diff options
Diffstat (limited to 'src/drivers/ao_74hc165.c')
| -rw-r--r-- | src/drivers/ao_74hc165.c | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/drivers/ao_74hc165.c b/src/drivers/ao_74hc165.c new file mode 100644 index 00000000..143f4e3f --- /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_spi_get(AO_74HC165_SPI_BUS); + ao_spi_set_speed(AO_74HC165_SPI_BUS, AO_SPI_SPEED_FAST); + AO_74HC165_CS = 1; + ao_spi_recv(&state, 1, AO_74HC165_SPI_BUS); + AO_74HC165_CS = 0; + ao_spi_put(AO_74HC165_SPI_BUS); + 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]); +} |