HID: allow resizing and replacing report descriptors

Update hid_driver's report_fixup prototype to allow changing report
descriptor size and/or returning completely different report descriptor.
Update existing usage accordingly.

This is to give more freedom in descriptor fixup and to allow having a whole
fixed descriptor in the code for the sake of readability.

Signed-off-by: Nikolai Kondrashov <spbnick@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

17 files changed, 72 insertions, 56 deletions

diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
index bba05d0a898..eaeca564a8d 100644
--- a/drivers/hid/hid-apple.c
+++ b/drivers/hid/hid-apple.c
@@ -246,17 +246,18 @@ static int apple_event(struct hid_device *hdev, struct hid_field *field,
 /*
  * MacBook JIS keyboard has wrong logical maximum
  */
-static void apple_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *apple_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
 	struct apple_sc *asc = hid_get_drvdata(hdev);
 
-	if ((asc->quirks & APPLE_RDESC_JIS) && rsize >= 60 &&
+	if ((asc->quirks & APPLE_RDESC_JIS) && *rsize >= 60 &&
 			rdesc[53] == 0x65 && rdesc[59] == 0x65) {
 		dev_info(&hdev->dev, "fixing up MacBook JIS keyboard report "
 				"descriptor\n");
 		rdesc[53] = rdesc[59] = 0xe7;
 	}
+	return rdesc;
 }
 
 static void apple_setup_input(struct input_dev *input)
diff --git a/drivers/hid/hid-cherry.c b/drivers/hid/hid-cherry.c
index 24663a8717b..e880086c231 100644
--- a/drivers/hid/hid-cherry.c
+++ b/drivers/hid/hid-cherry.c
@@ -26,15 +26,16 @@
  * Cherry Cymotion keyboard have an invalid HID report descriptor,
  * that needs fixing before we can parse it.
  */
-static void ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *ch_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 17 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
+	if (*rsize >= 17 && rdesc[11] == 0x3c && rdesc[12] == 0x02) {
 		dev_info(&hdev->dev, "fixing up Cherry Cymotion report "
 				"descriptor\n");
 		rdesc[11] = rdesc[16] = 0xff;
 		rdesc[12] = rdesc[17] = 0x03;
 	}
+	return rdesc;
 }
 
 #define ch_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index e635199a0cd..ec20e83cbd6 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -651,7 +651,7 @@ int hid_parse_report(struct hid_device *device, __u8 *start,
 	};
 
 	if (device->driver->report_fixup)
-		device->driver->report_fixup(device, start, size);
+		start = device->driver->report_fixup(device, start, &size);
 
 	device->rdesc = kmemdup(start, size, GFP_KERNEL);
 	if (device->rdesc == NULL)
diff --git a/drivers/hid/hid-cypress.c b/drivers/hid/hid-cypress.c
index 998b6f443d7..4cd0e234599 100644
--- a/drivers/hid/hid-cypress.c
+++ b/drivers/hid/hid-cypress.c
@@ -31,16 +31,16 @@
  * Some USB barcode readers from cypress have usage min and usage max in
  * the wrong order
  */
-static void cp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *cp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
 	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
 	unsigned int i;
 
 	if (!(quirks & CP_RDESC_SWAPPED_MIN_MAX))
-		return;
+		return rdesc;
 
-	for (i = 0; i < rsize - 4; i++)
+	for (i = 0; i < *rsize - 4; i++)
 		if (rdesc[i] == 0x29 && rdesc[i + 2] == 0x19) {
 			__u8 tmp;
 
@@ -50,6 +50,7 @@ static void cp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 			rdesc[i + 3] = rdesc[i + 1];
 			rdesc[i + 1] = tmp;
 		}
+	return rdesc;
 }
 
 static int cp_input_mapped(struct hid_device *hdev, struct hid_input *hi,
diff --git a/drivers/hid/hid-elecom.c b/drivers/hid/hid-elecom.c
index 7a40878f46b..6e31f305397 100644
--- a/drivers/hid/hid-elecom.c
+++ b/drivers/hid/hid-elecom.c
@@ -20,14 +20,15 @@
 
 #include "hid-ids.h"
 
