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 unsigned long pll_div_fact;
  55
  56 void calc_baud(void)
  57 {
  58         unsigned char i;
  59         int     temp;
  60
  61         for(i = 0; i < sizeof(baud_table)/sizeof(int); i++) {
  62                 temp =  CONFIG_SCLK_HZ/(baud_table[i]*8);
  63                 if ( temp && 0x1 == 1 ) {
  64                         temp++;
  65                 }
  66                 temp = temp/2;
  67                 hw_baud_table[i].dl_high = (temp >> 8)& 0xFF;
  68                 hw_baud_table[i].dl_low = (temp) & 0xFF;
  69         }
  70 }
  71
  72 void serial_setbrg(void)
  73 {
  74         int i;
  75         DECLARE_GLOBAL_DATA_PTR;
  76
  77         calc_baud();
  78
  79         for (i = 0; i < sizeof(baud_table) / sizeof(int); i++) {
  80                 if (gd->baudrate == baud_table[i])
  81                         break;
  82         }
  83
  84         /* Enable UART */
  85         *pUART_GCTL |= UART_GCTL_UCEN;
  86         asm("ssync;");
  87
  88         /* Set DLAB in LCR to Access DLL and DLH */
  89         ACCESS_LATCH;
  90         asm("ssync;");
  91
  92         *pUART_DLL = hw_baud_table[i].dl_low;
  93         asm("ssync;");
  94         *pUART_DLH = hw_baud_table[i].dl_high;
  95         asm("ssync;");
  96
  97         /* Clear DLAB in LCR to Access THR RBR IER */
  98         ACCESS_PORT_IER;
  99         asm("ssync;");
 100
 101         /* Enable  ERBFI and ELSI interrupts
 102         * to poll SIC_ISR register*/
 103         *pUART_IER = UART_IER_ELSI | UART_IER_ERBFI | UART_IER_ETBEI;
 104         asm("ssync;");
 105
 106         /* Set LCR to Word Lengh 8-bit word select */
 107         *pUART_LCR = UART_LCR_WLS8;
 108         asm("ssync;");
 109
 110         return;
 111 }
 112
 113 int serial_init(void)
 114 {
 115         serial_setbrg();
 116         return (0);
 117 }
 118
 119 void serial_putc(const char c)
 120 {
 121         if ((*pUART_LSR) & UART_LSR_TEMT)
 122         {
 123                 if (c == '\n')
 124                         serial_putc('\r');
 125
 126                 local_put_char(c);
 127         }
 128
 129         while (!((*pUART_LSR) & UART_LSR_TEMT))
 130                 SYNC_ALL;
 131
 132         return;
 133 }
 134
 135 int serial_tstc(void)
 136 {
 137         if (*pUART_LSR & UART_LSR_DR)
 138                 return 1;
 139         else
 140                 return 0;
 141 }
 142
 143 int serial_getc(void)
 144 {
 145         unsigned short uart_lsr_val, uart_rbr_val;
 146         unsigned long isr_val;
 147         int ret;
 148
 149         /* Poll for RX Interrupt */
 150         while (!((isr_val = *(volatile unsigned long *)SIC_ISR) & IRQ_UART_RX_BIT));
 151         asm("csync;");
 152
 153         uart_lsr_val = *pUART_LSR;      /* Clear status bit */
 154         uart_rbr_val = *pUART_RBR;      /* getc() */
 155
 156         if (isr_val & IRQ_UART_ERROR_BIT) {
 157                 ret =  -1;
 158         }
 159         else
 160         {
 161                 ret = uart_rbr_val & 0xff;
 162         }
 163
 164         return ret;
 165 }
 166
 167 void serial_puts(const char *s)
 168 {
 169         while (*s) {
 170                 serial_putc(*s++);
 171         }
 172 }
 173
 174 static void local_put_char(char ch)
 175 {
 176         int flags = 0;
 177         unsigned long isr_val;
 178
 179         save_and_cli(flags);
 180
 181         /* Poll for TX Interruput */
 182         while (!((isr_val = *pSIC_ISR) & IRQ_UART_TX_BIT));
 183         asm("csync;");
 184
 185         *pUART_THR = ch;                        /* putc() */
 186
 187         if (isr_val & IRQ_UART_ERROR_BIT) {
 188                 printf("?");
 189         }
 190
 191         restore_flags(flags);
 192
 193         return ;
 194 }