FS#7738 - Scroll wheel acceleration for iPod

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@15681 a1c6a512-1295-4272-9138-f99709370657

10 files changed, 223 insertions, 58 deletions

diff --git a/firmware/drivers/button.c b/firmware/drivers/button.c
index 000c478..c7d532e 100644
--- a/firmware/drivers/button.c
+++ b/firmware/drivers/button.c
@@ -522,26 +522,40 @@ void button_clear_queue(void)
 #endif /* SIMULATOR */
 
 #ifdef HAVE_SCROLLWHEEL
+/* WHEEL_ACCEL_FACTOR = 2^16 / WHEEL_ACCEL_START */
+#define WHEEL_ACCEL_FACTOR (1<<16)/WHEEL_ACCEL_START
 /**
  * data:
  *    [31] Use acceleration
  * [30:24] Message post count (skipped + 1) (1-127)
- *  [23:0] Velocity - clicks/uS - 0.24 fixed point
+ *  [23:0] Velocity - degree/sec
  *
- * factor:
- * Wheel acceleration scaling factor - x.24 fixed point -
- * no greater than what will not overflow 64 bits when multiplied
- * by the driver's maximum velocity in (clicks/usec)^2 in 0.24 
+ * WHEEL_ACCEL_FACTOR:
+ * Value in degree/sec -- configurable via settings -- above which 
+ * the accelerated scrolling starts. Factor is internally scaled by 
+ * 1<<16 in respect to the following 32bit integer operations.
  */
-int button_apply_acceleration(unsigned int data, unsigned int factor)
+int button_apply_acceleration(const unsigned int data)
 {
     int delta = (data >> 24) & 0x7f;
 
     if ((data & (1 << 31)) != 0)
     {
+        /* read driver's velocity from data */
         unsigned int v = data & 0xffffff;
 
-        v = factor * (unsigned long long)v*v / 0xffffffffffffull;
+        /* v = 28.4 fixed point */
+        v = (WHEEL_ACCEL_FACTOR * v)>>(16-4);
+
+        /* Calculate real numbers item to scroll based upon acceleration
+         * setting, use correct roundoff */
+#if   (WHEEL_ACCELERATION == 1)
+        v = (v*v     + (1<< 7))>> 8;
+#elif (WHEEL_ACCELERATION == 2)
+        v = (v*v*v   + (1<<11))>>12;
+#elif (WHEEL_ACCELERATION == 3)
+        v = (v*v*v*v + (1<<15))>>16;
+#endif
 
         if (v > 1)
             delta *= v;
diff --git a/firmware/export/button.h b/firmware/export/button.h
index a38385c..f50f3dd 100644
--- a/firmware/export/button.h
+++ b/firmware/export/button.h
@@ -52,7 +52,7 @@ void wheel_send_events(bool send);
 #endif
 
 #ifdef HAVE_SCROLLWHEEL
-int button_apply_acceleration(unsigned int data, unsigned int factor);
+int button_apply_acceleration(const unsigned int data);
 #endif
 
 #define BUTTON_NONE    0x00000000
diff --git a/firmware/export/config-e200.h b/firmware/export/config-e200.h
index e2274bc..f5ba8f0 100644
--- a/firmware/export/config-e200.h
+++ b/firmware/export/config-e200.h
@@ -100,9 +100,10 @@
 
 /* define this if the unit uses a scrollwheel for navigation */
 #define HAVE_SCROLLWHEEL
-/* define wheel acceleration scaling factor */
-/* Range for this target: 0xffffff*(0.0-16.000000894069724921567733381255) */
-#define WHEEL_ACCELERATION_FACTOR   (0xffffff*7)
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 540
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 1
 
 /* define this if you have a flash memory storage */
 #define HAVE_FLASH_STORAGE
diff --git a/firmware/export/config-ipod4g.h b/firmware/export/config-ipod4g.h
index fc28050..7ed7901 100644
--- a/firmware/export/config-ipod4g.h
+++ b/firmware/export/config-ipod4g.h
@@ -86,6 +86,13 @@
 /* Define this for LCD backlight available */
 #define HAVE_BACKLIGHT
 
