From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh

---
 kernel/drivers/hid/hid-core.c |  219 ++++++++++++++++++++++++++++++++++++++++++++++++++----
 1 files changed, 200 insertions(+), 19 deletions(-)

diff --git a/kernel/drivers/hid/hid-core.c b/kernel/drivers/hid/hid-core.c
index 02cd33f..eaaf732 100644
--- a/kernel/drivers/hid/hid-core.c
+++ b/kernel/drivers/hid/hid-core.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  HID support for Linux
  *
@@ -8,10 +9,6 @@
  */
 
 /*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -125,6 +122,7 @@
 {
 	struct hid_collection *collection;
 	unsigned usage;
+	int collection_index;
 
 	usage = parser->local.usage[0];
 
@@ -167,11 +165,13 @@
 	parser->collection_stack[parser->collection_stack_ptr++] =
 		parser->device->maxcollection;
 
-	collection = parser->device->collection +
-		parser->device->maxcollection++;
+	collection_index = parser->device->maxcollection++;
+	collection = parser->device->collection + collection_index;
 	collection->type = type;
 	collection->usage = usage;
 	collection->level = parser->collection_stack_ptr - 1;
+	collection->parent_idx = (collection->level == 0) ? -1 :
+		parser->collection_stack[collection->level - 1];
 
 	if (type == HID_COLLECTION_APPLICATION)
 		parser->device->maxapplication++;
@@ -317,6 +317,7 @@
 		field->usage[i].collection_index =
 			parser->local.collection_index[j];
 		field->usage[i].usage_index = i;
+		field->usage[i].resolution_multiplier = 1;
 	}
 
 	field->maxusage = usages;
@@ -433,7 +434,7 @@
 
 	case HID_GLOBAL_ITEM_TAG_REPORT_SIZE:
 		parser->global.report_size = item_udata(item);
-		if (parser->global.report_size > 128) {
+		if (parser->global.report_size > 256) {
 			hid_err(parser->device, "invalid report_size %d\n",
 					parser->global.report_size);
 			return -1;
@@ -813,6 +814,13 @@
 
 	if ((parser->global.usage_page << 16) >= HID_UP_MSVENDOR)
 		parser->scan_flags |= HID_SCAN_FLAG_VENDOR_SPECIFIC;
+
+	if ((parser->global.usage_page << 16) == HID_UP_GOOGLEVENDOR)
+		for (i = 0; i < parser->local.usage_index; i++)
+			if (parser->local.usage[i] ==
+					(HID_UP_GOOGLEVENDOR | 0x0001))
+				parser->device->group =
+					HID_GROUP_VIVALDI;
 }
 
