Wheel acceleration for e200. A general acceleration interface intended for use on any scroll target and by any code. A general interface to obtain data associated with most recently dequeued button presses and actions. Use #define HAVE_SCROLLWHEEL and set appropriate constants, values in the scroller driver that feel right.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13959 a1c6a512-1295-4272-9138-f99709370657

4 files changed, 123 insertions, 27 deletions

diff --git a/firmware/drivers/button.c b/firmware/drivers/button.c
index f9f355c..715d4d3 100644
--- a/firmware/drivers/button.c
+++ b/firmware/drivers/button.c
@@ -49,6 +49,7 @@ struct event_queue button_queue;
 
 static long lastbtn;   /* Last valid button status */
 static long last_read; /* Last button status, for debouncing/filtering */
+static intptr_t button_data; /* data value from last message dequeued */
 #ifdef HAVE_LCD_BITMAP
 static bool flipped;  /* buttons can be flipped to match the LCD flip */
 #endif
@@ -309,7 +310,7 @@ long button_get(bool block)
         if (current_tick - ev.tick > MAX_EVENT_AGE)
             return BUTTON_NONE;
 #endif
-        
+        button_data = ev.data;
         return ev.id;
     }
     
@@ -329,7 +330,17 @@ long button_get_w_tmo(int ticks)
 #endif
     
     queue_wait_w_tmo(&button_queue, &ev, ticks);
-    return (ev.id != SYS_TIMEOUT)? ev.id: BUTTON_NONE;
+    if (ev.id == SYS_TIMEOUT)
+        ev.id = BUTTON_NONE;
+    else
+        button_data = ev.data;
+
+    return ev.id;
+}
+
+intptr_t button_get_data(void)
+{
+    return button_data;
 }
 
 void button_init(void)
@@ -470,3 +481,33 @@ void button_clear_queue(void)
 {
     queue_clear(&button_queue);
 }
+
+#ifdef HAVE_SCROLLWHEEL
+/**
+ * data:
+ *    [31] Use acceleration
+ * [30:24] Message post count (skipped + 1) (1-127)
+ *  [23:0] Velocity - clicks/uS - 0.24 fixed point
+ *
+ * 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 
+ */
+int button_apply_acceleration(unsigned int data, unsigned int factor)
+{
+    int delta = (data >> 24) & 0x7f;
+
+    if ((data & (1 << 31)) != 0)
+    {
+        unsigned int v = data & 0xffffff;
+
+        v = factor * (unsigned long long)v*v / 0xffffffffffffull;
+
+        if (v > 1)
+            delta *= v;
+    }
+
+    return delta;
+}
+#endif /* HAVE_SCROLLWHEEL */
diff --git a/firmware/export/button.h b/firmware/export/button.h
index f675824..8b8c966 100644
--- a/firmware/export/button.h
+++ b/firmware/export/button.h
@@ -20,6 +20,7 @@
 #define _BUTTON_H_
 
 #include <stdbool.h>
+#include <inttypes.h>
 #include "config.h"
 #include "button-target.h"
 
@@ -28,6 +29,7 @@ extern struct event_queue button_queue;
 void button_init (void);
 long button_get (bool block);
 long button_get_w_tmo(int ticks);
+intptr_t button_get_data(void);
 int button_status(void);
 void button_clear_queue(void);
 #ifdef HAVE_LCD_BITMAP
@@ -48,6 +50,10 @@ int wheel_status(void);
 void wheel_send_events(bool send);
 #endif
 
+#ifdef HAVE_SCROLLWHEEL
+int button_apply_acceleration(unsigned int data, unsigned int factor);
+#endif
+
 #define BUTTON_NONE    0x00000000
 
 /* Button modifiers */
diff --git a/firmware/export/config-e200.h b/firmware/export/config-e200.h
index 6edab71..c7f058e 100644
--- a/firmware/export/config-e200.h
+++ b/firmware/export/config-e200.h
@@ -170,4 +170,10 @@
 
 #define ICODE_ATTR_TREMOR_NOT_MDCT
 
-#endif
+/* 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)
+
+#endif /* SIMULATOR */
diff --git a/firmware/target/arm/sandisk/sansa-e200/button-e200.c b/firmware/target/arm/sandisk/sansa-e200/button-e200.c
index 5e2c38e..734416b 100644
--- a/firmware/target/arm/sandisk/sansa-e200/button-e200.c
+++ b/firmware/target/arm/sandisk/sansa-e200/button-e200.c
@@ -23,19 +23,21 @@
 #include "button.h"
 #include "backlight.h"
 
-#define WHEEL_REPEAT_INTERVAL   30
-#define WHEEL_FAST_ON_INTERVAL  2
-#define WHEEL_FAST_OFF_INTERVAL 6
+#define WHEEL_REPEAT_INTERVAL   300000
+#define WHEEL_FAST_ON_INTERVAL   20000
+#define WHEEL_FAST_OFF_INTERVAL  60000
 
