+/*
+ * 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]);
+}