From cfe35f8fd4f5c689dc1a92f7462f135df8af21ae Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 00:37:51 +0300
Subject: [PATCH 01/25] Introduce UsbPeripheral trait

---
 src/lib.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 5bd5692..29e6aa2 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -31,3 +31,11 @@ pub use crate::target::usb_pins::UsbPinsType;
 pub type UsbBusType = UsbBus<UsbPinsType>;
 
 mod pac;
+
+/// A trait for device-specific USB peripherals. Implement this to add support for a new hardware
+/// platform. Peripherals that have this trait must have the same register block as STM32 USBFS
+/// peripherals.
+pub unsafe trait UsbPeripheral: Send + Sync {
+    /// Pointer to the register block
+    const REGISTERS: *const ();
+}

From e534d70b79a6cb6f95f2c0ab86f83e01eeb81749 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 00:40:00 +0300
Subject: [PATCH 02/25] Use UsbPeripheral instead of USB from pac

---
 src/bus.rs       | 29 +++++++++++++++++------------
 src/endpoint.rs  | 17 +++++++++++------
 src/lib.rs       |  2 ++
 src/registers.rs | 28 ++++++++++++++++++++++++++++
 src/target.rs    | 35 -----------------------------------
 5 files changed, 58 insertions(+), 53 deletions(-)
 create mode 100644 src/registers.rs

diff --git a/src/bus.rs b/src/bus.rs
index 5edde03..18bcd49 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -1,6 +1,5 @@
 //! USB peripheral driver.
 
-use core::marker::PhantomData;
 use core::mem;
 use cortex_m::asm::delay;
 use cortex_m::interrupt::{self, Mutex};
@@ -10,28 +9,31 @@ use usb_device::{Result, UsbDirection, UsbError};
 
 use crate::endpoint::{calculate_count_rx, Endpoint, EndpointStatus};
 use crate::endpoint_memory::EndpointMemoryAllocator;
-use crate::target::{apb_usb_enable, UsbPins, UsbRegisters, NUM_ENDPOINTS, USB};
+use crate::registers::UsbRegisters;
+use crate::target::{apb_usb_enable, NUM_ENDPOINTS};
+use crate::UsbPeripheral;
 
 /// USB peripheral driver for STM32 microcontrollers.
-pub struct UsbBus<PINS> {
-    regs: Mutex<UsbRegisters>,
-    endpoints: [Endpoint; NUM_ENDPOINTS],
+pub struct UsbBus<USB> {
+    peripheral: USB,
+    regs: Mutex<UsbRegisters<USB>>,
+    endpoints: [Endpoint<USB>; NUM_ENDPOINTS],
     ep_allocator: EndpointMemoryAllocator,
     max_endpoint: usize,
-    pins: PhantomData<PINS>,
 }
 
-impl<PINS: UsbPins + Sync> UsbBus<PINS> {
+impl<USB: UsbPeripheral> UsbBus<USB> {
     /// Constructs a new USB peripheral driver.
-    pub fn new(regs: USB, _pins: PINS) -> UsbBusAllocator<Self> {
+    pub fn new(peripheral: USB) -> UsbBusAllocator<Self> {
         apb_usb_enable();
 
         let bus = UsbBus {
-            regs: Mutex::new(UsbRegisters::new(regs)),
+            peripheral,
+            regs: Mutex::new(UsbRegisters::new()),
             ep_allocator: EndpointMemoryAllocator::new(),
             max_endpoint: 0,
             endpoints: unsafe {
-                let mut endpoints: [Endpoint; NUM_ENDPOINTS] = mem::uninitialized();
+                let mut endpoints: [Endpoint<USB>; NUM_ENDPOINTS] = mem::uninitialized();
 
                 for i in 0..NUM_ENDPOINTS {
                     endpoints[i] = Endpoint::new(i as u8);
@@ -39,12 +41,15 @@ impl<PINS: UsbPins + Sync> UsbBus<PINS> {
 
                 endpoints
             },
-            pins: PhantomData,
         };
 
         UsbBusAllocator::new(bus)
     }
 
+    pub fn free(self) -> USB {
+        self.peripheral
+    }
+
     /// Simulates a disconnect from the USB bus, causing the host to reset and re-enumerate the
     /// device.
     ///
@@ -69,7 +74,7 @@ impl<PINS: UsbPins + Sync> UsbBus<PINS> {
     }
 }
 
-impl<PINS: Send + Sync> usb_device::bus::UsbBus for UsbBus<PINS> {
+impl<USB: UsbPeripheral> usb_device::bus::UsbBus for UsbBus<USB> {
     fn alloc_ep(
         &mut self,
         ep_dir: UsbDirection,
diff --git a/src/endpoint.rs b/src/endpoint.rs
index 8d2aa34..1c46ac9 100644
--- a/src/endpoint.rs
+++ b/src/endpoint.rs
@@ -1,5 +1,8 @@
 use crate::endpoint_memory::{BufferDescriptor, EndpointBuffer, EndpointMemoryAllocator};
-use crate::target::{usb, UsbAccessType, UsbRegisters};
+use crate::registers::UsbRegisters;
+use crate::target::{usb, UsbAccessType};
+use crate::UsbPeripheral;
+use core::marker::PhantomData;
 use core::mem;
 use cortex_m::interrupt::{self, CriticalSection, Mutex};
 use usb_device::endpoint::EndpointType;
@@ -7,11 +10,12 @@ use usb_device::{Result, UsbError};
 
 /// Arbitrates access to the endpoint-specific registers and packet buffer memory.
 #[derive(Default)]
-pub struct Endpoint {
+pub struct Endpoint<USB> {
     out_buf: Option<Mutex<EndpointBuffer>>,
     in_buf: Option<Mutex<EndpointBuffer>>,
     ep_type: Option<EndpointType>,
     index: u8,
+    _marker: PhantomData<USB>,
 }
 
 pub fn calculate_count_rx(mut size: usize) -> Result<(usize, u16)> {
@@ -34,13 +38,14 @@ pub fn calculate_count_rx(mut size: usize) -> Result<(usize, u16)> {
     }
 }
 
