101 строка
2.9 KiB
C
101 строка
2.9 KiB
C
/*
|
|
* The platform specific code for virtex devices since a boot loader is not
|
|
* always used.
|
|
*
|
|
* (C) Copyright 2008 Xilinx, Inc.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published
|
|
* by the Free Software Foundation.
|
|
*/
|
|
|
|
#include "ops.h"
|
|
#include "io.h"
|
|
#include "stdio.h"
|
|
|
|
#define UART_DLL 0 /* Out: Divisor Latch Low */
|
|
#define UART_DLM 1 /* Out: Divisor Latch High */
|
|
#define UART_FCR 2 /* Out: FIFO Control Register */
|
|
#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
|
|
#define UART_FCR_CLEAR_XMIT 0x04 /* Clear the XMIT FIFO */
|
|
#define UART_LCR 3 /* Out: Line Control Register */
|
|
#define UART_MCR 4 /* Out: Modem Control Register */
|
|
#define UART_MCR_RTS 0x02 /* RTS complement */
|
|
#define UART_MCR_DTR 0x01 /* DTR complement */
|
|
#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
|
|
#define UART_LCR_WLEN8 0x03 /* Wordlength: 8 bits */
|
|
|
|
static int virtex_ns16550_console_init(void *devp)
|
|
{
|
|
unsigned char *reg_base;
|
|
u32 reg_shift, reg_offset, clk, spd;
|
|
u16 divisor;
|
|
int n;
|
|
|
|
if (dt_get_virtual_reg(devp, (void **)®_base, 1) < 1)
|
|
return -1;
|
|
|
|
n = getprop(devp, "reg-offset", ®_offset, sizeof(reg_offset));
|
|
if (n == sizeof(reg_offset))
|
|
reg_base += reg_offset;
|
|
|
|
n = getprop(devp, "reg-shift", ®_shift, sizeof(reg_shift));
|
|
if (n != sizeof(reg_shift))
|
|
reg_shift = 0;
|
|
|
|
n = getprop(devp, "current-speed", (void *)&spd, sizeof(spd));
|
|
if (n != sizeof(spd))
|
|
spd = 9600;
|
|
|
|
/* should there be a default clock rate?*/
|
|
n = getprop(devp, "clock-frequency", (void *)&clk, sizeof(clk));
|
|
if (n != sizeof(clk))
|
|
return -1;
|
|
|
|
divisor = clk / (16 * spd);
|
|
|
|
/* Access baud rate */
|
|
out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_DLAB);
|
|
|
|
/* Baud rate based on input clock */
|
|
out_8(reg_base + (UART_DLL << reg_shift), divisor & 0xFF);
|
|
out_8(reg_base + (UART_DLM << reg_shift), divisor >> 8);
|
|
|
|
/* 8 data, 1 stop, no parity */
|
|
out_8(reg_base + (UART_LCR << reg_shift), UART_LCR_WLEN8);
|
|
|
|
/* RTS/DTR */
|
|
out_8(reg_base + (UART_MCR << reg_shift), UART_MCR_RTS | UART_MCR_DTR);
|
|
|
|
/* Clear transmitter and receiver */
|
|
out_8(reg_base + (UART_FCR << reg_shift),
|
|
UART_FCR_CLEAR_XMIT | UART_FCR_CLEAR_RCVR);
|
|
return 0;
|
|
}
|
|
|
|
/* For virtex, the kernel may be loaded without using a bootloader and if so
|
|
some UARTs need more setup than is provided in the normal console init
|
|
*/
|
|
int platform_specific_init(void)
|
|
{
|
|
void *devp;
|
|
char devtype[MAX_PROP_LEN];
|
|
char path[MAX_PATH_LEN];
|
|
|
|
devp = finddevice("/chosen");
|
|
if (devp == NULL)
|
|
return -1;
|
|
|
|
if (getprop(devp, "linux,stdout-path", path, MAX_PATH_LEN) > 0) {
|
|
devp = finddevice(path);
|
|
if (devp == NULL)
|
|
return -1;
|
|
|
|
if ((getprop(devp, "device_type", devtype, sizeof(devtype)) > 0)
|
|
&& !strcmp(devtype, "serial")
|
|
&& (dt_is_compatible(devp, "ns16550")))
|
|
virtex_ns16550_console_init(devp);
|
|
}
|
|
return 0;
|
|
}
|