static void set_i2c_clock(uint32_t instance, uint32_t baud)
{
// Adjust the divider to get the closest SCL frequency to baud rate
uint32_t src_clk = get_main_clock(IPG_PER_CLK);
uint32_t divider = src_clk / baud;
uint8_t index = 0;
if (divider < i2c_freq_div[0][0])
{
divider = i2c_freq_div[0][0];
index = 0;
/* debug_printf("Warning :can't find a smaller divider than %d.\n", divider);
debug_printf("SCL frequency is set at %d - expected was %d.\n", src_clk/divider, baud);
*/
}
else if (divider > i2c_freq_div[49][0])
{
divider = i2c_freq_div[49][0];
index = 49;
/*
debug_printf("Warning: can't find a bigger divider than %d.\n", divider);
debug_printf("SCL frequency is set at %d - expected was %d.\n", src_clk/divider, baud);
*/
}
else
{
for (index = 0; i2c_freq_div[index][0] < divider; index++);
divider = i2c_freq_div[index][0];
}
HW_I2C_IFDR_WR(instance, BF_I2C_IFDR_IC(i2c_freq_div[index][1]));
}
int rt_hw_timer_init(void)
{
uint32_t freq;
// Make sure the timer is off.
HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 0;
HW_ARMGLOBALTIMER_CONTROL.B.FCR0 =1;
HW_ARMGLOBALTIMER_CONTROL.B.FCR1 =0;
HW_ARMGLOBALTIMER_CONTROL.B.DBG_ENABLE =0;
// Clear counter.
HW_ARMGLOBALTIMER_COUNTER_HI_WR(0);
HW_ARMGLOBALTIMER_COUNTER_LO_WR(0);
// Now turn on the timer.
HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 1;
freq = get_main_clock(IPG_CLK);
epit_init(HW_EPIT1, CLKSRC_IPG_CLK, freq / 1000000,
SET_AND_FORGET, 10000, WAIT_MODE_EN | STOP_MODE_EN);
epit_counter_enable(HW_EPIT1, 10000, IRQ_MODE);
rt_hw_interrupt_install(IMX_INT_EPIT1, rt_hw_timer_isr, RT_NULL, "tick");
rt_hw_interrupt_umask(IMX_INT_EPIT1);
return 0;
}
int rt_hw_timer_init(void)
{
uint32_t freq;
// The ARM private peripheral clock is half the CPU clock.
uint32_t periphClock = get_main_clock(CPU_CLK) / 2;
uint32_t prescaler = (periphClock / 1000000) - 1;
// Divide down the prescaler until it fits into 8 bits. We add up the number of ticks
// it takes to equal a microsecond interval.
while (prescaler > 0xff)
{
prescaler /= 2;
}
// Make sure the timer is off.
HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 0;
// Clear counter.
HW_ARMGLOBALTIMER_COUNTERn_WR(0, 0);
HW_ARMGLOBALTIMER_COUNTERn_WR(1, 0);
// Set prescaler and clear other flags.
HW_ARMGLOBALTIMER_CONTROL_WR(BF_ARMGLOBALTIMER_CONTROL_PRESCALER(prescaler));
// Now turn on the timer.
HW_ARMGLOBALTIMER_CONTROL.B.TIMER_ENABLE = 1;
freq = get_main_clock(IPG_CLK);
epit_init(HW_EPIT1, CLKSRC_IPG_CLK, freq / 1000000,
SET_AND_FORGET, 10000, WAIT_MODE_EN | STOP_MODE_EN);
epit_counter_enable(HW_EPIT1, 10000, IRQ_MODE);
rt_hw_interrupt_install(IMX_INT_EPIT1, rt_hw_timer_isr, RT_NULL, "tick");
rt_hw_interrupt_umask(IMX_INT_EPIT1);
return 0;
}