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stm32/rcc: remove Rcc struct, RccExt trait.

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All the RCC configuration is executed in init().
This commit is contained in:
Dario Nieuwenhuis
2022-01-04 23:58:13 +01:00
parent c3fd9a0f44
commit 2eb0cc5df7
31 changed files with 2586 additions and 3196 deletions
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883
embassy-stm32/src/rcc/h7.rs
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@ -7,9 +7,9 @@ use stm32_metapac::rcc::vals::{Mco1, Mco2};
use crate::gpio::sealed::Pin as __GpioPin;
use crate::gpio::Pin;
use crate::pac::rcc::vals::Timpre;
use crate::pac::{RCC, SYSCFG};
use crate::pac::rcc::vals::{Ckpersel, Dppre, Hpre, Hsebyp, Hsidiv, Pllsrc, Sw};
use crate::pac::{PWR, RCC, SYSCFG};
use crate::peripherals;
use crate::pwr::{Power, VoltageScale};
use crate::rcc::{set_freqs, Clocks};
use crate::time::Hertz;
@ -20,6 +20,22 @@ const CSI: Hertz = Hertz(4_000_000);
const HSI48: Hertz = Hertz(48_000_000);
const LSI: Hertz = Hertz(32_000);
/// Voltage Scale
///
/// Represents the voltage range feeding the CPU core. The maximum core
/// clock frequency depends on this value.
#[derive(Copy, Clone, PartialEq)]
pub enum VoltageScale {
/// VOS 0 range VCORE 1.26V - 1.40V
Scale0,
/// VOS 1 range VCORE 1.15V - 1.26V
Scale1,
/// VOS 2 range VCORE 1.05V - 1.15V
Scale2,
/// VOS 3 range VCORE 0.95V - 1.05V
Scale3,
}
/// Core clock frequencies
#[derive(Clone, Copy)]
pub struct CoreClocks {
@ -72,439 +88,151 @@ pub struct Config {
pub pll3: PllConfig,
}
pub struct Rcc<'d> {
inner: PhantomData<&'d ()>,
config: Config,
/// Setup traceclk
/// Returns a pll1_r_ck
fn traceclk_setup(config: &mut Config, sys_use_pll1_p: bool) {
let pll1_r_ck = match (sys_use_pll1_p, config.pll1.r_ck) {
// pll1_p_ck selected as system clock but pll1_r_ck not
// set. The traceclk mux is synchronous with the system
// clock mux, but has pll1_r_ck as an input. In order to
// keep traceclk running, we force a pll1_r_ck.
(true, None) => Some(Hertz(unwrap!(config.pll1.p_ck).0 / 2)),
// Either pll1 not selected as system clock, free choice
// of pll1_r_ck. Or pll1 is selected, assume user has set
// a suitable pll1_r_ck frequency.
_ => config.pll1.r_ck,
};
config.pll1.r_ck = pll1_r_ck;
}
impl<'d> Rcc<'d> {
pub fn new(_rcc: impl Unborrow<Target = peripherals::RCC> + 'd, config: Config) -> Self {
Self {
inner: PhantomData,
config,
}
}
/// Divider calculator for pclk 1 - 4
///
/// Returns real pclk, bits, ppre and the timer kernel clock
fn ppre_calculate(
requested_pclk: u32,
hclk: u32,
max_pclk: u32,
tim_pre: Option<Timpre>,
) -> (u32, u8, u8, Option<u32>) {
let (bits, ppre) = match (hclk + requested_pclk - 1) / requested_pclk {
0 => panic!(),
1 => (0b000, 1),
2 => (0b100, 2),
3..=5 => (0b101, 4),
6..=11 => (0b110, 8),
_ => (0b111, 16),
};
let real_pclk = hclk / u32::from(ppre);
assert!(real_pclk <= max_pclk);
/// Freeze the core clocks, returning a Core Clocks Distribution
/// and Reset (CCDR) structure. The actual frequency of the clocks
/// configured is returned in the `clocks` member of the CCDR
/// structure.
///
/// Note that `freeze` will never result in a clock _faster_ than
/// that specified. It may result in a clock that is a factor of [1,
/// 2) slower.
///
/// `syscfg` is required to enable the I/O compensation cell.
