FS#11172 - Fuzev2: Read the scrollwheel scrollwheel via IRQ

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25736 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 180 insertions, 18 deletions

diff --git a/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c b/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
index db08414ae5..9421076cce 100644
--- a/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
+++ b/firmware/target/arm/as3525/sansa-fuzev2/button-fuzev2.c
@@ -24,37 +24,198 @@
 #include "button.h"
 #include "backlight.h"
 
-extern void scrollwheel(unsigned wheel_value);
-
 #ifdef HAS_BUTTON_HOLD
 static bool hold_button = false;
 #endif
+
+#ifdef HAVE_SCROLLWHEEL
+#define SCROLLWHEEL_BITS        (1<<7|1<<6)
+                                                      /* TIMER units */
+#define TIMER_TICK              (TIMER_FREQ/HZ)       /* how long a tick lasts */
+#define TIMER_MS                (TIMER_TICK/(1000/HZ))/* how long a ms lasts */
+
+#define WHEEL_REPEAT_INTERVAL   (300*TIMER_MS)      /* 300ms */
+#define WHEEL_FAST_ON_INTERVAL  ( 20*TIMER_MS)      /*  20ms */
+#define WHEEL_FAST_OFF_INTERVAL ( 60*TIMER_MS)      /*  60ms */
+/* phsyical clicks per rotation * wheel value changes per phys click */
+#define WHEEL_CHANGES_PER_CLICK         4
+#define WHEELCLICKS_PER_ROTATION        (12*WHEEL_CHANGES_PER_CLICK)
+
+/*
+ * based on button-e200.c, adjusted to the AMS timers and fuzev2's
+ * scrollwheel and cleaned up a little
+ */
+static void scrollwheel(unsigned int wheel_value)
+{
+    /* wheel values and times from the previous irq */
+    static unsigned int  old_wheel_value   = 0;
+    static unsigned int  wheel_repeat      = BUTTON_NONE;
+    static          long last_wheel_post   = 0;
+
+    /* We only post every 4th action, as this matches better with the physical
+     * clicks of the wheel */
+    static unsigned int  wheel_click_count = 0;
+    /* number of items to skip in lists, 1 in slow mode */
+    static unsigned int  wheel_delta       = 0;
+    /* accumulated wheel rotations per second */
+    static unsigned long wheel_velocity    = 0;
+    /* fast or slow mode? */
+    static          int  wheel_fast_mode   = 0;
+
+    /* Read wheel
+     * Bits 6 and 7 of GPIOA change as follows (Gray Code):
+     * Clockwise rotation   00 -> 01 -> 11 -> 10 -> 00
+     * Counter-clockwise    00 -> 10 -> 11 -> 01 -> 00
+     *
+     * For easy look-up, actual wheel values act as indicies also,
+     * which is why the table seems to be not ordered correctly
+     */
+    static const unsigned char wheel_tbl[2][4] =
+    {
+        { 2, 0, 3, 1 }, /* Clockwise rotation */
+        { 1, 3, 0, 2 }, /* Counter-clockwise  */
+    };
+
+    unsigned int btn = BUTTON_NONE;
+
+    if (old_wheel_value == wheel_tbl[0][wheel_value])
+        btn = BUTTON_SCROLL_FWD;
+    else if (old_wheel_value == wheel_tbl[1][wheel_value])
+        btn = BUTTON_SCROLL_BACK;
+
+    if (btn == BUTTON_NONE)
+    {
+        old_wheel_value = wheel_value;
+        return;
+    }
+
+    int  repeat = 1; /* assume repeat */
+    long time = TIMER1_VALUE + current_tick*TIMER_TICK; /* to timer unit */
+    long v = (time - last_wheel_post);
+
+   /* interpolate velocity in timer_freq/timer_unit == 1/s */
+    if (v) v = TIMER_FREQ / v;
+
+    /* accumulate velocities over time with each v */
+    wheel_velocity = (7*wheel_velocity + v) / 8;
+
+    if (btn != wheel_repeat)
+    {
+        /* direction reversals nullify all fast mode states */
+        wheel_repeat      = btn;
+        repeat            =
+        wheel_velocity    =
+        wheel_click_count = 0;
+    }
+
+    if (wheel_fast_mode != 0)
+    {
+        /* fast OFF happens immediately when velocity drops below
+           threshold */
+        if (TIME_AFTER(time,
+                last_wheel_post + WHEEL_FAST_OFF_INTERVAL))
+        {
+            /* 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
+    {
+        /* fast ON gets filtered to avoid inadvertent jumps to fast mode */
+        if (repeat && wheel_velocity > TIMER_FREQ/WHEEL_FAST_ON_INTERVAL)
+        {
+            /* moving into fast mode */
+            wheel_fast_mode = 1 << 31;
+            wheel_click_count = 0;
+            wheel_velocity = TIMER_FREQ/WHEEL_FAST_OFF_INTERVAL;
+        }
+        else if (++wheel_click_count < WHEEL_CHANGES_PER_CLICK)
+        {   /* skip some wheel changes, so that 1 post represents
+             * 1 item in lists */
+            btn = BUTTON_NONE;
+        }
+
+        /* wheel_delta is always 1 in slow mode */
+        wheel_delta = 1;
+    }
+
+    if (btn != BUTTON_NONE)
+    {
+        wheel_click_count = 0;
+
+        /* generate repeats if quick enough */
+        if (repeat && TIME_BEFORE(time,
+                last_wheel_post + WHEEL_REPEAT_INTERVAL))
+            btn |= BUTTON_REPEAT;
+            
+        last_wheel_post = time;
+
+        if (queue_empty(&button_queue))
+        {
+            queue_post(&button_queue, btn, wheel_fast_mode |
+                   (wheel_delta << 24) | wheel_velocity*360/WHEELCLICKS_PER_ROTATION);
+            /* message posted - reset delta and poke backlight on*/
+            wheel_delta = 1;
+            backlight_on();
+            buttonlight_on();
+        }
+        else
+        {
+            /* skipped post - increment delta */
+            if (++wheel_delta > 0x7f)
+                wheel_delta = 0x7f;
+        }
+    }
+
+    old_wheel_value = wheel_value;
+}
+#endif
+
 void button_init_device(void)
 {
+#if defined(HAVE_SCROLLWHEEL)
     GPIOA_DIR &= ~(1<<6|1<<7);
     GPIOC_DIR = 0;
     GPIOB_DIR |= (1<<4)|(1<<0);
 
