Add on-chip voltage regulator (VREG) voltage setting function

on-target-tests/Cargo.toml

@@ -36,6 +36,10 @@ harness = false
 name = "i2c_loopback_async"
 harness = false
 
+[[test]]
+name = "vreg_change_voltage"
+harness = false
+
 [dependencies]
 cortex-m = "0.7"
 cortex-m-rt = "0.7"

on-target-tests/tests/vreg_change_voltage.rs

@@ -0,0 +1,95 @@
+#![no_std]
+#![no_main]
+#![cfg(test)]
+
+use defmt_rtt as _; // defmt transport
+use defmt_test as _;
+use panic_probe as _; // panic handler
+use rp2040_hal as hal; // memory layout
+
+/// The linker will place this boot block at the start of our program image. We
+/// need this to help the ROM bootloader get our code up and running.
+/// Note: This boot block is not necessary when using a rp-hal based BSP
+/// as the BSPs already perform this step.
+#[link_section = ".boot2"]
+#[used]
+pub static BOOT2: [u8; 256] = rp2040_boot2::BOOT_LOADER_GENERIC_03H;
+
+/// External high-speed crystal on the Raspberry Pi Pico board is 12 MHz. Adjust
+/// if your board has a different frequency
+const XTAL_FREQ_HZ: u32 = 12_000_000u32;
+
+struct State {
+    vreg: hal::pac::VREG_AND_CHIP_RESET,
+}
+
+#[defmt_test::tests]
+mod tests {
+    use crate::{State, XTAL_FREQ_HZ};
+    use defmt::assert;
+    use defmt_rtt as _;
+    use panic_probe as _;
+    use rp2040_hal as hal;
+
+    use hal::pac::vreg_and_chip_reset::vreg::VSEL_A;
+    use hal::vreg;
+    use hal::{clocks::init_clocks_and_plls, pac, watchdog::Watchdog};
+
+    #[init]
+    fn setup() -> State {
+        unsafe {
+            hal::sio::spinlock_reset();
+        }
+        let mut pac = pac::Peripherals::take().unwrap();
+        let _core = pac::CorePeripherals::take().unwrap();
+        let mut watchdog = Watchdog::new(pac.WATCHDOG);
+
+        let _clocks = init_clocks_and_plls(
+            XTAL_FREQ_HZ,
+            pac.XOSC,
+            pac.CLOCKS,
+            pac.PLL_SYS,
+            pac.PLL_USB,
+            &mut pac.RESETS,
+            &mut watchdog,
+        )
+        .ok()
+        .unwrap();
+        State {
+            vreg: pac.VREG_AND_CHIP_RESET,
+        }
+    }
+
+    #[test]
+    fn change_onchip_regulator_voltage(state: &mut State) {
+        // Set the voltage to 1.05V
+        let target_voltage = VSEL_A::VOLTAGE1_05;
+        vreg::set_voltage(&mut state.vreg, target_voltage);
+        let v = vreg::get_voltage(&mut state.vreg).unwrap();
+        assert!(v == target_voltage);
+
+        // Set the voltage to 1.10V
+        let target_voltage = VSEL_A::VOLTAGE1_10;
+        vreg::set_voltage(&mut state.vreg, target_voltage);
+        let v = vreg::get_voltage(&mut state.vreg).unwrap();
+        assert!(v == target_voltage);
+
+        // Set the voltage to 1.15V
+        let target_voltage = VSEL_A::VOLTAGE1_15;
+        vreg::set_voltage(&mut state.vreg, target_voltage);
+        let v = vreg::get_voltage(&mut state.vreg).unwrap();
+        assert!(v == target_voltage);
+
+        // Set the voltage to 1.20V
+        let target_voltage = VSEL_A::VOLTAGE1_20;
+        vreg::set_voltage(&mut state.vreg, target_voltage);
+        let v = vreg::get_voltage(&mut state.vreg).unwrap();
+        assert!(v == target_voltage);
+
+        // Reset to default voltage (1.10V)
+        let target_voltage = VSEL_A::VOLTAGE1_10;
+        vreg::set_voltage(&mut state.vreg, target_voltage);
+        let v = vreg::get_voltage(&mut state.vreg).unwrap();
+        assert!(v == target_voltage);
+    }
+}

rp2040-hal/src/lib.rs

@@ -76,6 +76,7 @@ pub mod typelevel;
 pub mod uart;
 pub mod usb;
 pub mod vector_table;
+pub mod vreg;
 pub mod watchdog;
 pub mod xosc;
 

rp2040-hal/src/vreg.rs

@@ -0,0 +1,37 @@
+//! On-chip voltage regulator (VREG)
+//!
+//! See [Chapter 2, Section 10](https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf) of the datasheet for more details
+//!
+//! ## Usage
+//! ```no_run
+//! use rp2040_hal::pac::vreg_and_chip_reset::vreg::VSEL_A;
+//! use rp2040_hal::{vreg::set_voltage, pac};
+//! let mut pac = pac::Peripherals::take().unwrap();
+//! // Set voltage to 1.20V
+//! set_voltage(&mut pac.VREG_AND_CHIP_RESET, VSEL_A::VOLTAGE1_20);
+//! ```
+
+use crate::pac::vreg_and_chip_reset::vreg::VSEL_A;
+use crate::pac::VREG_AND_CHIP_RESET;
+
+/// Set voltage to the on-chip voltage regulator.
+///
+/// There is no guarantee that the device will operate at all of the available voltages.
+/// Appropriate values should be selected in consideration of the system clock frequency and other factors to be set.
+///
+/// # Arguments
+///
+/// * `vreg_dev` - VREG peripheral
+/// * `voltage` - Voltage to set
+pub fn set_voltage(vreg_dev: &mut VREG_AND_CHIP_RESET, voltage: VSEL_A) {
+    vreg_dev.vreg().write(|w| w.vsel().variant(voltage));
+}
+
+/// Get voltage from the on-chip voltage regulator
+///
+/// # Arguments
+///
+/// * `vreg_dev` - VREG peripheral
+pub fn get_voltage(vreg_dev: &VREG_AND_CHIP_RESET) -> Option<VSEL_A> {
+    vreg_dev.vreg().read().vsel().variant()
+}