-impl Endpoint {
-    pub fn new(index: u8) -> Endpoint {
-        Endpoint {
+impl<USB: UsbPeripheral> Endpoint<USB> {
+    pub fn new(index: u8) -> Self {
+        Self {
             out_buf: None,
             in_buf: None,
             ep_type: None,
             index,
+            _marker: PhantomData,
         }
     }
 
@@ -83,7 +88,7 @@ impl Endpoint {
     }
 
     fn reg(&self) -> &'static usb::EPR {
-        UsbRegisters::ep_register(self.index)
+        UsbRegisters::<USB>::ep_register(self.index)
     }
 
     #[rustfmt::skip]
diff --git a/src/lib.rs b/src/lib.rs
index 29e6aa2..809893a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,6 +17,8 @@ mod endpoint;
 #[cfg(feature = "family-selected")]
 mod endpoint_memory;
 
+mod registers;
+
 #[cfg(feature = "family-selected")]
 mod target;
 
diff --git a/src/registers.rs b/src/registers.rs
new file mode 100644
index 0000000..51b2bc7
--- /dev/null
+++ b/src/registers.rs
@@ -0,0 +1,28 @@
+use crate::pac::usb::{RegisterBlock, EPR};
+use crate::UsbPeripheral;
+use core::marker::PhantomData;
+
+/// Wrapper around device-specific peripheral that provides unified register interface
+pub struct UsbRegisters<USB> {
+    _marker: PhantomData<USB>,
+}
+
+impl<USB: UsbPeripheral> core::ops::Deref for UsbRegisters<USB> {
+    type Target = RegisterBlock;
+
+    fn deref(&self) -> &Self::Target {
+        let ptr = USB::REGISTERS as *const Self::Target;
+        unsafe { &*ptr }
+    }
+}
+
+impl<USB: UsbPeripheral> UsbRegisters<USB> {
+    pub fn new() -> Self {
+        Self { _marker: PhantomData }
+    }
+
+    pub fn ep_register(index: u8) -> &'static EPR {
+        let usb_ptr = USB::REGISTERS as *const RegisterBlock;
+        unsafe { &(*usb_ptr).epr[index as usize] }
+    }
+}
diff --git a/src/target.rs b/src/target.rs
index e493fcb..f7edac1 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -12,18 +12,6 @@ pub use stm32l0xx_hal as hal;
 #[cfg(feature = "stm32l4")]
 pub use stm32l4xx_hal as hal;
 
-// USB PAC reexports
-#[cfg(feature = "stm32f0")]
-pub use hal::stm32::USB;
-#[cfg(feature = "stm32f1")]
-pub use hal::stm32::USB;
-#[cfg(feature = "stm32f3")]
-pub use hal::stm32::USB;
-#[cfg(feature = "stm32l0")]
-pub use hal::stm32::USB;
-#[cfg(feature = "stm32l4")]
-pub use hal::stm32::USB;
-
 // Use bundled register definitions instead of device-specific ones
 // This should work because register definitions from newer chips seem to be
 // compatible with definitions for older ones.
@@ -59,29 +47,6 @@ pub fn apb_usb_enable() {
     });
 }
 
-/// Wrapper around device-specific peripheral that provides unified register interface
-pub struct UsbRegisters(USB);
-
-impl core::ops::Deref for UsbRegisters {
-    type Target = usb::RegisterBlock;
-
-    fn deref(&self) -> &Self::Target {
-        let ptr = USB::ptr() as *const Self::Target;
-        unsafe { &*ptr }
-    }
-}
-
-impl UsbRegisters {
-    pub fn new(usb: USB) -> Self {
-        Self(usb)
-    }
-
-    pub fn ep_register(index: u8) -> &'static usb::EPR {
-        let usb_ptr = USB::ptr() as *const usb::RegisterBlock;
-        unsafe { &(*usb_ptr).epr[index as usize] }
-    }
-}
-
 pub trait UsbPins: Send {}
 
 #[cfg(feature = "stm32f0")]

From e7f44a12458a0086e4b715a53a0366625fd781ab Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 00:55:28 +0300
Subject: [PATCH 03/25] Remove UsbPins trait

---
 src/lib.rs    |  4 ----
 src/target.rs | 50 --------------------------------------------------
 2 files changed, 54 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 809893a..d4c843d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -27,10 +27,6 @@ pub mod bus;
 
 #[cfg(feature = "family-selected")]
 pub use crate::bus::UsbBus;
-#[cfg(feature = "family-selected")]
-pub use crate::target::usb_pins::UsbPinsType;
-#[cfg(feature = "family-selected")]
-pub type UsbBusType = UsbBus<UsbPinsType>;
 
 mod pac;
 
diff --git a/src/target.rs b/src/target.rs
index f7edac1..52cb70d 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -46,53 +46,3 @@ pub fn apb_usb_enable() {
         }
     });
 }
-
-pub trait UsbPins: Send {}
-
-#[cfg(feature = "stm32f0")]
-pub mod usb_pins {
-    use super::hal::gpio::gpioa::{PA11, PA12};
-    use super::hal::gpio::{Floating, Input};
-
-    pub type UsbPinsType = (PA11<Input<Floating>>, PA12<Input<Floating>>);
-    impl super::UsbPins for UsbPinsType {}
-}
-
-#[cfg(feature = "stm32f1")]
-pub mod usb_pins {
-    use super::hal::gpio::gpioa::{PA11, PA12};
-    use super::hal::gpio::{Floating, Input};
-
-    pub type UsbPinsType = (PA11<Input<Floating>>, PA12<Input<Floating>>);
-    impl super::UsbPins for UsbPinsType {}
-}
-
-#[cfg(feature = "stm32f3")]
-pub mod usb_pins {
-    use super::hal::gpio::gpioa::{PA11, PA12};
-    use super::hal::gpio::AF14;
-
-    pub type UsbPinsType = (PA11<AF14>, PA12<AF14>);
-    impl super::UsbPins for UsbPinsType {}
-}
-
-#[cfg(feature = "stm32l0")]
-pub mod usb_pins {
-    use super::hal::gpio::gpioa::{PA11, PA12};
-    use super::hal::gpio::{Floating, Input};
-
-    pub type UsbPinsType = (PA11<Input<Floating>>, PA12<Input<Floating>>);
-    impl super::UsbPins for UsbPinsType {}
-}
-
-#[cfg(feature = "stm32l4")]
-pub mod usb_pins {
-    use super::hal::gpio::gpioa::{PA11, PA12};
-    use super::hal::gpio::{Alternate, Floating, Input, AF10};
-
-    pub type UsbPinsType = (
-        PA11<Alternate<AF10, Input<Floating>>>,
-        PA12<Alternate<AF10, Input<Floating>>>,
-    );
-    impl super::UsbPins for UsbPinsType {}
-}

