static inline void modem_clock_init(void)
{
/* Use the CLK_OUT of the modem as the clock source. */
/* Enable GPIO clock gates */
KW2XDRF_PORT_CLKEN();
KW2XDRF_CLK_CTRL_CLKEN();
/* Modem RST_B is connected to PTB19 and can be used to reset the modem. */
KW2XDRF_PORT_DEV->PCR[KW2XDRF_RST_PIN] = PORT_PCR_MUX(1);
BITBAND_REG32(KW2XDRF_GPIO->PDDR, KW2XDRF_RST_PIN) = 1;
KW2XDRF_GPIO->PCOR = (1 << KW2XDRF_RST_PIN);
/* Modem GPIO5 is connected to PTC0 and can be used to select CLK_OUT frequency, */
/* set PTC0 high for CLK_OUT=32.787kHz and low for CLK_OUT=4MHz. */
KW2XDRF_CLK_CTRL_PORT_DEV->PCR[KW2XDRF_CLK_CTRL_PIN] = PORT_PCR_MUX(1);
BITBAND_REG32(KW2XDRF_CLK_CTRL_GPIO->PDDR, KW2XDRF_CLK_CTRL_PIN) = 1;
KW2XDRF_CLK_CTRL_GPIO->PCOR = (1 << KW2XDRF_CLK_CTRL_PIN);
/* Modem IRQ_B is connected to PTB3, modem interrupt request to the MCU. */
KW2XDRF_PORT_DEV->PCR[KW2XDRF_IRQ_PIN] = PORT_PCR_MUX(1);
BITBAND_REG32(KW2XDRF_GPIO->PDDR, KW2XDRF_IRQ_PIN) = 0;
/* release the reset */
KW2XDRF_GPIO->PSOR = (1 << KW2XDRF_RST_PIN);
/* wait for modem IRQ_B interrupt request */
while (KW2XDRF_GPIO->PDIR & (1 << KW2XDRF_IRQ_PIN));
}
void hwrng_read(void *buf, unsigned int num)
{
unsigned int count = 0;
uint8_t *b = (uint8_t *)buf;
HWRNG_CLKEN();
if ((KINETIS_RNGB->VER & RNG_VER_TYPE_MASK) != 0b0001) {
/* Wrong type of RNG */
/* TODO: Handle */
}
/* Software reset, bit is self-clearing */
BITBAND_REG32(KINETIS_RNGB->CMD, RNG_CMD_SR_SHIFT) = 1;
/* Set up automatic reseed */
KINETIS_RNGB->CR = RNG_CR_AR_MASK | RNG_CR_MASKERR_MASK | RNG_CR_MASKDONE_MASK;
while (count < num) {
uint32_t tmp;
/* wait for random data to be ready to read */
while (!(KINETIS_RNGB->SR & RNG_SR_FIFO_LVL_MASK));
tmp = KINETIS_RNGB->OUT;
/* copy data into result vector */
for (int i = 0; i < 4 && count < num; i++) {
b[count++] = (uint8_t)tmp;
tmp = tmp >> 8;
}
}
KINETIS_RNGB->CR = 0;
HWRNG_CLKDIS();
}
void pre_startup(void)
{
/* disable the WDOG */
wdog_disable();
#ifdef SIM_SCGC7_FLEXBUS_SHIFT
/*
* Workaround for hardware errata e4218: "SIM/FLEXBUS: SIM_SCGC7[FLEXBUS]
* bit should be cleared when the FlexBus is not being used."
*/
BITBAND_REG32(SIM->SCGC7, SIM_SCGC7_FLEXBUS_SHIFT) = 0;
#endif
}
void random_poweron(void)
{
RANDOM_CLKEN();
if ((KINETIS_RNGB->VER & RNG_VER_TYPE_MASK) != 0b0001) {
/* Wrong type of RNG */
/* TODO: Handle */
}
/* Software reset, bit is self-clearing */
BITBAND_REG32(KINETIS_RNGB->CMD, RNG_CMD_SR_SHIFT) = 1;
/* Set up automatic reseed */
KINETIS_RNGB->CR = RNG_CR_AR_MASK | RNG_CR_MASKERR_MASK | RNG_CR_MASKDONE_MASK;
}
