blob: 0b7e541f06fa952ca115ac66eed4262b792380ee [file] [log] [blame] [edit]
/*
* Copyright (c) 2015-2021, Xilinx Inc.
* Written by Michal Simek.
*
* SPDX-License-Identifier: BSD-3-Clause
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 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.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <errno.h>
#include <stddef.h>
#include <arch_helpers.h>
#include <drivers/arm/dcc.h>
#include <drivers/console.h>
#include <drivers/delay_timer.h>
#include <lib/mmio.h>
/* DCC Status Bits */
#define DCC_STATUS_RX BIT(30)
#define DCC_STATUS_TX BIT(29)
#define TIMEOUT_COUNT_US U(0x10624)
struct dcc_console {
struct console console;
};
static inline uint32_t __dcc_getstatus(void)
{
return read_mdccsr_el0();
}
static inline char __dcc_getchar(void)
{
char c;
c = read_dbgdtrrx_el0();
return c;
}
static inline void __dcc_putchar(char c)
{
/*
* The typecast is to make absolutely certain that 'c' is
* zero-extended.
*/
write_dbgdtrtx_el0((unsigned char)c);
}
static int32_t dcc_status_timeout(uint32_t mask)
{
const unsigned int timeout_count = TIMEOUT_COUNT_US;
uint64_t timeout;
unsigned int status;
timeout = timeout_init_us(timeout_count);
do {
status = (__dcc_getstatus() & mask);
if (timeout_elapsed(timeout)) {
return -ETIMEDOUT;
}
} while ((status != 0U));
return 0;
}
static int32_t dcc_console_putc(int32_t ch, struct console *console)
{
unsigned int status;
status = dcc_status_timeout(DCC_STATUS_TX);
if (status != 0U) {
return status;
}
__dcc_putchar(ch);
return ch;
}
static int32_t dcc_console_getc(struct console *console)
{
unsigned int status;
status = dcc_status_timeout(DCC_STATUS_RX);
if (status != 0U) {
return status;
}
return __dcc_getchar();
}
int32_t dcc_console_init(unsigned long base_addr, uint32_t uart_clk,
uint32_t baud_rate)
{
return 0; /* No init needed */
}
/**
* dcc_console_flush() - Function to force a write of all buffered data
* that hasn't been output.
* @console Console struct
*
*/
static void dcc_console_flush(struct console *console)
{
unsigned int status;
status = dcc_status_timeout(DCC_STATUS_TX);
if (status != 0U) {
return;
}
}
static struct dcc_console dcc_console = {
.console = {
.flags = CONSOLE_FLAG_BOOT |
CONSOLE_FLAG_RUNTIME,
.putc = dcc_console_putc,
.getc = dcc_console_getc,
.flush = dcc_console_flush,
},
};
int console_dcc_register(void)
{
return console_register(&dcc_console.console);
}