drivers/serial_pl010.c

   1 /*
   2  * (C) Copyright 2000
   3  * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
   4  *
   5  * (C) Copyright 2004
   6  * ARM Ltd.
   7  * Philippe Robin, <philippe.robin@arm.com>
   8  *
   9  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License as
  14  * published by the Free Software Foundation; either version 2 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25  * MA 02111-1307 USA
  26  */
  27
  28 /* Simple U-Boot driver for the PrimeCell PL011 UARTs on the IntegratorCP */
  29 /* Should be fairly simple to make it work with the PL010 as well */
  30
  31 #include <common.h>
  32
  33 #ifdef CFG_PL010_SERIAL
  34
  35 #include "serial_pl011.h"
  36
  37 #define IO_WRITE(addr, val) (*(volatile unsigned int *)(addr) = (val))
  38 #define IO_READ(addr) (*(volatile unsigned int *)(addr))
  39
  40 /* Integrator AP has two UARTs, we use the first one, at 38400-8-N-1 */
  41 #define CONSOLE_PORT CONFIG_CONS_INDEX
  42 #define baudRate CONFIG_BAUDRATE
  43 static volatile unsigned char *const port[] = CONFIG_PL01x_PORTS;
  44 #define NUM_PORTS (sizeof(port)/sizeof(port[0]))
  45
  46
  47 static void pl010_putc (int portnum, char c);
  48 static int pl010_getc (int portnum);
  49 static int pl010_tstc (int portnum);
  50
  51
  52 int serial_init (void)
  53 {
  54         unsigned int divisor;
  55
  56         /*
  57          ** First, disable everything.
  58          */
  59         IO_WRITE (port[CONSOLE_PORT] + UART_PL010_CR, 0x0);
  60
  61         /*
  62          ** Set baud rate
  63          **
  64          */
  65         switch (baudRate) {
  66         case 9600:
  67                 divisor = UART_PL010_BAUD_9600;
  68                 break;
  69
  70         case 19200:
  71                 divisor = UART_PL010_BAUD_9600;
  72                 break;
  73
  74         case 38400:
  75                 divisor = UART_PL010_BAUD_38400;
  76                 break;
  77
  78         case 57600:
  79                 divisor = UART_PL010_BAUD_57600;
  80                 break;
  81
  82         case 115200:
  83                 divisor = UART_PL010_BAUD_115200;
  84                 break;
  85
  86         default:
  87                 divisor = UART_PL010_BAUD_38400;
  88         }
  89
  90         IO_WRITE (port[CONSOLE_PORT] + UART_PL010_LCRM,
  91                   ((divisor & 0xf00) >> 8));
  92         IO_WRITE (port[CONSOLE_PORT] + UART_PL010_LCRL, (divisor & 0xff));
  93
  94         /*
  95          ** Set the UART to be 8 bits, 1 stop bit, no parity, fifo enabled.
  96          */
  97         IO_WRITE (port[CONSOLE_PORT] + UART_PL010_LCRH,
  98                   (UART_PL010_LCRH_WLEN_8 | UART_PL010_LCRH_FEN));
  99
 100         /*
 101          ** Finally, enable the UART
 102          */
 103         IO_WRITE (port[CONSOLE_PORT] + UART_PL010_CR, (UART_PL010_CR_UARTEN));
 104
 105         return (0);
 106 }
 107
 108 void serial_putc (const char c)
 109 {
 110         if (c == '\n')
 111                 pl010_putc (CONSOLE_PORT, '\r');
 112
 113         pl010_putc (CONSOLE_PORT, c);
 114 }
 115
 116 void serial_puts (const char *s)
 117 {
 118         while (*s) {
 119                 serial_putc (*s++);
 120         }
 121 }
 122
 123 int serial_getc (void)
 124 {
 125         return pl010_getc (CONSOLE_PORT);
 126 }
 127
 128 int serial_tstc (void)
 129 {
 130         return pl010_tstc (CONSOLE_PORT);
 131 }
 132
 133 void serial_setbrg (void)
 134 {
 135 }
 136
 137 static void pl010_putc (int portnum, char c)
 138 {
 139         /* Wait until there is space in the FIFO */
 140         while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_TXFF);
 141
 142         /* Send the character */
 143         IO_WRITE (port[portnum] + UART_PL01x_DR, c);
 144 }
 145
 146 static int pl010_getc (int portnum)
 147 {
 148         unsigned int data;
 149
 150         /* Wait until there is data in the FIFO */
 151         while (IO_READ (port[portnum] + UART_PL01x_FR) & UART_PL01x_FR_RXFE);
 152
 153         data = IO_READ (port[portnum] + UART_PL01x_DR);
 154
 155         /* Check for an error flag */
 156         if (data & 0xFFFFFF00) {
 157                 /* Clear the error */
 158                 IO_WRITE (port[portnum] + UART_PL01x_ECR, 0xFFFFFFFF);
 159                 return -1;
 160         }
 161
 162         return (int) data;
 163 }
 164
 165 static int pl010_tstc (int portnum)
 166 {
 167         return !(IO_READ (port[portnum] + UART_PL01x_FR) &
 168                  UART_PL01x_FR_RXFE);
 169 }
 170
 171 #endif