cpu/bf533/serial.c

   1 /*
   2  * U-boot - serial.c Serial driver for BF533
   3  *
   4  * Copyright (c) 2005 blackfin.uclinux.org
   5  *
   6  * This file is based on
   7  * bf533_serial.c: Serial driver for BlackFin BF533 DSP internal UART.
   8  * Copyright (c) 2003   Bas Vermeulen <bas@buyways.nl>,
   9  *                      BuyWays B.V. (www.buyways.nl)
  10  *
  11  * Based heavily on blkfinserial.c
  12  * blkfinserial.c: Serial driver for BlackFin DSP internal USRTs.
  13  * Copyright(c) 2003    Metrowerks      <mwaddel@metrowerks.com>
  14  * Copyright(c) 2001    Tony Z. Kou     <tonyko@arcturusnetworks.com>
  15  * Copyright(c) 2001-2002 Arcturus Networks Inc. <www.arcturusnetworks.com>
  16  *
  17  * Based on code from 68328 version serial driver imlpementation which was:
  18  * Copyright (C) 1995       David S. Miller    <davem@caip.rutgers.edu>
  19  * Copyright (C) 1998       Kenneth Albanowski <kjahds@kjahds.com>
  20  * Copyright (C) 1998, 1999 D. Jeff Dionne     <jeff@uclinux.org>
  21  * Copyright (C) 1999       Vladimir Gurevich  <vgurevic@cisco.com>
  22  *
  23  * (C) Copyright 2000-2004
  24  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  25  *
  26  * See file CREDITS for list of people who contributed to this
  27  * project.
  28  *
  29  * This program is free software; you can redistribute it and/or
  30  * modify it under the terms of the GNU General Public License as
  31  * published by the Free Software Foundation; either version 2 of
  32  * the License, or (at your option) any later version.
  33  *
  34  * This program is distributed in the hope that it will be useful,
  35  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  36  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  37  * GNU General Public License for more details.
  38  *
  39  * You should have received a copy of the GNU General Public License
  40  * along with this program; if not, write to the Free Software
  41  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  42  * MA 02111-1307 USA
  43  */
  44
  45 #include <common.h>
  46 #include <asm/irq.h>
  47 #include <asm/system.h>
  48 #include <asm/segment.h>
  49 #include <asm/bitops.h>
  50 #include <asm/delay.h>
  51 #include <asm/uaccess.h>
  52 #include "bf533_serial.h"
  53
  54 DECLARE_GLOBAL_DATA_PTR;
  55
  56 unsigned long pll_div_fact;
  57
  58 void calc_baud(void)
  59 {
  60         unsigned char i;
  61         int     temp;
  62
  63         for(i = 0; i < sizeof(baud_table)/sizeof(int); i++) {
  64                 temp =  CONFIG_SCLK_HZ/(baud_table[i]*8);
  65                 if ( temp && 0x1 == 1 ) {
  66                         temp++;
  67                 }
  68                 temp = temp/2;
  69                 hw_baud_table[i].dl_high = (temp >> 8)& 0xFF;
  70                 hw_baud_table[i].dl_low = (temp) & 0xFF;
  71         }
  72 }
  73
  74 void serial_setbrg(void)
  75 {
  76         int i;
  77
  78         calc_baud();
  79
  80         for (i = 0; i < sizeof(baud_table) / sizeof(int); i++) {
  81                 if (gd->baudrate == baud_table[i])
  82                         break;
  83         }
  84
  85         /* Enable UART */
  86         *pUART_GCTL |= UART_GCTL_UCEN;
  87         asm("ssync;");
  88
  89         /* Set DLAB in LCR to Access DLL and DLH */
  90         ACCESS_LATCH;
  91         asm("ssync;");
  92
  93         *pUART_DLL = hw_baud_table[i].dl_low;
  94         asm("ssync;");
  95         *pUART_DLH = hw_baud_table[i].dl_high;
  96         asm("ssync;");
  97
  98         /* Clear DLAB in LCR to Access THR RBR IER */
  99         ACCESS_PORT_IER;
 100         asm("ssync;");
 101
 102         /* Enable  ERBFI and ELSI interrupts
 103         * to poll SIC_ISR register*/
 104         *pUART_IER = UART_IER_ELSI | UART_IER_ERBFI | UART_IER_ETBEI;
 105         asm("ssync;");
 106
 107         /* Set LCR to Word Lengh 8-bit word select */
 108         *pUART_LCR = UART_LCR_WLS8;
 109         asm("ssync;");
 110
 111         return;
 112 }
 113
 114 int serial_init(void)
 115 {
 116         serial_setbrg();
 117         return (0);
 118 }
 119
 120 void serial_putc(const char c)
 121 {
 122         if ((*pUART_LSR) & UART_LSR_TEMT)
 123         {
 124                 if (c == '\n')
 125                         serial_putc('\r');
 126
 127                 local_put_char(c);
 128         }
 129
 130         while (!((*pUART_LSR) & UART_LSR_TEMT))
 131                 SYNC_ALL;
 132
 133         return;
 134 }
 135
 136 int serial_tstc(void)
 137 {
 138         if (*pUART_LSR & UART_LSR_DR)
 139                 return 1;
 140         else
 141                 return 0;
 142 }
 143
 144 int serial_getc(void)
 145 {
 146         unsigned short uart_lsr_val, uart_rbr_val;
 147         unsigned long isr_val;
 148         int ret;
 149
 150         /* Poll for RX Interrupt */
 151         while (!((isr_val = *(volatile unsigned long *)SIC_ISR) & IRQ_UART_RX_BIT));
 152         asm("csync;");
 153
 154         uart_lsr_val = *pUART_LSR;      /* Clear status bit */
 155         uart_rbr_val = *pUART_RBR;      /* getc() */
 156
 157         if (isr_val & IRQ_UART_ERROR_BIT) {
 158                 ret =  -1;
 159         }
 160         else
 161         {
 162                 ret = uart_rbr_val & 0xff;
 163         }
 164
 165         return ret;
 166 }
 167
 168 void serial_puts(const char *s)
 169 {
 170         while (*s) {
 171                 serial_putc(*s++);
 172         }
 173 }
 174
 175 static void local_put_char(char ch)
 176 {
 177         int flags = 0;
 178         unsigned long isr_val;
 179
 180         save_and_cli(flags);
 181
 182         /* Poll for TX Interruput */
 183         while (!((isr_val = *pSIC_ISR) & IRQ_UART_TX_BIT));
 184         asm("csync;");
 185
 186         *pUART_THR = ch;                        /* putc() */
 187
 188         if (isr_val & IRQ_UART_ERROR_BIT) {
 189                 printf("?");
 190         }
 191
 192         restore_flags(flags);
 193
 194         return ;
 195 }