/* buttons.c
*
* Buttons driver for the Milkymist One board
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* COPYRIGHT (c) 2011 Sebastien Bourdeauducq
*/
#define RTEMS_STATUS_CHECKS_USE_PRINTK
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <rtems.h>
#include <rtems/status-checks.h>
#include <bsp.h>
#include <bsp/irq-generic.h>
#include <rtems/libio.h>
#include "../include/system_conf.h"
#include "milkymist_buttons.h"
#define DEVICE_NAME "/dev/buttons"
static rtems_id event_q;
static void send_byte(char b)
{
rtems_message_queue_send(event_q, &b, 1);
}
static rtems_isr interrupt_handler(rtems_vector_number n)
{
static unsigned int previous_keys;
unsigned int keys, pushed_keys, released_keys;
keys = MM_READ(MM_GPIO_IN) & (GPIO_BTN1|GPIO_BTN2|GPIO_BTN3);
pushed_keys = keys & ~previous_keys;
released_keys = previous_keys & ~keys;
previous_keys = keys;
if(pushed_keys & GPIO_BTN1)
send_byte('A');
if(pushed_keys & GPIO_BTN2)
send_byte('B');
if(pushed_keys & GPIO_BTN3)
send_byte('C');
if(released_keys & GPIO_BTN1)
send_byte('a');
if(released_keys & GPIO_BTN2)
send_byte('b');
if(released_keys & GPIO_BTN3)
send_byte('c');
lm32_interrupt_ack(1 << MM_IRQ_GPIO);
}
rtems_device_driver buttons_initialize(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_status_code sc;
rtems_isr_entry dummy;
sc = rtems_io_register_name(DEVICE_NAME, major, 0);
RTEMS_CHECK_SC(sc, "create buttons device");
sc = rtems_message_queue_create(
rtems_build_name('B', 'T', 'N', 'Q'),
24,
1,
0,
&event_q
);
RTEMS_CHECK_SC(sc, "create buttons event queue");
rtems_interrupt_catch(interrupt_handler, MM_IRQ_GPIO, &dummy);
bsp_interrupt_vector_enable(MM_IRQ_GPIO);
MM_WRITE(MM_GPIO_INTEN, GPIO_BTN1|GPIO_BTN2|GPIO_BTN3);
return RTEMS_SUCCESSFUL;
}
rtems_device_driver buttons_open(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
uint32_t count;
rtems_message_queue_flush(event_q, &count);
return RTEMS_SUCCESSFUL;
}
rtems_device_driver buttons_read(
rtems_device_major_number major,
rtems_device_minor_number minor,
void *arg
)
{
rtems_libio_rw_args_t *rw_args = (rtems_libio_rw_args_t *)arg;
rtems_status_code sc;
if(rw_args->count < 1) {
rw_args->bytes_moved = 0;
return RTEMS_UNSATISFIED;
}
sc = rtems_message_queue_receive(
event_q,
rw_args->buffer,
(size_t *)&rw_args->bytes_moved,
RTEMS_WAIT,
RTEMS_NO_TIMEOUT
);
if(sc == RTEMS_SUCCESSFUL)
return RTEMS_SUCCESSFUL;
else {
rw_args->bytes_moved = 0;
return RTEMS_UNSATISFIED;
}
}