static void setup_clocks(void) {
// Turn on HSI. We'll switch to and run off of this while we're
// setting up the main PLL.
rcc_turn_on_clk(RCC_CLK_HSI);
// Turn off and reset the clock subsystems we'll be using, as well
// as the clock security subsystem (CSS). Note that resetting CFGR
// to its default value of 0 implies a switch to HSI for SYSCLK.
RCC_BASE->CFGR = 0x00000000;
rcc_disable_css();
rcc_turn_off_clk(RCC_CLK_PLL);
rcc_turn_off_clk(RCC_CLK_HSE);
wirish::priv::board_reset_pll();
// Clear clock readiness interrupt flags and turn off clock
// readiness interrupts.
RCC_BASE->CIR = 0x00000000;
// Enable HSE, and wait until it's ready.
rcc_turn_on_clk(RCC_CLK_HSE);
while (!rcc_is_clk_ready(RCC_CLK_HSE))
;
// Configure AHBx, APBx, etc. prescalers and the main PLL.
wirish::priv::board_setup_clock_prescalers();
rcc_configure_pll(&wirish::priv::w_board_pll_cfg);
// Enable the PLL, and wait until it's ready.
rcc_turn_on_clk(RCC_CLK_PLL);
while(!rcc_is_clk_ready(RCC_CLK_PLL))
;
// Finally, switch to the now-ready PLL as the main clock source.
rcc_switch_sysclk(RCC_CLKSRC_PLL);
}
__deprecated
void rcc_clk_init(rcc_sysclk_src sysclk_src,
rcc_pllsrc pll_src,
rcc_pll_multiplier pll_mul)
{
/* Assume that we're going to clock the chip off the PLL, fed by
* the HSE */
ASSERT(sysclk_src == RCC_CLKSRC_PLL &&
pll_src == RCC_PLLSRC_HSE);
RCC_BASE->CFGR = pll_src | pll_mul | (0x3 << 22);
/* Turn on, and wait for, HSE. */
rcc_turn_on_clk(RCC_CLK_HSE);
while (!rcc_is_clk_ready(RCC_CLK_HSE))
;
/* Do the same for the main PLL. */
rcc_turn_on_clk(RCC_CLK_PLL);
while (!rcc_is_clk_ready(RCC_CLK_PLL))
;
/* Finally, switch over to the PLL. */
rcc_switch_sysclk(RCC_CLKSRC_PLL);
}