altos: Add telefire-v0.1

[fw/altos] / src / drivers / ao_74hc497.c

diff --git a/src/drivers/ao_74hc497.c b/src/drivers/ao_74hc497.c
new file mode 100644 (file)
index 0000000..93c544c
--- /dev/null
+++ b/src/drivers/ao_74hc497.c
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+/*
+ * 74HC597 driver.
+ * Reads a single byte from the shift register
+ */
+
+#include <ao.h>
+#include <ao_74hc497.h>
+
+uint8_t
+ao_74hc497_read(void)
+{
+       static __xdata state;
+       ao_spi_get_bit(AO_74HC497_CS_PORT, AO_74HC497_CS_PIN, AO_74HC497_CS, AO_74HC497_SPI_BUS, AO_SPI_SPEED_FAST);
+       ao_spi_send(&state, 1, AO_74HC497_SPI_BUS);
+       ao_spi_put_bit(AO_74HC497_CS_PORT, AO_74HC497_CS_PIN, AO_74HC497_CS, AO_74HC497_SPI_BUS);
+       return state;
+}
+
+void
+ao_74hc497_init(void)
+{
+       ao_enable_output(AO_74HC497_CS_PORT, AO_74HC497_CS_PIN, AO_74HC497_CS, 1);
+}