android_kernel_xiaomi_sm8350/arch/ppc/boot/simple/uartlite_tty.c
Grant Likely bedfc8a040 [POWERPC] Uartlite: Flush RX fifo in bootwrapper
Flush the uartlite RX fifo so that characters typed before entry into
the zImage wrapper do not muck up the kernel command line.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2007-10-03 07:23:16 -05:00

46 lines
1.1 KiB
C

/*
* Xilinx UARTLITE bootloader driver
*
* Copyright (c) 2007 Secret Lab Technologies Ltd.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/types.h>
#include <asm/serial.h>
#include <asm/io.h>
#include <platforms/4xx/xparameters/xparameters.h>
#define UARTLITE_BASEADDR ((void*)(XPAR_UARTLITE_0_BASEADDR))
unsigned long
serial_init(int chan, void *ignored)
{
/* Clear the RX FIFO */
out_be32(UARTLITE_BASEADDR + 0x0C, 0x2);
return 0;
}
void
serial_putc(unsigned long com_port, unsigned char c)
{
while ((in_be32(UARTLITE_BASEADDR + 0x8) & 0x08) != 0); /* spin */
out_be32(UARTLITE_BASEADDR + 0x4, c);
}
unsigned char
serial_getc(unsigned long com_port)
{
while ((in_be32(UARTLITE_BASEADDR + 0x8) & 0x01) == 0); /* spin */
return in_be32(UARTLITE_BASEADDR);
}
int
serial_tstc(unsigned long com_port)
{
return ((in_be32(UARTLITE_BASEADDR + 0x8) & 0x01) != 0);
}