From 797a054f9ef3d4ddfe014867f963107d7e318761 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:00:10 +0300
Subject: [PATCH 04/25] Move apb_usb_enable() to the UsbPeripheral trait

---
 src/bus.rs    |  4 ++--
 src/lib.rs    |  3 +++
 src/target.rs | 13 -------------
 3 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/src/bus.rs b/src/bus.rs
index 18bcd49..0eef0b8 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -10,7 +10,7 @@ use usb_device::{Result, UsbDirection, UsbError};
 use crate::endpoint::{calculate_count_rx, Endpoint, EndpointStatus};
 use crate::endpoint_memory::EndpointMemoryAllocator;
 use crate::registers::UsbRegisters;
-use crate::target::{apb_usb_enable, NUM_ENDPOINTS};
+use crate::target::NUM_ENDPOINTS;
 use crate::UsbPeripheral;
 
 /// USB peripheral driver for STM32 microcontrollers.
@@ -25,7 +25,7 @@ pub struct UsbBus<USB> {
 impl<USB: UsbPeripheral> UsbBus<USB> {
     /// Constructs a new USB peripheral driver.
     pub fn new(peripheral: USB) -> UsbBusAllocator<Self> {
-        apb_usb_enable();
+        USB::enable();
 
         let bus = UsbBus {
             peripheral,
diff --git a/src/lib.rs b/src/lib.rs
index d4c843d..31fc0d6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -36,4 +36,7 @@ mod pac;
 pub unsafe trait UsbPeripheral: Send + Sync {
     /// Pointer to the register block
     const REGISTERS: *const ();
+
+    /// Enables USB device on its peripheral bus
+    fn enable();
 }
diff --git a/src/target.rs b/src/target.rs
index 52cb70d..76cea04 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -33,16 +33,3 @@ pub const EP_MEM_SIZE: usize = 512;
 pub const EP_MEM_SIZE: usize = 1024;
 
 pub const NUM_ENDPOINTS: usize = 8;
-
-/// Enables USB peripheral
-pub fn apb_usb_enable() {
-    cortex_m::interrupt::free(|_| {
-        let rcc = unsafe { (&*hal::stm32::RCC::ptr()) };
-        match () {
-            #[cfg(any(feature = "stm32f0", feature = "stm32f1", feature = "stm32f3", feature = "stm32l0"))]
-            () => rcc.apb1enr.modify(|_, w| w.usben().set_bit()),
-            #[cfg(feature = "stm32l4")]
-            () => rcc.apb1enr1.modify(|_, w| w.usbfsen().set_bit()),
-        }
-    });
-}

From 29c5f2fb6934e4e9133777fdd76e1a994e6827e0 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:04:20 +0300
Subject: [PATCH 05/25] Remove hal dependencies

---
 Cargo.toml    | 31 +++++++++++++------------------
 src/target.rs | 12 ------------
 2 files changed, 13 insertions(+), 30 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 8e02f57..0617c2d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,20 +12,15 @@ keywords = ["no-std", "embedded", "usb"]
 [dependencies]
 vcell = "0.1.2"
 cortex-m = "0.6.1"
-stm32f0xx-hal = { version = "0.15", features = ["rt"], optional = true }
-stm32f1xx-hal = { version = "0.4", features = ["rt"], optional = true }
-stm32f3xx-hal = { version = "0.3", features = ["rt"], optional = true }
-stm32l0xx-hal = { version = "0.3", features = ["rt"], optional = true }
-stm32l4xx-hal = { version = "0.5", features = ["rt"], optional = true }
 usb-device = "0.2.3"
 
 [features]
 # Device family
-stm32f0 = ['stm32f0xx-hal', 'family-selected']
-stm32f1 = ['stm32f1xx-hal', 'family-selected']
-stm32f3 = ['stm32f3xx-hal', 'family-selected']
-stm32l0 = ['stm32l0xx-hal', 'family-selected']
-stm32l4 = ['stm32l4xx-hal', 'family-selected']
+stm32f0 = ['family-selected']
+stm32f1 = ['family-selected']
+stm32f3 = ['family-selected']
+stm32l0 = ['family-selected']
+stm32l4 = ['family-selected']
 
 # Dedicated USB RAM size
 ram_size_512 = []
@@ -45,14 +40,14 @@ ram_addr_40006c00 = []
 delay_workaround = []  # deprecated: cortex-m 0.6.1 contains a fix
 
 # Known devices
-stm32f042xx = ['stm32f0', 'stm32f0xx-hal/stm32f042', 'new_gen']
-stm32f048xx = ['stm32f0', 'stm32f0xx-hal/stm32f048', 'new_gen']
-stm32f072xx = ['stm32f0', 'stm32f0xx-hal/stm32f072', 'new_gen']
-stm32f078xx = ['stm32f0', 'stm32f0xx-hal/stm32f078', 'new_gen']
-stm32f103xx = ['stm32f1', 'stm32f1xx-hal/stm32f103', 'old_gen']
-stm32f303xc = ['stm32f3', 'stm32f3xx-hal/stm32f303', 'old_gen']
-stm32l0x2xx = ['stm32l0', 'stm32l0xx-hal/stm32l0x2', 'new_gen']
-stm32l4x2xx = ['stm32l4', 'stm32l4xx-hal/stm32l4x2', 'new_gen', 'ram_addr_40006c00']
+stm32f042xx = ['stm32f0', 'new_gen']
+stm32f048xx = ['stm32f0', 'new_gen']
+stm32f072xx = ['stm32f0', 'new_gen']
+stm32f078xx = ['stm32f0', 'new_gen']
+stm32f103xx = ['stm32f1', 'old_gen']
+stm32f303xc = ['stm32f3', 'old_gen']
+stm32l0x2xx = ['stm32l0', 'new_gen']
+stm32l4x2xx = ['stm32l4', 'new_gen', 'ram_addr_40006c00']
 
 # Auxiliary features
 old_gen = ['ram_size_512', 'ram_access_1x16']
diff --git a/src/target.rs b/src/target.rs
index 76cea04..49f7e9c 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -1,17 +1,5 @@
 //! Target-specific definitions
 
-// Export HAL
-#[cfg(feature = "stm32f0")]
-pub use stm32f0xx_hal as hal;
-#[cfg(feature = "stm32f1")]
-pub use stm32f1xx_hal as hal;
-#[cfg(feature = "stm32f3")]
-pub use stm32f3xx_hal as hal;
-#[cfg(feature = "stm32l0")]
-pub use stm32l0xx_hal as hal;
-#[cfg(feature = "stm32l4")]
-pub use stm32l4xx_hal as hal;
-
 // Use bundled register definitions instead of device-specific ones
 // This should work because register definitions from newer chips seem to be
 // compatible with definitions for older ones.

