HID: wacom: Replace magic masks and comparisons with switch cases

Reasoning through the conditions under which a particular block of code
in 'wacom_intuos_general' will be reached is not at all easy due to the
sheer number of magic masks and comparisons. Remove these and replace
them with a switch statement over the various 'types' of packets that
will be encountered.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index e39568837b58441ef06636d5be83a6f280cfb1dd..a426cb2a1834b1f917d38944400db09846fc4d1f 100644 (file)
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -886,6 +886,7 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
        unsigned char *data = wacom->data;
        struct input_dev *input = wacom->pen_input;
        int idx = (features->type == INTUOS) ? (data[1] & 0x01) : 0;
+       unsigned char type = (data[1] >> 1) & 0x0F;
        unsigned int t;
 
        if (data[0] != WACOM_REPORT_PENABLED && data[0] != WACOM_REPORT_CINTIQ &&
@@ -902,8 +903,12 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                input_report_abs(input, ABS_DISTANCE, ((data[9] >> 3) & 0x1f));
        }
 
-       /* general pen packet */
-       if ((data[1] & 0xb8) == 0xa0) {
+       switch (type) {
+       case 0x00:
+       case 0x01:
+       case 0x02:
+       case 0x03:
+               /* general pen packet */
                t = (data[6] << 2) | ((data[7] >> 6) & 3);
                if (features->pressure_max == 2047) {
                        t = (t << 1) | (data[1] & 1);
@@ -917,36 +922,40 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                input_report_key(input, BTN_STYLUS, data[1] & 2);
                input_report_key(input, BTN_STYLUS2, data[1] & 4);
                input_report_key(input, BTN_TOUCH, t > 10);
-       }
+               break;
 
-       /* airbrush second packet */
-       if ((data[1] & 0xbc) == 0xb4) {
+       case 0x0a:
+       case 0x0b:
+               /* airbrush second packet */
                input_report_abs(input, ABS_WHEEL,
                                (data[6] << 2) | ((data[7] >> 6) & 3));
                input_report_abs(input, ABS_TILT_X,
                                 (((data[7] << 1) & 0x7e) | (data[8] >> 7)) - 64);
                input_report_abs(input, ABS_TILT_Y, (data[8] & 0x7f) - 64);
-       }
+               break;
 
-       /* 4D mouse, 2D mouse, marker pen rotation, tilt mouse, or Lens cursor packets */
-       if ((data[1] & 0xbc) == 0xa8 || (data[1] & 0xbe) == 0xb0 || (data[1] & 0xbc) == 0xac) {
-
-               if (data[1] & 0x02) {
-                       /* Rotation packet */
-                       if (features->type >= INTUOS3S) {
-                               /* I3 marker pen rotation */
-                               t = (data[6] << 3) | ((data[7] >> 5) & 7);
-                               t = (data[7] & 0x20) ? ((t > 900) ? ((t-1) / 2 - 1350) :
-                                       ((t-1) / 2 + 450)) : (450 - t / 2) ;
-                               input_report_abs(input, ABS_Z, t);
-                       } else {
-                               /* 4D mouse rotation packet */
-                               t = (data[6] << 3) | ((data[7] >> 5) & 7);
-                               input_report_abs(input, ABS_RZ, (data[7] & 0x20) ?
-                                       ((t - 1) / 2) : -t / 2);
-                       }
+       case 0x05:
+       case 0x07:
+               /* Rotation packet */
+               if (features->type >= INTUOS3S) {
+                       /* I3 marker pen rotation */
+                       t = (data[6] << 3) | ((data[7] >> 5) & 7);
+                       t = (data[7] & 0x20) ? ((t > 900) ? ((t-1) / 2 - 1350) :
+                               ((t-1) / 2 + 450)) : (450 - t / 2) ;
+                       input_report_abs(input, ABS_Z, t);
+               } else {
+                       /* 4D mouse rotation packet */
+                       t = (data[6] << 3) | ((data[7] >> 5) & 7);
+                       input_report_abs(input, ABS_RZ, (data[7] & 0x20) ?
+                               ((t - 1) / 2) : -t / 2);
+               }
+               break;
 
-               } else if (!(data[1] & 0x10) && features->type < INTUOS3S) {
+       /* 4D mouse, 2D mouse, marker pen rotation, tilt mouse, or Lens cursor packets */
+       case 0x04:
+       case 0x06:
+       case 0x08:
+               if (features->type < INTUOS3S && type != 0x08) {
                        /* 4D mouse packet */
                        input_report_key(input, BTN_LEFT,   data[8] & 0x01);
                        input_report_key(input, BTN_MIDDLE, data[8] & 0x02);
@@ -956,8 +965,8 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                        input_report_key(input, BTN_EXTRA,  data[8] & 0x10);
                        t = (data[6] << 2) | ((data[7] >> 6) & 3);
                        input_report_abs(input, ABS_THROTTLE, (data[8] & 0x08) ? -t : t);
-
-               } else if (wacom->tool[idx] == BTN_TOOL_MOUSE) {
+               }
+               else if (wacom->tool[idx] == BTN_TOOL_MOUSE) {
                        /* I4 mouse */
                        if (features->type >= INTUOS4S && features->type <= INTUOSPL) {
                                input_report_key(input, BTN_LEFT,   data[6] & 0x01);
@@ -985,10 +994,11 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                                        input_report_key(input, BTN_EXTRA,  data[8] & 0x20);
                                }
                        }
-               } else if ((features->type < INTUOS3S || features->type == INTUOS3L ||
-                               features->type == INTUOS4L || features->type == INTUOS5L ||
-                               features->type == INTUOSPL) &&
-                          wacom->tool[idx] == BTN_TOOL_LENS) {
+               }
+               else if ((features->type < INTUOS3S || features->type == INTUOS3L ||
+                         features->type == INTUOS4L || features->type == INTUOS5L ||
+                         features->type == INTUOSPL) &&
+                        wacom->tool[idx] == BTN_TOOL_LENS) {
                        /* Lens cursor packets */
                        input_report_key(input, BTN_LEFT,   data[8] & 0x01);
                        input_report_key(input, BTN_MIDDLE, data[8] & 0x02);
@@ -996,6 +1006,15 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
                        input_report_key(input, BTN_SIDE,   data[8] & 0x10);
                        input_report_key(input, BTN_EXTRA,  data[8] & 0x08);
                }
+               break;
+
+       case 0x09:
+       case 0x0c:
+       case 0x0d:
+       case 0x0e:
+       case 0x0f:
+               /* unhandled */
+               break;
        }
 
        input_report_abs(input, ABS_MISC, wacom->id[idx]); /* report tool id */