/* Write the Configuration Register.
* This updates the states of the corresponding clocks. The bit values are not
* saved - when the register is read, its value will be built using the clock
* states.
*/
static void stm32_rcc_RCC_CR_write(Stm32Rcc *s, uint32_t new_value, bool init)
{
bool new_pllon, new_hseon, new_hsion;
new_pllon = new_value & BIT(RCC_CR_PLLON_BIT);
if((clktree_is_enabled(s->PLLCLK) && !new_pllon) &&
s->RCC_CFGR_SW == SW_PLL_SELECTED) {
stm32_hw_warn("PLL cannot be disabled while it is selected as the system clock.");
}
clktree_set_enabled(s->PLL_VCO, new_pllon);
clktree_set_enabled(s->PLLCLK, new_pllon);
new_hseon = new_value & BIT(RCC_CR_HSEON_BIT);
if((clktree_is_enabled(s->HSECLK) && !new_hseon) &&
(s->RCC_CFGR_SW == SW_HSE_SELECTED ||
(s->RCC_CFGR_SW == SW_PLL_SELECTED && s->RCC_PLLCFGR_PLLSRC == PLLSRC_HSE_SELECTED)
)
) {
stm32_hw_warn("HSE oscillator cannot be disabled while it is driving the system clock.");
}
clktree_set_enabled(s->HSECLK, new_hseon);
new_hsion = new_value & BIT(RCC_CR_HSION_BIT);
if((clktree_is_enabled(s->HSECLK) && !new_hseon) &&
(s->RCC_CFGR_SW == SW_HSI_SELECTED ||
(s->RCC_CFGR_SW == SW_PLL_SELECTED && s->RCC_PLLCFGR_PLLSRC == PLLSRC_HSI_SELECTED)
)
) {
stm32_hw_warn("HSI oscillator cannot be disabled while it is driving the system clock.");
}
clktree_set_enabled(s->HSICLK, new_hsion);
}
/* Enable the peripheral clock if the specified bit is set in the value. */
static void stm32_rcc_periph_enable(
Stm32Rcc *s,
uint32_t new_value,
bool init,
int periph,
uint32_t bit_pos)
{
if(s->PERIPHCLK[periph] == NULL)
{
stm32_hw_warn("Attempted to enable clock that isn't set: %s", stm32_periph_name(periph));
return;
}
if(new_value & BIT(bit_pos))
{
if(!clktree_is_enabled(s->PERIPHCLK[periph]))
DPRINT("Enabling periphial %s\n", stm32_periph_name(periph));
}
else
{
if(clktree_is_enabled(s->PERIPHCLK[periph]))
DPRINT("Disabling periphial %s\n", stm32_periph_name(periph));
}
clktree_set_enabled(s->PERIPHCLK[periph], new_value & BIT(bit_pos));
}
/* Enable the peripheral clock if the specified bit is set in the value. */
static void stm32_rcc_periph_enable(
Stm32Rcc *s,
uint32_t new_value,
bool init,
int periph,
uint32_t bit_mask)
{
clktree_set_enabled(s->PERIPHCLK[periph], IS_BIT_SET(new_value, bit_mask));
}
/* Works the same way as stm32_rcc_RCC_CR_write */
static void stm32_rcc_RCC_CSR_write(Stm32Rcc *s, uint32_t new_value, bool init)
{
clktree_set_enabled(s->LSICLK, IS_BIT_SET(new_value, RCC_CSR_LSION_BIT));
}