arch/ppc/syslib/gen550_dbg.c

   1 /*
   2  * arch/ppc/syslib/gen550_dbg.c
   3  *
   4  * A library of polled 16550 serial routines.  These are intended to
   5  * be used to support progress messages, xmon, kgdb, etc. on a
   6  * variety of platforms.
   7  *
   8  * Adapted from lots of code ripped from the arch/ppc/boot/ polled
   9  * 16550 support.
  10  *
  11  * Author: Matt Porter <mporter@mvista.com>
  12  *
  13  * 2002-2003 (c) MontaVista Software, Inc.  This file is licensed under
  14  * the terms of the GNU General Public License version 2.  This program
  15  * is licensed "as is" without any warranty of any kind, whether express
  16  * or implied.
  17  */
  18
  19 #include <linux/config.h>
  20 #include <linux/types.h>
  21 #include <linux/serial.h>
  22 #include <linux/tty.h>          /* For linux/serial_core.h */
  23 #include <linux/serial_core.h>
  24 #include <linux/serialP.h>
  25 #include <linux/serial_reg.h>
  26 #include <asm/machdep.h>
  27 #include <asm/serial.h>
  28 #include <asm/io.h>
  29
  30 #define SERIAL_BAUD     9600
  31
  32 static struct serial_state rs_table[RS_TABLE_SIZE] = {
  33         SERIAL_PORT_DFNS        /* defined in <asm/serial.h> */
  34 };
  35
  36 static void (*serial_outb)(unsigned long, unsigned char);
  37 static unsigned long (*serial_inb)(unsigned long);
  38
  39 static int shift;
  40
  41 unsigned long direct_inb(unsigned long addr)
  42 {
  43         return readb(addr);
  44 }
  45
  46 void direct_outb(unsigned long addr, unsigned char val)
  47 {
  48         writeb(val, addr);
  49 }
  50
  51 unsigned long io_inb(unsigned long port)
  52 {
  53         return inb(port);
  54 }
  55
  56 void io_outb(unsigned long port, unsigned char val)
  57 {
  58         outb(val, port);
  59 }
  60
  61 unsigned long serial_init(int chan, void *ignored)
  62 {
  63         unsigned long com_port;
  64         unsigned char lcr, dlm;
  65
  66         /* We need to find out which type io we're expecting.  If it's
  67          * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
  68          * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */
  69         switch (rs_table[chan].io_type) {
  70                 case SERIAL_IO_PORT:
  71                         com_port = rs_table[chan].port;
  72                         serial_outb = io_outb;
  73                         serial_inb = io_inb;
  74                         break;
  75                 case SERIAL_IO_MEM:
  76                         com_port = (unsigned long)rs_table[chan].iomem_base;
  77                         serial_outb = direct_outb;
  78                         serial_inb = direct_inb;
  79                         break;
  80                 default:
  81                         /* We can't deal with it. */
  82                         return -1;
  83         }
  84
  85         /* How far apart the registers are. */
  86         shift = rs_table[chan].iomem_reg_shift;
  87
  88         /* save the LCR */
  89         lcr = serial_inb(com_port + (UART_LCR << shift));
  90
  91         /* Access baud rate */
  92         serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
  93         dlm = serial_inb(com_port + (UART_DLM << shift));
  94
  95         /*
  96          * Test if serial port is unconfigured
  97          * We assume that no-one uses less than 110 baud or
  98          * less than 7 bits per character these days.
  99          *  -- paulus.
 100          */
 101         if ((dlm <= 4) && (lcr & 2)) {
 102                 /* port is configured, put the old LCR back */
 103                 serial_outb(com_port + (UART_LCR << shift), lcr);
 104         }
 105         else {
 106                 /* Input clock. */
 107                 serial_outb(com_port + (UART_DLL << shift),
 108                         (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
 109                 serial_outb(com_port + (UART_DLM << shift),
 110                                 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
 111                 /* 8 data, 1 stop, no parity */
 112                 serial_outb(com_port + (UART_LCR << shift), 0x03);
 113                 /* RTS/DTR */
 114                 serial_outb(com_port + (UART_MCR << shift), 0x03);
 115
 116                 /* Clear & enable FIFOs */
 117                 serial_outb(com_port + (UART_FCR << shift), 0x07);
 118         }
 119
 120         return (com_port);
 121 }
 122
 123 void
 124 serial_putc(unsigned long com_port, unsigned char c)
 125 {
 126         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
 127                 ;
 128         serial_outb(com_port, c);
 129 }
 130
 131 unsigned char
 132 serial_getc(unsigned long com_port)
 133 {
 134         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
 135                 ;
 136         return serial_inb(com_port);
 137 }
 138
 139 int
 140 serial_tstc(unsigned long com_port)
 141 {
 142         return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
 143 }
 144
 145 void
 146 serial_close(unsigned long com_port)
 147 {
 148 }
 149
 150 void
 151 gen550_init(int i, struct uart_port *serial_req)
 152 {
 153         rs_table[i].io_type = serial_req->iotype;
 154         rs_table[i].port = serial_req->iobase;
 155         rs_table[i].iomem_base = serial_req->membase;
 156         rs_table[i].iomem_reg_shift = serial_req->regshift;
 157 }
 158
 159 #ifdef CONFIG_SERIAL_TEXT_DEBUG
 160 void
 161 gen550_progress(char *s, unsigned short hex)
 162 {
 163         volatile unsigned int progress_debugport;
 164         volatile char c;
 165
 166         progress_debugport = serial_init(0, NULL);
 167
 168         serial_putc(progress_debugport, '\r');
 169
 170         while ((c = *s++) != 0)
 171                 serial_putc(progress_debugport, c);
 172
 173         serial_putc(progress_debugport, '\n');
 174         serial_putc(progress_debugport, '\r');
 175 }
 176 #endif /* CONFIG_SERIAL_TEXT_DEBUG */