cpu/arm920t/ks8695/serial.c

   1 /*
   2  * serial.c -- KS8695 serial driver
   3  *
   4  * (C) Copyright 2004, Greg Ungerer <greg.ungerer@opengear.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include <common.h>
  22 #include <asm/arch/platform.h>
  23
  24 #ifndef CONFIG_SERIAL1
  25 #error "Bad: you didn't configure serial ..."
  26 #endif
  27
  28 /*
  29  *      Define the UART hardware register access structure.
  30  */
  31 struct ks8695uart {
  32         unsigned int    RX;             /* 0x00 - Receive data (r) */
  33         unsigned int    TX;             /* 0x04 - Transmit data (w) */
  34         unsigned int    FCR;            /* 0x08 - Fifo Control (r/w) */
  35         unsigned int    LCR;            /* 0x0c - Line Control (r/w) */
  36         unsigned int    MCR;            /* 0x10 - Modem Control (r/w) */
  37         unsigned int    LSR;            /* 0x14 - Line Status (r/w) */
  38         unsigned int    MSR;            /* 0x18 - Modem Status (r/w) */
  39         unsigned int    BD;             /* 0x1c - Baud Rate (r/w) */
  40         unsigned int    SR;             /* 0x20 - Status (r/w) */
  41 };
  42
  43 #define KS8695_UART_ADDR        ((void *) (KS8695_IO_BASE + KS8695_UART_RX_BUFFER))
  44 #define KS8695_UART_CLK         25000000
  45
  46
  47 /*
  48  * Under some circumstances we want to be "quiet" and not issue any
  49  * serial output - though we want u-boot to otherwise work and behave
  50  * the same. By default be noisy.
  51  */
  52 int serial_console = 1;
  53
  54
  55 void serial_setbrg(void)
  56 {
  57         DECLARE_GLOBAL_DATA_PTR;
  58         volatile struct ks8695uart *uartp = KS8695_UART_ADDR;
  59
  60         /* Set to global baud rate and 8 data bits, no parity, 1 stop bit*/
  61         uartp->BD = KS8695_UART_CLK / gd->baudrate;
  62         uartp->LCR = KS8695_UART_LINEC_WLEN8;
  63 }
  64
  65 int serial_init(void)
  66 {
  67         serial_console = 1;
  68         serial_setbrg();
  69         return 0;
  70 }
  71
  72 void serial_raw_putc(const char c)
  73 {
  74         volatile struct ks8695uart *uartp = KS8695_UART_ADDR;
  75         int i;
  76
  77         for (i = 0; (i < 0x100000); i++) {
  78                 if (uartp->LSR & KS8695_UART_LINES_TXFE)
  79                         break;
  80         }
  81
  82         uartp->TX = c;
  83 }
  84
  85 void serial_putc(const char c)
  86 {
  87         if (serial_console) {
  88                 serial_raw_putc(c);
  89                 if (c == '\n')
  90                         serial_raw_putc('\r');
  91         }
  92 }
  93
  94 int serial_tstc(void)
  95 {
  96         volatile struct ks8695uart *uartp = KS8695_UART_ADDR;
  97         if (serial_console)
  98                 return ((uartp->LSR & KS8695_UART_LINES_RXFE) ? 1 : 0);
  99         return 0;
 100 }
 101
 102 void serial_puts(const char *s)
 103 {
 104         char c;
 105         while ((c = *s++) != 0)
 106                 serial_putc(c);
 107 }
 108
 109 int serial_getc(void)
 110 {
 111         volatile struct ks8695uart *uartp = KS8695_UART_ADDR;
 112
 113         while ((uartp->LSR & KS8695_UART_LINES_RXFE) == 0)
 114                 ;
 115         return (uartp->RX);
 116 }