 /* Clickwheel */
 #ifndef BOOTLOADER
 static unsigned int  old_wheel_value   = 0;
 static unsigned int  wheel_repeat      = BUTTON_NONE;
 static unsigned int  wheel_click_count = 0;
+static unsigned int  wheel_delta       = 0;
 static          int  wheel_fast_mode   = 0;
-static unsigned long last_wheel_tick   = 0;
-static unsigned long last_wheel_post   = 0;
-static unsigned long next_backlight_on = 0;
+static unsigned long last_wheel_usec   = 0;
+static unsigned long wheel_velocity    = 0;
+static          long last_wheel_post   = 0;
+static          long next_backlight_on = 0;
 /* Buttons */
 static bool hold_button     = false;
 static bool hold_button_old = false;
@@ -64,8 +66,8 @@ void button_init_device(void)
     GPIOH_INT_EN &= ~0xc0;
 
     /* Get current tick before enabling button interrupts */
-    last_wheel_tick = current_tick;
-    last_wheel_post = current_tick;
+    last_wheel_usec = USEC_TIMER;
+    last_wheel_post = last_wheel_usec;
 
     GPIOH_ENABLE |= 0xc0;
     GPIOH_OUTPUT_EN &= ~0xc0;
@@ -130,38 +132,67 @@ void clickwheel_int(void)
 
         if (btn != BUTTON_NONE)
         {
-            int repeat = 1;
+            int repeat = 1; /* assume repeat */
+            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;
+
+            /* some velocity filtering to smooth things out */
+            wheel_velocity = (7*wheel_velocity + v) / 8;
 
             if (btn != wheel_repeat)
             {
+                /* direction reversals nullify all fast mode states */
                 wheel_repeat      = btn;
                 repeat            =
                 wheel_fast_mode   =
+                wheel_velocity    =
                 wheel_click_count = 0;
             }
 
-            if (wheel_fast_mode)
+            if (wheel_fast_mode != 0)
             {
-                if (TIME_AFTER(current_tick,
-                    last_wheel_tick + WHEEL_FAST_OFF_INTERVAL))
+                /* fast OFF happens immediately when velocity drops below
+                   threshold */
+                if (TIME_AFTER(usec,
+                        last_wheel_usec + WHEEL_FAST_OFF_INTERVAL))
                 {
-                    if (++wheel_click_count < 2)
-                        btn = BUTTON_NONE;
+                    /* moving out of fast mode */
                     wheel_fast_mode = 0;
+                    /* reset velocity */
+                    wheel_velocity = 0;
+                    /* wheel_delta is always 1 in slow mode */
+                    wheel_delta = 1;
                 }
             }
             else
             {
-                if (repeat && TIME_BEFORE(current_tick,
-                    last_wheel_tick + WHEEL_FAST_ON_INTERVAL))
-                    wheel_fast_mode = 1;
+                /* fast ON gets filtered to avoid inadvertent jumps to fast mode */
+                if (repeat && wheel_velocity > 0xffffff/WHEEL_FAST_ON_INTERVAL)
+                {
+                    /* moving into fast mode */
+                    wheel_fast_mode = 1 << 31;
+                    wheel_click_count = 0;
+                    wheel_velocity = 0xffffff/WHEEL_FAST_OFF_INTERVAL;
+                }
                 else if (++wheel_click_count < 2)
+                {
                     btn = BUTTON_NONE;
+                }
+
+                /* wheel_delta is always 1 in slow mode */
+                wheel_delta = 1;
             }
 
-            if (TIME_AFTER(current_tick, next_backlight_on))
+            if (TIME_AFTER(usec, next_backlight_on))
             {
-                next_backlight_on = current_tick + HZ/4;
+                /* poke backlight to turn it on or maintain it no more often
+                   than every 1/4 second*/
+                next_backlight_on = usec + 1000000/4;
                 backlight_on();
                 button_backlight_on();
             }
@@ -170,17 +201,29 @@ void clickwheel_int(void)
             {
                 wheel_click_count = 0;
 
-                if (repeat && TIME_BEFORE(current_tick,
-                    last_wheel_post + WHEEL_REPEAT_INTERVAL))
+                /* generate repeats if quick enough */
+                if (repeat && TIME_BEFORE(usec,
+                        last_wheel_post + WHEEL_REPEAT_INTERVAL))
                     btn |= BUTTON_REPEAT;
 
-                last_wheel_post = current_tick;
+                last_wheel_post = usec;
 
                 if (queue_empty(&button_queue))
-                    queue_post(&button_queue, btn, 0);
+                {
+                    queue_post(&button_queue, btn, wheel_fast_mode |
+                               (wheel_delta << 24) | wheel_velocity);
+                    /* message posted - reset delta */
+                    wheel_delta = 1;
+                }
+                else
+                {
+                    /* skipped post - increment delta */
+                    if (++wheel_delta > 0x7f)
+                        wheel_delta = 0x7f;
+                }
             }
 
-            last_wheel_tick = current_tick;
+            last_wheel_usec = usec;
         }
     }