From 2ce8a2754a74a0ee159b4d98000418f3f330ca49 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:18:44 +0300
Subject: [PATCH 06/25] Move chip specific delay() into the UsbPeripheral trait

---
 src/bus.rs | 5 +----
 src/lib.rs | 6 ++++++
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/bus.rs b/src/bus.rs
index 0eef0b8..c806536 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -1,7 +1,6 @@
 //! USB peripheral driver.
 
 use core::mem;
-use cortex_m::asm::delay;
 use cortex_m::interrupt::{self, Mutex};
 use usb_device::bus::{PollResult, UsbBusAllocator};
 use usb_device::endpoint::{EndpointAddress, EndpointType};
@@ -141,9 +140,7 @@ impl<USB: UsbPeripheral> usb_device::bus::UsbBus for UsbBus<USB> {
 
             regs.cntr.modify(|_, w| w.pdwn().clear_bit());
 
-            // There is a chip specific startup delay. For STM32F103xx it's 1µs and this should wait for
-            // at least that long.
-            delay(72);
+            USB::startup_delay();
 
             regs.btable.modify(|_, w| w.btable().bits(0));
             regs.cntr.modify(|_, w| { w
diff --git a/src/lib.rs b/src/lib.rs
index 31fc0d6..fb7b55a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -39,4 +39,10 @@ pub unsafe trait UsbPeripheral: Send + Sync {
 
     /// Enables USB device on its peripheral bus
     fn enable();
+
+    /// Performs a chip specific startup delay
+    ///
+    /// This function is called in `UsbBus::enable()` after deasserting the `pdwn` bit and before
+    /// peripheral initialization.
+    fn startup_delay();
 }

From 316bf8b499ed1c68fcaf51ee746ef2ee8f82f283 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:21:43 +0300
Subject: [PATCH 07/25] Refactoring

---
 src/endpoint.rs | 7 ++++++-
 src/target.rs   | 5 -----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/endpoint.rs b/src/endpoint.rs
index 1c46ac9..1d1a861 100644
--- a/src/endpoint.rs
+++ b/src/endpoint.rs
@@ -1,6 +1,6 @@
 use crate::endpoint_memory::{BufferDescriptor, EndpointBuffer, EndpointMemoryAllocator};
 use crate::registers::UsbRegisters;
-use crate::target::{usb, UsbAccessType};
+use crate::target::UsbAccessType;
 use crate::UsbPeripheral;
 use core::marker::PhantomData;
 use core::mem;
@@ -8,6 +8,11 @@ use cortex_m::interrupt::{self, CriticalSection, Mutex};
 use usb_device::endpoint::EndpointType;
 use usb_device::{Result, UsbError};
 
+// Use bundled register definitions instead of device-specific ones
+// This should work because register definitions from newer chips seem to be
+// compatible with definitions for older ones.
+pub use crate::pac::usb;
+
 /// Arbitrates access to the endpoint-specific registers and packet buffer memory.
 #[derive(Default)]
 pub struct Endpoint<USB> {
diff --git a/src/target.rs b/src/target.rs
index 49f7e9c..3c19b8d 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -1,10 +1,5 @@
 //! Target-specific definitions
 
-// Use bundled register definitions instead of device-specific ones
-// This should work because register definitions from newer chips seem to be
-// compatible with definitions for older ones.
-pub use crate::pac::usb;
-
 #[cfg(feature = "ram_access_1x16")]
 pub type UsbAccessType = u32;
 #[cfg(feature = "ram_access_2x16")]

From 8fc41abc7971ae34479042adbcd8f229c135cf6e Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:26:08 +0300
Subject: [PATCH 08/25] Remove device family features

---
 Cargo.toml | 23 ++++++++---------------
 src/lib.rs | 18 +-----------------
 2 files changed, 9 insertions(+), 32 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 0617c2d..378209d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,13 +15,6 @@ cortex-m = "0.6.1"
 usb-device = "0.2.3"
 
 [features]
-# Device family
-stm32f0 = ['family-selected']
-stm32f1 = ['family-selected']
-stm32f3 = ['family-selected']
-stm32l0 = ['family-selected']
-stm32l4 = ['family-selected']
-
 # Dedicated USB RAM size
 ram_size_512 = []
 ram_size_1024 = []
@@ -40,14 +33,14 @@ ram_addr_40006c00 = []
 delay_workaround = []  # deprecated: cortex-m 0.6.1 contains a fix
 
 # Known devices
-stm32f042xx = ['stm32f0', 'new_gen']
-stm32f048xx = ['stm32f0', 'new_gen']
-stm32f072xx = ['stm32f0', 'new_gen']
-stm32f078xx = ['stm32f0', 'new_gen']
-stm32f103xx = ['stm32f1', 'old_gen']
-stm32f303xc = ['stm32f3', 'old_gen']
-stm32l0x2xx = ['stm32l0', 'new_gen']
-stm32l4x2xx = ['stm32l4', 'new_gen', 'ram_addr_40006c00']
+stm32f042xx = ['new_gen']
+stm32f048xx = ['new_gen']
+stm32f072xx = ['new_gen']
+stm32f078xx = ['new_gen']
+stm32f103xx = ['old_gen']
+stm32f303xc = ['old_gen']
+stm32l0x2xx = ['new_gen']
+stm32l4x2xx = ['new_gen', 'ram_addr_40006c00']
 
