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 /* SERIAL_PORT_DFNS is defined in <asm/serial.h> */
  33 #ifndef SERIAL_PORT_DFNS
  34 #define SERIAL_PORT_DFNS
  35 #endif
  36
  37 static struct serial_state rs_table[RS_TABLE_SIZE] = {
  38         SERIAL_PORT_DFNS        /* defined in <asm/serial.h> */
  39 };
  40
  41 static void (*serial_outb)(unsigned long, unsigned char);
  42 static unsigned long (*serial_inb)(unsigned long);
  43
  44 static int shift;
  45
  46 unsigned long direct_inb(unsigned long addr)
  47 {
  48         return readb((void __iomem *)addr);
  49 }
  50
  51 void direct_outb(unsigned long addr, unsigned char val)
  52 {
  53         writeb(val, (void __iomem *)addr);
  54 }
  55
  56 unsigned long io_inb(unsigned long port)
  57 {
  58         return inb(port);
  59 }
  60
  61 void io_outb(unsigned long port, unsigned char val)
  62 {
  63         outb(val, port);
  64 }
  65
  66 unsigned long serial_init(int chan, void *ignored)
  67 {
  68         unsigned long com_port;
  69         unsigned char lcr, dlm;
  70
  71         /* We need to find out which type io we're expecting.  If it's
  72          * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
  73          * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */
  74         switch (rs_table[chan].io_type) {
  75                 case SERIAL_IO_PORT:
  76                         com_port = rs_table[chan].port;
  77                         serial_outb = io_outb;
  78                         serial_inb = io_inb;
  79                         break;
  80                 case SERIAL_IO_MEM:
  81                         com_port = (unsigned long)rs_table[chan].iomem_base;
  82                         serial_outb = direct_outb;
  83                         serial_inb = direct_inb;
  84                         break;
  85                 default:
  86                         /* We can't deal with it. */
  87                         return -1;
  88         }
  89
  90         /* How far apart the registers are. */
  91         shift = rs_table[chan].iomem_reg_shift;
  92
  93         /* save the LCR */
  94         lcr = serial_inb(com_port + (UART_LCR << shift));
  95
  96         /* Access baud rate */
  97         serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
  98         dlm = serial_inb(com_port + (UART_DLM << shift));
  99
 100         /*
 101          * Test if serial port is unconfigured
 102          * We assume that no-one uses less than 110 baud or
 103          * less than 7 bits per character these days.
 104          *  -- paulus.
 105          */
 106         if ((dlm <= 4) && (lcr & 2)) {
 107                 /* port is configured, put the old LCR back */
 108                 serial_outb(com_port + (UART_LCR << shift), lcr);
 109         }
 110         else {
 111                 /* Input clock. */
 112                 serial_outb(com_port + (UART_DLL << shift),
 113                         (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
 114                 serial_outb(com_port + (UART_DLM << shift),
 115                                 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
 116                 /* 8 data, 1 stop, no parity */
 117                 serial_outb(com_port + (UART_LCR << shift), 0x03);
 118                 /* RTS/DTR */
 119                 serial_outb(com_port + (UART_MCR << shift), 0x03);
 120
 121                 /* Clear & enable FIFOs */
 122                 serial_outb(com_port + (UART_FCR << shift), 0x07);
 123         }
 124
 125         return (com_port);
 126 }
 127
 128 void
 129 serial_putc(unsigned long com_port, unsigned char c)
 130 {
 131         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
 132                 ;
 133         serial_outb(com_port, c);
 134 }
 135
 136 unsigned char
 137 serial_getc(unsigned long com_port)
 138 {
 139         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
 140                 ;
 141         return serial_inb(com_port);
 142 }
 143
 144 int
 145 serial_tstc(unsigned long com_port)
 146 {
 147         return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
 148 }
 149
 150 void
 151 serial_close(unsigned long com_port)
 152 {
 153 }
 154
 155 void
 156 gen550_init(int i, struct uart_port *serial_req)
 157 {
 158         rs_table[i].io_type = serial_req->iotype;
 159         rs_table[i].port = serial_req->iobase;
 160         rs_table[i].iomem_base = serial_req->membase;
 161         rs_table[i].iomem_reg_shift = serial_req->regshift;
 162         rs_table[i].baud_base = serial_req->uartclk ? serial_req->uartclk / 16 : BASE_BAUD;
 163 }
 164
 165 #ifdef CONFIG_SERIAL_TEXT_DEBUG
 166 void
 167 gen550_progress(char *s, unsigned short hex)
 168 {
 169         volatile unsigned int progress_debugport;
 170         volatile char c;
 171
 172         progress_debugport = serial_init(0, NULL);
 173
 174         serial_putc(progress_debugport, '\r');
 175
 176         while ((c = *s++) != 0)
 177                 serial_putc(progress_debugport, c);
 178
 179         serial_putc(progress_debugport, '\n');
 180         serial_putc(progress_debugport, '\r');
 181 }
 182 #endif /* CONFIG_SERIAL_TEXT_DEBUG */