+/* define this if the unit uses a scrollwheel for navigation */
+#define HAVE_SCROLLWHEEL
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 270
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 3
+
 /* Define this if you can detect headphones */
 #define HAVE_HEADPHONE_DETECTION
 
diff --git a/firmware/export/config-ipodcolor.h b/firmware/export/config-ipodcolor.h
index 0aba8c3..25a7fb3 100644
--- a/firmware/export/config-ipodcolor.h
+++ b/firmware/export/config-ipodcolor.h
@@ -73,6 +73,13 @@
 /* Define this for LCD backlight available */
 #define HAVE_BACKLIGHT
 
+/* define this if the unit uses a scrollwheel for navigation */
+#define HAVE_SCROLLWHEEL
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 270
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 3
+
 /* Define this if you can detect headphones */
 #define HAVE_HEADPHONE_DETECTION
 
diff --git a/firmware/export/config-ipodmini2g.h b/firmware/export/config-ipodmini2g.h
index 5dd2293..0d3dceb 100644
--- a/firmware/export/config-ipodmini2g.h
+++ b/firmware/export/config-ipodmini2g.h
@@ -83,6 +83,13 @@
 /* We can fade the backlight by using PWM */
 #define HAVE_BACKLIGHT_PWM_FADING
 
+/* define this if the unit uses a scrollwheel for navigation */
+#define HAVE_SCROLLWHEEL
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 270
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 3
+
 /* Define this if you can detect headphones */
 #define HAVE_HEADPHONE_DETECTION
 
diff --git a/firmware/export/config-ipodnano.h b/firmware/export/config-ipodnano.h
index 6909561..27e1594 100644
--- a/firmware/export/config-ipodnano.h
+++ b/firmware/export/config-ipodnano.h
@@ -82,6 +82,13 @@
 /* We can fade the backlight by using PWM */
 #define HAVE_BACKLIGHT_PWM_FADING
 
+/* define this if the unit uses a scrollwheel for navigation */
+#define HAVE_SCROLLWHEEL
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 270
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 3
+
 /* Define this if you can detect headphones */
 #define HAVE_HEADPHONE_DETECTION
 
diff --git a/firmware/export/config-ipodvideo.h b/firmware/export/config-ipodvideo.h
index 60a5dd8..c66f6d9 100644
--- a/firmware/export/config-ipodvideo.h
+++ b/firmware/export/config-ipodvideo.h
@@ -82,6 +82,13 @@
 /* We can fade the backlight by using PWM */
 #define HAVE_BACKLIGHT_PWM_FADING
 
+/* define this if the unit uses a scrollwheel for navigation */
+#define HAVE_SCROLLWHEEL
+/* define from which rotation speed [degree/sec] on the acceleration starts */
+#define WHEEL_ACCEL_START 270
+/* define type of acceleration (1 = ^2, 2 = ^3, 3 = ^4) */
+#define WHEEL_ACCELERATION 3
+
 /* Define this if you can detect headphones */
 #define HAVE_HEADPHONE_DETECTION
 
diff --git a/firmware/target/arm/ipod/button-clickwheel.c b/firmware/target/arm/ipod/button-clickwheel.c
index 15f3cdd..f01666a 100644
--- a/firmware/target/arm/ipod/button-clickwheel.c
+++ b/firmware/target/arm/ipod/button-clickwheel.c
@@ -40,6 +40,30 @@
 #include "system.h"
 #include "powermgmt.h"
 
+#define WHEEL_FAST_OFF_TIMEOUT   250000 /* timeout for acceleration = 250ms */
+#define WHEEL_REPEAT_TIMEOUT     250000 /* timeout for button repeat = 250ms */
+#define WHEEL_UNTOUCH_TIMEOUT    150000 /* timeout for untouching wheel = 100ms */
+#define WHEELCLICKS_PER_ROTATION     96 /* wheelclicks per full rotation */
+
+/* This amount of clicks is needed for at least scrolling 1 item. Choose small values 
+ * to have high sensitivity but few precision, choose large values to have less 
+ * sensitivity and good precision. */
+#if defined(IPOD_NANO)
+#define WHEEL_SENSITIVITY 6 /* iPod nano has smaller wheel, lower sensitivity needed */
+#else
+#define WHEEL_SENSITIVITY 4 /* default sensitivity */
+#endif
+
+int  old_wheel_value  = -1;
+int  new_wheel_value  = 0;
+int  repeat           = 0;
+int  wheel_delta      = 0;
+bool wheel_is_touched = false;
+unsigned int  accumulated_wheel_delta = 0;
+unsigned int  wheel_repeat            = 0;
+unsigned int  wheel_velocity          = 0;
+unsigned long last_wheel_usec         = 0;
+
 /* Variable to use for setting button status in interrupt handler */
 int int_btn = BUTTON_NONE;
 #ifdef HAVE_WHEEL_POSITION
@@ -89,16 +113,15 @@ static inline int ipod_4g_button_read(void)
 