 # Auxiliary features
 old_gen = ['ram_size_512', 'ram_access_1x16']
diff --git a/src/lib.rs b/src/lib.rs
index fb7b55a..f311fee 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,27 +5,11 @@
 
 #![no_std]
 
-#[cfg(not(feature = "family-selected"))]
-compile_error!(
-    "This crate requires one of the device family features enabled.
-Check Cargo.toml for supported families ('Device family' section)"
-);
-
-#[cfg(feature = "family-selected")]
+pub mod bus;
 mod endpoint;
-
-#[cfg(feature = "family-selected")]
 mod endpoint_memory;
-
 mod registers;
-
-#[cfg(feature = "family-selected")]
 mod target;
-
-#[cfg(feature = "family-selected")]
-pub mod bus;
-
-#[cfg(feature = "family-selected")]
 pub use crate::bus::UsbBus;
 
 mod pac;

From 728cb58d8868098069f999390438010f9207e4ae Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:32:10 +0300
Subject: [PATCH 09/25] Remove deprecated delay_workaround feature

---
 Cargo.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 378209d..d3f59df 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -30,7 +30,6 @@ dp_pull_up_support = []
 
 # Hacks
 ram_addr_40006c00 = []
-delay_workaround = []  # deprecated: cortex-m 0.6.1 contains a fix
 
 # Known devices
 stm32f042xx = ['new_gen']

From 22cefbe079547c3f0e1d5a2f419e53fd3bef4eb1 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:36:27 +0300
Subject: [PATCH 10/25] Move dp_pull_up_support feature into the UsbPeripheral
 trait

---
 Cargo.toml | 3 +--
 src/bus.rs | 5 +++--
 src/lib.rs | 3 +++
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index d3f59df..e5950ba 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,7 +26,6 @@ ram_access_2x16 = []
 # USB peripheral features
 lpm_support = []
 bcd_support = []
-dp_pull_up_support = []
 
 # Hacks
 ram_addr_40006c00 = []
@@ -43,7 +42,7 @@ stm32l4x2xx = ['new_gen', 'ram_addr_40006c00']
 
 # Auxiliary features
 old_gen = ['ram_size_512', 'ram_access_1x16']
-new_gen = ['ram_size_1024', 'ram_access_2x16', 'lpm_support', 'bcd_support', 'dp_pull_up_support']
+new_gen = ['ram_size_1024', 'ram_access_2x16', 'lpm_support', 'bcd_support']
 family-selected = []
 
 [package.metadata.docs.rs]
diff --git a/src/bus.rs b/src/bus.rs
index c806536..c0bbb95 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -152,8 +152,9 @@ impl<USB: UsbPeripheral> usb_device::bus::UsbBus for UsbBus<USB> {
             });
             regs.istr.modify(|_, w| unsafe { w.bits(0) });
 
-            #[cfg(feature = "dp_pull_up_support")]
-            regs.bcdr.modify(|_, w| w.dppu().set_bit());
+            if USB::DP_PULL_UP_FEATURE {
+                regs.bcdr.modify(|_, w| w.dppu().set_bit());
+            }
         });
     }
 
diff --git a/src/lib.rs b/src/lib.rs
index f311fee..a979d28 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -21,6 +21,9 @@ pub unsafe trait UsbPeripheral: Send + Sync {
     /// Pointer to the register block
     const REGISTERS: *const ();
 
+    /// Embedded pull-up resistor on USB_DP line
+    const DP_PULL_UP_FEATURE: bool;
+
     /// Enables USB device on its peripheral bus
     fn enable();
 

From 60f537509ed19cdf33089e3050e5901da970a944 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:39:55 +0300
Subject: [PATCH 11/25] Remove unused lpm_support and bcd_support features

---
 Cargo.toml | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index e5950ba..75337cf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,10 +23,6 @@ ram_size_1024 = []
 ram_access_1x16 = []
 ram_access_2x16 = []
 
-# USB peripheral features
-lpm_support = []
-bcd_support = []
-
 # Hacks
 ram_addr_40006c00 = []
 
@@ -42,7 +38,7 @@ stm32l4x2xx = ['new_gen', 'ram_addr_40006c00']
 
 # Auxiliary features
 old_gen = ['ram_size_512', 'ram_access_1x16']
-new_gen = ['ram_size_1024', 'ram_access_2x16', 'lpm_support', 'bcd_support']
+new_gen = ['ram_size_1024', 'ram_access_2x16']
 family-selected = []
 
 [package.metadata.docs.rs]

From 27c21f9acf88f63aaefbd61fbbd43f032bcb78b5 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 01:42:31 +0300
Subject: [PATCH 12/25] Remove family-selected feature

---
 Cargo.toml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 75337cf..1bdcc02 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -39,7 +39,6 @@ stm32l4x2xx = ['new_gen', 'ram_addr_40006c00']
 # Auxiliary features
 old_gen = ['ram_size_512', 'ram_access_1x16']
 new_gen = ['ram_size_1024', 'ram_access_2x16']
-family-selected = []
 
 [package.metadata.docs.rs]
 features = ["stm32f103xx"]

From 96232aa130e1ed6d1b9a2f0b9fa78c68303313a0 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:01:36 +0300
Subject: [PATCH 13/25] Move EP_MEM_ADDR and EP_MEM_SIZE into the UsbPeripheral
 trait

---
 Cargo.toml             | 13 +++----------
 src/bus.rs             |  2 +-
 src/endpoint.rs        |  6 +++---
 src/endpoint_memory.rs | 28 ++++++++++++++++------------
 src/lib.rs             |  6 ++++++
 src/target.rs          | 10 ----------
 6 files changed, 29 insertions(+), 36 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 1bdcc02..3fb5cf1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,17 +15,10 @@ cortex-m = "0.6.1"
 usb-device = "0.2.3"
 
 [features]
-# Dedicated USB RAM size
-ram_size_512 = []
-ram_size_1024 = []
-
 # USB RAM access scheme
 ram_access_1x16 = []
 ram_access_2x16 = []
 
-# Hacks
-ram_addr_40006c00 = []
-
 # Known devices
 stm32f042xx = ['new_gen']
 stm32f048xx = ['new_gen']
@@ -34,11 +27,11 @@ stm32f078xx = ['new_gen']
 stm32f103xx = ['old_gen']
 stm32f303xc = ['old_gen']
 stm32l0x2xx = ['new_gen']
-stm32l4x2xx = ['new_gen', 'ram_addr_40006c00']
+stm32l4x2xx = ['new_gen']
 
