altos: Add quadrature driver

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/drivers/ao_quadrature.c b/src/drivers/ao_quadrature.c
new file mode 100644 (file)
index 0000000..1cde32e
--- /dev/null
+++ b/src/drivers/ao_quadrature.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_quadrature.h>
+#include <ao_exti.h>
+
+__xdata int32_t ao_quadrature_count;
+
+static uint8_t wait_clear;
+
+static void
+ao_quadrature_isr(void)
+{
+       if (wait_clear) {
+               wait_clear = 0;
+               ao_exti_set_mode(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_EXTI_MODE_RISING);
+       } else {
+               wait_clear = 1;
+               ao_exti_set_mode(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_EXTI_MODE_FALLING);
+               if (ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_QUADRATURE_B_PIN))
+                       ao_quadrature_count++;
+               else
+                       ao_quadrature_count--;
+               ao_wakeup(&ao_quadrature_count);
+       }
+}
+
+int32_t
+ao_quadrature_poll(void)
+{
+       int32_t ret;
+       ao_arch_critical(ret = ao_quadrature_count;);
+       return ret;
+}
+
+int32_t
+ao_quadrature_wait(void)
+{
+       ao_sleep(&ao_quadrature_count);
+       return ao_quadrature_poll();
+}
+
+static void
+ao_quadrature_test(void)
+{
+#if 0
+       for (;;) {
+               int32_t c;
+               printf ("waiting...\n");
+               flush();
+               c = ao_quadrature_wait();
+               printf ("new count %d\n", c);
+               if (ao_stdin_ready)
+                       break;
+       }
+#endif
+       uint8_t a, old_a, b, old_b;
+
+       old_a = 2; old_b = 2;
+       for (;;) {
+               a = ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_A, AO_QUADRATURE_A_PIN);
+               b = ao_gpio_get(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_QUADRATURE_B_PIN);
+               if (a != old_a || b != old_b) {
+                       printf ("A %d B %d\n", a, b);
+                       flush();
+                       ao_yield();
+                       old_a = a;
+                       old_b = b;
+               }
+               if (ao_stdin_ready)
+                       break;
+       }
+               
+}
+
+static const struct ao_cmds ao_quadrature_cmds[] = {
+       { ao_quadrature_test,   "q\0Test quadrature" },
+       { 0, NULL }
+};
+
+void
+ao_quadrature_init(void)
+{
+       ao_quadrature_count = 0;
+
+       ao_enable_port(AO_QUADRATURE_PORT);
+       ao_exti_setup(AO_QUADRATURE_PORT, AO_QUADRATURE_A,
+                     AO_EXTI_MODE_PULL_UP|AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_MED,
+                     ao_quadrature_isr);
+       ao_exti_enable(AO_QUADRATURE_PORT, AO_QUADRATURE_A);
+       ao_enable_input(AO_QUADRATURE_PORT, AO_QUADRATURE_B, AO_EXTI_MODE_PULL_UP);
+       ao_cmd_register(&ao_quadrature_cmds[0]);
+}

diff --git a/src/drivers/ao_quadrature.h b/src/drivers/ao_quadrature.h
new file mode 100644 (file)
index 0000000..7e1048b
--- /dev/null
+++ b/src/drivers/ao_quadrature.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef _AO_QUADRATURE_H_
+#define _AO_QUADRATURE_H_
+
+int32_t
+ao_quadrature_wait(void);
+
+int32_t
+ao_quadrature_poll(void);
+
+void
+ao_quadrature_init(void);
+
+#endif /* _AO_QUADRATURE_H_ */