///
/// # Panics
///
/// If a clock specification cannot be achieved within the
/// hardware specification then this function will panic. This
/// function may also panic if a clock specification can be
/// achieved, but the mechanism for doing so is not yet
/// implemented here.
pub fn freeze(mut self, pwr: &Power) -> CoreClocks {
use crate::pac::rcc::vals::{Ckpersel, Dppre, Hpre, Hsebyp, Hsidiv, Pllsrc, Sw};
let srcclk = self.config.hse.unwrap_or(HSI); // Available clocks
let (sys_ck, sys_use_pll1_p) = self.sys_ck_setup(srcclk);
// Configure traceclk from PLL if needed
self.traceclk_setup(sys_use_pll1_p);
// NOTE(unsafe) We have exclusive access to the RCC
let (pll1_p_ck, pll1_q_ck, pll1_r_ck) =
unsafe { pll::pll_setup(srcclk.0, &self.config.pll1, 0) };
let (pll2_p_ck, pll2_q_ck, pll2_r_ck) =
unsafe { pll::pll_setup(srcclk.0, &self.config.pll2, 1) };
let (pll3_p_ck, pll3_q_ck, pll3_r_ck) =
unsafe { pll::pll_setup(srcclk.0, &self.config.pll3, 2) };
let sys_ck = if sys_use_pll1_p {
Hertz(unwrap!(pll1_p_ck)) // Must have been set by sys_ck_setup
} else {
sys_ck
let tim_ker_clk = if let Some(tim_pre) = tim_pre {
let clk = match (bits, tim_pre) {
(0b101, Timpre::DEFAULTX2) => hclk / 2,
(0b110, Timpre::DEFAULTX4) => hclk / 2,
(0b110, Timpre::DEFAULTX2) => hclk / 4,
(0b111, Timpre::DEFAULTX4) => hclk / 4,
(0b111, Timpre::DEFAULTX2) => hclk / 8,
_ => hclk,
};
Some(clk)
} else {
None
};
(real_pclk, bits, ppre, tim_ker_clk)
}
// NOTE(unsafe) We own the regblock
unsafe {
// This routine does not support HSIDIV != 1. To
// do so it would need to ensure all PLLxON bits are clear
// before changing the value of HSIDIV
let cr = RCC.cr().read();
assert!(cr.hsion());
assert!(cr.hsidiv() == Hsidiv::DIV1);
/// Setup sys_ck
/// Returns sys_ck frequency, and a pll1_p_ck
fn sys_ck_setup(config: &mut Config, srcclk: Hertz) -> (Hertz, bool) {
// Compare available with wanted clocks
let sys_ck = config.sys_ck.unwrap_or(srcclk);
RCC.csr().modify(|w| w.set_lsion(true));
while !RCC.csr().read().lsirdy() {}
}
// per_ck from HSI by default
let (per_ck, ckpersel) = match (self.config.per_ck == self.config.hse, self.config.per_ck) {
(true, Some(hse)) => (hse, Ckpersel::HSE), // HSE
(_, Some(CSI)) => (CSI, Ckpersel::CSI), // CSI
_ => (HSI, Ckpersel::HSI), // HSI
};
// D1 Core Prescaler
// Set to 1
let d1cpre_bits = 0;
let d1cpre_div = 1;
let sys_d1cpre_ck = sys_ck.0 / d1cpre_div;
// Refer to part datasheet "General operating conditions"
// table for (rev V). We do not assert checks for earlier
// revisions which may have lower limits.