 # Auxiliary features
-old_gen = ['ram_size_512', 'ram_access_1x16']
-new_gen = ['ram_size_1024', 'ram_access_2x16']
+old_gen = ['ram_access_1x16']
+new_gen = ['ram_access_2x16']
 
 [package.metadata.docs.rs]
 features = ["stm32f103xx"]
diff --git a/src/bus.rs b/src/bus.rs
index c0bbb95..2f6945e 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -17,7 +17,7 @@ pub struct UsbBus<USB> {
     peripheral: USB,
     regs: Mutex<UsbRegisters<USB>>,
     endpoints: [Endpoint<USB>; NUM_ENDPOINTS],
-    ep_allocator: EndpointMemoryAllocator,
+    ep_allocator: EndpointMemoryAllocator<USB>,
     max_endpoint: usize,
 }
 
diff --git a/src/endpoint.rs b/src/endpoint.rs
index 1d1a861..14ec13e 100644
--- a/src/endpoint.rs
+++ b/src/endpoint.rs
@@ -67,7 +67,7 @@ impl<USB: UsbPeripheral> Endpoint<USB> {
     }
 
     pub fn set_out_buf(&mut self, buffer: EndpointBuffer, size_bits: u16) {
-        let offset = buffer.offset();
+        let offset = buffer.offset::<USB>();
         self.out_buf = Some(Mutex::new(buffer));
 
         let descr = self.descr();
@@ -80,7 +80,7 @@ impl<USB: UsbPeripheral> Endpoint<USB> {
     }
 
     pub fn set_in_buf(&mut self, buffer: EndpointBuffer) {
-        let offset = buffer.offset();
+        let offset = buffer.offset::<USB>();
         self.in_buf = Some(Mutex::new(buffer));
 
         let descr = self.descr();
@@ -89,7 +89,7 @@ impl<USB: UsbPeripheral> Endpoint<USB> {
     }
 
     fn descr(&self) -> &'static BufferDescriptor {
-        EndpointMemoryAllocator::buffer_descriptor(self.index)
+        EndpointMemoryAllocator::<USB>::buffer_descriptor(self.index)
     }
 
     fn reg(&self) -> &'static usb::EPR {
diff --git a/src/endpoint_memory.rs b/src/endpoint_memory.rs
index e96b540..3c6e032 100644
--- a/src/endpoint_memory.rs
+++ b/src/endpoint_memory.rs
@@ -1,14 +1,16 @@
-use crate::target::{UsbAccessType, EP_MEM_ADDR, EP_MEM_SIZE, NUM_ENDPOINTS};
+use crate::target::{UsbAccessType, NUM_ENDPOINTS};
+use crate::UsbPeripheral;
+use core::marker::PhantomData;
 use core::{mem, slice};
 use usb_device::{Result, UsbError};
 use vcell::VolatileCell;
 
-const EP_MEM_PTR: *mut VolatileCell<UsbAccessType> = EP_MEM_ADDR as *mut VolatileCell<UsbAccessType>;
-
 pub struct EndpointBuffer(&'static mut [VolatileCell<UsbAccessType>]);
 
 impl EndpointBuffer {
-    pub fn new(offset_bytes: usize, size_bytes: usize) -> Self {
+    pub fn new<USB: UsbPeripheral>(offset_bytes: usize, size_bytes: usize) -> Self {
+        let EP_MEM_PTR = USB::EP_MEMORY as *mut VolatileCell<UsbAccessType>;
+
         let mem =
             unsafe { slice::from_raw_parts_mut(EP_MEM_PTR.offset((offset_bytes >> 1) as isize), size_bytes >> 1) };
         Self(mem)
@@ -59,9 +61,9 @@ impl EndpointBuffer {
         }
     }
 
-    pub fn offset(&self) -> usize {
+    pub fn offset<USB: UsbPeripheral>(&self) -> usize {
         let buffer_address = self.0.as_ptr() as usize;
-        let index = (buffer_address - EP_MEM_ADDR) / mem::size_of::<UsbAccessType>();
+        let index = (buffer_address - USB::EP_MEMORY as usize) / mem::size_of::<UsbAccessType>();
         index << 1
     }
 
@@ -78,32 +80,34 @@ pub struct BufferDescriptor {
     pub count_rx: VolatileCell<UsbAccessType>,
 }
 
-pub struct EndpointMemoryAllocator {
+pub struct EndpointMemoryAllocator<USB> {
     next_free_offset: usize,
+    _marker: PhantomData<USB>,
 }
 
-impl EndpointMemoryAllocator {
+impl<USB: UsbPeripheral> EndpointMemoryAllocator<USB> {
     pub fn new() -> Self {
         Self {
             next_free_offset: NUM_ENDPOINTS * 8,
+            _marker: PhantomData,
         }
     }
 
     pub fn allocate_buffer(&mut self, size: usize) -> Result<EndpointBuffer> {
         assert!(size & 1 == 0);
-        assert!(size < EP_MEM_SIZE);
+        assert!(size < USB::EP_MEMORY_SIZE);
 
         let offset = self.next_free_offset;
-        if offset as usize + size > EP_MEM_SIZE {
+        if offset as usize + size > USB::EP_MEMORY_SIZE {
             return Err(UsbError::EndpointMemoryOverflow);
         }
 
         self.next_free_offset += size;
 
-        Ok(EndpointBuffer::new(offset, size))
+        Ok(EndpointBuffer::new::<USB>(offset, size))
     }
 
     pub fn buffer_descriptor(index: u8) -> &'static BufferDescriptor {
-        unsafe { &*(EP_MEM_ADDR as *const BufferDescriptor).offset(index as isize) }
+        unsafe { &*(USB::EP_MEMORY as *const BufferDescriptor).offset(index as isize) }
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index a979d28..412d427 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -24,6 +24,12 @@ pub unsafe trait UsbPeripheral: Send + Sync {
     /// Embedded pull-up resistor on USB_DP line
     const DP_PULL_UP_FEATURE: bool;
 
