target/linux/brcm63xx-2.6/files/arch/mips/bcm963xx/ser_init.c

   1 /*
   2 <:copyright-gpl
   3  Copyright 2004 Broadcom Corp. All Rights Reserved.
   4
   5  This program is free software; you can distribute it and/or modify it
   6  under the terms of the GNU General Public License (Version 2) as
   7  published by the Free Software Foundation.
   8
   9  This program is distributed in the hope it will be useful, but WITHOUT
  10  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  for more details.
  13
  14  You should have received a copy of the GNU General Public License along
  15  with this program; if not, write to the Free Software Foundation, Inc.,
  16  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17 :>
  18 */
  19 /*
  20  *  Broadcom bcm63xx serial port initialization, also prepare for printk
  21  *  by registering with console_init
  22  *
  23  */
  24
  25 #include <linux/autoconf.h>
  26 #include <linux/init.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/kernel.h>
  29 #include <linux/types.h>
  30 #include <linux/console.h>
  31 #include <linux/sched.h>
  32
  33 #include <asm/addrspace.h>
  34 #include <asm/irq.h>
  35 #include <asm/reboot.h>
  36 #include <asm/gdb-stub.h>
  37 #include <asm/mc146818rtc.h>
  38
  39 #include <bcm_map_part.h>
  40 #include <6348_map_part.h>
  41 #include <board.h>
  42
  43 #define  SER63XX_DEFAULT_BAUD      115200
  44 #define BD_BCM63XX_TIMER_CLOCK_INPUT    (FPERIPH)
  45 #define stUart ((volatile Uart * const) UART_BASE)
  46
  47 // Transmit interrupts
  48 #define TXINT       (TXFIFOEMT | TXUNDERR | TXOVFERR)
  49 // Receive interrupts
  50 #define RXINT       (RXFIFONE | RXOVFERR)
  51
  52 /* --------------------------------------------------------------------------
  53     Name: serial_init
  54  Purpose: Initalize the UART
  55 -------------------------------------------------------------------------- */
  56 void __init serial_init(void)
  57 {
  58     u32 tmpVal = SER63XX_DEFAULT_BAUD;
  59     ULONG clockFreqHz;
  60
  61 #if defined(CONFIG_BCM96345)
  62     // Make sure clock is ticking
  63     PERF->blkEnables |= UART_CLK_EN;
  64 #endif
  65
  66     /* Dissable channel's receiver and transmitter.                */
  67     stUart->control &= ~(BRGEN|TXEN|RXEN);
  68
  69     /*--------------------------------------------------------------------*/
  70     /* Write the table value to the clock select register.                */
  71     /* DPullen - this is the equation to use:                             */
  72     /*       value = clockFreqHz / baud / 32-1;                           */
  73     /*   (snmod) Actually you should also take into account any necessary */
  74     /*           rounding.  Divide by 16, look at lsb, if 0, divide by 2  */
  75     /*           and subtract 1.  If 1, just divide by 2                  */
  76     /*--------------------------------------------------------------------*/
  77     clockFreqHz = BD_BCM63XX_TIMER_CLOCK_INPUT;
  78     tmpVal = (clockFreqHz / tmpVal) / 16;
  79     if( tmpVal & 0x01 )
  80         tmpVal /= 2;  //Rounding up, so sub is already accounted for
  81     else
  82         tmpVal = (tmpVal / 2) - 1; // Rounding down so we must sub 1
  83     stUart->baudword = tmpVal;
  84
  85     /* Finally, re-enable the transmitter and receiver.            */
  86     stUart->control |= (BRGEN|TXEN|RXEN);
  87
  88     stUart->config   = (BITS8SYM | ONESTOP);
  89     // Set the FIFO interrupt depth ... stUart->fifocfg  = 0xAA;
  90     stUart->fifoctl  =  RSTTXFIFOS | RSTRXFIFOS;
  91     stUart->intMask  = 0;
  92     stUart->intMask = RXINT | TXINT;
  93 }
  94
  95
  96 /* prom_putc()
  97  * Output a character to the UART
  98  */
  99 void prom_putc(char c)
 100 {
 101         /* Wait for Tx uffer to empty */
 102         while (! (READ16(stUart->intStatus) & TXFIFOEMT));
 103         /* Send character */
 104         stUart->Data = c;
 105 }
 106
 107 /* prom_puts()
 108  * Write a string to the UART
 109  */
 110 void prom_puts(const char *s)
 111 {
 112         while (*s) {
 113                 if (*s == '\n') {
 114                         prom_putc('\r');
 115                 }
 116                 prom_putc(*s++);
 117         }
 118 }
 119
 120
 121 /* prom_getc_nowait()
 122  * Returns a character from the UART
 123  * Returns -1 if no characters available or corrupted
 124  */
 125 int prom_getc_nowait(void)
 126 {
 127     uint16  uStatus;
 128     int    cData = -1;
 129
 130      uStatus = READ16(stUart->intStatus);
 131
 132      if (uStatus & RXFIFONE) { /* Do we have a character? */
 133            cData =  READ16(stUart->Data) & 0xff; /* Read character */
 134            if (uStatus & (RXFRAMERR | RXPARERR)) {  /* If we got an error, throw it away */
 135                cData = -1;
 136            }
 137   }
 138
 139    return cData;
 140 }
 141
 142 /* prom_getc()
 143  * Returns a charcter from the serial port
 144  * Will block until it receives a valid character
 145 */
 146 char prom_getc(void)
 147 {
 148     int    cData = -1;
 149
 150     /* Loop until we get a valid character */
 151     while(cData == -1) {
 152         cData = prom_getc_nowait();
 153     }
 154    return (char) cData;
 155 }
 156
 157 /* prom_testc()
 158  * Returns 0 if no characters available
 159  */
 160 int prom_testc(void)
 161 {
 162     uint16  uStatus;
 163
 164      uStatus = READ16(stUart->intStatus);
 165
 166      return (uStatus & RXFIFONE);
 167 }
 168
 169 #if defined (CONFIG_REMOTE_DEBUG)
 170 /* Prevent other code from writing to the serial port */
 171 void _putc(char c) { }
 172 void _puts(const char *ptr) { }
 173 #else
 174 /* Low level outputs call prom routines */
 175 void _putc(char c) {
 176         prom_putc(c);
 177 }
 178 void _puts(const char *ptr) {
 179         prom_puts(ptr);
 180 }
 181 #endif