Merge #129

129: Update `remap_pins` stuff r=therealprof a=david-sawatzke

I'd also prefer it taking the hal `Rcc`, but that'd be a breaking change. @therealprof Your thoughts?

Co-authored-by: David Sawatzke <d-git@sawatzke.dev>

Author: bors[bot]

examples/usb_serial.rs

@@ -15,6 +15,15 @@ use usbd_serial::{SerialPort, USB_CLASS_CDC};
 fn main() -> ! {
     let mut dp = pac::Peripherals::take().unwrap();
 
+    /*
+     * IMPORTANT: if you have a chip in TSSOP20 (STM32F042F) or UFQFPN28 (STM32F042G) package,
+     * and want to use USB, make sure you call `remap_pins(rcc, syscfg)`, otherwise the device will not enumerate.
+     *
+     * Uncomment the following function if the situation above applies to you.
+     */
+
+    // stm32f0xx_hal::usb::remap_pins(&mut dp.RCC, &mut dp.SYSCFG);
+
     let mut rcc = dp
         .RCC
         .configure()
@@ -41,15 +50,6 @@ fn main() -> ! {
 
     let mut serial = SerialPort::new(&usb_bus);
 
-    /*
-     * IMPORTANT: if you have a chip in TSSOP20 (STM32F042F) or UFQFPN28 (STM32F042G) package,
-     * and want to use USB, make sure you call `remap_pins(rcc, syscfg)`, otherwise the device will not enumerate.
-     *
-     * Uncomment the following function if the situation above applies to you.
-     */
-
-    //usb_bus.remap_pins();
-
     let mut usb_dev = UsbDeviceBuilder::new(&usb_bus, UsbVidPid(0x16c0, 0x27dd))
         .manufacturer("Fake company")
         .product("Serial port")

src/usb.rs

@@ -46,13 +46,11 @@ unsafe impl UsbPeripheral for Peripheral {
     }
 }
 
+/// Remap PA11/PA12 pins to PA09/PA10 for USB on
+/// TSSOP20 (STM32F042F) or UFQFPN28 (STM32F042G) packages
 pub fn remap_pins(rcc: &mut RCC, syscfg: &mut SYSCFG) {
-    cortex_m::interrupt::free(|_| {
-        // Remap PA11/PA12 pins to PA09/PA10 for USB on
-        // TSSOP20 (STM32F042F) or UFQFPN28 (STM32F042G) packages
-        rcc.apb2enr.modify(|_, w| w.syscfgen().set_bit());
-        syscfg.cfgr1.modify(|_, w| w.pa11_pa12_rmp().remapped());
-    });
+    rcc.apb2enr.modify(|_, w| w.syscfgen().set_bit());
+    syscfg.cfgr1.modify(|_, w| w.pa11_pa12_rmp().remapped());
 }
 
 pub type UsbBusType = UsbBus<Peripheral>;