     int btn = BUTTON_NONE;
     unsigned reg = 0x7000c104;
-    if ((inl(0x7000c104) & 0x4000000) != 0) {
+    if ((inl(0x7000c104) & 0x4000000) != 0) 
+    {
         unsigned status = inl(0x7000c140);
 
         reg = reg + 0x3C;      /* 0x7000c140 */
         outl(0x0, 0x7000c140); /* clear interrupt status? */
 
-        if ((status & 0x800000ff) == 0x8000001a) {
-            static int old_wheel_value IDATA_ATTR = -1;
-            static int wheel_repeat = 0;
-
+        if ((status & 0x800000ff) == 0x8000001a) 
+        {
             if (status & 0x100)
                 btn |= BUTTON_SELECT;
             if (status & 0x200)
@@ -109,63 +132,152 @@ static inline int ipod_4g_button_read(void)
                 btn |= BUTTON_PLAY;
             if (status & 0x1000)
                 btn |= BUTTON_MENU;
-            if (status & 0x40000000) {
-                /* NB: highest wheel = 0x5F, clockwise increases */
-                int new_wheel_value = (status << 9) >> 25;
+            if (status & 0x40000000) 
+            {
+                unsigned long usec = USEC_TIMER;
+                
+                /* Highest wheel = 0x5F, clockwise increases */
+                new_wheel_value = (status >> 16) & 0x7f;
                 whl = new_wheel_value;
+                
+                /* switch on backlight (again), reset power-off timer */
                 backlight_on();
                 reset_poweroff_timer();
-                /* The queue should have no other events when scrolling */
-                if (queue_empty(&button_queue) && old_wheel_value >= 0) {
+                
+                /* Check whether the scrollwheel was untouched by accident or by will. */
+                /* This is needed because wheel may be untoched very shortly during rotation */
+                if ( (!wheel_is_touched) && TIME_AFTER(usec, last_wheel_usec + WHEEL_UNTOUCH_TIMEOUT) )
+                {
+                    /* wheel has been really untouched -> reset internal variables */
+                    old_wheel_value         = -1;
+                    wheel_velocity          = 0;
+                    accumulated_wheel_delta = 0;
+                    wheel_repeat            = BUTTON_NONE;
+                }
+                else
+                {
+                    /* wheel was shortly untouched by accident -> leave internal variables */
+                    wheel_is_touched = true;
+                }
 