     GPIOB_PIN(4) = 1<<4; /* activate the wheel */
-}
 
-void get_scrollwheel(void)
-{
-#if defined(HAVE_SCROLLWHEEL) && !defined(BOOTLOADER)
-    /* scroll wheel handling */
+    /* setup scrollwheel isr */
+    /* clear previous irq if any */
+    GPIOA_IC = SCROLLWHEEL_BITS;
+    /* enable edge detecting */
+    GPIOA_IS &= ~SCROLLWHEEL_BITS;
+    /* detect both raising and falling edges */
+    GPIOA_IBE |= SCROLLWHEEL_BITS;
+    /* lastly, enable the interrupt */
+    GPIOA_IE |= SCROLLWHEEL_BITS;
+#endif
+}
 
+    /* read the 2 bits at the same time */
 #define GPIOA_PIN76_offset ((1<<(6+2)) | (1<<(7+2)))
 #define GPIOA_PIN76 (*(volatile unsigned char*)(GPIOA_BASE+GPIOA_PIN76_offset))
-    scrollwheel(GPIOA_PIN76 >> 6);
 
+void button_gpioa_isr(void)
+{
+#if defined(HAVE_SCROLLWHEEL)
+    /* scroll wheel handling */
+    if (GPIOA_MIS & SCROLLWHEEL_BITS)
+        scrollwheel(GPIOA_PIN76 >> 6);
+
+    /* ack interrupt */
+    GPIOA_IC = SCROLLWHEEL_BITS;
 #endif
 }
 
+
 /*
  * Get button pressed from hardware
  */
-
-
 int button_read_device(void)
 {
     int btn = 0;
@@ -62,12 +223,12 @@ int button_read_device(void)
     static long power_counter = 0;
     unsigned gpiod6;
 
-
     /* if we don't wait for the fifo to empty, we'll see screen corruption
      * (the higher the CPU frequency the higher the corruption) */
     while ((DBOP_STAT & (1<<10)) == 0);
 
-    get_scrollwheel();
+    int delay = 30;
+    while(delay--) nop;
 
     CCU_IO &= ~(1<<12);
 
@@ -77,6 +238,7 @@ int button_read_device(void)
     gpiod6 = GPIOD_PIN(6);
 
     GPIOB_PIN(0) = 0;
+
     udelay(1);
 
     if (GPIOC_PIN(1) & 1<<1)
@@ -114,6 +276,12 @@ int button_read_device(void)
     {
         hold_button_old = hold_button;
         backlight_hold_changed(hold_button);
+        /* mask scrollwheel irq so we don't need to check for
+         * the hold button in the isr */
+        if (hold_button)
+            GPIOA_IE &= ~SCROLLWHEEL_BITS;
+        else
+            GPIOA_IE |= SCROLLWHEEL_BITS;
     }
 #else
     (void)hold_button_old;
diff --git a/firmware/target/arm/as3525/sansa-fuzev2/button-target.h b/firmware/target/arm/as3525/sansa-fuzev2/button-target.h
index d7ef9623f9..c64c68f951 100644
--- a/firmware/target/arm/as3525/sansa-fuzev2/button-target.h
+++ b/firmware/target/arm/as3525/sansa-fuzev2/button-target.h
@@ -30,12 +30,6 @@
 void button_init_device(void);
 bool button_hold(void);
 int button_read_device(void);
-void get_scrollwheel(void);
- 
-#define WHEEL_REPEAT_INTERVAL   (HZ/5)
-#define WHEEL_COUNTER_DIV       4
-#define ACCEL_INCREMENT         2
-#define ACCEL_SHIFT             2
 /* Sandisk Sansa Fuze button codes */
 
 /* Main unit's buttons */