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 #ifdef CONFIG_MCFUART
  33
  34 #include <asm/immap.h>
  35 #include <asm/uart.h>
  36
  37 DECLARE_GLOBAL_DATA_PTR;
  38
  39 extern void uart_port_conf(void);
  40
  41 int serial_init(void)
  42 {
  43         volatile uart_t *uart;
  44         u32 counter;
  45
  46         uart = (volatile uart_t *)(CFG_UART_BASE);
  47
  48         uart_port_conf();
  49
  50         /* write to SICR: SIM2 = uart mode,dcd does not affect rx */
  51         uart->ucr = UART_UCR_RESET_RX;
  52         uart->ucr = UART_UCR_RESET_TX;
  53         uart->ucr = UART_UCR_RESET_ERROR;
  54         uart->ucr = UART_UCR_RESET_MR;
  55         __asm__("nop");
  56
  57         uart->uimr = 0;
  58
  59         /* write to CSR: RX/TX baud rate from timers */
  60         uart->ucsr = (UART_UCSR_RCS_SYS_CLK | UART_UCSR_TCS_SYS_CLK);
  61
  62         uart->umr = (UART_UMR_BC_8 | UART_UMR_PM_NONE);
  63         uart->umr = UART_UMR_SB_STOP_BITS_1;
  64
  65         /* Setting up BaudRate */
  66         counter = (u32) ((gd->bus_clk / 32) + (gd->baudrate / 2));
  67         counter = counter / gd->baudrate;
  68
  69         /* write to CTUR: divide counter upper byte */
  70         uart->ubg1 = (u8) ((counter & 0xff00) >> 8);
  71         /* write to CTLR: divide counter lower byte */
  72         uart->ubg2 = (u8) (counter & 0x00ff);
  73
  74         uart->ucr = (UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED);
  75
  76         return (0);
  77 }
  78
  79 void serial_putc(const char c)
  80 {
  81         volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
  82
  83         if (c == '\n')
  84                 serial_putc('\r');
  85
  86         /* Wait for last character to go. */
  87         while (!(uart->usr & UART_USR_TXRDY)) ;
  88
  89         uart->utb = c;
  90 }
  91
  92 void serial_puts(const char *s)
  93 {
  94         while (*s) {
  95                 serial_putc(*s++);
  96         }
  97 }
  98
  99 int serial_getc(void)
 100 {
 101         volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
 102
 103         /* Wait for a character to arrive. */
 104         while (!(uart->usr & UART_USR_RXRDY)) ;
 105         return uart->urb;
 106 }
 107
 108 int serial_tstc(void)
 109 {
 110         volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
 111
 112         return (uart->usr & UART_USR_RXRDY);
 113 }
 114
 115 void serial_setbrg(void)
 116 {
 117         volatile uart_t *uart = (volatile uart_t *)(CFG_UART_BASE);
 118         u32 counter;
 119
 120         counter = ((gd->bus_clk / gd->baudrate)) >> 5;
 121         counter++;
 122
 123         /* write to CTUR: divide counter upper byte */
 124         uart->ubg1 = ((counter & 0xff00) >> 8);
 125         /* write to CTLR: divide counter lower byte */
 126         uart->ubg2 = (counter & 0x00ff);
 127
 128         uart->ucr = UART_UCR_RESET_RX;
 129         uart->ucr = UART_UCR_RESET_TX;
 130
 131         uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
 132 }
 133 #endif                          /* CONFIG_MCFUART */