+    /// Pointer to the endpoint memory
+    const EP_MEMORY: *const ();
+
+    /// Endpoint memory size in bytes
+    const EP_MEMORY_SIZE: usize;
+
     /// Enables USB device on its peripheral bus
     fn enable();
 
diff --git a/src/target.rs b/src/target.rs
index 3c19b8d..e67cad2 100644
--- a/src/target.rs
+++ b/src/target.rs
@@ -5,14 +5,4 @@ pub type UsbAccessType = u32;
 #[cfg(feature = "ram_access_2x16")]
 pub type UsbAccessType = u16;
 
-#[cfg(not(feature = "ram_addr_40006c00"))]
-pub const EP_MEM_ADDR: usize = 0x4000_6000;
-#[cfg(feature = "ram_addr_40006c00")]
-pub const EP_MEM_ADDR: usize = 0x4000_6C00;
-
-#[cfg(feature = "ram_size_512")]
-pub const EP_MEM_SIZE: usize = 512;
-#[cfg(feature = "ram_size_1024")]
-pub const EP_MEM_SIZE: usize = 1024;
-
 pub const NUM_ENDPOINTS: usize = 8;

From f652574845379ab794767e46643e12f33540c253 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:02:37 +0300
Subject: [PATCH 14/25] Use assert_eq

---
 src/endpoint_memory.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/endpoint_memory.rs b/src/endpoint_memory.rs
index 3c6e032..2e44927 100644
--- a/src/endpoint_memory.rs
+++ b/src/endpoint_memory.rs
@@ -94,7 +94,7 @@ impl<USB: UsbPeripheral> EndpointMemoryAllocator<USB> {
     }
 
     pub fn allocate_buffer(&mut self, size: usize) -> Result<EndpointBuffer> {
-        assert!(size & 1 == 0);
+        assert_eq!(size & 1, 0);
         assert!(size < USB::EP_MEMORY_SIZE);
 
         let offset = self.next_free_offset;

From eebef0272f83e9fcbf0374ad7ef70ad845bc1a89 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:05:52 +0300
Subject: [PATCH 15/25] Remove old_gen and new_gen features

---
 Cargo.toml | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 3fb5cf1..8c56808 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -20,18 +20,14 @@ ram_access_1x16 = []
 ram_access_2x16 = []
 
 # Known devices
-stm32f042xx = ['new_gen']
-stm32f048xx = ['new_gen']
-stm32f072xx = ['new_gen']
-stm32f078xx = ['new_gen']
-stm32f103xx = ['old_gen']
-stm32f303xc = ['old_gen']
-stm32l0x2xx = ['new_gen']
-stm32l4x2xx = ['new_gen']
-
-# Auxiliary features
-old_gen = ['ram_access_1x16']
-new_gen = ['ram_access_2x16']
+stm32f042xx = ['ram_access_2x16']
+stm32f048xx = ['ram_access_2x16']
+stm32f072xx = ['ram_access_2x16']
+stm32f078xx = ['ram_access_2x16']
+stm32f103xx = ['ram_access_1x16']
+stm32f303xc = ['ram_access_1x16']
+stm32l0x2xx = ['ram_access_2x16']
+stm32l4x2xx = ['ram_access_2x16']
 
 [package.metadata.docs.rs]
 features = ["stm32f103xx"]

From c6b36d1cc444e77467fc535be94d1834da06b138 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:16:57 +0300
Subject: [PATCH 16/25] Fix warning

---
 src/endpoint_memory.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/endpoint_memory.rs b/src/endpoint_memory.rs
index 2e44927..15f42a0 100644
--- a/src/endpoint_memory.rs
+++ b/src/endpoint_memory.rs
@@ -9,10 +9,10 @@ pub struct EndpointBuffer(&'static mut [VolatileCell<UsbAccessType>]);
 
 impl EndpointBuffer {
     pub fn new<USB: UsbPeripheral>(offset_bytes: usize, size_bytes: usize) -> Self {
-        let EP_MEM_PTR = USB::EP_MEMORY as *mut VolatileCell<UsbAccessType>;
+        let ep_mem_ptr = USB::EP_MEMORY as *mut VolatileCell<UsbAccessType>;
 
         let mem =
-            unsafe { slice::from_raw_parts_mut(EP_MEM_PTR.offset((offset_bytes >> 1) as isize), size_bytes >> 1) };
+            unsafe { slice::from_raw_parts_mut(ep_mem_ptr.offset((offset_bytes >> 1) as isize), size_bytes >> 1) };
         Self(mem)
     }
 

From 6c1f9465dcaea6f0880e52f6301c633c8a1f40c2 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:17:42 +0300
Subject: [PATCH 17/25] Replace mem::uninitialized() with MaybeUninit

---
 src/bus.rs | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/src/bus.rs b/src/bus.rs
index 2f6945e..336aa39 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -1,6 +1,6 @@
 //! USB peripheral driver.
 
-use core::mem;
+use core::mem::{self, MaybeUninit};
 use cortex_m::interrupt::{self, Mutex};
 use usb_device::bus::{PollResult, UsbBusAllocator};
 use usb_device::endpoint::{EndpointAddress, EndpointType};
@@ -31,14 +31,15 @@ impl<USB: UsbPeripheral> UsbBus<USB> {
             regs: Mutex::new(UsbRegisters::new()),
             ep_allocator: EndpointMemoryAllocator::new(),
             max_endpoint: 0,
-            endpoints: unsafe {
-                let mut endpoints: [Endpoint<USB>; NUM_ENDPOINTS] = mem::uninitialized();
+            endpoints: {
+                let mut endpoints: [MaybeUninit<Endpoint<USB>>; NUM_ENDPOINTS] =
+                    unsafe { MaybeUninit::uninit().assume_init() };
 
                 for i in 0..NUM_ENDPOINTS {
-                    endpoints[i] = Endpoint::new(i as u8);
+                    endpoints[i] = MaybeUninit::new(Endpoint::new(i as u8));
                 }
 
-                endpoints
+                unsafe { mem::transmute::<_, [Endpoint<USB>; NUM_ENDPOINTS]>(endpoints) }
             },
         };
 

From a5a7e6c92cdf5a5fc9ebe509d38624a22aa4aca1 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 02:22:34 +0300
Subject: [PATCH 18/25] Move things around

