altos: Add driver for 74hc165 shift register

Just reads one byte from the shift register using the SPI driver and returns it

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

2 files changed, 85 insertions, 0 deletions

diff --git a/src/drivers/ao_74hc165.c b/src/drivers/ao_74hc165.c
new file mode 100644
index 00000000..f24fce37
--- /dev/null
+++ b/src/drivers/ao_74hc165.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2013 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.
+ */
+
+/*
+ * 74HC165 driver.
+ * Reads a single byte from the shift register
+ */
+
+#include <ao.h>
+#include <ao_74hc165.h>
+
+uint8_t
+ao_74hc165_read(void)
+{
+	static __xdata state;
+	ao_mutex_get(&ao_spi_mutex);
+	ao_spi_set_speed(AO_SPI_SPEED_FAST);
+	AO_74HC165_CS = 1;
+	ao_spi_recv(&state, 1, AO_74HC165_SPI_BUS);
+	AO_74HC165_CS = 0;
+	ao_mutex_put(&ao_spi_mutex);
+	return state;
+}
+
+static void
+ao_74hc165_cmd(void)
+{
+	uint8_t	v;
+
+	v = ao_74hc165_read();
+	printf ("Switches: 0x%02x\n", v);
+}
+
+static const struct ao_cmds ao_74hc165_cmds[] = {
+	{ ao_74hc165_cmd, "L\0Show 74hc165" },
+	{ 0, NULL }
+};
+
+void
+ao_74hc165_init(void)
+{
+	ao_enable_output(AO_74HC165_CS_PORT, AO_74HC165_CS_PIN, AO_74HC165_CS, 0);
+	ao_cmd_register(&ao_74hc165_cmds[0]);
+}
diff --git a/src/drivers/ao_74hc165.h b/src/drivers/ao_74hc165.h
new file mode 100644
index 00000000..3ae51353
--- /dev/null
+++ b/src/drivers/ao_74hc165.h
@@ -0,0 +1,27 @@
+/*
+ * Copyright © 2013 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_74HC165_H_
+#define _AO_74HC165_H_
+
+uint8_t
+ao_74hc165_read(void);
+
+void
+ao_74hc165_init(void);
+
+#endif /* _AO_74HC165_H_ */