blob: 97e411a93063f2fa762a371ea90b97d25d354473 [file] [log] [blame]
/*
* Copyright (c) 2021 EPAM Systems
*
* SPDX-License-Identifier: Apache-2.0
*
* This driver implements input/output API for Xen domain through the
* Xen consoleio interface. This should be used only for Zephyr as initial
* domain (Dom0). For unprivileged domains regular ring buffer HVC driver
* should be used (uart_hvc_xen.c), this console will not be available.
*/
#include <zephyr/arch/arm64/hypercall.h>
#include <zephyr/xen/public/xen.h>
#include <zephyr/device.h>
#include <zephyr/drivers/uart.h>
#include <zephyr/init.h>
#include <zephyr/kernel.h>
#define DT_DRV_COMPAT xen_hvc_consoleio
static int xen_consoleio_poll_in(const struct device *dev,
unsigned char *c)
{
int ret = 0;
char temp;
ret = HYPERVISOR_console_io(CONSOLEIO_read, sizeof(temp), &temp);
if (!ret) {
/* Char was not received */
return -1;
}
*c = temp;
return 0;
}
static void xen_consoleio_poll_out(const struct device *dev,
unsigned char c)
{
(void) HYPERVISOR_console_io(CONSOLEIO_write, sizeof(c), &c);
}
static const struct uart_driver_api xen_consoleio_hvc_api = {
.poll_in = xen_consoleio_poll_in,
.poll_out = xen_consoleio_poll_out,
};
static int xen_consoleio_init(const struct device *dev)
{
/* Nothing to do, but still needed for device API */
return 0;
}
DEVICE_DT_INST_DEFINE(0, xen_consoleio_init, NULL, NULL,
NULL, PRE_KERNEL_1, CONFIG_XEN_HVC_INIT_PRIORITY,
&xen_consoleio_hvc_api);