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