hid_device *);
 extern void hid_destroy_device(struct hid_device *);
@@ -815,21 +821,9 @@ int hid_pidff_init(struct hid_device *hid);
 #define hid_pidff_init NULL
 #endif
 
-#ifdef CONFIG_HID_DEBUG
 #define dbg_hid(format, arg...) if (hid_debug) \
                                 printk(KERN_DEBUG "%s: " format ,\
                                 __FILE__ , ## arg)
-#define dbg_hid_line(format, arg...) if (hid_debug) \
-                                printk(format, ## arg)
-#else
-static inline int __attribute__((format(printf, 1, 2)))
-dbg_hid(const char *fmt, ...)
-{
-        return 0;
-}
-#define dbg_hid_line dbg_hid
-#endif /* HID_DEBUG */
-
 #define err_hid(format, arg...) printk(KERN_ERR "%s: " format "\n" , \
                 __FILE__ , ## arg)
 #endif /* HID_FF */