source: rtems/bsps/arm/rtl22xx/console/uart.c

/*
 *  console driver for RTL22xx UARTs
 *
 *  If you want the driver to be interrupt driven, you
 *  need to write the ISR, and in the ISR insert the
 *  chars into termios's queue.
 */

/*
 *  Copyright (c) By ray <rayx.cn@gmail.com>
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#include <bsp.h>                /* Must be before libio.h */
#include <rtems/libio.h>
#include <termios.h>
#include <rtems/bspIo.h>

/* Put the CPU (or UART) specific header file #include here */
#include <lpc22xx.h>
#include "lpc22xx_uart.h"

#include <libchip/serial.h>
#include <libchip/sersupp.h>

/* How many serial ports? */
#define NUM_DEVS       1

int dbg_dly;

/* static function prototypes */
static int     uart_first_open(int major, int minor, void *arg);
static int     uart_last_close(int major, int minor, void *arg);
static int     uart_read(int minor);
static ssize_t uart_write(int minor, const char *buf, size_t len);
static void    uart_init(int minor);
static void    uart_write_polled(int minor, char c);
static int     uart_set_attributes(int minor, const struct termios *t);

/* These are used by code in console.c */
unsigned long Console_Configuration_Count = NUM_DEVS;

/* Pointers to functions for handling the UART. */
const console_fns uart_fns = {
  libchip_serial_default_probe,
  uart_first_open,
  uart_last_close,
  uart_read,
  uart_write,
  uart_init,
  uart_write_polled,   /* not used in this driver */
  uart_set_attributes,
  FALSE                /* TRUE if interrupt driven, FALSE if not. */
};

/*
 * There's one item in array for each UART.
 *
 * Some of these fields are marked "NOT USED". They are not used
 * by console.c, but may be used by drivers in libchip
 */
console_tbl Console_Configuration_Ports[] = {
{
    "/dev/com0",                      /* sDeviceName */
    SERIAL_CUSTOM,                    /* deviceType */
    &uart_fns,                        /* pDeviceFns */
    NULL,                             /* deviceProbe */
    NULL,                             /* pDeviceFlow */
    0,                                /* ulMargin - NOT USED */
    0,                                /* ulHysteresis - NOT USED */
    NULL,                             /* pDeviceParams */
    0,                                /* ulCtrlPort1  - NOT USED */
    0,                                /* ulCtrlPort2  - NOT USED */
    0,                                /* ulDataPort  - NOT USED */
    NULL,                             /* getRegister - NOT USED */
    NULL,                             /* setRegister - NOT USED */
    NULL,                             /* getData - NOT USED */
    NULL,                             /* setData - NOT USED */
    0,                                /* ulClock - NOT USED */
    0                                 /* ulIntVector - NOT USED */
}
#if 0
{
    "/dev/com1",                      /* sDeviceName */
    SERIAL_CUSTOM,                    /* deviceType */
    &uart_fns,                        /* pDeviceFns */
    NULL,                             /* deviceProbe */
    NULL,                             /* pDeviceFlow */
    0,                                /* ulMargin - NOT USED */
    0,                                /* ulHysteresis - NOT USED */
    NULL,                             /* pDeviceParams */
    0,                                /* ulCtrlPort1  - NOT USED */
    0,                                /* ulCtrlPort2  - NOT USED */
    0,                                /* ulDataPort  - NOT USED */
    NULL,                             /* getRegister - NOT USED */
    NULL,                             /* setRegister - NOT USED */
    NULL,                             /* getData - NOT USED */
    NULL,                             /* setData - NOT USED */
    0,                                /* ulClock - NOT USED */
    0                                 /* ulIntVector - NOT USED */
}
#endif
};

/*
 * This is called the first time each device is opened. If the driver
 * is interrupt driven, you should enable interrupts here. Otherwise,
 * it's probably safe to do nothing.
 *
 * Since micromonitor already set up the UART, we do nothing.
 */
static int uart_first_open(int major, int minor, void *arg)
{
  return 0;
}

/*
 * This is called the last time each device is closed. If the driver
 * is interrupt driven, you should disable interrupts here. Otherwise,
 * it's probably safe to do nothing.
 */
static int uart_last_close(int major, int minor, void *arg)
{
  return 0;
}