-static void elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *elecom_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
+	if (*rsize >= 48 && rdesc[46] == 0x05 && rdesc[47] == 0x0c) {
 		dev_info(&hdev->dev, "Fixing up Elecom BM084 "
 				"report descriptor.\n");
 		rdesc[47] = 0x00;
 	}
+    return rdesc;
 }
 
 static const struct hid_device_id elecom_devices[] = {
diff --git a/drivers/hid/hid-kye.c b/drivers/hid/hid-kye.c
index f8871712b7b..817247ee006 100644
--- a/drivers/hid/hid-kye.c
+++ b/drivers/hid/hid-kye.c
@@ -23,10 +23,10 @@
  *   - report size 8 count 1 must be size 1 count 8 for button bitfield
  *   - change the button usage range to 4-7 for the extra buttons
  */
-static void kye_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *kye_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 74 &&
+	if (*rsize >= 74 &&
 		rdesc[61] == 0x05 && rdesc[62] == 0x08 &&
 		rdesc[63] == 0x19 && rdesc[64] == 0x08 &&
 		rdesc[65] == 0x29 && rdesc[66] == 0x0f &&
@@ -40,6 +40,7 @@ static void kye_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		rdesc[72] = 0x01;
 		rdesc[74] = 0x08;
 	}
+	return rdesc;
 }
 
 static const struct hid_device_id kye_devices[] = {
diff --git a/drivers/hid/hid-lg.c b/drivers/hid/hid-lg.c
index f6433d8050a..68c0b68856c 100644
--- a/drivers/hid/hid-lg.c
+++ b/drivers/hid/hid-lg.c
@@ -41,25 +41,26 @@
  * above the logical maximum described in descriptor. This extends
  * the original value of 0x28c of logical maximum to 0x104d
  */
-static void lg_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *lg_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
 	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
 
-	if ((quirks & LG_RDESC) && rsize >= 90 && rdesc[83] == 0x26 &&
+	if ((quirks & LG_RDESC) && *rsize >= 90 && rdesc[83] == 0x26 &&
 			rdesc[84] == 0x8c && rdesc[85] == 0x02) {
 		dev_info(&hdev->dev, "fixing up Logitech keyboard report "
 				"descriptor\n");
 		rdesc[84] = rdesc[89] = 0x4d;
 		rdesc[85] = rdesc[90] = 0x10;
 	}
-	if ((quirks & LG_RDESC_REL_ABS) && rsize >= 50 &&
+	if ((quirks & LG_RDESC_REL_ABS) && *rsize >= 50 &&
 			rdesc[32] == 0x81 && rdesc[33] == 0x06 &&
 			rdesc[49] == 0x81 && rdesc[50] == 0x06) {
 		dev_info(&hdev->dev, "fixing up rel/abs in Logitech "
 				"report descriptor\n");
 		rdesc[33] = rdesc[50] = 0x02;
 	}
+	return rdesc;
 }
 
 #define lg_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-microsoft.c b/drivers/hid/hid-microsoft.c
index 359cc447c6c..dc618c33d0a 100644
--- a/drivers/hid/hid-microsoft.c
+++ b/drivers/hid/hid-microsoft.c
@@ -33,18 +33,19 @@
  * Microsoft Wireless Desktop Receiver (Model 1028) has
  * 'Usage Min/Max' where it ought to have 'Physical Min/Max'
  */
-static void ms_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *ms_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
 	unsigned long quirks = (unsigned long)hid_get_drvdata(hdev);
 
-	if ((quirks & MS_RDESC) && rsize == 571 && rdesc[557] == 0x19 &&
+	if ((quirks & MS_RDESC) && *rsize == 571 && rdesc[557] == 0x19 &&
 			rdesc[559] == 0x29) {
 		dev_info(&hdev->dev, "fixing up Microsoft Wireless Receiver "
 				"Model 1028 report descriptor\n");
 		rdesc[557] = 0x35;
 		rdesc[559] = 0x45;
 	}
+	return rdesc;
 }
 
 #define ms_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-monterey.c b/drivers/hid/hid-monterey.c
index 2cd05aa244b..c95c31e2d86 100644
--- a/drivers/hid/hid-monterey.c
+++ b/drivers/hid/hid-monterey.c
@@ -22,14 +22,15 @@
 
 #include "hid-ids.h"
 
-static void mr_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *mr_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 30 && rdesc[29] == 0x05 && rdesc[30] == 0x09) {
+	if (*rsize >= 30 && rdesc[29] == 0x05 && rdesc[30] == 0x09) {
 		dev_info(&hdev->dev, "fixing up button/consumer in HID report "
 				"descriptor\n");
 		rdesc[30] = 0x0c;
 	}
+	return rdesc;
 }
 
 #define mr_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-ortek.c b/drivers/hid/hid-ortek.c
index aa9a960f73a..2e79716dca3 100644
--- a/drivers/hid/hid-ortek.c
+++ b/drivers/hid/hid-ortek.c
@@ -19,14 +19,15 @@
 
 #include "hid-ids.h"
 
