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   1 /*
   2  * Copyright © 2012 Keith Packard <keithp@keithp.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; version 2 of the License.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  16  */
  17
  18 #include <ao.h>
  19 #include <ao_quadrature.h>
  20 #include <ao_exti.h>
  21 #include <ao_fast_timer.h>
  22 #include <ao_event.h>
  23
  24 __xdata int32_t ao_quadrature_count[AO_QUADRATURE_COUNT];
  25 static uint8_t  ao_quadrature_state[AO_QUADRATURE_COUNT];
  26
  27 #define port(q) AO_QUADRATURE_ ## q ## _PORT
  28 #define bita(q) AO_QUADRATURE_ ## q ## _A
  29 #define bitb(q) AO_QUADRATURE_ ## q ## _B
  30 #define pina(q) AO_QUADRATURE_ ## q ## _A ## _PIN
  31 #define pinb(q) AO_QUADRATURE_ ## q ## _B ## _PIN
  32 #define isr(q)  ao_quadrature_isr_ ## q
  33
  34 static inline uint16_t
  35 ao_quadrature_read(struct stm_gpio *gpio, uint8_t pin_a, uint8_t pin_b) {
  36         uint16_t        v = stm_gpio_get_all(gpio);
  37
  38         return ~((((v >> pin_a) & 1) | (((v >> pin_b) & 1) << 1))) & 3;
  39 }
  40
  41 #define _ao_quadrature_get(q)   ao_quadrature_read(port(q), bita(q), bitb(q))
  42
  43 static void
  44 _ao_quadrature_queue(uint8_t q, int8_t step)
  45 {
  46         ao_quadrature_count[q] += step;
  47 #if AO_EVENT
  48         ao_event_put_isr(AO_EVENT_QUADRATURE, q, step);
  49 #endif
  50         ao_wakeup(&ao_quadrature_count[q]);
  51 }
  52
  53
  54 static void
  55 _ao_quadrature_set(uint8_t q, uint8_t new) {
  56         uint8_t old = ao_quadrature_state[q];
  57
  58         if (old != new && new == 0) {
  59                 if (old & 2)
  60                         _ao_quadrature_queue(q, 1);
  61                 else if (old & 1)
  62                         _ao_quadrature_queue(q, -1);
  63         }
  64         ao_quadrature_state[q] = new;
  65 }
  66
  67 static void
  68 ao_quadrature_isr(void)
  69 {
  70 #if AO_QUADRATURE_COUNT > 0
  71         _ao_quadrature_set(0, _ao_quadrature_get(0));
  72 #endif
  73 #if AO_QUADRATURE_COUNT > 1
  74         _ao_quadrature_set(1, _ao_quadrature_get(1));
  75 #endif
  76 }
  77
  78 int32_t
  79 ao_quadrature_poll(uint8_t q)
  80 {
  81         int32_t ret;
  82         ao_arch_critical(ret = ao_quadrature_count[q];);
  83         return ret;
  84 }
  85
  86 int32_t
  87 ao_quadrature_wait(uint8_t q)
  88 {
  89         ao_sleep(&ao_quadrature_count[q]);
  90         return ao_quadrature_poll(q);
  91 }
  92
  93 static void
  94 ao_quadrature_test(void)
  95 {
  96         uint8_t q;
  97         int32_t c;
  98         uint8_t s;
  99
 100         ao_cmd_decimal();
 101         q = ao_cmd_lex_i;
 102         if (q >= AO_QUADRATURE_COUNT) {
 103                 ao_cmd_status = ao_cmd_syntax_error;
 104                 return;
 105         }
 106
 107         c = -10000;
 108         s = 0;
 109         while (ao_quadrature_count[q] != 10) {
 110                 if (ao_quadrature_count[q] != c ||
 111                     ao_quadrature_state[q] != s) {
 112                         c = ao_quadrature_count[q];
 113                         s = ao_quadrature_state[q];
 114                         printf ("count %3d state %2x\n", c, s);
 115                         flush();
 116                 }
 117         }
 118 #if 0
 119         for (;;) {
 120                 int32_t c;
 121                 flush();
 122                 c = ao_quadrature_wait(q);
 123                 printf ("new count %6d\n", c);
 124                 if (c == 100)
 125                         break;
 126         }
 127 #endif
 128 }
 129
 130 static const struct ao_cmds ao_quadrature_cmds[] = {
 131         { ao_quadrature_test,   "q <unit>\0Test quadrature" },
 132         { 0, NULL }
 133 };
 134
 135 #define init(q) do {                                    \
 136                 ao_enable_input(port(q), bita(q), 0);   \
 137                 ao_enable_input(port(q), bitb(q), 0);   \
 138         } while (0)
 139
 140 void
 141 ao_quadrature_init(void)
 142 {
 143 #if AO_QUADRATURE_COUNT > 0
 144         init(0);
 145 #endif
 146 #if AO_QUADRATURE_COUNT > 1
 147         init(1);
 148 #endif
 149         ao_fast_timer_init();
 150         ao_fast_timer_on(ao_quadrature_isr);
 151         ao_cmd_register(&ao_quadrature_cmds[0]);
 152 }