 static int hid_scan_main(struct hid_parser *parser, struct hid_item *item)
@@ -919,7 +927,7 @@
 /**
  * hid_parse_report - parse device report
  *
- * @device: hid device
+ * @hid: hid device
  * @start: report start
  * @size: report size
  *
@@ -944,7 +952,7 @@
 /**
  * hid_validate_values - validate existing device report's value indexes
  *
- * @device: hid device
+ * @hid: hid device
  * @type: which report type to examine
  * @id: which report ID to examine (0 for first)
  * @field_index: which report field to examine
@@ -1003,6 +1011,169 @@
 	return report;
 }
 EXPORT_SYMBOL_GPL(hid_validate_values);
+
+static int hid_calculate_multiplier(struct hid_device *hid,
+				     struct hid_field *multiplier)
+{
+	int m;
+	__s32 v = *multiplier->value;
+	__s32 lmin = multiplier->logical_minimum;
+	__s32 lmax = multiplier->logical_maximum;
+	__s32 pmin = multiplier->physical_minimum;
+	__s32 pmax = multiplier->physical_maximum;
+
+	/*
+	 * "Because OS implementations will generally divide the control's
+	 * reported count by the Effective Resolution Multiplier, designers
+	 * should take care not to establish a potential Effective
+	 * Resolution Multiplier of zero."
+	 * HID Usage Table, v1.12, Section 4.3.1, p31
+	 */
+	if (lmax - lmin == 0)
+		return 1;
+	/*
+	 * Handling the unit exponent is left as an exercise to whoever
+	 * finds a device where that exponent is not 0.
+	 */
+	m = ((v - lmin)/(lmax - lmin) * (pmax - pmin) + pmin);
+	if (unlikely(multiplier->unit_exponent != 0)) {
+		hid_warn(hid,
+			 "unsupported Resolution Multiplier unit exponent %d\n",
+			 multiplier->unit_exponent);
+	}
+
+	/* There are no devices with an effective multiplier > 255 */
+	if (unlikely(m == 0 || m > 255 || m < -255)) {
+		hid_warn(hid, "unsupported Resolution Multiplier %d\n", m);
+		m = 1;
+	}
+
+	return m;
+}
+
+static void hid_apply_multiplier_to_field(struct hid_device *hid,
+					  struct hid_field *field,
+					  struct hid_collection *multiplier_collection,
+					  int effective_multiplier)
+{
+	struct hid_collection *collection;
+	struct hid_usage *usage;
+	int i;
+
+	/*
+	 * If multiplier_collection is NULL, the multiplier applies
+	 * to all fields in the report.
+	 * Otherwise, it is the Logical Collection the multiplier applies to
+	 * but our field may be in a subcollection of that collection.
+	 */
+	for (i = 0; i < field->maxusage; i++) {
+		usage = &field->usage[i];
+
+		collection = &hid->collection[usage->collection_index];
+		while (collection->parent_idx != -1 &&
+		       collection != multiplier_collection)
+			collection = &hid->collection[collection->parent_idx];
+
+		if (collection->parent_idx != -1 ||
+		    multiplier_collection == NULL)
+			usage->resolution_multiplier = effective_multiplier;
+
+	}
+}
+
+static void hid_apply_multiplier(struct hid_device *hid,
+				 struct hid_field *multiplier)
+{
+	struct hid_report_enum *rep_enum;
+	struct hid_report *rep;
+	struct hid_field *field;
+	struct hid_collection *multiplier_collection;
+	int effective_multiplier;
+	int i;
+
+	/*
+	 * "The Resolution Multiplier control must be contained in the same
+	 * Logical Collection as the control(s) to which it is to be applied.
+	 * If no Resolution Multiplier is defined, then the Resolution
+	 * Multiplier defaults to 1.  If more than one control exists in a
+	 * Logical Collection, the Resolution Multiplier is associated with
+	 * all controls in the collection. If no Logical Collection is
+	 * defined, the Resolution Multiplier is associated with all
+	 * controls in the report."
+	 * HID Usage Table, v1.12, Section 4.3.1, p30
+	 *
+	 * Thus, search from the current collection upwards until we find a
+	 * logical collection. Then search all fields for that same parent
+	 * collection. Those are the fields the multiplier applies to.
+	 *
+	 * If we have more than one multiplier, it will overwrite the
+	 * applicable fields later.
+	 */
+	multiplier_collection = &hid->collection[multiplier->usage->collection_index];
+	while (multiplier_collection->parent_idx != -1 &&
+	       multiplier_collection->type != HID_COLLECTION_LOGICAL)
+		multiplier_collection = &hid->collection[multiplier_collection->parent_idx];
+
+	effective_multiplier = hid_calculate_multiplier(hid, multiplier);
+
+	rep_enum = &hid->report_enum[HID_INPUT_REPORT];
+	list_for_each_entry(rep, &rep_enum->report_list, list) {
+		for (i = 0; i < rep->maxfield; i++) {
+			field = rep->field[i];
+			hid_apply_multiplier_to_field(hid, field,
+						      multiplier_collection,
+						      effective_multiplier);
+		}
+	}
+}
+
+/*
+ * hid_setup_resolution_multiplier - set up all resolution multipliers
+ *
+ * @device: hid device
+ *
+ * Search for all Resolution Multiplier Feature Reports and apply their
+ * value to all matching Input items. This only updates the internal struct
+ * fields.
+ *
+ * The Resolution Multiplier is applied by the hardware. If the multiplier
+ * is anything other than 1, the hardware will send pre-multiplied events
+ * so that the same physical interaction generates an accumulated
+ *	accumulated_value = value * * multiplier
+ * This may be achieved by sending
+ * - "value * multiplier" for each event, or
+ * - "value" but "multiplier" times as frequently, or
+ * - a combination of the above
+ * The only guarantee is that the same physical interaction always generates
+ * an accumulated 'value * multiplier'.
+ *
+ * This function must be called before any event processing and after
+ * any SetRequest to the Resolution Multiplier.
+ */
+void hid_setup_resolution_multiplier(struct hid_device *hid)
+{
+	struct hid_report_enum *rep_enum;
+	struct hid_report *rep;
+	struct hid_usage *usage;
+	int i, j;
+
+	rep_enum = &hid->report_enum[HID_FEATURE_REPORT];
+	list_for_each_entry(rep, &rep_enum->report_list, list) {
+		for (i = 0; i < rep->maxfield; i++) {
+			/* Ignore if report count is out of bounds. */
+			if (rep->field[i]->report_count < 1)
+				continue;
+
+			for (j = 0; j < rep->field[i]->maxusage; j++) {
+				usage = &rep->field[i]->usage[j];
+				if (usage->hid == HID_GD_RESOLUTION_MULTIPLIER)
+					hid_apply_multiplier(hid,
+							     rep->field[i]);
+			}
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(hid_setup_resolution_multiplier);
 