-static void ortek_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *ortek_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 56 && rdesc[54] == 0x25 && rdesc[55] == 0x01) {
+	if (*rsize >= 56 && rdesc[54] == 0x25 && rdesc[55] == 0x01) {
 		dev_info(&hdev->dev, "Fixing up Ortek WKB-2000 "
 				"report descriptor.\n");
 		rdesc[55] = 0x92;
 	}
+	return rdesc;
 }
 
 static const struct hid_device_id ortek_devices[] = {
diff --git a/drivers/hid/hid-petalynx.c b/drivers/hid/hid-petalynx.c
index 500fbd0652d..308d6ae48a3 100644
--- a/drivers/hid/hid-petalynx.c
+++ b/drivers/hid/hid-petalynx.c
@@ -23,10 +23,10 @@
 #include "hid-ids.h"
 
 /* Petalynx Maxter Remote has maximum for consumer page set too low */
-static void pl_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *pl_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 60 && rdesc[39] == 0x2a && rdesc[40] == 0xf5 &&
+	if (*rsize >= 60 && rdesc[39] == 0x2a && rdesc[40] == 0xf5 &&
 			rdesc[41] == 0x00 && rdesc[59] == 0x26 &&
 			rdesc[60] == 0xf9 && rdesc[61] == 0x00) {
 		dev_info(&hdev->dev, "fixing up Petalynx Maxter Remote report "
@@ -34,6 +34,7 @@ static void pl_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		rdesc[60] = 0xfa;
 		rdesc[40] = 0xfa;
 	}
+	return rdesc;
 }
 
 #define pl_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-prodikeys.c b/drivers/hid/hid-prodikeys.c
index 845f428b809..48eab84f53b 100644
--- a/drivers/hid/hid-prodikeys.c
+++ b/drivers/hid/hid-prodikeys.c
@@ -740,10 +740,10 @@ int pcmidi_snd_terminate(struct pcmidi_snd *pm)
 /*
  * PC-MIDI report descriptor for report id is wrong.
  */
-static void pk_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *pk_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize == 178 &&
+	if (*rsize == 178 &&
 	      rdesc[111] == 0x06 && rdesc[112] == 0x00 &&
 	      rdesc[113] == 0xff) {
 		dev_info(&hdev->dev, "fixing up pc-midi keyboard report "
@@ -751,6 +751,7 @@ static void pk_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 
 		rdesc[144] = 0x18; /* report 4: was 0x10 report count */
 	}
+	return rdesc;
 }
 
 static int pk_input_mapping(struct hid_device *hdev, struct hid_input *hi,
diff --git a/drivers/hid/hid-samsung.c b/drivers/hid/hid-samsung.c
index bda0fd60c98..35894444e00 100644
--- a/drivers/hid/hid-samsung.c
+++ b/drivers/hid/hid-samsung.c
@@ -61,10 +61,10 @@ static inline void samsung_irda_dev_trace(struct hid_device *hdev,
 			"descriptor\n", rsize);
 }
 
-static void samsung_irda_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *samsung_irda_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize == 184 && rdesc[175] == 0x25 && rdesc[176] == 0x40 &&
+	if (*rsize == 184 && rdesc[175] == 0x25 && rdesc[176] == 0x40 &&
 			rdesc[177] == 0x75 && rdesc[178] == 0x30 &&
 			rdesc[179] == 0x95 && rdesc[180] == 0x01 &&
 			rdesc[182] == 0x40) {
@@ -74,24 +74,25 @@ static void samsung_irda_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		rdesc[180] = 0x06;
 		rdesc[182] = 0x42;
 	} else
-	if (rsize == 203 && rdesc[192] == 0x15 && rdesc[193] == 0x0 &&
+	if (*rsize == 203 && rdesc[192] == 0x15 && rdesc[193] == 0x0 &&
 			rdesc[194] == 0x25 && rdesc[195] == 0x12) {
 		samsung_irda_dev_trace(hdev, 203);
 		rdesc[193] = 0x1;
 		rdesc[195] = 0xf;
 	} else
-	if (rsize == 135 && rdesc[124] == 0x15 && rdesc[125] == 0x0 &&
+	if (*rsize == 135 && rdesc[124] == 0x15 && rdesc[125] == 0x0 &&
 			rdesc[126] == 0x25 && rdesc[127] == 0x11) {
 		samsung_irda_dev_trace(hdev, 135);
 		rdesc[125] = 0x1;
 		rdesc[127] = 0xe;
 	} else
-	if (rsize == 171 && rdesc[160] == 0x15 && rdesc[161] == 0x0 &&
+	if (*rsize == 171 && rdesc[160] == 0x15 && rdesc[161] == 0x0 &&
 			rdesc[162] == 0x25 && rdesc[163] == 0x01) {
 		samsung_irda_dev_trace(hdev, 171);
 		rdesc[161] = 0x1;
 		rdesc[163] = 0x3;
 	}
+	return rdesc;
 }
 