let (sys_d1cpre_ck_max, rcc_hclk_max, pclk_max) = match pwr.vos {
VoltageScale::Scale0 => (480_000_000, 240_000_000, 120_000_000),
VoltageScale::Scale1 => (400_000_000, 200_000_000, 100_000_000),
VoltageScale::Scale2 => (300_000_000, 150_000_000, 75_000_000),
_ => (200_000_000, 100_000_000, 50_000_000),
};
assert!(sys_d1cpre_ck <= sys_d1cpre_ck_max);
let rcc_hclk = self
.config
.rcc_hclk
.map(|v| v.0)
.unwrap_or(sys_d1cpre_ck / 2);
assert!(rcc_hclk <= rcc_hclk_max);
// Estimate divisor
let (hpre_bits, hpre_div) = match (sys_d1cpre_ck + rcc_hclk - 1) / rcc_hclk {
0 => panic!(),
1 => (Hpre::DIV1, 1),
2 => (Hpre::DIV2, 2),
3..=5 => (Hpre::DIV4, 4),
6..=11 => (Hpre::DIV8, 8),
12..=39 => (Hpre::DIV16, 16),
40..=95 => (Hpre::DIV64, 64),
96..=191 => (Hpre::DIV128, 128),
192..=383 => (Hpre::DIV256, 256),
_ => (Hpre::DIV512, 512),
};
// Calculate real AXI and AHB clock
let rcc_hclk = sys_d1cpre_ck / hpre_div;
assert!(rcc_hclk <= rcc_hclk_max);
let rcc_aclk = rcc_hclk; // AXI clock is always equal to AHB clock on H7
// Timer prescaler selection
let timpre = Timpre::DEFAULTX2;
let requested_pclk1 = self
.config
.pclk1
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk1, ppre1_bits, ppre1, rcc_timerx_ker_ck) =
Self::ppre_calculate(requested_pclk1, rcc_hclk, pclk_max, Some(timpre));
let requested_pclk2 = self
.config
.pclk2
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk2, ppre2_bits, ppre2, rcc_timery_ker_ck) =
Self::ppre_calculate(requested_pclk2, rcc_hclk, pclk_max, Some(timpre));
let requested_pclk3 = self
.config
.pclk3
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk3, ppre3_bits, ppre3, _) =
Self::ppre_calculate(requested_pclk3, rcc_hclk, pclk_max, None);
let requested_pclk4 = self
.config
.pclk4
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk4, ppre4_bits, ppre4, _) =
Self::ppre_calculate(requested_pclk4, rcc_hclk, pclk_max, None);
Self::flash_setup(rcc_aclk, pwr.vos);
// Start switching clocks -------------------
// NOTE(unsafe) We have the RCC singleton
unsafe {
// Ensure CSI is on and stable
RCC.cr().modify(|w| w.set_csion(true));
while !RCC.cr().read().csirdy() {}
// Ensure HSI48 is on and stable
RCC.cr().modify(|w| w.set_hsi48on(true));
while !RCC.cr().read().hsi48on() {}
// XXX: support MCO ?
let hse_ck = match self.config.hse {
Some(hse) => {
// Ensure HSE is on and stable
RCC.cr().modify(|w| {
w.set_hseon(true);
w.set_hsebyp(if self.config.bypass_hse {
Hsebyp::BYPASSED
} else {
Hsebyp::NOTBYPASSED
});
});
while !RCC.cr().read().hserdy() {}
Some(hse)
}
None => None,
};
let pllsrc = if self.config.hse.is_some() {
Pllsrc::HSE
} else {
Pllsrc::HSI
};
RCC.pllckselr().modify(|w| w.set_pllsrc(pllsrc));
let enable_pll = |pll| {
RCC.cr().modify(|w| w.set_pllon(pll, true));
while !RCC.cr().read().pllrdy(pll) {}
};
if pll1_p_ck.is_some() {
enable_pll(0);
}
if pll2_p_ck.is_some() {
enable_pll(1);
}
if pll3_p_ck.is_some() {
enable_pll(2);
}
// Core Prescaler / AHB Prescaler / APB3 Prescaler
RCC.d1cfgr().modify(|w| {
w.set_d1cpre(Hpre(d1cpre_bits));
w.set_d1ppre(Dppre(ppre3_bits));
w.set_hpre(hpre_bits)
});
// Ensure core prescaler value is valid before future lower
// core voltage
while RCC.d1cfgr().read().d1cpre().0 != d1cpre_bits {}
// APB1 / APB2 Prescaler
RCC.d2cfgr().modify(|w| {
w.set_d2ppre1(Dppre(ppre1_bits));
w.set_d2ppre2(Dppre(ppre2_bits));
});
// APB4 Prescaler
RCC.d3cfgr().modify(|w| w.set_d3ppre(Dppre(ppre4_bits)));
// Peripheral Clock (per_ck)
RCC.d1ccipr().modify(|w| w.set_ckpersel(ckpersel));
// Set timer clocks prescaler setting
RCC.cfgr().modify(|w| w.set_timpre(timpre));
// Select system clock source
let sw = match (sys_use_pll1_p, self.config.hse.is_some()) {
(true, _) => Sw::PLL1,
(false, true) => Sw::HSE,
_ => Sw::HSI,
};
RCC.cfgr().modify(|w| w.set_sw(sw));
while RCC.cfgr().read().sws() != sw.0 {}
// IO compensation cell - Requires CSI clock and SYSCFG
assert!(RCC.cr().read().csirdy());
RCC.apb4enr().modify(|w| w.set_syscfgen(true));
// Enable the compensation cell, using back-bias voltage code
// provide by the cell.
