/*
* Copyright (c) 2015 University of York.
* Hesham Almatary <hesham@alumni.york.ac.uk>
*
* Copyright (c) 2013, The Regents of the University of California (Regents).
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <dev/serial/htif.h>
#include <assert.h>
/* Most of the code below is copied from riscv-pk project */
# define TOHOST_CMD(dev, cmd, payload) \
(((uint64_t)(dev) << 56) | ((uint64_t)(cmd) << 48) | (uint64_t)(payload))
#define FROMHOST_DEV(fromhost_value) ((uint64_t)(fromhost_value) >> 56)
#define FROMHOST_CMD(fromhost_value) ((uint64_t)(fromhost_value) << 8 >> 56)
#define FROMHOST_DATA(fromhost_value) ((uint64_t)(fromhost_value) << 16 >> 16)
volatile uint64_t tohost __attribute__((section(".htif")));
volatile uint64_t fromhost __attribute__((section(".htif")));
volatile uint64_t riscv_fill_up_htif_section[510] __attribute__((section(".htif")));
volatile int htif_console_buf;
static void __check_fromhost(void)
{
uint64_t fh = fromhost;
if (!fh) {
return;
}
fromhost = 0;
// this should be from the console
assert(FROMHOST_DEV(fh) == 1);
switch (FROMHOST_CMD(fh)) {
case 0:
htif_console_buf = 1 + (uint8_t)FROMHOST_DATA(fh);
break;
case 1:
break;
default:
assert(0);
}
}
static void __set_tohost(uintptr_t dev, uintptr_t cmd, uintptr_t data)
{
while (tohost) {
__check_fromhost();
}
tohost = TOHOST_CMD(dev, cmd, data);
}
int htif_console_poll_char(rtems_termios_device_context *base)
{
__check_fromhost();
int ch = htif_console_buf;
if (ch >= 0) {
htif_console_buf = -1;
__set_tohost(1, 0, 0);
}
return ch - 1;
}
void htif_console_write_polled(
rtems_termios_device_context *base,
const char *buf,
size_t len
)
{
size_t i;
for (i = 0; i < len; ++i) {
__set_tohost(1, 1, buf[i]);
}
}
void htif_poweroff(void)
{
while (1) {
fromhost = 0;
tohost = 1;
}
}
void htif_console_context_init(
rtems_termios_device_context *base,
int device_tree_node
)
{
rtems_termios_device_context_initialize(base, "HTIF");
}
static bool htif_console_first_open(
struct rtems_termios_tty *tty,
rtems_termios_device_context *base,
struct termios *term,
rtems_libio_open_close_args_t *args
)
{
return true;
}
const rtems_termios_device_handler htif_console_handler = {
.first_open = htif_console_first_open,
.write = htif_console_write_polled,
.poll_read = htif_console_poll_char,
.mode = TERMIOS_POLLED
};