arch/all-native/bootconsole/serial_16450_unused.c

   1 /*
   2  * This code was rescued from arch/x86_64/exec/serialrawio.c before x86-64 port update.
   3  * Perhaps it can be useful in future, however it's questionable whether it is really
   4  * needed for debugging console.
   5  */
   6
   7 #include <asm/io.h>
   8 #include <hardware/uart.h>
   9
  10 /** UART Types **/
  11 #define SER_UART_INS8250       1
  12 #define SER_UART_NS16450       2
  13 #define SER_UART_NS16550A      3
  14 #define SER_UART_NS16C552      4
  15
  16 unsigned char __ser_UARTType(short port)
  17 {
  18     outb_p(0xAA, port + UART_LCR);                  /* set Divisor-Latch */
  19     if (inb_p(port + UART_LCR) != 0xAA)
  20         return 0;
  21     outb_p(0x55, port + UART_DLM);                   /* write Divisor */
  22     if (inb_p(port + UART_DLM) != 0x55)
  23         return 0;
  24     outb_p(0x55, port + UART_LCR);                  /* clear Divisor-Latch */
  25     if (inb_p(port + UART_LCR) != 0x55)
  26         return 0;
  27     outb_p(0x55, port + UART_IER);
  28     if (inb_p(port + UART_IER) != 0x05)
  29         return 0;
  30     outb_p(0, port + UART_FCR);                     /* clear FIFO and IRQ */
  31     outb_p(0, port + UART_IER);
  32     if (inb_p(port + UART_IIR) != 1)
  33         return 0;
  34     outb_p(0xF5, port + UART_MCR);
  35     if (inb_p(port + UART_MCR) != 0x15)
  36         return 0;
  37     outb_p(UART_MCR_LOOP, port + UART_MCR);         /* Looping */
  38     inb_p(port + UART_MSR);
  39     if ((inb_p(port + UART_MSR) & 0xF0) != 0)
  40         return 0;
  41     outb_p(0x1F, port + UART_MCR);
  42     if ((inb_p(port + UART_MSR) & 0xF0) != 0xF0)
  43         return 0;
  44     outb_p(SER_MCR_DTR | SER_MCR_RTS, port + UART_MCR);
  45
  46     outb_p(0x55, port + UART_SCR);                  /* Scratch-Register ?*/
  47     if (inb_p(port + UART_SCR) != 0x55)
  48         return SER_UART_INS8250;
  49     outb_p(0, port + UART_SCR);
  50
  51     outb_p(0xCF, port + UART_FCR);                  /* FIFO ? */
  52     if ((inb_p(port + UART_IIR) & 0xC0) != 0xC0)
  53         return SER_UART_NS16450;
  54     outb_p(0, port + UART_FCR);
  55
  56     outb_p(UART_LCR_DLAB, port + UART_LCR);    /* Alternate-Function Register ? */
  57     outb_p(0x07, port + UART_EFR);
  58     if (inb_p(port + UART_EFR ) != 0x07)
  59     {
  60         outb_p(0, port + UART_LCR);
  61         return SER_UART_NS16550A;
  62     }
  63     outb_p(0, port + UART_LCR);                     /* reset registers */
  64     outb_p(0, port + UART_EFR);
  65     return SER_UART_NS16C552;
  66 }
  67
  68 static void __ser_FIFOLevel(short port, BYTE level)
  69 {
  70     if (level)
  71         outb_p(level | UART_FCR_ENABLE_FIFO, port + UART_FCR);
  72     else
  73         outb_p(UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT, port + UART_FCR);
  74 }