critical_section::with(|_| {
SYSCFG.cccsr().modify(|w| {
w.set_en(true);
w.set_cs(false);
w.set_hslv(false);
})
});
while !SYSCFG.cccsr().read().ready() {}
CoreClocks {
hclk: Hertz(rcc_hclk),
pclk1: Hertz(rcc_pclk1),
pclk2: Hertz(rcc_pclk2),
pclk3: Hertz(rcc_pclk3),
pclk4: Hertz(rcc_pclk4),
ppre1,
ppre2,
ppre3,
ppre4,
csi_ck: Some(CSI),
hsi_ck: Some(HSI),
hsi48_ck: Some(HSI48),
lsi_ck: Some(LSI),
per_ck: Some(per_ck),
hse_ck,
pll1_p_ck: pll1_p_ck.map(Hertz),
pll1_q_ck: pll1_q_ck.map(Hertz),
pll1_r_ck: pll1_r_ck.map(Hertz),
pll2_p_ck: pll2_p_ck.map(Hertz),
pll2_q_ck: pll2_q_ck.map(Hertz),
pll2_r_ck: pll2_r_ck.map(Hertz),
pll3_p_ck: pll3_p_ck.map(Hertz),
pll3_q_ck: pll3_q_ck.map(Hertz),
pll3_r_ck: pll3_r_ck.map(Hertz),
timx_ker_ck: rcc_timerx_ker_ck.map(Hertz),
timy_ker_ck: rcc_timery_ker_ck.map(Hertz),
sys_ck,
c_ck: Hertz(sys_d1cpre_ck),
}
}
}
/// Setup traceclk
/// Returns a pll1_r_ck
fn traceclk_setup(&mut self, sys_use_pll1_p: bool) {
let pll1_r_ck = match (sys_use_pll1_p, self.config.pll1.r_ck) {
// pll1_p_ck selected as system clock but pll1_r_ck not
// set. The traceclk mux is synchronous with the system
// clock mux, but has pll1_r_ck as an input. In order to
// keep traceclk running, we force a pll1_r_ck.
(true, None) => Some(Hertz(unwrap!(self.config.pll1.p_ck).0 / 2)),
// Either pll1 not selected as system clock, free choice
// of pll1_r_ck. Or pll1 is selected, assume user has set
// a suitable pll1_r_ck frequency.
_ => self.config.pll1.r_ck,
};
self.config.pll1.r_ck = pll1_r_ck;
}
/// Divider calculator for pclk 1 - 4
///
/// Returns real pclk, bits, ppre and the timer kernel clock
fn ppre_calculate(
requested_pclk: u32,
hclk: u32,
max_pclk: u32,
tim_pre: Option<Timpre>,
) -> (u32, u8, u8, Option<u32>) {
let (bits, ppre) = match (hclk + requested_pclk - 1) / requested_pclk {
0 => panic!(),
1 => (0b000, 1),
2 => (0b100, 2),
3..=5 => (0b101, 4),
6..=11 => (0b110, 8),
_ => (0b111, 16),
};
let real_pclk = hclk / u32::from(ppre);
assert!(real_pclk <= max_pclk);
let tim_ker_clk = if let Some(tim_pre) = tim_pre {
let clk = match (bits, tim_pre) {
(0b101, Timpre::DEFAULTX2) => hclk / 2,
(0b110, Timpre::DEFAULTX4) => hclk / 2,
(0b110, Timpre::DEFAULTX2) => hclk / 4,
(0b111, Timpre::DEFAULTX4) => hclk / 4,
(0b111, Timpre::DEFAULTX2) => hclk / 8,
_ => hclk,
};
Some(clk)
} else {
None
};
(real_pclk, bits, ppre, tim_ker_clk)
}
/// Setup sys_ck
/// Returns sys_ck frequency, and a pll1_p_ck
fn sys_ck_setup(&mut self, srcclk: Hertz) -> (Hertz, bool) {
// Compare available with wanted clocks
let sys_ck = self.config.sys_ck.unwrap_or(srcclk);
if sys_ck != srcclk {
// The requested system clock is not the immediately available
// HSE/HSI clock. Perhaps there are other ways of obtaining
// the requested system clock (such as `HSIDIV`) but we will
// ignore those for now.
