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/tty.h>          /* For linux/serial_core.h */
  21 #include <linux/serial_core.h>
  22 #include <linux/serialP.h>
  23 #include <linux/serial_reg.h>
  24 #include <asm/machdep.h>
  25 #include <asm/serial.h>
  26 #include <asm/io.h>
  27
  28 #define SERIAL_BAUD     9600
  29
  30 static struct serial_state rs_table[RS_TABLE_SIZE] = {
  31         SERIAL_PORT_DFNS        /* defined in <asm/serial.h> */
  32 };
  33
  34 static void (*serial_outb)(unsigned long, unsigned char);
  35 static unsigned long (*serial_inb)(unsigned long);
  36
  37 static int shift;
  38
  39 unsigned long direct_inb(unsigned long addr)
  40 {
  41         return readb(addr);
  42 }
  43
  44 void direct_outb(unsigned long addr, unsigned char val)
  45 {
  46         writeb(val, addr);
  47 }
  48
  49 unsigned long io_inb(unsigned long port)
  50 {
  51         return inb(port);
  52 }
  53
  54 void io_outb(unsigned long port, unsigned char val)
  55 {
  56         outb(val, port);
  57 }
  58
  59 unsigned long serial_init(int chan, void *ignored)
  60 {
  61         unsigned long com_port;
  62         unsigned char lcr, dlm;
  63
  64         /* We need to find out which type io we're expecting.  If it's
  65          * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
  66          * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */
  67         switch (rs_table[chan].io_type) {
  68                 case SERIAL_IO_PORT:
  69                         com_port = rs_table[chan].port;
  70                         serial_outb = io_outb;
  71                         serial_inb = io_inb;
  72                         break;
  73                 case SERIAL_IO_MEM:
  74                         com_port = (unsigned long)rs_table[chan].iomem_base;
  75                         serial_outb = direct_outb;
  76                         serial_inb = direct_inb;
  77                         break;
  78                 default:
  79                         /* We can't deal with it. */
  80                         return -1;
  81         }
  82
  83         /* How far apart the registers are. */
  84         shift = rs_table[chan].iomem_reg_shift;
  85
  86         /* save the LCR */
  87         lcr = serial_inb(com_port + (UART_LCR << shift));
  88
  89         /* Access baud rate */
  90         serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
  91         dlm = serial_inb(com_port + (UART_DLM << shift));
  92
  93         /*
  94          * Test if serial port is unconfigured
  95          * We assume that no-one uses less than 110 baud or
  96          * less than 7 bits per character these days.
  97          *  -- paulus.
  98          */
  99         if ((dlm <= 4) && (lcr & 2)) {
 100                 /* port is configured, put the old LCR back */
 101                 serial_outb(com_port + (UART_LCR << shift), lcr);
 102         }
 103         else {
 104                 /* Input clock. */
 105                 serial_outb(com_port + (UART_DLL << shift),
 106                         (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
 107                 serial_outb(com_port + (UART_DLM << shift),
 108                                 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
 109                 /* 8 data, 1 stop, no parity */
 110                 serial_outb(com_port + (UART_LCR << shift), 0x03);
 111                 /* RTS/DTR */
 112                 serial_outb(com_port + (UART_MCR << shift), 0x03);
 113
 114                 /* Clear & enable FIFOs */
 115                 serial_outb(com_port + (UART_FCR << shift), 0x07);
 116         }
 117
 118         return (com_port);
 119 }
 120
 121 void
 122 serial_putc(unsigned long com_port, unsigned char c)
 123 {
 124         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
 125                 ;
 126         serial_outb(com_port, c);
 127 }
 128
 129 unsigned char
 130 serial_getc(unsigned long com_port)
 131 {
 132         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
 133                 ;
 134         return serial_inb(com_port);
 135 }
 136
 137 int
 138 serial_tstc(unsigned long com_port)
 139 {
 140         return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
 141 }
 142
 143 void
 144 serial_close(unsigned long com_port)
 145 {
 146 }
 147
 148 void
 149 gen550_init(int i, struct uart_port *serial_req)
 150 {
 151         rs_table[i].io_type = serial_req->iotype;
 152         rs_table[i].port = serial_req->line;
 153         rs_table[i].iomem_base = serial_req->membase;
 154         rs_table[i].iomem_reg_shift = serial_req->regshift;
 155 }
 156
 157 #ifdef CONFIG_SERIAL_TEXT_DEBUG
 158 void
 159 gen550_progress(char *s, unsigned short hex)
 160 {
 161         volatile unsigned int progress_debugport;
 162         volatile char c;
 163
 164         progress_debugport = serial_init(0, NULL);
 165
 166         serial_putc(progress_debugport, '\r');
 167
 168         while ((c = *s++) != 0)
 169                 serial_putc(progress_debugport, c);
 170
 171         serial_putc(progress_debugport, '\n');
 172         serial_putc(progress_debugport, '\r');
 173 }
 174 #endif /* CONFIG_SERIAL_TEXT_DEBUG */