HID: use debugfs for events/reports dumping

This is a followup patch to the one implemeting rdesc representation in debugfs
rather than being dependent on compile-time CONFIG_HID_DEBUG setting.

The API of the appropriate formatting functions is slightly modified -- if
they are passed seq_file pointer, the one-shot output for 'rdesc' file mode
is used, and therefore the message is formatted into the corresponding seq_file
immediately.

Otherwise the called function allocated a new buffer, formats the text into the
buffer and returns the pointer to it, so that it can be queued into the ring-buffer
of the processess blocked waiting on input on 'events' file in debugfs.

'debug' parameter to the 'hid' module is now used solely for the prupose of inetrnal
driver state debugging (parser, transport, etc).

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Author: Jiri Kosina

drivers/hid/hid-core.c

@@ -46,7 +46,7 @@
 
 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);
 
 /*
@@ -859,7 +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);
@@ -981,7 +981,7 @@ 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);
@@ -1075,6 +1075,7 @@ int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int i
 	struct hid_report_enum *report_enum = hid->report_enum + type;
 	struct hid_driver *hdrv = hid->driver;
 	struct hid_report *report;
+	char *buf;
 	unsigned int i;
 	int ret;
 
@@ -1086,18 +1087,36 @@ 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)
 		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)
@@ -1756,6 +1775,9 @@ 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);
@@ -1844,8 +1866,8 @@ static int __init hid_init(void)
 	int ret;
 
 	if (hid_debug)
-		printk(KERN_WARNING "HID: hid_debug parameter has been deprecated. "
-				"Debugging data are now provided via debugfs\n");
+		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) {