//
// Therefore we must use pll1_p_ck
let pll1_p_ck = match self.config.pll1.p_ck {
Some(p_ck) => {
assert!(p_ck == sys_ck,
if sys_ck != srcclk {
// The requested system clock is not the immediately available
// HSE/HSI clock. Perhaps there are other ways of obtaining
// the requested system clock (such as `HSIDIV`) but we will
// ignore those for now.
//
// Therefore we must use pll1_p_ck
let pll1_p_ck = match config.pll1.p_ck {
Some(p_ck) => {
assert!(p_ck == sys_ck,
"Error: Cannot set pll1_p_ck independently as it must be used to generate sys_ck");
Some(p_ck)
}
None => Some(sys_ck),
};
self.config.pll1.p_ck = pll1_p_ck;
(sys_ck, true)
} else {
// sys_ck is derived directly from a source clock
// (HSE/HSI). pll1_p_ck can be as requested
(sys_ck, false)
}
}
fn flash_setup(rcc_aclk: u32, vos: VoltageScale) {
use crate::pac::FLASH;
// ACLK in MHz, round down and subtract 1 from integers. eg.
// 61_999_999 -> 61MHz
// 62_000_000 -> 61MHz
// 62_000_001 -> 62MHz
let rcc_aclk_mhz = (rcc_aclk - 1) / 1_000_000;
// See RM0433 Rev 7 Table 17. FLASH recommended number of wait
// states and programming delay
let (wait_states, progr_delay) = match vos {
// VOS 0 range VCORE 1.26V - 1.40V
VoltageScale::Scale0 => match rcc_aclk_mhz {
0..=69 => (0, 0),
70..=139 => (1, 1),
140..=184 => (2, 1),
185..=209 => (2, 2),
210..=224 => (3, 2),
225..=239 => (4, 2),
_ => (7, 3),
},
// VOS 1 range VCORE 1.15V - 1.26V
VoltageScale::Scale1 => match rcc_aclk_mhz {
0..=69 => (0, 0),
70..=139 => (1, 1),
140..=184 => (2, 1),
185..=209 => (2, 2),
210..=224 => (3, 2),
_ => (7, 3),
},
// VOS 2 range VCORE 1.05V - 1.15V
VoltageScale::Scale2 => match rcc_aclk_mhz {
0..=54 => (0, 0),
55..=109 => (1, 1),
110..=164 => (2, 1),
165..=224 => (3, 2),
_ => (7, 3),
},
// VOS 3 range VCORE 0.95V - 1.05V
VoltageScale::Scale3 => match rcc_aclk_mhz {
0..=44 => (0, 0),
45..=89 => (1, 1),
90..=134 => (2, 1),
135..=179 => (3, 2),
180..=224 => (4, 2),
_ => (7, 3),
},
Some(p_ck)
}
None => Some(sys_ck),
};
config.pll1.p_ck = pll1_p_ck;
// NOTE(unsafe) Atomic write
unsafe {
FLASH.acr().write(|w| {
w.set_wrhighfreq(progr_delay);
w.set_latency(wait_states)
});
while FLASH.acr().read().latency() != wait_states {}
}
(sys_ck, true)
} else {
// sys_ck is derived directly from a source clock
// (HSE/HSI). pll1_p_ck can be as requested
(sys_ck, false)
}
}
fn flash_setup(rcc_aclk: u32, vos: VoltageScale) {
use crate::pac::FLASH;
// ACLK in MHz, round down and subtract 1 from integers. eg.
