arch/ppc/syslib/gen550_dbg.c

   1 /*
   2  * A library of polled 16550 serial routines.  These are intended to
   3  * be used to support progress messages, xmon, kgdb, etc. on a
   4  * variety of platforms.
   5  *
   6  * Adapted from lots of code ripped from the arch/ppc/boot/ polled
   7  * 16550 support.
   8  *
   9  * Author: Matt Porter <mporter@mvista.com>
  10  *
  11  * 2002-2003 (c) MontaVista Software, Inc.  This file is licensed under
  12  * the terms of the GNU General Public License version 2.  This program
  13  * is licensed "as is" without any warranty of any kind, whether express
  14  * or implied.
  15  */
  16
  17 #include <linux/types.h>
  18 #include <linux/serial.h>
  19 #include <linux/tty.h>          /* For linux/serial_core.h */
  20 #include <linux/serial_core.h>
  21 #include <linux/serialP.h>
  22 #include <linux/serial_reg.h>
  23 #include <asm/machdep.h>
  24 #include <asm/serial.h>
  25 #include <asm/io.h>
  26
  27 #define SERIAL_BAUD     9600
  28
  29 /* SERIAL_PORT_DFNS is defined in <asm/serial.h> */
  30 #ifndef SERIAL_PORT_DFNS
  31 #define SERIAL_PORT_DFNS
  32 #endif
  33
  34 static struct serial_state rs_table[RS_TABLE_SIZE] = {
  35         SERIAL_PORT_DFNS        /* defined in <asm/serial.h> */
  36 };
  37
  38 static void (*serial_outb)(unsigned long, unsigned char);
  39 static unsigned long (*serial_inb)(unsigned long);
  40
  41 static int shift;
  42
  43 unsigned long direct_inb(unsigned long addr)
  44 {
  45         return readb((void __iomem *)addr);
  46 }
  47
  48 void direct_outb(unsigned long addr, unsigned char val)
  49 {
  50         writeb(val, (void __iomem *)addr);
  51 }
  52
  53 unsigned long io_inb(unsigned long port)
  54 {
  55         return inb(port);
  56 }
  57
  58 void io_outb(unsigned long port, unsigned char val)
  59 {
  60         outb(val, port);
  61 }
  62
  63 unsigned long serial_init(int chan, void *ignored)
  64 {
  65         unsigned long com_port;
  66         unsigned char lcr, dlm;
  67
  68         /* We need to find out which type io we're expecting.  If it's
  69          * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
  70          * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */
  71         switch (rs_table[chan].io_type) {
  72                 case SERIAL_IO_PORT:
  73                         com_port = rs_table[chan].port;
  74                         serial_outb = io_outb;
  75                         serial_inb = io_inb;
  76                         break;
  77                 case SERIAL_IO_MEM:
  78                         com_port = (unsigned long)rs_table[chan].iomem_base;
  79                         serial_outb = direct_outb;
  80                         serial_inb = direct_inb;
  81                         break;
  82                 default:
  83                         /* We can't deal with it. */
  84                         return -1;
  85         }
  86
  87         /* How far apart the registers are. */
  88         shift = rs_table[chan].iomem_reg_shift;
  89
  90         /* save the LCR */
  91         lcr = serial_inb(com_port + (UART_LCR << shift));
  92
  93         /* Access baud rate */
  94         serial_outb(com_port + (UART_LCR << shift), UART_LCR_DLAB);
  95         dlm = serial_inb(com_port + (UART_DLM << shift));
  96
  97         /*
  98          * Test if serial port is unconfigured
  99          * We assume that no-one uses less than 110 baud or
 100          * less than 7 bits per character these days.
 101          *  -- paulus.
 102          */
 103         if ((dlm <= 4) && (lcr & 2)) {
 104                 /* port is configured, put the old LCR back */
 105                 serial_outb(com_port + (UART_LCR << shift), lcr);
 106         }
 107         else {
 108                 /* Input clock. */
 109                 serial_outb(com_port + (UART_DLL << shift),
 110                         (rs_table[chan].baud_base / SERIAL_BAUD) & 0xFF);
 111                 serial_outb(com_port + (UART_DLM << shift),
 112                                 (rs_table[chan].baud_base / SERIAL_BAUD) >> 8);
 113                 /* 8 data, 1 stop, no parity */
 114                 serial_outb(com_port + (UART_LCR << shift), 0x03);
 115                 /* RTS/DTR */
 116                 serial_outb(com_port + (UART_MCR << shift), 0x03);
 117
 118                 /* Clear & enable FIFOs */
 119                 serial_outb(com_port + (UART_FCR << shift), 0x07);
 120         }
 121
 122         return (com_port);
 123 }
 124
 125 void
 126 serial_putc(unsigned long com_port, unsigned char c)
 127 {
 128         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
 129                 ;
 130         serial_outb(com_port, c);
 131 }
 132
 133 unsigned char
 134 serial_getc(unsigned long com_port)
 135 {
 136         while ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
 137                 ;
 138         return serial_inb(com_port);
 139 }
 140
 141 int
 142 serial_tstc(unsigned long com_port)
 143 {
 144         return ((serial_inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
 145 }
 146
 147 void
 148 serial_close(unsigned long com_port)
 149 {
 150 }
 151
 152 void
 153 gen550_init(int i, struct uart_port *serial_req)
 154 {
 155         rs_table[i].io_type = serial_req->iotype;
 156         rs_table[i].port = serial_req->iobase;
 157         rs_table[i].iomem_base = serial_req->membase;
 158         rs_table[i].iomem_reg_shift = serial_req->regshift;
 159         rs_table[i].baud_base = serial_req->uartclk ? serial_req->uartclk / 16 : BASE_BAUD;
 160 }
 161
 162 #ifdef CONFIG_SERIAL_TEXT_DEBUG
 163 void
 164 gen550_progress(char *s, unsigned short hex)
 165 {
 166         volatile unsigned int progress_debugport;
 167         volatile char c;
 168
 169         progress_debugport = serial_init(0, NULL);
 170
 171         serial_putc(progress_debugport, '\r');
 172
 173         while ((c = *s++) != 0)
 174                 serial_putc(progress_debugport, c);
 175
 176         serial_putc(progress_debugport, '\n');
 177         serial_putc(progress_debugport, '\r');
 178 }
 179 #endif /* CONFIG_SERIAL_TEXT_DEBUG */