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/*
* AU1X00 UART support
*
* Hardcoded to UART 0 for now
* Speed and options also hardcoded to 115200 8N1
*
* Copyright (c) 2003 Thomas.Lange@corelatus.se
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <common.h>
#include <asm/au1x00.h>
#include <serial.h>
#include <linux/compiler.h>
/******************************************************************************
*
* serial_init - initialize a channel
*
* This routine initializes the number of data bits, parity
* and set the selected baud rate. Interrupts are disabled.
* Set the modem control signals if the option is selected.
*
* RETURNS: N/A
*/
static int au1x00_serial_init(void)
{
volatile u32 *uart_fifoctl = (volatile u32*)(UART0_ADDR+UART_FCR);
volatile u32 *uart_enable = (volatile u32*)(UART0_ADDR+UART_ENABLE);
/* Enable clocks first */
*uart_enable = UART_EN_CE;
/* Then release reset */
/* Must release reset before setting other regs */
*uart_enable = UART_EN_CE|UART_EN_E;
/* Activate fifos, reset tx and rx */
/* Set tx trigger level to 12 */
*uart_fifoctl = UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|
UART_FCR_CLEAR_XMIT|UART_FCR_T_TRIGGER_12;
serial_setbrg();
return 0;
}
static void au1x00_serial_setbrg(void)
{
volatile u32 *uart_clk = (volatile u32*)(UART0_ADDR+UART_CLK);
volatile u32 *uart_lcr = (volatile u32*)(UART0_ADDR+UART_LCR);
volatile u32 *sys_powerctrl = (u32 *)SYS_POWERCTRL;
int sd;
int divisorx2;
/* sd is system clock divisor */
/* see section 10.4.5 in au1550 datasheet */
sd = (*sys_powerctrl & 0x03) + 2;
/* calulate 2x baudrate and round */
divisorx2 = ((CONFIG_SYS_MIPS_TIMER_FREQ/(sd * 16 * CONFIG_BAUDRATE)));
if (divisorx2 & 0x01)
divisorx2 = divisorx2 + 1;
*uart_clk = divisorx2 / 2;
/* Set parity, stop bits and word length to 8N1 */
*uart_lcr = UART_LCR_WLEN8;
}
static void au1x00_serial_putc(const char c)
{
volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
volatile u32 *uart_tx = (volatile u32*)(UART0_ADDR+UART_TX);
if (c == '\n')
au1x00_serial_putc('\r');
/* Wait for fifo to shift out some bytes */
while((*uart_lsr&UART_LSR_THRE)==0);
*uart_tx = (u32)c;
}
static int au1x00_serial_getc(void)
{
volatile u32 *uart_rx = (volatile u32*)(UART0_ADDR+UART_RX);
char c;
while (!serial_tstc());
c = (*uart_rx&0xFF);
return c;
}
static int au1x00_serial_tstc(void)
{
volatile u32 *uart_lsr = (volatile u32*)(UART0_ADDR+UART_LSR);
if(*uart_lsr&UART_LSR_DR){
/* Data in rfifo */
return(1);
}
return 0;
}
static struct serial_device au1x00_serial_drv = {
.name = "au1x00_serial",
.start = au1x00_serial_init,
.stop = NULL,
.setbrg = au1x00_serial_setbrg,
.putc = au1x00_serial_putc,
.puts = default_serial_puts,
.getc = au1x00_serial_getc,
.tstc = au1x00_serial_tstc,
};
void au1x00_serial_initialize(void)
{
serial_register(&au1x00_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &au1x00_serial_drv;
}
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