// 61_999_999 -> 61MHz
// 62_000_000 -> 61MHz
// 62_000_001 -> 62MHz
let rcc_aclk_mhz = (rcc_aclk - 1) / 1_000_000;
// See RM0433 Rev 7 Table 17. FLASH recommended number of wait
// states and programming delay
let (wait_states, progr_delay) = match vos {
// VOS 0 range VCORE 1.26V - 1.40V
VoltageScale::Scale0 => match rcc_aclk_mhz {
0..=69 => (0, 0),
70..=139 => (1, 1),
140..=184 => (2, 1),
185..=209 => (2, 2),
210..=224 => (3, 2),
225..=239 => (4, 2),
_ => (7, 3),
},
// VOS 1 range VCORE 1.15V - 1.26V
VoltageScale::Scale1 => match rcc_aclk_mhz {
0..=69 => (0, 0),
70..=139 => (1, 1),
140..=184 => (2, 1),
185..=209 => (2, 2),
210..=224 => (3, 2),
_ => (7, 3),
},
// VOS 2 range VCORE 1.05V - 1.15V
VoltageScale::Scale2 => match rcc_aclk_mhz {
0..=54 => (0, 0),
55..=109 => (1, 1),
110..=164 => (2, 1),
165..=224 => (3, 2),
_ => (7, 3),
},
// VOS 3 range VCORE 0.95V - 1.05V
VoltageScale::Scale3 => match rcc_aclk_mhz {
0..=44 => (0, 0),
45..=89 => (1, 1),
90..=134 => (2, 1),
135..=179 => (3, 2),
180..=224 => (4, 2),
_ => (7, 3),
},
};
// NOTE(unsafe) Atomic write
unsafe {
FLASH.acr().write(|w| {
w.set_wrhighfreq(progr_delay);
w.set_latency(wait_states)
});
while FLASH.acr().read().latency() != wait_states {}
}
}
pub enum McoClock {
Disabled,
Bypassed,
@ -681,10 +409,309 @@ impl<'d, T: McoInstance> Mco<'d, T> {
}
}
pub(crate) unsafe fn init(config: Config) {
let mut power = Power::new(<peripherals::PWR as embassy::util::Steal>::steal(), false);
let rcc = Rcc::new(<peripherals::RCC as embassy::util::Steal>::steal(), config);
let core_clocks = rcc.freeze(&mut power);
pub(crate) unsafe fn init(mut config: Config) {
// TODO make configurable?
let enable_overdrive = false;
// NB. The lower bytes of CR3 can only be written once after
// POR, and must be written with a valid combination. Refer to
// RM0433 Rev 7 6.8.4. This is partially enforced by dropping
// `self` at the end of this method, but of course we cannot
// know what happened between the previous POR and here.
#[cfg(pwr_h7)]
PWR.cr3().modify(|w| {
w.set_scuen(true);
w.set_ldoen(true);
w.set_bypass(false);
});
#[cfg(pwr_h7smps)]
PWR.cr3().modify(|w| {
// hardcode "Direct SPMS" for now, this is what works on nucleos with the
// default solderbridge configuration.
w.set_sden(true);
w.set_ldoen(false);
});
// Validate the supply configuration. If you are stuck here, it is
// because the voltages on your board do not match those specified
// in the D3CR.VOS and CR3.SDLEVEL fields. By default after reset
// VOS = Scale 3, so check that the voltage on the VCAP pins =
// 1.0V.
while !PWR.csr1().read().actvosrdy() {}
// Go to Scale 1
PWR.d3cr().modify(|w| w.set_vos(0b11));
while !PWR.d3cr().read().vosrdy() {}
let pwr_vos = if !enable_overdrive {
VoltageScale::Scale1
} else {
critical_section::with(|_| {
RCC.apb4enr().modify(|w| w.set_syscfgen(true));
SYSCFG.pwrcr().modify(|w| w.set_oden(1));
});
while !PWR.d3cr().read().vosrdy() {}
VoltageScale::Scale0
};
// Freeze the core clocks, returning a Core Clocks Distribution
// and Reset (CCDR) structure. The actual frequency of the clocks
// configured is returned in the `clocks` member of the CCDR
// structure.
//
// Note that `freeze` will never result in a clock _faster_ than
// that specified. It may result in a clock that is a factor of [1,
// 2) slower.
//
// `syscfg` is required to enable the I/O compensation cell.
//
// # Panics
//
// If a clock specification cannot be achieved within the
// hardware specification then this function will panic. This
// function may also panic if a clock specification can be
// achieved, but the mechanism for doing so is not yet
// implemented here.
