1 files changed, 26 insertions, 21 deletions

diff --git a/drivers/input/mouse/bcm5974.c b/drivers/input/mouse/bcm5974.c
index 2998a6ac9ae4..bda873393b0d 100644
--- a/drivers/input/mouse/bcm5974.c
+++ b/drivers/input/mouse/bcm5974.c
@@ -96,14 +96,15 @@ struct bt_data {
         u8 rel_y;               /* relative y coordinate */
 };
 
-/* trackpad header structure */
-struct tp_header {
-        u8 unknown1[16];        /* constants, timers, etc */
-        u8 fingers;             /* number of fingers on trackpad */
-        u8 unknown2[9];         /* constants, timers, etc */
+/* trackpad header types */
+enum tp_type {
+        TYPE1                   /* plain trackpad */
 };
 
-/* trackpad finger structure */
+/* trackpad finger data offsets, le16-aligned */
+#define FINGER_TYPE1            (13 * sizeof(__le16))
+
+/* trackpad finger structure, le16-aligned */
 struct tp_finger {
         __le16 origin;          /* zero when switching track finger */
         __le16 abs_x;           /* absolute x coodinate */
@@ -117,13 +118,11 @@ struct tp_finger {
         __le16 force_minor;     /* trackpad force, minor axis? */
         __le16 unused[3];       /* zeros */
         __le16 multi;           /* one finger: varies, more fingers: constant */
-};
+} __attribute__((packed,aligned(2)));
 
-/* trackpad data structure, empirically at least ten fingers */
-struct tp_data {
-        struct tp_header header;
-        struct tp_finger finger[16];
-};
+/* trackpad finger data size, empirically at least ten fingers */
+#define SIZEOF_FINGER           sizeof(struct tp_finger)
+#define SIZEOF_ALL_FINGERS      (16 * SIZEOF_FINGER)
 
 /* device-specific parameters */
 struct bcm5974_param {
@@ -139,6 +138,8 @@ struct bcm5974_config {
         int bt_ep;              /* the endpoint of the button interface */
         int bt_datalen;         /* data length of the button interface */
         int tp_ep;              /* the endpoint of the trackpad interface */
+        enum tp_type tp_type;   /* type of trackpad interface */
+        int tp_offset;          /* offset to trackpad finger data */
         int tp_datalen;         /* data length of the trackpad interface */
         struct bcm5974_param p; /* finger pressure limits */
         struct bcm5974_param w; /* finger width limits */
@@ -158,7 +159,7 @@ struct bcm5974 {
         struct urb *bt_urb;             /* button usb request block */
         struct bt_data *bt_data;        /* button transferred data */
         struct urb *tp_urb;             /* trackpad usb request block */
-        struct tp_data *tp_data;        /* trackpad transferred data */
+        u8 *tp_data;                    /* trackpad transferred data */
         int fingers;                    /* number of fingers on trackpad */
 };
 
@@ -184,7 +185,7 @@ static const struct bcm5974_config bcm5974_config_table[] = {
                 USB_DEVICE_ID_APPLE_WELLSPRING_ISO,
                 USB_DEVICE_ID_APPLE_WELLSPRING_JIS,
                 0x84, sizeof(struct bt_data),
-                0x81, sizeof(struct tp_data),
+                0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
                 { DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
                 { DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
                 { DIM_X, DIM_X / SN_COORD, -4824, 5342 },
@@ -195,7 +196,7 @@ static const struct bcm5974_config bcm5974_config_table[] = {
                 USB_DEVICE_ID_APPLE_WELLSPRING2_ISO,
                 USB_DEVICE_ID_APPLE_WELLSPRING2_JIS,
                 0x84, sizeof(struct bt_data),
-                0x81, sizeof(struct tp_data),
+                0x81, TYPE1, FINGER_TYPE1, FINGER_TYPE1 + SIZEOF_ALL_FINGERS,
                 { DIM_PRESSURE, DIM_PRESSURE / SN_PRESSURE, 0, 256 },
                 { DIM_WIDTH, DIM_WIDTH / SN_WIDTH, 0, 2048 },
                 { DIM_X, DIM_X / SN_COORD, -4824, 4824 },
@@ -276,18 +277,21 @@ static int report_bt_state(struct bcm5974 *dev, int size)
 static int report_tp_state(struct bcm5974 *dev, int size)
 {
         const struct bcm5974_config *c = &dev->cfg;
-        const struct tp_finger *f = dev->tp_data->finger;
+        const struct tp_finger *f;
         struct input_dev *input = dev->input;
-        const int fingers = (size - 26) / 28;
-        int raw_p, raw_w, raw_x, raw_y;
+        int raw_p, raw_w, raw_x, raw_y, raw_n;
         int ptest = 0, origin = 0, nmin = 0, nmax = 0;
         int abs_p = 0, abs_w = 0, abs_x = 0, abs_y = 0;
 
-        if (size < 26 || (size - 26) % 28 != 0)
+        if (size < c->tp_offset || (size - c->tp_offset) % SIZEOF_FINGER != 0)
                 return -EIO;
 
+        /* finger data, le16-aligned */
+        f = (const struct tp_finger *)(dev->tp_data + c->tp_offset);
+        raw_n = (size - c->tp_offset) / SIZEOF_FINGER;
+
         /* always track the first finger; when detached, start over */
-        if (fingers) {
+        if (raw_n) {
                 raw_p = raw2int(f->force_major);
                 raw_w = raw2int(f->size_major);
                 raw_x = raw2int(f->abs_x);
@@ -307,12 +311,13 @@ static int report_tp_state(struct bcm5974 *dev, int size)
                 abs_w = int2bound(&c->w, raw_w);
                 abs_x = int2bound(&c->x, raw_x - c->x.devmin);
                 abs_y = int2bound(&c->y, c->y.devmax - raw_y);
-                for (; f != dev->tp_data->finger + fingers; f++) {
+                while (raw_n--) {
                         ptest = int2bound(&c->p, raw2int(f->force_major));
                         if (ptest > PRESSURE_LOW)
                                 nmax++;
                         if (ptest > PRESSURE_HIGH)
                                 nmin++;
+                        f++;
                 }
         }