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Diffstat (limited to '')
| -rw-r--r-- | drivers/arm/dcc/dcc_console.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/arm/dcc/dcc_console.c b/drivers/arm/dcc/dcc_console.c new file mode 100644 index 0000000..19c3450 --- /dev/null +++ b/drivers/arm/dcc/dcc_console.c @@ -0,0 +1,159 @@ +/* + * 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(); +} + +#if ENABLE_CONSOLE_GETC +static inline char __dcc_getchar(void) +{ + char c; + + c = read_dbgdtrrx_el0(); + + return c; +} +#endif + +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; +} + +#if ENABLE_CONSOLE_GETC +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(); +} +#endif + +/** + * 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 | + CONSOLE_FLAG_CRASH, + .putc = dcc_console_putc, +#if ENABLE_CONSOLE_GETC + .getc = dcc_console_getc, +#endif + .flush = dcc_console_flush, + }, +}; + +int console_dcc_register(void) +{ + return console_register(&dcc_console.console); +} + +void console_dcc_unregister(void) +{ + dcc_console_flush(&dcc_console.console); + (void)console_unregister(&dcc_console.console); +} |