let srcclk = config.hse.unwrap_or(HSI); // Available clocks
let (sys_ck, sys_use_pll1_p) = sys_ck_setup(&mut config, srcclk);
// Configure traceclk from PLL if needed
traceclk_setup(&mut config, sys_use_pll1_p);
// NOTE(unsafe) We have exclusive access to the RCC
let (pll1_p_ck, pll1_q_ck, pll1_r_ck) = pll::pll_setup(srcclk.0, &config.pll1, 0);
let (pll2_p_ck, pll2_q_ck, pll2_r_ck) = pll::pll_setup(srcclk.0, &config.pll2, 1);
let (pll3_p_ck, pll3_q_ck, pll3_r_ck) = pll::pll_setup(srcclk.0, &config.pll3, 2);
let sys_ck = if sys_use_pll1_p {
Hertz(unwrap!(pll1_p_ck)) // Must have been set by sys_ck_setup
} else {
sys_ck
};
// This routine does not support HSIDIV != 1. To
// do so it would need to ensure all PLLxON bits are clear
// before changing the value of HSIDIV
let cr = RCC.cr().read();
assert!(cr.hsion());
assert!(cr.hsidiv() == Hsidiv::DIV1);
RCC.csr().modify(|w| w.set_lsion(true));
while !RCC.csr().read().lsirdy() {}
// per_ck from HSI by default
let (per_ck, ckpersel) = match (config.per_ck == config.hse, config.per_ck) {
(true, Some(hse)) => (hse, Ckpersel::HSE), // HSE
(_, Some(CSI)) => (CSI, Ckpersel::CSI), // CSI
_ => (HSI, Ckpersel::HSI), // HSI
};
// D1 Core Prescaler
// Set to 1
let d1cpre_bits = 0;
let d1cpre_div = 1;
let sys_d1cpre_ck = sys_ck.0 / d1cpre_div;
// Refer to part datasheet "General operating conditions"
// table for (rev V). We do not assert checks for earlier
// revisions which may have lower limits.
let (sys_d1cpre_ck_max, rcc_hclk_max, pclk_max) = match pwr_vos {
VoltageScale::Scale0 => (480_000_000, 240_000_000, 120_000_000),
VoltageScale::Scale1 => (400_000_000, 200_000_000, 100_000_000),
VoltageScale::Scale2 => (300_000_000, 150_000_000, 75_000_000),
_ => (200_000_000, 100_000_000, 50_000_000),
};
assert!(sys_d1cpre_ck <= sys_d1cpre_ck_max);
let rcc_hclk = config.rcc_hclk.map(|v| v.0).unwrap_or(sys_d1cpre_ck / 2);
assert!(rcc_hclk <= rcc_hclk_max);
// Estimate divisor
let (hpre_bits, hpre_div) = match (sys_d1cpre_ck + rcc_hclk - 1) / rcc_hclk {
0 => panic!(),
1 => (Hpre::DIV1, 1),
2 => (Hpre::DIV2, 2),
3..=5 => (Hpre::DIV4, 4),
6..=11 => (Hpre::DIV8, 8),
12..=39 => (Hpre::DIV16, 16),
40..=95 => (Hpre::DIV64, 64),
96..=191 => (Hpre::DIV128, 128),
192..=383 => (Hpre::DIV256, 256),
_ => (Hpre::DIV512, 512),
};
// Calculate real AXI and AHB clock
let rcc_hclk = sys_d1cpre_ck / hpre_div;
assert!(rcc_hclk <= rcc_hclk_max);
let rcc_aclk = rcc_hclk; // AXI clock is always equal to AHB clock on H7
// Timer prescaler selection
let timpre = Timpre::DEFAULTX2;
let requested_pclk1 = config
.pclk1
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk1, ppre1_bits, ppre1, rcc_timerx_ker_ck) =
ppre_calculate(requested_pclk1, rcc_hclk, pclk_max, Some(timpre));
let requested_pclk2 = config
.pclk2
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk2, ppre2_bits, ppre2, rcc_timery_ker_ck) =
ppre_calculate(requested_pclk2, rcc_hclk, pclk_max, Some(timpre));
let requested_pclk3 = config
.pclk3
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk3, ppre3_bits, ppre3, _) =
ppre_calculate(requested_pclk3, rcc_hclk, pclk_max, None);
let requested_pclk4 = config
.pclk4
.map(|v| v.0)
.unwrap_or_else(|| pclk_max.min(rcc_hclk / 2));
let (rcc_pclk4, ppre4_bits, ppre4, _) =
ppre_calculate(requested_pclk4, rcc_hclk, pclk_max, None);
flash_setup(rcc_aclk, pwr_vos);
// Start switching clocks -------------------
// Ensure CSI is on and stable
RCC.cr().modify(|w| w.set_csion(true));
while !RCC.cr().read().csirdy() {}
// Ensure HSI48 is on and stable
RCC.cr().modify(|w| w.set_hsi48on(true));
while !RCC.cr().read().hsi48on() {}
// XXX: support MCO ?
