usb_drv.c

at89c5132,at89c51snd1的usb与keyboard驱动程序。

* PARAMS:
* ep_num:       number of the addressed endpoint
* *rbuf:        address of the first data to write with the USB data
* data_length:  number of bytes to read
* return:       address of the next Ucharto send
*----------------------------------------------------------------------------
* PURPOSE: 
* This function moves the data stored in the selected endpoint fifo to 
* the address specified by *rbuf.
*----------------------------------------------------------------------------
* EXAMPLE:
* while(!(Usb_rx_complete));                      // wait new packet received
* usb_read_packet(4,&first_data,usb_get_nb_byte); // read packet from ep 4
* Usb_clear_rx();                                 // acknowledge the transmit
*----------------------------------------------------------------------------
* NOTE:
* rbuf is incremented of 'data_length'.
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
Uchar* usb_read_packet (Uchar ep_num, Uchar* rbuf, Uchar data_length)
{
Uchar i;

  Usb_select_ep(ep_num);

  for (i = data_length; i != 0 ; i--, rbuf++) { *rbuf = Usb_read_byte(); }

  return rbuf;
}

/*F**************************************************************************
* NAME: usb_halt_endpoint
*----------------------------------------------------------------------------
* PARAMS:
* ep_num:       number of the addressed endpoint
* return:       none
*----------------------------------------------------------------------------
* PURPOSE: 
* This function sends a STALL handshake for the next Host request. A STALL
* handshake will be send for each next request untill a SETUP or a Clear Halt
* Feature occurs for this endpoint.
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE:
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
void usb_halt_endpoint (Uchar ep_num)
{
  Usb_select_ep(ep_num);
  UEPSTAX = 0x00;
  Usb_set_stall_request();
}

/*F**************************************************************************
* NAME: usb_reset_endpoint
*----------------------------------------------------------------------------
* PARAMS:
* return:       none
*----------------------------------------------------------------------------
* PURPOSE: 
* This function resets the endpoint fifo. This should be performed before
* the first use of an endpoint and after a Clear Halt Feature for the 
* endpoint
*----------------------------------------------------------------------------
* EXAMPLE:
*----------------------------------------------------------------------------
* NOTE: 
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
void usb_reset_endpoint (Uchar ep_num)
{
  UEPRST = 0x01 << ep_num ;
  UEPRST = 0x00;
}

/*F**************************************************************************
* NAME: configure_usb_clock
*----------------------------------------------------------------------------
* PARAMS:
* return:       none
* The possible value for FOSC are :
*              3000   ( 3MHz)
*              6000   ( 6MHz)
*              8000   ( 8MHz)
*             12000   (12MHz)
*             16000   (16MHz)
*             18000   (18MHz)
*             20000   (20MHz)
*             24000   (24MHz)
*             32000   (32MHz)
*             40000   (40MHz)
*             48000   (48MHz)
*              0000   (frequency auto-dectection)
*----------------------------------------------------------------------------
* PURPOSE: 
* This function configure the PLL to generate the 48MHz clock required by
* the USB controller, considering the FOSC defined in the "config.h" file.
*----------------------------------------------------------------------------
* EXAMPLE:
* #define FOSC   8000 // 8MHz
* configure_usb_clock();
*----------------------------------------------------------------------------
* NOTE: 
*----------------------------------------------------------------------------
* REQUIREMENTS: 
*****************************************************************************/
void configure_usb_clock(void)
{
#if FOSC == 3000
  Pll_set_div(PLL_3MHz);
  Pll_enable();
#endif

#if FOSC == 4000
  Pll_set_div(PLL_4MHz);
  Pll_enable();
#endif

#if FOSC == 6000
  Pll_set_div(PLL_6MHz);
  Pll_enable();
#endif

#if FOSC == 8000
  Pll_set_div(PLL_8MHz);
  Pll_enable();
#endif

#if FOSC == 12000
  Pll_set_div(PLL_12MHz);
  Pll_enable();
#endif

#if FOSC == 16000
  Pll_set_div(PLL_16MHz);
  Pll_enable();
#endif

#if FOSC == 18000
  Pll_set_div(PLL_18MHz);
  Pll_enable();
#endif

#if FOSC == 20000
  Pll_set_div(PLL_20MHz);
  Pll_enable();
#endif

#if FOSC == 24000
  Pll_set_div(PLL_24MHz);
  Pll_enable();
#endif

#if FOSC == 32000
  Pll_set_div(PLL_32MHz);
  Pll_enable();
#endif

#if FOSC == 40000
  Pll_set_div(PLL_40MHz);
  Pll_enable();
#endif

#if FOSC == 48000
  Usb_set_EXT48()
#endif

#if FOSC == 0000            /* frequency Auto-detection */

Uchar i;
Uchar reload;
  
  PLLCON = 0x00;
  
  if (CKCON0 & MSK_X2)
  {
    CKCON0 |= MSK_T0X2;
    reload = 6; 
  }
  else
  {
    CKCON0 &= ~MSK_T0X2;
    reload = 9;
  }
  
  TMOD = 0x01;                            /* put Timer 0 in mode 1 */
  USBINT = 0x00;
  i=reload;
  
  while (!(USBINT & MSK_SOFINT))          /* Do until Start Of Frame detection */
  {
    if (i==9)
    {
      Pll_stop();                         /* external 48 MHz supposed */
      Usb_set_EXT48();
    }
    else
    {
      Usb_clear_EXT48();                  /* PLL output supposed */
      Pll_set_div(pll_value[i]);          /* configure PLL */
      Pll_enable();
    }
    TH0 = TH0_value[i];                   /* Run Timer 0 */
    TL0 = TL0_value[i];
    TCON |= 0x10;
    while(((TCON & 0x20) != 0x20));       /* Wait Timer 0 Overflow */
    TCON &= ~(0x30);
    if (i==0)
    {
      i=reload;
    }
    else
    {
      i--;
    }
  }

  TH0  = 0;                               /* Reset Timer 0 Registers */
  TL0  = 0;
  TCON = 0;
  TMOD = 0;
#endif
}