LXR uboot/drivers/serial/mcfuart.c

   1/*
   2 * (C) Copyright 2004-2007 Freescale Semiconductor, Inc.
   3 * TsiChung Liew, Tsi-Chung.Liew@freescale.com.
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 *
  23 */
  24
  25/*
  26 * Minimal serial functions needed to use one of the uart ports
  27 * as serial console interface.
  28 */
  29
  30#include <common.h>
  31
  32#include <asm/immap.h>
  33#include <asm/uart.h>
  34
  35DECLARE_GLOBAL_DATA_PTR;
  36
  37extern void uart_port_conf(int port);
  38
  39int serial_init(void)
  40{
  41        volatile uart_t *uart;
  42        u32 counter;
  43
  44        uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
  45
  46        uart_port_conf(CONFIG_SYS_UART_PORT);
  47
  48        /* write to SICR: SIM2 = uart mode,dcd does not affect rx */
  49        uart->ucr = UART_UCR_RESET_RX;
  50        uart->ucr = UART_UCR_RESET_TX;
  51        uart->ucr = UART_UCR_RESET_ERROR;
  52        uart->ucr = UART_UCR_RESET_MR;
  53        __asm__("nop");
  54
  55        uart->uimr = 0;
  56
  57        /* write to CSR: RX/TX baud rate from timers */
  58        uart->ucsr = (UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK);
  59
  60        uart->umr = (UART_UMR_BC_8 | UART_UMR_PM_NONE);
  61        uart->umr = UART_UMR_SB_STOP_BITS_1;
  62
  63        /* Setting up BaudRate */
  64        counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
  65        counter = counter / gd->baudrate;
  66
  67        /* write to CTUR: divide counter upper byte */
  68        uart->ubg1 = (u8) ((counter & 0xff00) >> 8);
  69        /* write to CTLR: divide counter lower byte */
  70        uart->ubg2 = (u8) (counter & 0x00ff);
  71
  72        uart->ucr = (UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED);
  73
  74        return (0);
  75}
  76
  77void serial_putc(const char c)
  78{
  79        volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
  80
  81        if (c == '\n')
  82                serial_putc('\r');
  83
  84        /* Wait for last character to go. */
  85        while (!(uart->usr & UART_USR_TXRDY)) ;
  86
  87        uart->utb = c;
  88}
  89
  90void serial_puts(const char *s)
  91{
  92        while (*s) {
  93                serial_putc(*s++);
  94        }
  95}
  96
  97int serial_getc(void)
  98{
  99        volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
 100
 101        /* Wait for a character to arrive. */
 102        while (!(uart->usr & UART_USR_RXRDY)) ;
 103        return uart->urb;
 104}
 105
 106int serial_tstc(void)
 107{
 108        volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
 109
 110        return (uart->usr & UART_USR_RXRDY);
 111}
 112
 113void serial_setbrg(void)
 114{
 115        volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
 116        u32 counter;
 117
 118        /* Setting up BaudRate */
 119        counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
 120        counter = counter / gd->baudrate;
 121
 122        /* write to CTUR: divide counter upper byte */
 123        uart->ubg1 = ((counter & 0xff00) >> 8);
 124        /* write to CTLR: divide counter lower byte */
 125        uart->ubg2 = (counter & 0x00ff);
 126
 127        uart->ucr = UART_UCR_RESET_RX;
 128        uart->ucr = UART_UCR_RESET_TX;
 129
 130        uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
 131}
 132