/**
* @brief Configure the controllers clock system
*/
static void cpu_clock_init(void)
{
const uint32_t CLOCK_CTRL_VALUE =
OSC_PD /**< Power down the oscillator not selected by OSC bit (hardware-controlled when selected). */
| (1 << IO_DIV_SHIFT) /**< 16 MHz IO_DIV */
| (1 << SYS_DIV_SHIFT) /**< 16 MHz SYS_DIV */
#if !SYS_CTRL_OSC32K_USE_XTAL
| OSC32K /**< Use internal RC oscillator. */
#endif
;
#if SYS_CTRL_OSC32K_USE_XTAL
/* Set the XOSC32K_Q pads to analog for the external crystal: */
gpio_software_control(GPIO_PD6);
gpio_dir_input(GPIO_PD6);
IOC_PXX_OVER[GPIO_PD6] = IOC_OVERRIDE_ANA;
gpio_software_control(GPIO_PD7);
gpio_dir_input(GPIO_PD7);
IOC_PXX_OVER[GPIO_PD7] = IOC_OVERRIDE_ANA;
#endif
/* Configure the clock settings: */
SYS_CTRL->cc2538_sys_ctrl_clk_ctrl.CLOCK_CTRL = CLOCK_CTRL_VALUE;
/* Wait for the new clock settings to take effect: */
while ((SYS_CTRL->cc2538_sys_ctrl_clk_sta.CLOCK_STA ^ CLOCK_CTRL_VALUE) & CLOCK_STA_MASK);
#if SYS_CTRL_OSC32K_USE_XTAL
/* Wait for the 32-kHz crystal oscillator to stabilize: */
while ( SYS_CTRL->CLOCK_STAbits.SYNC_32K);
while (!SYS_CTRL->CLOCK_STAbits.SYNC_32K);
#endif
}
int gpio_init_in(gpio_t dev, gpio_pp_t pushpull)
{
int pin;
if (!gpio_enabled(dev)) {
return -1;
}
pin = pin_lut[dev];
gpio_software_control(pin);
gpio_dir_input(pin);
/* configure the pin's pull resistor state */
IOC_PXX_OVER[pin] = ioc_mask_lut[pushpull];
return 0;
}
int gpio_init(gpio_t dev, gpio_mode_t mode)
{
int pin;
if (!gpio_enabled(dev)) {
return -1;
}
pin = pin_lut[dev];
gpio_software_control(pin);
switch (mode) {
case GPIO_IN:
gpio_dir_input(pin);
/* configure the pin's pull resistor state */
IOC_PXX_OVER[pin] = (IOC_OVERRIDE_DIS);
break;
case GPIO_IN_PD:
gpio_dir_input(pin);
/* configure the pin's pull resistor state */
IOC_PXX_OVER[pin] = (IOC_OVERRIDE_PDE);
break;
case GPIO_IN_PU:
gpio_dir_input(pin);
/* configure the pin's pull resistor state */
IOC_PXX_OVER[pin] = (IOC_OVERRIDE_PUE);
break;
case GPIO_OUT:
gpio_dir_output(pin);
/* configure the pin's pull resistor state */
IOC_PXX_OVER[pin] = (IOC_OVERRIDE_OE);
break;
default:
return -1;
}
return 0;
}
static void assert_scl(void) {
cc2538_gpio_clear(I2C_0_SCL_PIN);
IOC_PXX_OVER[I2C_0_SCL_PIN] |= IOC_OVERRIDE_OE;
gpio_dir_output(I2C_0_SCL_PIN);
gpio_software_control(I2C_0_SCL_PIN);
}
static void release_sda(void) {
IOC_PXX_OVER[I2C_0_SDA_PIN] &= ~(IOC_OVERRIDE_OE | IOC_OVERRIDE_PDE);
gpio_dir_input(I2C_0_SDA_PIN);
gpio_software_control(I2C_0_SDA_PIN);
}