+                if (old_wheel_value >= 0)
+                {
                     /* This is for later = BUTTON_SCROLL_TOUCH;*/
-                    int wheel_delta = new_wheel_value - old_wheel_value;
-                    unsigned long data;
-                    int wheel_keycode;
-
-                    if (wheel_delta < -48)
-                        wheel_delta += 96; /* Forward wrapping case */
-                    else if (wheel_delta > 48)
-                        wheel_delta -= 96; /* Backward wrapping case */
-
-                    if (wheel_delta > 4) {
+                    wheel_delta = new_wheel_value - old_wheel_value;
+                    unsigned int wheel_keycode = BUTTON_NONE;
+
+                    /* Taking into account wrapping during transition from highest 
+                     * to lowest wheel position and back */
+                    if      (wheel_delta < -WHEELCLICKS_PER_ROTATION/2)
+                        wheel_delta += WHEELCLICKS_PER_ROTATION; /* Forward wrapping case */
+                    else if (wheel_delta >  WHEELCLICKS_PER_ROTATION/2)
+                        wheel_delta -= WHEELCLICKS_PER_ROTATION; /* Backward wrapping case */
+    
+                    /* Getting direction and wheel_keycode from wheel_delta.
+                     * Need at least some clicks to be sure to avoid haptic fuzziness */
+                    if      (wheel_delta >=  WHEEL_SENSITIVITY)
                         wheel_keycode = BUTTON_SCROLL_FWD;
-                    } else if (wheel_delta < -4) {
+                    else if (wheel_delta <= -WHEEL_SENSITIVITY)
                         wheel_keycode = BUTTON_SCROLL_BACK;
-                    } else goto wheel_end;
+                    else 
+                        wheel_keycode = BUTTON_NONE;
+
+                    if (wheel_keycode != BUTTON_NONE)
+                    {
+                        long v = (usec - last_wheel_usec) & 0x7fffffff;
+                        
+                        /* undo signedness */
+                        wheel_delta = (wheel_delta>0) ? wheel_delta : -wheel_delta;
+                        
+                        /* add the current wheel_delta */
+                        accumulated_wheel_delta += wheel_delta;
+
+                        v = v ? (1000000 * wheel_delta) / v : 0;  /* clicks/sec = 1000000 * clicks/usec */
+                        v = (v * 360) / WHEELCLICKS_PER_ROTATION; /* conversion to degree/sec */
+                        v = (v<0) ? -v : v;                       /* undo signedness */
+            
+                        /* some velocity filtering to smooth things out */
+                        wheel_velocity = (31 * wheel_velocity + v) / 32;
+                        /* limit to 24 bit */
+                        wheel_velocity = (wheel_velocity>0xffffff) ? 0xffffff : wheel_velocity;
+
+                        /* assume REPEAT = off */
+                        repeat = 0;
+                        
+                        /* direction reversals must nullify acceleration and accumulator */
+                        if (wheel_keycode != wheel_repeat)
+                        {
+                            wheel_repeat            = wheel_keycode;
+                            wheel_velocity          = 0;
+                            accumulated_wheel_delta = 0;
+                        }
+                        /* on same direction REPEAT is assumed when new click is within timeout */
+                        else if (TIME_BEFORE(usec, last_wheel_usec + WHEEL_REPEAT_TIMEOUT))
+                        {
+                            repeat = BUTTON_REPEAT;
+                        }
+                        /* timeout nullifies acceleration and accumulator */
+                        if (TIME_AFTER(usec, last_wheel_usec + WHEEL_FAST_OFF_TIMEOUT))
+                        {
+                            wheel_velocity          = 0;
+                            accumulated_wheel_delta = 0;
+                        }
 
 #ifdef HAVE_WHEEL_POSITION
-                    if (send_events)
+                        if (send_events) 
 #endif
-                    {
-                        data = (wheel_delta << 16) | new_wheel_value;
-                        queue_post(&button_queue, wheel_keycode | wheel_repeat,
-                                   data);
+                        /* The queue should have no other events when scrolling */
+                        if (queue_empty(&button_queue))
+                        {
+                            /* each WHEEL_SENSITIVITY clicks = scrolling 1 item */
+                            accumulated_wheel_delta /= WHEEL_SENSITIVITY;
+#ifdef HAVE_SCROLLWHEEL
+                            /* use data-format for HAVE_SCROLLWHEEL */
+                            /* always use acceleration mode (1<<31) */
+                            /* always set message post count to (1<<24) for iPod */
+                            /* this way the scrolling is always calculated from wheel_velocity */
+                            queue_post(&button_queue, wheel_keycode | repeat, 
+                                       (1<<31) | (1 << 24) | wheel_velocity);
+                                       
+#else
+                            queue_post(&button_queue, wheel_keycode | repeat, 
+                                       (accumulated_wheel_delta << 16) | new_wheel_value);
+#endif
+                            accumulated_wheel_delta = 0;
+                        }
+                        last_wheel_usec = usec;
+                        old_wheel_value = new_wheel_value;
                     }
-
-                    if (!wheel_repeat) wheel_repeat = BUTTON_REPEAT;
                 }
-
-                old_wheel_value = new_wheel_value;
-            } else if (old_wheel_value >= 0) {
-                /* scroll wheel up */
-                old_wheel_value = -1;
-                wheel_repeat = 0;
+                else
+                {
+                    /* scrollwheel was touched for the first time after finger lifting */
+                    old_wheel_value = new_wheel_value;
+                    wheel_is_touched = true;
+                }
+            }
+            else
+            {
+                /* In this case the finger was lifted from the scrollwheel. */
+                wheel_is_touched = false; 
             }
 
-        } else if (status == 0xffffffff) {
+        }
+        else if (status == 0xffffffff) 
+        {
             opto_i2c_init();
         }
     }
 
