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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
  22 __xdata int32_t ao_quadrature_count;
  23
  24 static uint8_t  wait_clear;
  25
  26 static void
  27 ao_quadrature_isr(void)
  28 {
  29         if (wait_clear) {
  30                 wait_clear = 0;
  31                 ao_exti_set_mode(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_EXTI_MODE_RISING);
  32         } else {
  33                 wait_clear = 1;
  34                 ao_exti_set_mode(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_EXTI_MODE_FALLING);
  35                 if (ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_QUADRATURE_B_PIN))
  36                         ao_quadrature_count++;
  37                 else
  38                         ao_quadrature_count--;
  39                 ao_wakeup(&ao_quadrature_count);
  40         }
  41 }
  42
  43 int32_t
  44 ao_quadrature_poll(void)
  45 {
  46         int32_t ret;
  47         ao_arch_critical(ret = ao_quadrature_count;);
  48         return ret;
  49 }
  50
  51 int32_t
  52 ao_quadrature_wait(void)
  53 {
  54         ao_sleep(&ao_quadrature_count);
  55         return ao_quadrature_poll();
  56 }
  57
  58 static void
  59 ao_quadrature_test(void)
  60 {
  61 #if 0
  62         for (;;) {
  63                 int32_t c;
  64                 printf ("waiting...\n");
  65                 flush();
  66                 c = ao_quadrature_wait();
  67                 printf ("new count %d\n", c);
  68                 if (ao_stdin_ready)
  69                         break;
  70         }
  71 #endif
  72         uint8_t a, old_a, b, old_b;
  73
  74         old_a = 2; old_b = 2;
  75         for (;;) {
  76                 a = ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_QUADRATURE_A_PIN);
  77                 b = ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_QUADRATURE_B_PIN);
  78                 if (a != old_a || b != old_b) {
  79                         printf ("A %d B %d\n", a, b);
  80                         flush();
  81                         ao_yield();
  82                         old_a = a;
  83                         old_b = b;
  84                 }
  85                 if (ao_stdin_ready)
  86                         break;
  87         }
  88
  89 }
  90
  91 static const struct ao_cmds ao_quadrature_cmds[] = {
  92         { ao_quadrature_test,   "q\0Test quadrature" },
  93         { 0, NULL }
  94 };
  95
  96 void
  97 ao_quadrature_init(void)
  98 {
  99         ao_quadrature_count = 0;
 100
 101         ao_enable_port(AO_QUADRATURE_PORT);
 102         ao_exti_setup(AO_QUADRATURE_PORT, AO_QUADRATURE_A,
 103                       AO_EXTI_MODE_PULL_UP|AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_MED,
 104                       ao_quadrature_isr);
 105         ao_exti_enable(AO_QUADRATURE_PORT, AO_QUADRATURE_A);
 106         ao_enable_input(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_EXTI_MODE_PULL_UP);
 107         ao_cmd_register(&ao_quadrature_cmds[0]);
 108 }