drivers/ns16550.c

   1 /*
   2  * COM1 NS16550 support
   3  * originally from linux source (arch/ppc/boot/ns16550.c)
   4  * modified to use CFG_ISA_MEM and new defines
   5  */
   6
   7 #include <config.h>
   8
   9 #ifdef CFG_NS16550
  10
  11 #include <ns16550.h>
  12
  13 #define LCRVAL LCR_8N1                                  /* 8 data, 1 stop, no parity */
  14 #define MCRVAL (MCR_DTR | MCR_RTS)                      /* RTS/DTR */
  15 #define FCRVAL (FCR_FIFO_EN | FCR_RXSR | FCR_TXSR)      /* Clear & enable FIFOs */
  16
  17 void NS16550_init (NS16550_t com_port, int baud_divisor)
  18 {
  19         com_port->ier = 0x00;
  20 #ifdef CONFIG_OMAP
  21         com_port->mdr1 = 0x7;   /* mode select reset TL16C750*/
  22 #endif
  23         com_port->lcr = LCR_BKSE | LCRVAL;
  24         com_port->dll = baud_divisor & 0xff;
  25         com_port->dlm = (baud_divisor >> 8) & 0xff;
  26         com_port->lcr = LCRVAL;
  27         com_port->mcr = MCRVAL;
  28         com_port->fcr = FCRVAL;
  29 #if defined(CONFIG_OMAP)
  30 #if defined(CONFIG_APTIX)
  31         com_port->mdr1 = 3;     /* /13 mode so Aptix 6MHz can hit 115200 */
  32 #else
  33         com_port->mdr1 = 0;     /* /16 is proper to hit 115200 with 48MHz */
  34 #endif
  35 #endif
  36 }
  37
  38 void NS16550_reinit (NS16550_t com_port, int baud_divisor)
  39 {
  40         com_port->ier = 0x00;
  41         com_port->lcr = LCR_BKSE;
  42         com_port->dll = baud_divisor & 0xff;
  43         com_port->dlm = (baud_divisor >> 8) & 0xff;
  44         com_port->lcr = LCRVAL;
  45         com_port->mcr = MCRVAL;
  46         com_port->fcr = FCRVAL;
  47 }
  48
  49 void NS16550_putc (NS16550_t com_port, char c)
  50 {
  51         while ((com_port->lsr & LSR_THRE) == 0);
  52         com_port->thr = c;
  53 }
  54
  55 char NS16550_getc (NS16550_t com_port)
  56 {
  57         while ((com_port->lsr & LSR_DR) == 0) {
  58 #ifdef CONFIG_USB_TTY
  59                 extern void usbtty_poll(void);
  60                 usbtty_poll();
  61 #endif
  62         }
  63         return (com_port->rbr);
  64 }
  65
  66 int NS16550_tstc (NS16550_t com_port)
  67 {
  68         return ((com_port->lsr & LSR_DR) != 0);
  69 }
  70
  71 #endif