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
  35 DECLARE_GLOBAL_DATA_PTR;
  36
  37 extern void uart_port_conf(void);
  38
  39 int 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();
  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
  77 void 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
  90 void serial_puts(const char *s)
  91 {
  92         while (*s) {
  93                 serial_putc(*s++);
  94         }
  95 }
  96
  97 int 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
 106 int 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
 113 void serial_setbrg(void)
 114 {
 115         volatile uart_t *uart = (volatile uart_t *)(CONFIG_SYS_UART_BASE);
 116         u32 counter;
 117
 118         counter = ((gd->bus_clk / gd->baudrate)) >> 5;
 119         counter++;
 120
 121         /* write to CTUR: divide counter upper byte */
 122         uart->ubg1 = ((counter & 0xff00) >> 8);
 123         /* write to CTLR: divide counter lower byte */
 124         uart->ubg2 = (counter & 0x00ff);
 125
 126         uart->ucr = UART_UCR_RESET_RX;
 127         uart->ucr = UART_UCR_RESET_TX;
 128
 129         uart->ucr = UART_UCR_RX_ENABLED | UART_UCR_TX_ENABLED;
 130 }