u-boot/drivers/serial/mcfuart.c

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/*
* (C) Copyright 2004-2007 Freescale Semiconductor, Inc.
* TsiChung Liew, Tsi-Chung.Liew@freescale.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
*
*/
/*
* Minimal serial functions needed to use one of the uart ports
* as serial console interface.
*/
#include <common.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/immap.h>
#include <asm/uart.h>
DECLARE_GLOBAL_DATA_PTR;
extern void uart_port_conf(int port);
static int mcf_serial_init(void)
{
volatile uart_t *uart;
u32 counter;
uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
uart_port_conf(CONFIG_SYS_UART_PORT);
/* write to SICR: SIM2 = uart mode,dcd does not affect rx */
uart->ucr = UART_UCR_RESET_RX;
uart->ucr = UART_UCR_RESET_TX;
uart->ucr = UART_UCR_RESET_ERROR;
uart->ucr = UART_UCR_RESET_MR;
__asm__("nop");
uart->uimr = 0;
/* write to CSR: RX/TX baud rate from timers */
uart->ucsr = (UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK);
uart->umr = (UART_UMR_BC_8 | UART_UMR_PM_NONE);
uart->umr = UART_UMR_SB_STOP_BITS_1;
/* Setting up BaudRate */
counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
counter = counter / gd->baudrate;
/* write to CTUR: divide counter upper byte */
uart->ubg1 = (u8) ((counter & 0xff00) >> 8);
/* write to CTLR: divide counter lower byte */
uart->ubg2 = (u8) (counter & 0x00ff);
uart->ucr = (UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED);
return (0);
}
static void mcf_serial_putc(const char c)
{
volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
if (c == '\n')
serial_putc('\r');
/* Wait for last character to go. */
while (!(uart->usr & UART_USR_TXRDY)) ;
uart->utb = c;
}
static int mcf_serial_getc(void)
{
volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
/* Wait for a character to arrive. */
while (!(uart->usr & UART_USR_RXRDY)) ;
return uart->urb;
}
static int mcf_serial_tstc(void)
{
volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
return (uart->usr & UART_USR_RXRDY);
}
static void mcf_serial_setbrg(void)
{
volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
u32 counter;
/* Setting up BaudRate */
counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
counter = counter / gd->baudrate;
/* write to CTUR: divide counter upper byte */
uart->ubg1 = ((counter & 0xff00) >> 8);
/* write to CTLR: divide counter lower byte */
uart->ubg2 = (counter & 0x00ff);
uart->ucr = UART_UCR_RESET_RX;
uart->ucr = UART_UCR_RESET_TX;
uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
}
static struct serial_device mcf_serial_drv = {
.name = "mcf_serial",
.start = mcf_serial_init,
.stop = NULL,
.setbrg = mcf_serial_setbrg,
.putc = mcf_serial_putc,
.puts = default_serial_puts,
.getc = mcf_serial_getc,
.tstc = mcf_serial_tstc,
};
void mcf_serial_initialize(void)
{
serial_register(&mcf_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &mcf_serial_drv;
}