let hse_ck = match config.hse {
Some(hse) => {
// Ensure HSE is on and stable
RCC.cr().modify(|w| {
w.set_hseon(true);
w.set_hsebyp(if config.bypass_hse {
Hsebyp::BYPASSED
} else {
Hsebyp::NOTBYPASSED
});
});
while !RCC.cr().read().hserdy() {}
Some(hse)
}
None => None,
};
let pllsrc = if config.hse.is_some() {
Pllsrc::HSE
} else {
Pllsrc::HSI
};
RCC.pllckselr().modify(|w| w.set_pllsrc(pllsrc));
let enable_pll = |pll| {
RCC.cr().modify(|w| w.set_pllon(pll, true));
while !RCC.cr().read().pllrdy(pll) {}
};
if pll1_p_ck.is_some() {
enable_pll(0);
}
if pll2_p_ck.is_some() {
enable_pll(1);
}
if pll3_p_ck.is_some() {
enable_pll(2);
}
// Core Prescaler / AHB Prescaler / APB3 Prescaler
RCC.d1cfgr().modify(|w| {
w.set_d1cpre(Hpre(d1cpre_bits));
w.set_d1ppre(Dppre(ppre3_bits));
w.set_hpre(hpre_bits)
});
// Ensure core prescaler value is valid before future lower
// core voltage
while RCC.d1cfgr().read().d1cpre().0 != d1cpre_bits {}
// APB1 / APB2 Prescaler
RCC.d2cfgr().modify(|w| {
w.set_d2ppre1(Dppre(ppre1_bits));
w.set_d2ppre2(Dppre(ppre2_bits));
});
// APB4 Prescaler
RCC.d3cfgr().modify(|w| w.set_d3ppre(Dppre(ppre4_bits)));
// Peripheral Clock (per_ck)
RCC.d1ccipr().modify(|w| w.set_ckpersel(ckpersel));
// Set timer clocks prescaler setting
RCC.cfgr().modify(|w| w.set_timpre(timpre));
// Select system clock source
let sw = match (sys_use_pll1_p, config.hse.is_some()) {
(true, _) => Sw::PLL1,
(false, true) => Sw::HSE,
_ => Sw::HSI,
};
RCC.cfgr().modify(|w| w.set_sw(sw));
while RCC.cfgr().read().sws() != sw.0 {}
// IO compensation cell - Requires CSI clock and SYSCFG
assert!(RCC.cr().read().csirdy());
RCC.apb4enr().modify(|w| w.set_syscfgen(true));
// Enable the compensation cell, using back-bias voltage code
// provide by the cell.
critical_section::with(|_| {
SYSCFG.cccsr().modify(|w| {
w.set_en(true);
w.set_cs(false);
w.set_hslv(false);
})
});
while !SYSCFG.cccsr().read().ready() {}
let core_clocks = CoreClocks {
hclk: Hertz(rcc_hclk),
pclk1: Hertz(rcc_pclk1),
pclk2: Hertz(rcc_pclk2),
pclk3: Hertz(rcc_pclk3),
pclk4: Hertz(rcc_pclk4),
ppre1,
ppre2,
ppre3,
ppre4,
csi_ck: Some(CSI),
hsi_ck: Some(HSI),
hsi48_ck: Some(HSI48),
lsi_ck: Some(LSI),
per_ck: Some(per_ck),
hse_ck,
pll1_p_ck: pll1_p_ck.map(Hertz),
pll1_q_ck: pll1_q_ck.map(Hertz),
pll1_r_ck: pll1_r_ck.map(Hertz),
pll2_p_ck: pll2_p_ck.map(Hertz),
pll2_q_ck: pll2_q_ck.map(Hertz),
pll2_r_ck: pll2_r_ck.map(Hertz),
pll3_p_ck: pll3_p_ck.map(Hertz),
pll3_q_ck: pll3_q_ck.map(Hertz),
pll3_r_ck: pll3_r_ck.map(Hertz),
timx_ker_ck: rcc_timerx_ker_ck.map(Hertz),
timy_ker_ck: rcc_timery_ker_ck.map(Hertz),
sys_ck,
c_ck: Hertz(sys_d1cpre_ck),
};
set_freqs(Clocks {
sys: core_clocks.c_ck,
ahb1: core_clocks.hclk,