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 <board.h>
  41
  42 #define  SER63XX_DEFAULT_BAUD      115200
  43 #define BD_BCM63XX_TIMER_CLOCK_INPUT    (FPERIPH)
  44 #define stUart ((volatile Uart * const) UART_BASE)
  45
  46 // Transmit interrupts
  47 #define TXINT       (TXFIFOEMT | TXUNDERR | TXOVFERR)
  48 // Receive interrupts
  49 #define RXINT       (RXFIFONE | RXOVFERR)
  50
  51 /* --------------------------------------------------------------------------
  52     Name: serial_init
  53  Purpose: Initalize the UART
  54 -------------------------------------------------------------------------- */
  55 void __init serial_init(void)
  56 {
  57     UINT32 tmpVal = SER63XX_DEFAULT_BAUD;
  58     ULONG clockFreqHz;
  59
  60 #if defined(CONFIG_BCM96345)
  61     // Make sure clock is ticking
  62     PERF->blkEnables |= UART_CLK_EN;
  63 #endif
  64
  65     /* Dissable channel's receiver and transmitter.                */
  66     stUart->control &= ~(BRGEN|TXEN|RXEN);
  67
  68     /*--------------------------------------------------------------------*/
  69     /* Write the table value to the clock select register.                */
  70     /* DPullen - this is the equation to use:                             */
  71     /*       value = clockFreqHz / baud / 32-1;                           */
  72     /*   (snmod) Actually you should also take into account any necessary */
  73     /*           rounding.  Divide by 16, look at lsb, if 0, divide by 2  */
  74     /*           and subtract 1.  If 1, just divide by 2                  */
  75     /*--------------------------------------------------------------------*/
  76     clockFreqHz = BD_BCM63XX_TIMER_CLOCK_INPUT;
  77     tmpVal = (clockFreqHz / tmpVal) / 16;
  78     if( tmpVal & 0x01 )
  79         tmpVal /= 2;  //Rounding up, so sub is already accounted for
  80     else
  81         tmpVal = (tmpVal / 2) - 1; // Rounding down so we must sub 1
  82     stUart->baudword = tmpVal;
  83
  84     /* Finally, re-enable the transmitter and receiver.            */
  85     stUart->control |= (BRGEN|TXEN|RXEN);
  86
  87     stUart->config   = (BITS8SYM | ONESTOP);
  88     // Set the FIFO interrupt depth ... stUart->fifocfg  = 0xAA;
  89     stUart->fifoctl  =  RSTTXFIFOS | RSTRXFIFOS;
  90     stUart->intMask  = 0;
  91     stUart->intMask = RXINT | TXINT;
  92 }
  93
  94
  95 /* prom_putc()
  96  * Output a character to the UART
  97  */
  98 void prom_putc(char c)
  99 {
 100         /* Wait for Tx uffer to empty */
 101         while (! (READ16(stUart->intStatus) & TXFIFOEMT));
 102         /* Send character */
 103         stUart->Data = c;
 104 }
 105
 106 /* prom_puts()
 107  * Write a string to the UART
 108  */
 109 void prom_puts(const char *s)
 110 {
 111         while (*s) {
 112                 if (*s == '\n') {
 113                         prom_putc('\r');
 114                 }
 115                 prom_putc(*s++);
 116         }
 117 }
 118
 119
 120 /* prom_getc_nowait()
 121  * Returns a character from the UART
 122  * Returns -1 if no characters available or corrupted
 123  */
 124 int prom_getc_nowait(void)
 125 {
 126     uint16  uStatus;
 127     int    cData = -1;
 128
 129      uStatus = READ16(stUart->intStatus);
 130
 131      if (uStatus & RXFIFONE) { /* Do we have a character? */
 132            cData =  READ16(stUart->Data) & 0xff; /* Read character */
 133            if (uStatus & (RXFRAMERR | RXPARERR)) {  /* If we got an error, throw it away */
 134                cData = -1;
 135            }
 136   }
 137
 138    return cData;
 139 }
 140
 141 /* prom_getc()
 142  * Returns a charcter from the serial port
 143  * Will block until it receives a valid character
 144 */
 145 char prom_getc(void)
 146 {
 147     int    cData = -1;
 148
 149     /* Loop until we get a valid character */
 150     while(cData == -1) {
 151         cData = prom_getc_nowait();
 152     }
 153    return (char) cData;
 154 }
 155
 156 /* prom_testc()
 157  * Returns 0 if no characters available
 158  */
 159 int prom_testc(void)
 160 {
 161     uint16  uStatus;
 162
 163      uStatus = READ16(stUart->intStatus);
 164
 165      return (uStatus & RXFIFONE);
 166 }
 167
 168 #if defined (CONFIG_REMOTE_DEBUG)
 169 /* Prevent other code from writing to the serial port */
 170 void _putc(char c) { }
 171 void _puts(const char *ptr) { }
 172 #else
 173 /* Low level outputs call prom routines */
 174 void _putc(char c) {
 175         prom_putc(c);
 176 }
 177 void _puts(const char *ptr) {
 178         prom_puts(ptr);
 179 }
 180 #endif