drivers/serial/ns16550.c

   1 /*
   2  * COM1 NS16550 support
   3  * originally from linux source (arch/powerpc/boot/ns16550.c)
   4  * modified to use CONFIG_SYS_ISA_MEM and new defines
   5  */
   6
   7 #include <config.h>
   8 #include <ns16550.h>
   9 #include <watchdog.h>
  10
  11 #define UART_LCRVAL UART_LCR_8N1                /* 8 data, 1 stop, no parity */
  12 #define UART_MCRVAL (UART_MCR_DTR | \
  13                      UART_MCR_RTS)              /* RTS/DTR */
  14 #define UART_FCRVAL (UART_FCR_FIFO_EN | \
  15                      UART_FCR_RXSR |    \
  16                      UART_FCR_TXSR)             /* Clear & enable FIFOs */
  17
  18 void NS16550_init (NS16550_t com_port, int baud_divisor)
  19 {
  20         com_port->ier = 0x00;
  21 #if defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)
  22         com_port->mdr1 = 0x7;   /* mode select reset TL16C750*/
  23 #endif
  24         com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
  25         com_port->dll = 0;
  26         com_port->dlm = 0;
  27         com_port->lcr = UART_LCRVAL;
  28         com_port->mcr = UART_MCRVAL;
  29         com_port->fcr = UART_FCRVAL;
  30         com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
  31         com_port->dll = baud_divisor & 0xff;
  32         com_port->dlm = (baud_divisor >> 8) & 0xff;
  33         com_port->lcr = UART_LCRVAL;
  34 #if defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)
  35 #if defined(CONFIG_APTIX)
  36         com_port->mdr1 = 3;     /* /13 mode so Aptix 6MHz can hit 115200 */
  37 #else
  38         com_port->mdr1 = 0;     /* /16 is proper to hit 115200 with 48MHz */
  39 #endif
  40 #endif /* CONFIG_OMAP */
  41 }
  42
  43 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
  44 void NS16550_reinit (NS16550_t com_port, int baud_divisor)
  45 {
  46         com_port->ier = 0x00;
  47         com_port->lcr = UART_LCR_BKSE | UART_LCRVAL;
  48         com_port->dll = 0;
  49         com_port->dlm = 0;
  50         com_port->lcr = UART_LCRVAL;
  51         com_port->mcr = UART_MCRVAL;
  52         com_port->fcr = UART_FCRVAL;
  53         com_port->lcr = UART_LCR_BKSE;
  54         com_port->dll = baud_divisor & 0xff;
  55         com_port->dlm = (baud_divisor >> 8) & 0xff;
  56         com_port->lcr = UART_LCRVAL;
  57 }
  58 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */
  59
  60 void NS16550_putc (NS16550_t com_port, char c)
  61 {
  62         while ((com_port->lsr & UART_LSR_THRE) == 0);
  63         com_port->thr = c;
  64 }
  65
  66 #ifndef CONFIG_NS16550_MIN_FUNCTIONS
  67 char NS16550_getc (NS16550_t com_port)
  68 {
  69         while ((com_port->lsr & UART_LSR_DR) == 0) {
  70 #ifdef CONFIG_USB_TTY
  71                 extern void usbtty_poll(void);
  72                 usbtty_poll();
  73 #endif
  74                 WATCHDOG_RESET();
  75         }
  76         return (com_port->rbr);
  77 }
  78
  79 int NS16550_tstc (NS16550_t com_port)
  80 {
  81         return ((com_port->lsr & UART_LSR_DR) != 0);
  82 }
  83
  84 #endif /* CONFIG_NS16550_MIN_FUNCTIONS */