unsigned lpc176x_cclk( void )
{
const unsigned cclksel = LPC176X_SCB.cclksel;
unsigned cclk_in = 0u;
unsigned cclk = 0u;
if ( ( cclksel & LPC176X_SCB_CCLKSEL_CCLKSEL ) != 0u ) {
cclk_in = lpc176x_pllclk();
} else {
cclk_in = lpc176x_sysclk();
}
cclk = cclk_in / LPC176X_SCB_CCLKSEL_CCLKDIV_GET( cclksel );
return cclk;
}
/**
* @brief Checks the usb module.
*
* @return RTEMS_SUCCESFUL if the usb module is correct.
*/
static rtems_status_code check_usb_module( void )
{
rtems_status_code status_code = RTEMS_INCORRECT_STATE;
const uint32_t pllclk = lpc176x_pllclk();
const uint32_t usbclk = LPC176X_USB_CLOCK;
if ( pllclk % usbclk == 0u ) {
const uint32_t usbdiv = pllclk / usbclk;
LPC176X_SCB.usbclksel = LPC176X_SCB_USBCLKSEL_USBDIV( usbdiv ) |
LPC176X_SCB_USBCLKSEL_USBSEL( 1 );
status_code = RTEMS_SUCCESSFUL;
}
/* else implies that the module has an incorrect pllclk or usbclk value.
Also, there is nothing to do. */
return status_code;
}
