altos: Add SPI-based companion board support

[fw/altos] / src / ao_companion.c

diff --git a/src/ao_companion.c b/src/ao_companion.c
new file mode 100644 (file)
index 0000000..8db3273
--- /dev/null
+++ b/src/ao_companion.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright © 2011 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"
+
+#define COMPANION_SELECT()     ao_spi_get_bit(COMPANION_CS)
+#define COMPANION_DESELECT()   ao_spi_put_bit(COMPANION_CS)
+
+static __xdata struct ao_companion_command     ao_companion_command;
+__xdata struct ao_companion_setup              ao_companion_setup;
+
+__xdata uint16_t       ao_companion_data[AO_COMPANION_MAX_CHANNELS];
+__pdata uint8_t                ao_companion_running;
+__xdata uint8_t                ao_companion_mutex;
+
+static void
+ao_companion_send_command(uint8_t command)
+{
+       ao_companion_command.command = command;
+       ao_companion_command.flight_state = ao_flight_state;
+       ao_companion_command.tick = ao_time();
+       ao_spi_send(&ao_companion_command, sizeof (ao_companion_command));
+}
+
+static uint8_t
+ao_companion_get_setup(void)
+{
+       COMPANION_SELECT();
+       ao_companion_send_command(AO_COMPANION_SETUP);
+       ao_spi_recv(&ao_companion_setup, sizeof (ao_companion_setup));
+       COMPANION_DESELECT();
+       if (ao_companion_setup.board_id != ~ao_companion_setup.board_id)
+               return 0;
+       return 1;
+}
+
+static void
+ao_companion_get_data(void)
+{
+       COMPANION_SELECT();
+       ao_companion_send_command(AO_COMPANION_FETCH);
+       ao_mutex_get(&ao_companion_mutex);
+       ao_spi_recv(&ao_companion_data, ao_companion_setup.channels * 2);
+       ao_mutex_put(&ao_companion_mutex);
+       COMPANION_DESELECT();
+}
+
+void
+ao_companion(void)
+{
+       if (!ao_companion_get_setup())
+               ao_exit();
+       ao_companion_running = 1;
+       for (;;) {
+               ao_delay(ao_companion_setup.update_period);
+               ao_companion_get_data();
+       }
+}
+
+void
+ao_companion_status(void) __reentrant
+{
+}
+
+__code struct ao_cmds ao_companion_cmds[] = {
+       { ao_companion_status,  "L\0Companion link status" },
+       { 0, NULL },
+};
+
+static __xdata struct ao_task ao_companion_task;
+
+void
+ao_companion_init(void)
+{
+       COMPANION_CS_PORT |= COMPANION_CS_MASK; /* raise all CS pins */
+       COMPANION_CS_DIR |= COMPANION_CS_MASK;  /* set CS pins as outputs */
+       COMPANION_CS_SEL &= ~COMPANION_CS_MASK; /* set CS pins as GPIO */
+
+       ao_cmd_register(&ao_companion_cmds[0]);
+
+       ao_add_task(&ao_companion_task, ao_companion, "companion");
+}