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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 #if AO_EVENT
  22 #include <ao_event.h>
  23 #define ao_quadrature_queue(q)  ao_event_put_isr(AO_EVENT_QUADRATURE, q, ao_quadrature_count[q])
  24 #else
  25 #define ao_quadrature_queue(q)
  26 #endif
  27
  28 __xdata int32_t ao_quadrature_count[AO_QUADRATURE_COUNT];
  29
  30 static uint8_t  ao_quadrature_state[AO_QUADRATURE_COUNT];
  31
  32 #define BIT(a,b)        ((a) | ((b) << 1))
  33 #define STATE(old_a, old_b, new_a, new_b)       (((BIT(old_a, old_b) << 2) | BIT(new_a, new_b)))
  34
  35 #define port(q) AO_QUADRATURE_ ## q ## _PORT
  36 #define bita(q) AO_QUADRATURE_ ## q ## _A
  37 #define bitb(q) AO_QUADRATURE_ ## q ## _B
  38
  39 #define ao_quadrature_update(q) do {                                    \
  40                 ao_quadrature_state[q] = ((ao_quadrature_state[q] & 3) << 2); \
  41                 ao_quadrature_state[q] |= ao_gpio_get(port(q), bita(q), 0); \
  42                 ao_quadrature_state[q] |= ao_gpio_get(port(q), bitb(q), 0) << 1; \
  43         } while (0)
  44
  45
  46 static void
  47 ao_quadrature_isr(void)
  48 {
  49         uint8_t q;
  50 #if AO_QUADRATURE_COUNT > 0
  51         ao_quadrature_update(0);
  52 #endif
  53 #if AO_QUADRATURE_COUNT > 1
  54         ao_quadrature_update(1);
  55 #endif
  56
  57         for (q = 0; q < AO_QUADRATURE_COUNT; q++) {
  58                 switch (ao_quadrature_state[q]) {
  59                 case STATE(0, 1, 0, 0):
  60                         ao_quadrature_count[q]++;
  61                         break;
  62                 case STATE(1, 0, 0, 0):
  63                         ao_quadrature_count[q]--;
  64                         break;
  65                 default:
  66                         continue;
  67                 }
  68                 ao_quadrature_queue(q);
  69                 ao_wakeup(&ao_quadrature_count[q]);
  70         }
  71 }
  72
  73 int32_t
  74 ao_quadrature_poll(uint8_t q)
  75 {
  76         int32_t ret;
  77         ao_arch_critical(ret = ao_quadrature_count[q];);
  78         return ret;
  79 }
  80
  81 int32_t
  82 ao_quadrature_wait(uint8_t q)
  83 {
  84         ao_sleep(&ao_quadrature_count[q]);
  85         return ao_quadrature_poll(q);
  86 }
  87
  88 static void
  89 ao_quadrature_test(void)
  90 {
  91         uint8_t q;
  92
  93         ao_cmd_decimal();
  94         q = ao_cmd_lex_i;
  95         for (;;) {
  96                 int32_t c;
  97                 flush();
  98                 c = ao_quadrature_wait(q);
  99                 printf ("new count %6d\n", c);
 100                 if (c == 100)
 101                         break;
 102         }
 103 }
 104
 105 static const struct ao_cmds ao_quadrature_cmds[] = {
 106         { ao_quadrature_test,   "q <unit>\0Test quadrature" },
 107         { 0, NULL }
 108 };
 109
 110 #define init(q) do {                                                    \
 111                 ao_enable_port(port(q));                                \
 112                                                                         \
 113                 ao_exti_setup(port(q), bita(q),                         \
 114                               AO_QUADRATURE_MODE|AO_EXTI_MODE_FALLING|AO_EXTI_MODE_RISING|AO_EXTI_PRIORITY_MED, \
 115                               ao_quadrature_isr);                       \
 116                 ao_exti_enable(port(q), bita(q));                       \
 117                                                                         \
 118                 ao_exti_setup(port(q), bitb(q),                         \
 119                               AO_QUADRATURE_MODE|AO_EXTI_MODE_FALLING|AO_EXTI_MODE_RISING|AO_EXTI_PRIORITY_MED, \
 120                               ao_quadrature_isr);                       \
 121                 ao_exti_enable(port(q), bitb(q));                       \
 122         } while (0)
 123
 124 void
 125 ao_quadrature_init(void)
 126 {
 127 #if AO_QUADRATURE_COUNT > 0
 128         init(0);
 129 #endif
 130 #if AO_QUADRATURE_COUNT > 1
 131         init(1);
 132 #endif
 133         ao_cmd_register(&ao_quadrature_cmds[0]);
 134 }