-wheel_end:
-
-    if ((inl(reg) & 0x8000000) != 0) {
+    if ((inl(reg) & 0x8000000) != 0) 
+    {
         outl(0xffffffff, 0x7000c120);
         outl(0xffffffff, 0x7000c124);
     }
     /* Save the new absolute wheel position */
+#ifdef HAVE_WHEEL_POSITION
     wheel_position = whl;
+#endif
     return btn;
 }
 
@@ -200,14 +312,18 @@ void ipod_4g_button_int(void)
 void button_init_device(void)
 {
     opto_i2c_init();
+    
     /* hold button - enable as input */
     GPIOA_ENABLE |= 0x20;
     GPIOA_OUTPUT_EN &= ~0x20; 
+    
     /* hold button - set interrupt levels */
     GPIOA_INT_LEV = ~(GPIOA_INPUT_VAL & 0x20);
     GPIOA_INT_CLR = GPIOA_INT_STAT & 0x20;
+
     /* enable interrupts */
     GPIOA_INT_EN = 0x20;
+    
     /* unmask interrupt */
     CPU_INT_EN = 0x40000000;
     CPU_HI_INT_EN = I2C_MASK;
diff --git a/firmware/target/arm/sandisk/sansa-e200/button-e200.c b/firmware/target/arm/sandisk/sansa-e200/button-e200.c
index 5988e16..a74d860 100644
--- a/firmware/target/arm/sandisk/sansa-e200/button-e200.c
+++ b/firmware/target/arm/sandisk/sansa-e200/button-e200.c
@@ -27,6 +27,7 @@
 #define WHEEL_REPEAT_INTERVAL   300000
 #define WHEEL_FAST_ON_INTERVAL   20000
 #define WHEEL_FAST_OFF_INTERVAL  60000
+#define WHEELCLICKS_PER_ROTATION    48 /* wheelclicks per full rotation */
 
 /* Clickwheel */
 #ifndef BOOTLOADER
@@ -137,10 +138,8 @@ void clickwheel_int(void)
             unsigned long usec = USEC_TIMER;
             unsigned v = (usec - last_wheel_usec) & 0x7fffffff;
 
-            /* wheel velocity in 0.24 fixed point - clicks/uS */
-
-            /* velocity cap to 18 bits to allow up to x16 scaling */
-            v = (v < 0x40) ? 0xffffff / 0x40 : 0xffffff / v;
+            v = (v>0) ? 1000000 / v : 0;     /* clicks/sec = 1000000 * clicks/usec */
+            v = (v>0xffffff) ? 0xffffff : v; /* limit to 24 bit */
 
             /* some velocity filtering to smooth things out */
             wheel_velocity = (7*wheel_velocity + v) / 8;
@@ -173,12 +172,12 @@ void clickwheel_int(void)
             else
             {
                 /* fast ON gets filtered to avoid inadvertent jumps to fast mode */
-                if (repeat && wheel_velocity > 0xffffff/WHEEL_FAST_ON_INTERVAL)
+                if (repeat && wheel_velocity > 1000000/WHEEL_FAST_ON_INTERVAL)
                 {
                     /* moving into fast mode */
                     wheel_fast_mode = 1 << 31;
                     wheel_click_count = 0;
-                    wheel_velocity = 0xffffff/WHEEL_FAST_OFF_INTERVAL;
+                    wheel_velocity = 1000000/WHEEL_FAST_OFF_INTERVAL;
                 }
                 else if (++wheel_click_count < 2)
                 {
@@ -190,7 +189,7 @@ void clickwheel_int(void)
             }
 
             if (TIME_AFTER(current_tick, next_backlight_on) ||
-                v <= 0xffffff/(1000000/4))
+                v <= 4)
             {
                 /* poke backlight to turn it on or maintain it no more often
                    than every 1/4 second*/
@@ -214,7 +213,7 @@ void clickwheel_int(void)
                 if (queue_empty(&button_queue))
                 {
                     queue_post(&button_queue, btn, wheel_fast_mode |
-                               (wheel_delta << 24) | wheel_velocity);
+                               (wheel_delta << 24) | wheel_velocity*360/WHEELCLICKS_PER_ROTATION);
                     /* message posted - reset delta */
                     wheel_delta = 1;
                 }