arch/ppc/boot/common/ns16550.c

   1 /*
   2  * COM1 NS16550 support
   3  */
   4
   5 #include <linux/types.h>
   6 #include <linux/serial.h>
   7 #include <linux/serial_reg.h>
   8 #include <asm/serial.h>
   9
  10 #if defined(CONFIG_XILINX_VIRTEX)
  11 #include <platforms/4xx/xparameters/xparameters.h>
  12 #endif
  13 #include "nonstdio.h"
  14 #include "serial.h"
  15
  16 #define SERIAL_BAUD     9600
  17
  18 extern unsigned long ISA_io;
  19
  20 static struct serial_state rs_table[RS_TABLE_SIZE] = {
  21         SERIAL_PORT_DFNS        /* Defined in <asm/serial.h> */
  22 };
  23
  24 static int shift;
  25
  26 unsigned long serial_init(int chan, void *ignored)
  27 {
  28         unsigned long com_port, base_baud;
  29         unsigned char lcr, dlm;
  30
  31         /* We need to find out which type io we're expecting.  If it's
  32          * 'SERIAL_IO_PORT', we get an offset from the isa_io_base.
  33          * If it's 'SERIAL_IO_MEM', we can the exact location.  -- Tom */
  34         switch (rs_table[chan].io_type) {
  35                 case SERIAL_IO_PORT:
  36                         com_port = rs_table[chan].port;
  37                         break;
  38                 case SERIAL_IO_MEM:
  39                         com_port = (unsigned long)rs_table[chan].iomem_base;
  40                         break;
  41                 default:
  42                         /* We can't deal with it. */
  43                         return -1;
  44         }
  45
  46         /* How far apart the registers are. */
  47         shift = rs_table[chan].iomem_reg_shift;
  48         /* Base baud.. */
  49         base_baud = rs_table[chan].baud_base;
  50
  51         /* save the LCR */
  52         lcr = inb(com_port + (UART_LCR << shift));
  53         /* Access baud rate */
  54         outb(com_port + (UART_LCR << shift), 0x80);
  55         dlm = inb(com_port + (UART_DLM << shift));
  56         /*
  57          * Test if serial port is unconfigured.
  58          * We assume that no-one uses less than 110 baud or
  59          * less than 7 bits per character these days.
  60          *  -- paulus.
  61          */
  62
  63         if ((dlm <= 4) && (lcr & 2))
  64                 /* port is configured, put the old LCR back */
  65                 outb(com_port + (UART_LCR << shift), lcr);
  66         else {
  67                 /* Input clock. */
  68                 outb(com_port + (UART_DLL << shift),
  69                      (base_baud / SERIAL_BAUD) & 0xFF);
  70                 outb(com_port + (UART_DLM << shift),
  71                      (base_baud / SERIAL_BAUD) >> 8);
  72                 /* 8 data, 1 stop, no parity */
  73                 outb(com_port + (UART_LCR << shift), 0x03);
  74                 /* RTS/DTR */
  75                 outb(com_port + (UART_MCR << shift), 0x03);
  76         }
  77         /* Clear & enable FIFOs */
  78         outb(com_port + (UART_FCR << shift), 0x07);
  79
  80         return (com_port);
  81 }
  82
  83 void
  84 serial_putc(unsigned long com_port, unsigned char c)
  85 {
  86         while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0)
  87                 ;
  88         outb(com_port, c);
  89 }
  90
  91 unsigned char
  92 serial_getc(unsigned long com_port)
  93 {
  94         while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0)
  95                 ;
  96         return inb(com_port);
  97 }
  98
  99 int
 100 serial_tstc(unsigned long com_port)
 101 {
 102         return ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0);
 103 }