 /**
  * hid_open_report - open a driver-specific device report
@@ -1102,9 +1273,17 @@
 				hid_err(device, "unbalanced delimiter at end of report description\n");
 				goto err;
 			}
+
+			/*
+			 * fetch initial values in case the device's
+			 * default multiplier isn't the recommended 1
+			 */
+			hid_setup_resolution_multiplier(device);
+
 			kfree(parser->collection_stack);
 			vfree(parser);
 			device->status |= HID_STAT_PARSED;
+
 			return 0;
 		}
 	}
@@ -1130,6 +1309,9 @@
 {
 	if (!value || !n)
 		return 0;
+
+	if (n > 32)
+		n = 32;
 
 	switch (n) {
 	case 8:  return ((__s8)value);
@@ -1194,8 +1376,8 @@
 			unsigned offset, unsigned n)
 {
 	if (n > 32) {
-		hid_warn(hid, "hid_field_extract() called with n (%d) > 32! (%s)\n",
-			 n, current->comm);
+		hid_warn_once(hid, "%s() called with n (%d) > 32! (%s)\n",
+			      __func__, n, current->comm);
 		n = 32;
 	}
 
@@ -1275,7 +1457,7 @@
  * hid_match_report - check if driver's raw_event should be called
  *
  * @hid: hid device
- * @report_type: type to match against
+ * @report: hid report to match against
  *
  * compare hid->driver->report_table->report_type to report->type
  */
@@ -1527,7 +1709,7 @@
  * Implement a generic .request() callback, using .raw_request()
  * DO NOT USE in hid drivers directly, but through hid_hw_request instead.
  */
-void __hid_request(struct hid_device *hid, struct hid_report *report,
+int __hid_request(struct hid_device *hid, struct hid_report *report,
 		int reqtype)
 {
 	char *buf;
@@ -1536,7 +1718,7 @@
 
 	buf = hid_alloc_report_buf(report, GFP_KERNEL);
 	if (!buf)
-		return;
+		return -ENOMEM;
 
 	len = hid_report_len(report);
 
@@ -1553,8 +1735,11 @@
 	if (reqtype == HID_REQ_GET_REPORT)
 		hid_input_report(hid, report->type, buf, ret, 0);
 
+	ret = 0;
+
 out:
 	kfree(buf);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(__hid_request);
 
@@ -1951,7 +2136,7 @@
 
 /**
  * store_new_id - add a new HID device ID to this driver and re-probe devices
- * @driver: target device driver
+ * @drv: target device driver
  * @buf: buffer for scanning device ID data
  * @count: input size
  *
@@ -2443,11 +2628,7 @@
 	hid_quirks_exit(HID_BUS_ANY);
 }
 
-#ifdef CONFIG_ROCKCHIP_THUNDER_BOOT
-rootfs_initcall(hid_init);
-#else
 module_init(hid_init);
-#endif
 module_exit(hid_exit);
 
 MODULE_AUTHOR("Andreas Gal");

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