/*
 * Read one character from UART.
 *
 * Return -1 if there's no data, otherwise return
 * the character in lowest 8 bits of returned int.
 */
static int uart_read(int minor)
{
  char c;

  switch (minor) {
    case 0:
      if (U0LSR & ULSR_RDR) {
        c = U0RBR;
        return c;
      }
      return -1;
    case 1:
      if (U1LSR & ULSR_RDR) {
        c = U1RBR;
        return c;
      }
      return -1;
    default:
      break;
  }
  printk("Unknown console minor number %d\n", minor);
  return -1;
}

/*
 * Write buffer to UART
 *
 * return 1 on success, -1 on error
 */
static ssize_t uart_write(int minor, const char *buf, size_t len)
{
  size_t i;

  switch (minor) {
    case 0:
      for (i = 0; i < len; i++) {
        while (!(U0LSR & ULSR_THRE))   /* wait for TX buffer to empty*/
          continue;                    /* also either WDOG() or swap()*/
        U0THR = (char) buf[i];
      }
      break;
    case 1:
      for (i = 0; i < len; i++) {
        while (!(U0LSR & ULSR_THRE))   /* wait for TX buffer to empty*/
          continue;                    /* also either WDOG() or swap()*/
        U0THR = (char) buf[i];
      }
      break;
    default:
      printk("Unknown console minor number %d\n", minor);
      return -1;
  }

  return len;
}

/* Set up the UART. */
static void uart_init(int minor)
{
#if 0 //init will be done in bspstart.c
  int baud=6;
  int mode =0x03;
  if(minor==0){
    // set port pins for UART0
    PINSEL0 =  (PINSEL0 & ~U0_PINMASK) | U0_PINSEL;

    U0IER = 0x00;                         // disable all interrupts

    // set the baudrate
    U0LCR = 1<<7;             // select divisor latches
    U0DLL = (uint8_t)baud;                // set for baud low byte
    U0DLM = (uint8_t)(baud >> 8);         // set for baud high byte

    // set the number of characters and other
    // user specified operating parameters
    U0LCR = (mode & ~ULCR_DLAB_ENABLE);
    U0FCR = mode>>8; /*fifo mode*/

    // set port pins for UART1
    PINSEL0 = (PINSEL0 & ~U1_PINMASK) | U1_PINSEL;

    U1IER = 0x00;              // disable all interrupts
  }else if(minor==1){
    // set the baudrate
    U1LCR = ULCR_DLAB_ENABLE;        // select divisor latches
    U1DLL = (uint8_t)baud;          // set for baud low byte
    U1DLM = (uint8_t)(baud >> 8);      // set for baud high byte

    // set the number of characters and other
    // user specified operating parameters
    U1LCR = (mode & ~ULCR_DLAB_ENABLE);
    U1FCR = mode>>8;/*fifo mode*/
  }

#endif
}

/* I'm not sure this is needed for the shared console driver. */
static void uart_write_polled(int minor, char c)
{
  uart_write(minor, &c, 1);
}

/* This is for setting baud rate, bits, etc. */
static int uart_set_attributes(int minor, const struct termios *t)
{
  return 0;
}

/*
 * Write a character to the console. This is used by printk() and
 * maybe other low level functions. It should not use interrupts or any
 * RTEMS system calls. It needs to be very simple
 */
static void _BSP_put_char( char c )
{
  uart_write_polled(0, c);
}

BSP_output_char_function_type BSP_output_char = _BSP_put_char;

static int _BSP_get_char(void)
{
  return uart_read(0);
}

BSP_polling_getchar_function_type BSP_poll_char = _BSP_get_char;

/*
 * init USART 0: 8 bit, 1 Stop,No checkout, BPS115200
 */
void UART0_Ini(void)
{
  long Fdiv;
  int i;

  PINSEL0 = 0x00000005;        // I/O to UART0
  U0LCR = 0x83;                // DLAB = 1
  Fdiv = (Fpclk >>4) / UART_BPS;  // configure BPS
  U0DLM = Fdiv/256;
  U0DLL = Fdiv%256;
  U0LCR = 0x03;

  for(i=0;i<10;i++){
    U0THR = 67;    //send a C to see if is OK
    while ( (U0LSR&0x40)==0 );
  }
}