 #define samsung_kbd_mouse_map_key_clear(c) \
@@ -130,11 +131,12 @@ static int samsung_kbd_mouse_input_mapping(struct hid_device *hdev,
 	return 1;
 }
 
-static void samsung_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-	unsigned int rsize)
+static __u8 *samsung_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+	unsigned int *rsize)
 {
 	if (USB_DEVICE_ID_SAMSUNG_IR_REMOTE == hdev->product)
-		samsung_irda_report_fixup(hdev, rdesc, rsize);
+		rdesc = samsung_irda_report_fixup(hdev, rdesc, rsize);
+	return rdesc;
 }
 
 static int samsung_input_mapping(struct hid_device *hdev, struct hid_input *hi,
diff --git a/drivers/hid/hid-sony.c b/drivers/hid/hid-sony.c
index 402d5574b57..9fa03491518 100644
--- a/drivers/hid/hid-sony.c
+++ b/drivers/hid/hid-sony.c
@@ -31,17 +31,18 @@ struct sony_sc {
 };
 
 /* Sony Vaio VGX has wrongly mouse pointer declared as constant */
-static void sony_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *sony_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
 	struct sony_sc *sc = hid_get_drvdata(hdev);
 
 	if ((sc->quirks & VAIO_RDESC_CONSTANT) &&
-			rsize >= 56 && rdesc[54] == 0x81 && rdesc[55] == 0x07) {
+			*rsize >= 56 && rdesc[54] == 0x81 && rdesc[55] == 0x07) {
 		dev_info(&hdev->dev, "Fixing up Sony Vaio VGX report "
 				"descriptor\n");
 		rdesc[55] = 0x06;
 	}
+	return rdesc;
 }
 
 /*
diff --git a/drivers/hid/hid-sunplus.c b/drivers/hid/hid-sunplus.c
index 438107d9f1b..164ed568f6c 100644
--- a/drivers/hid/hid-sunplus.c
+++ b/drivers/hid/hid-sunplus.c
@@ -22,16 +22,17 @@
 
 #include "hid-ids.h"
 
-static void sp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-		unsigned int rsize)
+static __u8 *sp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+		unsigned int *rsize)
 {
-	if (rsize >= 107 && rdesc[104] == 0x26 && rdesc[105] == 0x80 &&
+	if (*rsize >= 107 && rdesc[104] == 0x26 && rdesc[105] == 0x80 &&
 			rdesc[106] == 0x03) {
 		dev_info(&hdev->dev, "fixing up Sunplus Wireless Desktop "
 				"report descriptor\n");
 		rdesc[105] = rdesc[110] = 0x03;
 		rdesc[106] = rdesc[111] = 0x21;
 	}
+	return rdesc;
 }
 
 #define sp_map_key_clear(c)	hid_map_usage_clear(hi, usage, bit, max, \
diff --git a/drivers/hid/hid-zydacron.c b/drivers/hid/hid-zydacron.c
index 9e8d35a203e..aac1f927314 100644
--- a/drivers/hid/hid-zydacron.c
+++ b/drivers/hid/hid-zydacron.c
@@ -27,10 +27,10 @@ struct zc_device {
 * Zydacron remote control has an invalid HID report descriptor,
 * that needs fixing before we can parse it.
 */
-static void zc_report_fixup(struct hid_device *hdev, __u8 *rdesc,
-	unsigned int rsize)
+static __u8 *zc_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+	unsigned int *rsize)
 {
-	if (rsize >= 253 &&
+	if (*rsize >= 253 &&
 		rdesc[0x96] == 0xbc && rdesc[0x97] == 0xff &&
 		rdesc[0xca] == 0xbc && rdesc[0xcb] == 0xff &&
 		rdesc[0xe1] == 0xbc && rdesc[0xe2] == 0xff) {
@@ -40,6 +40,7 @@ static void zc_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 			rdesc[0x96] = rdesc[0xca] = rdesc[0xe1] = 0x0c;
 			rdesc[0x97] = rdesc[0xcb] = rdesc[0xe2] = 0x00;
 		}
+	return rdesc;
 }
 
 #define zc_map_key_clear(c) \
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 42a0f1d1136..0a34fb07137 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -626,8 +626,8 @@ struct hid_driver {
 	int (*event)(struct hid_device *hdev, struct hid_field *field,
 			struct hid_usage *usage, __s32 value);
 
-	void (*report_fixup)(struct hid_device *hdev, __u8 *buf,
-			unsigned int size);
+	__u8 *(*report_fixup)(struct hid_device *hdev, __u8 *buf,
+			unsigned int *size);
 
 	int (*input_mapping)(struct hid_device *hdev,
 			struct hid_input *hidinput, struct hid_field *field,