u-boot/cpu/leon2/serial.c
Daniel Hellstrom b330990c2f SPARC: Added support for SPARC LEON2 SOC Processor.
Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
2008-04-08 07:58:32 +00:00

165 lines
4.1 KiB
C

/* GRLIB APBUART Serial controller driver
*
* (C) Copyright 2008
* Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
*/
#include <common.h>
#include <asm/processor.h>
#include <asm/leon.h>
DECLARE_GLOBAL_DATA_PTR;
/* Force cache miss each time a serial controller reg is read */
#define CACHE_BYPASS 1
#ifdef CACHE_BYPASS
#define READ_BYTE(var) SPARC_NOCACHE_READ_BYTE((unsigned int)&(var))
#define READ_HWORD(var) SPARC_NOCACHE_READ_HWORD((unsigned int)&(var))
#define READ_WORD(var) SPARC_NOCACHE_READ((unsigned int)&(var))
#define READ_DWORD(var) SPARC_NOCACHE_READ_DWORD((unsigned int)&(var))
#endif
int serial_init(void)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
LEON2_Uart_regs *regs;
unsigned int tmp;
/* Init LEON2 UART
*
* Set scaler / baud rate
*
* Receiver & transmitter enable
*/
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif
regs->UART_Scaler = CFG_LEON2_UART1_SCALER;
/* Let bit 11 be unchanged (debug bit for GRMON) */
tmp = READ_WORD(regs->UART_Control);
regs->UART_Control = ((tmp & LEON2_UART_CTRL_DBG) |
(LEON2_UART1_LOOPBACK_ENABLE << 7) |
(LEON2_UART1_FLOWCTRL_ENABLE << 6) |
(LEON2_UART1_PARITY_ENABLE << 5) |
(LEON2_UART1_ODDPAR_ENABLE << 4) |
LEON2_UART_CTRL_RE | LEON2_UART_CTRL_TE);
return 0;
}
void serial_putc(const char c)
{
if (c == '\n')
serial_putc_raw('\r');
serial_putc_raw(c);
}
void serial_putc_raw(const char c)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
LEON2_Uart_regs *regs;
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif
/* Wait for last character to go. */
while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_THE)) ;
/* Send data */
regs->UART_Channel = c;
#ifdef LEON_DEBUG
/* Wait for data to be sent */
while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_TSE)) ;
#endif
}
void serial_puts(const char *s)
{
while (*s) {
serial_putc(*s++);
}
}
int serial_getc(void)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
LEON2_Uart_regs *regs;
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif
/* Wait for a character to arrive. */
while (!(READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR)) ;
/* read data */
return READ_WORD(regs->UART_Channel);
}
int serial_tstc(void)
{
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
LEON2_Uart_regs *regs;
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif
return (READ_WORD(regs->UART_Status) & LEON2_UART_STAT_DR);
}
/* set baud rate for uart */
void serial_setbrg(void)
{
/* update baud rate settings, read it from gd->baudrate */
unsigned int scaler;
LEON2_regs *leon2 = (LEON2_regs *) LEON2_PREGS;
LEON2_Uart_regs *regs;
#if LEON2_CONSOLE_SELECT == LEON_CONSOLE_UART1
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_1;
#else
regs = (LEON2_Uart_regs *) & leon2->UART_Channel_2;
#endif
if (gd->baudrate > 0) {
scaler =
(((CONFIG_SYS_CLK_FREQ * 10) / (gd->baudrate * 8)) -
5) / 10;
regs->UART_Scaler = scaler;
}
}