coreboot-kgpe-d16/src/drivers/uart/util.c
Patrick Georgi 6b5bc77c9b treewide: Remove "this file is part of" lines
Stefan thinks they don't add value.

Command used:
sed -i -e '/file is part of /d' $(git grep "file is part of " |egrep ":( */\*.*\*/\$|#|;#|-- | *\* )" | cut -d: -f1 |grep -v crossgcc |grep -v gcov | grep -v /elf.h |grep -v nvramtool)

The exceptions are for:
 - crossgcc (patch file)
 - gcov (imported from gcc)
 - elf.h (imported from GNU's libc)
 - nvramtool (more complicated header)

The removed lines are:
-       fmt.Fprintln(f, "/* This file is part of the coreboot project. */")
-# This file is part of a set of unofficial pre-commit hooks available
-/* This file is part of coreboot */
-# This file is part of msrtool.
-/* This file is part of msrtool. */
- * This file is part of ncurses, designed to be appended after curses.h.in
-/* This file is part of pgtblgen. */
- * This file is part of the coreboot project.
- /* This file is part of the coreboot project. */
-#  This file is part of the coreboot project.
-# This file is part of the coreboot project.
-## This file is part of the coreboot project.
--- This file is part of the coreboot project.
-/* This file is part of the coreboot project */
-/* This file is part of the coreboot project. */
-;## This file is part of the coreboot project.
-# This file is part of the coreboot project. It originated in the
- * This file is part of the coreinfo project.
-## This file is part of the coreinfo project.
- * This file is part of the depthcharge project.
-/* This file is part of the depthcharge project. */
-/* This file is part of the ectool project. */
- * This file is part of the GNU C Library.
- * This file is part of the libpayload project.
-## This file is part of the libpayload project.
-/* This file is part of the Linux kernel. */
-## This file is part of the superiotool project.
-/* This file is part of the superiotool project */
-/* This file is part of uio_usbdebug */

Change-Id: I82d872b3b337388c93d5f5bf704e9ee9e53ab3a9
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41194
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2020-05-11 17:11:40 +00:00

72 lines
2.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
#include <console/uart.h>
#include <types.h>
#include <timer.h>
/* Calculate divisor. Do not floor but round to nearest integer. */
unsigned int uart_baudrate_divisor(unsigned int baudrate,
unsigned int refclk, unsigned int oversample)
{
return (1 + (2 * refclk) / (baudrate * oversample)) / 2;
}
#if !CONFIG(UART_OVERRIDE_INPUT_CLOCK_DIVIDER)
unsigned int uart_input_clock_divider(void)
{
/* Specify the default oversample rate for the UART.
*
* UARTs oversample the receive data. The UART's input clock first
* enters the baud-rate divider to generate the oversample clock. Then
* the UART typically divides the result by 16. The asynchronous
* receive data is synchronized with the oversample clock and when a
* start bit is detected the UART delays half a bit time using the
* oversample clock. Samples are then taken to verify the start bit and
* if present, samples are taken for the rest of the frame.
*/
return 16;
}
#endif
#if !CONFIG(UART_OVERRIDE_REFCLK)
unsigned int uart_platform_refclk(void)
{
/* Specify the default input clock frequency for the UART.
*
* The older UART's used an input clock frequency of 1.8432 MHz which
* with the 16x oversampling provided the maximum baud-rate of 115200.
* Specify this as maximum baud-rate multiplied by oversample so that
* it is obvious that the maximum baud rate is 115200 when divided by
* oversample clock. Also note that crystal on the board does not
* change when software selects another input clock divider.
*/
return 115200 * 16;
}
#endif
/* Helper function to allow bitbanging an 8n1 UART. */
void uart_bitbang_tx_byte(unsigned char data, void (*set_tx)(int line_state))
{
const int baud_rate = get_uart_baudrate();
int i;
struct stopwatch sw;
stopwatch_init(&sw);
/* Send start bit */
set_tx(0);
while (stopwatch_duration_usecs(&sw) < MHz / baud_rate)
stopwatch_tick(&sw);
/* 'i' counts the total bits sent at the end of the loop */
for (i = 2; i < 10; i++) {
set_tx(data & 1);
data >>= 1;
while (stopwatch_duration_usecs(&sw) < i * MHz / baud_rate)
stopwatch_tick(&sw);
}
/* Send stop bit */
set_tx(1);
while (stopwatch_duration_usecs(&sw) < i * MHz / baud_rate)
stopwatch_tick(&sw);
}