mirror of
https://github.com/AsahiLinux/u-boot
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e101550a9a
Implements the tstc() interface for the serial driver. Multiplexing the console between the serial port and a keyboard uses a polling method of checking if characters are available; this means that the serial console must be non-blocking when attempting to read characters. Signed-off-by: Taylor Hutt <thutt@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org>
118 lines
2.8 KiB
C
118 lines
2.8 KiB
C
/*
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* Copyright (c) 2011 The Chromium OS Authors.
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/*
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* This provide a test serial port. It provides an emulated serial port where
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* a test program and read out the serial output and inject serial input for
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* U-Boot.
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*/
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#include <common.h>
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#include <os.h>
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#include <serial.h>
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#include <linux/compiler.h>
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/*
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*
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* serial_buf: A buffer that holds keyboard characters for the
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* Sandbox U-boot.
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*
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* invariants:
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* serial_buf_write == serial_buf_read -> empty buffer
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* (serial_buf_write + 1) % 16 == serial_buf_read -> full buffer
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*/
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static char serial_buf[16];
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static unsigned int serial_buf_write;
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static unsigned int serial_buf_read;
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static int sandbox_serial_init(void)
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{
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os_tty_raw(0);
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return 0;
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}
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static void sandbox_serial_setbrg(void)
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{
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}
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static void sandbox_serial_putc(const char ch)
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{
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os_write(1, &ch, 1);
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}
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static void sandbox_serial_puts(const char *str)
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{
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os_write(1, str, strlen(str));
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}
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static unsigned int increment_buffer_index(unsigned int index)
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{
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return (index + 1) % ARRAY_SIZE(serial_buf);
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}
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static int sandbox_serial_tstc(void)
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{
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const unsigned int next_index =
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increment_buffer_index(serial_buf_write);
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ssize_t count;
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os_usleep(100);
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if (next_index == serial_buf_read)
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return 1; /* buffer full */
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count = os_read_no_block(0, &serial_buf[serial_buf_write], 1);
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if (count == 1)
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serial_buf_write = next_index;
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return serial_buf_write != serial_buf_read;
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}
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static int sandbox_serial_getc(void)
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{
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int result;
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while (!sandbox_serial_tstc())
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; /* buffer empty */
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result = serial_buf[serial_buf_read];
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serial_buf_read = increment_buffer_index(serial_buf_read);
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return result;
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}
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static struct serial_device sandbox_serial_drv = {
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.name = "sandbox_serial",
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.start = sandbox_serial_init,
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.stop = NULL,
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.setbrg = sandbox_serial_setbrg,
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.putc = sandbox_serial_putc,
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.puts = sandbox_serial_puts,
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.getc = sandbox_serial_getc,
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.tstc = sandbox_serial_tstc,
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};
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void sandbox_serial_initialize(void)
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{
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serial_register(&sandbox_serial_drv);
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}
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__weak struct serial_device *default_serial_console(void)
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{
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return &sandbox_serial_drv;
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}
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