Switch from GPLv2 to GPLv2+

[fw/altos] / src / drivers / ao_quadrature.c

diff --git a/src/drivers/ao_quadrature.c b/src/drivers/ao_quadrature.c
index d07488d08d4f9307b661a0f690f9447dab4fec73..deecfb79422b9c2980507a0a00e9eb3344b64842 100644 (file)
--- a/src/drivers/ao_quadrature.c
+++ b/src/drivers/ao_quadrature.c
@@ -3,7 +3,8 @@
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -22,11 +23,14 @@
 #include <ao_event.h>
 
 __xdata int32_t ao_quadrature_count[AO_QUADRATURE_COUNT];
-static uint8_t ao_quadrature_state[AO_QUADRATURE_COUNT];
-static int8_t  ao_quadrature_raw[AO_QUADRATURE_COUNT];
+static uint8_t  ao_quadrature_state[AO_QUADRATURE_COUNT];
 
-#define BIT(a,b)       ((a) | ((b) << 1))
-#define STATE(old_a, old_b, new_a, new_b)      (((BIT(old_a, old_b) << 2) | BIT(new_a, new_b)))
+struct ao_debounce {
+       uint8_t state;
+       uint8_t count;
+};
+
+static struct ao_debounce ao_debounce_state[AO_QUADRATURE_COUNT][2];
 
 #define port(q)        AO_QUADRATURE_ ## q ## _PORT
 #define bita(q) AO_QUADRATURE_ ## q ## _A
@@ -35,14 +39,35 @@ static int8_t       ao_quadrature_raw[AO_QUADRATURE_COUNT];
 #define pinb(q) AO_QUADRATURE_ ## q ## _B ## _PIN
 #define isr(q)  ao_quadrature_isr_ ## q
 
-static inline uint16_t
-ao_quadrature_read(struct stm_gpio *gpio, uint8_t pin_a, uint8_t pin_b) {
-       uint16_t        v = stm_gpio_get_all(gpio);
+#define DEBOUNCE       10
 
-       return ~((((v >> pin_a) & 1) | (((v >> pin_b) & 1) << 1))) & 3;
+static uint8_t
+ao_debounce(uint8_t cur, struct ao_debounce *debounce)
+{
+       if (cur == debounce->state)
+               debounce->count = 0;
+       else {
+               if (++debounce->count == DEBOUNCE) {
+                       debounce->state = cur;
+                       debounce->count = 0;
+               }
+       }
+       return debounce->state;
 }
 
-#define _ao_quadrature_get(q)  ao_quadrature_read(port(q), bita(q), bitb(q))
+static uint16_t
+ao_quadrature_read(struct stm_gpio *gpio, uint8_t pin_a, uint8_t pin_b, struct ao_debounce debounce_state[2]) {
+       uint16_t        v = ~stm_gpio_get_all(gpio);
+       uint8_t         a = (v >> pin_a) & 1;
+       uint8_t         b = (v >> pin_b) & 1;
+
+       a = ao_debounce(a, &debounce_state[0]);
+       b = ao_debounce(b, &debounce_state[1]);
+
+       return a | (b << 1);
+}
+
+#define _ao_quadrature_get(q)  ao_quadrature_read(port(q), bita(q), bitb(q), ao_debounce_state[q])
 
 static void
 _ao_quadrature_queue(uint8_t q, int8_t step)
@@ -54,51 +79,28 @@ _ao_quadrature_queue(uint8_t q, int8_t step)
        ao_wakeup(&ao_quadrature_count[q]);
 }
 
-static const int8_t    step[16] = {
-       [STATE(0,0,0,0)] = 0,
-       [STATE(0,0,0,1)] = -1,
-       [STATE(0,0,1,0)] = 1,
-       [STATE(0,0,1,1)] = 0,
-       [STATE(0,1,0,0)] = 1,
-       [STATE(0,1,1,0)] = 0,
-       [STATE(0,1,1,1)] = -1,
-       [STATE(1,0,0,0)] = -1,
-       [STATE(1,0,0,1)] = 0,
-       [STATE(1,0,1,0)] = 0,
-       [STATE(1,0,1,1)] = 1,
-       [STATE(1,1,0,0)] = 0,
-       [STATE(1,1,0,1)] = 1,
-       [STATE(1,1,1,0)] = -1,
-       [STATE(1,1,1,1)] = 0
-};
-
 static void
-_ao_quadrature_set(uint8_t q, uint8_t value) {
-       uint8_t v;
-       
-       v = ao_quadrature_state[q] & 3;
-       value = value & 3;
-
-       if (v == value)
-               return;
-       
-       ao_quadrature_state[q] = (v << 2) | value;
+_ao_quadrature_set(uint8_t q, uint8_t new) {
+       uint8_t old = ao_quadrature_state[q];
 
-       ao_quadrature_raw[q] += step[ao_quadrature_state[q]];
-       if (value == 0) {
-               if (ao_quadrature_raw[q] == 4)
+       if (old != new && new == 0) {
+               if (old & 2)
                        _ao_quadrature_queue(q, 1);
-               else if (ao_quadrature_raw[q] == -4)
+               else if (old & 1)
                        _ao_quadrature_queue(q, -1);
-               ao_quadrature_raw[q] = 0;
        }
+       ao_quadrature_state[q] = new;
 }
 
 static void
 ao_quadrature_isr(void)
 {
+#if AO_QUADRATURE_COUNT > 0
        _ao_quadrature_set(0, _ao_quadrature_get(0));
+#endif
+#if AO_QUADRATURE_COUNT > 1
        _ao_quadrature_set(1, _ao_quadrature_get(1));
+#endif
 }
 
 int32_t
@@ -120,6 +122,8 @@ static void
 ao_quadrature_test(void)
 {
        uint8_t q;
+       int32_t c;
+       uint8_t s;
 
        ao_cmd_decimal();
        q = ao_cmd_lex_i;
@@ -127,10 +131,18 @@ ao_quadrature_test(void)
                ao_cmd_status = ao_cmd_syntax_error;
                return;
        }
-       printf ("count %d state %x raw %d\n",
-               ao_quadrature_count[q],
-               ao_quadrature_state[q],
-               ao_quadrature_raw[q]);
+
+       c = -10000;
+       s = 0;
+       while (ao_quadrature_count[q] != 10) {
+               if (ao_quadrature_count[q] != c ||
+                   ao_quadrature_state[q] != s) {
+                       c = ao_quadrature_count[q];
+                       s = ao_quadrature_state[q];
+                       printf ("count %3d state %2x\n", c, s);
+                       flush();
+               }
+       }
 #if 0
        for (;;) {
                int32_t c;