---
 src/bus.rs             | 3 +--
 src/endpoint.rs        | 5 +++--
 src/endpoint_memory.rs | 7 ++++++-
 src/lib.rs             | 1 -
 src/target.rs          | 8 --------
 5 files changed, 10 insertions(+), 14 deletions(-)
 delete mode 100644 src/target.rs

diff --git a/src/bus.rs b/src/bus.rs
index 336aa39..931f916 100644
--- a/src/bus.rs
+++ b/src/bus.rs
@@ -6,10 +6,9 @@ use usb_device::bus::{PollResult, UsbBusAllocator};
 use usb_device::endpoint::{EndpointAddress, EndpointType};
 use usb_device::{Result, UsbDirection, UsbError};
 
-use crate::endpoint::{calculate_count_rx, Endpoint, EndpointStatus};
+use crate::endpoint::{calculate_count_rx, Endpoint, EndpointStatus, NUM_ENDPOINTS};
 use crate::endpoint_memory::EndpointMemoryAllocator;
 use crate::registers::UsbRegisters;
-use crate::target::NUM_ENDPOINTS;
 use crate::UsbPeripheral;
 
 /// USB peripheral driver for STM32 microcontrollers.
diff --git a/src/endpoint.rs b/src/endpoint.rs
index 14ec13e..22ed60f 100644
--- a/src/endpoint.rs
+++ b/src/endpoint.rs
@@ -1,6 +1,5 @@
-use crate::endpoint_memory::{BufferDescriptor, EndpointBuffer, EndpointMemoryAllocator};
+use crate::endpoint_memory::{BufferDescriptor, EndpointBuffer, EndpointMemoryAllocator, UsbAccessType};
 use crate::registers::UsbRegisters;
-use crate::target::UsbAccessType;
 use crate::UsbPeripheral;
 use core::marker::PhantomData;
 use core::mem;
@@ -13,6 +12,8 @@ use usb_device::{Result, UsbError};
 // compatible with definitions for older ones.
 pub use crate::pac::usb;
 
+pub const NUM_ENDPOINTS: usize = 8;
+
 /// Arbitrates access to the endpoint-specific registers and packet buffer memory.
 #[derive(Default)]
 pub struct Endpoint<USB> {
diff --git a/src/endpoint_memory.rs b/src/endpoint_memory.rs
index 15f42a0..ea62f86 100644
--- a/src/endpoint_memory.rs
+++ b/src/endpoint_memory.rs
@@ -1,10 +1,15 @@
-use crate::target::{UsbAccessType, NUM_ENDPOINTS};
+use crate::endpoint::NUM_ENDPOINTS;
 use crate::UsbPeripheral;
 use core::marker::PhantomData;
 use core::{mem, slice};
 use usb_device::{Result, UsbError};
 use vcell::VolatileCell;
 
+#[cfg(feature = "ram_access_1x16")]
+pub type UsbAccessType = u32;
+#[cfg(feature = "ram_access_2x16")]
+pub type UsbAccessType = u16;
+
 pub struct EndpointBuffer(&'static mut [VolatileCell<UsbAccessType>]);
 
 impl EndpointBuffer {
diff --git a/src/lib.rs b/src/lib.rs
index 412d427..95cb002 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -9,7 +9,6 @@ pub mod bus;
 mod endpoint;
 mod endpoint_memory;
 mod registers;
-mod target;
 pub use crate::bus::UsbBus;
 
 mod pac;
diff --git a/src/target.rs b/src/target.rs
deleted file mode 100644
index e67cad2..0000000
--- a/src/target.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-//! Target-specific definitions
-
-#[cfg(feature = "ram_access_1x16")]
-pub type UsbAccessType = u32;
-#[cfg(feature = "ram_access_2x16")]
-pub type UsbAccessType = u16;
-
-pub const NUM_ENDPOINTS: usize = 8;

From 292ccee5678722c8e0dcdf3a895661819f634a36 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Fri, 8 Nov 2019 12:10:14 +0300
Subject: [PATCH 19/25] Check features

---
 src/lib.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index 95cb002..8836c22 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,6 +5,11 @@
 
 #![no_std]
 
+#[cfg(not(any(feature = "ram_access_1x16", feature = "ram_access_2x16")))]
+compile_error!("This crate requires one of the ram_access features enabled");
+#[cfg(all(feature = "ram_access_1x16", feature = "ram_access_2x16"))]
+compile_error!("Multiple ram_access features are specified. Only a single feature can be specified.");
+
 pub mod bus;
 mod endpoint;
 mod endpoint_memory;

From 33958c120a490e1bd51f5668dbb7e04dfe0697da Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Mon, 11 Nov 2019 18:01:48 +0300
Subject: [PATCH 20/25] Remove 'Known devices' features

---
 Cargo.toml | 12 +-----------
 1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 8c56808..62484bf 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -19,15 +19,5 @@ usb-device = "0.2.3"
 ram_access_1x16 = []
 ram_access_2x16 = []
 
-# Known devices
-stm32f042xx = ['ram_access_2x16']
-stm32f048xx = ['ram_access_2x16']
-stm32f072xx = ['ram_access_2x16']
-stm32f078xx = ['ram_access_2x16']
-stm32f103xx = ['ram_access_1x16']
-stm32f303xc = ['ram_access_1x16']
-stm32l0x2xx = ['ram_access_2x16']
-stm32l4x2xx = ['ram_access_2x16']
-
 [package.metadata.docs.rs]
-features = ["stm32f103xx"]
+features = ["ram_access_2x16"]

From 33f7a2126b10c11606c26258bf855ae651efa9e8 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Mon, 11 Nov 2019 18:19:05 +0300
Subject: [PATCH 21/25] Add hal example

---
 Cargo.toml      |  7 +++++++
 examples/hal.rs | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 examples/hal.rs

diff --git a/Cargo.toml b/Cargo.toml
index 62484bf..4cc3196 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,6 +14,9 @@ vcell = "0.1.2"
 cortex-m = "0.6.1"
 usb-device = "0.2.3"
 
+[dev-dependencies]
+stm32f1xx-hal = { version = "0.4.0", features = ["stm32f103"] }
+
 [features]
 # USB RAM access scheme
 ram_access_1x16 = []
@@ -21,3 +24,7 @@ ram_access_2x16 = []
 
 [package.metadata.docs.rs]
 features = ["ram_access_2x16"]
+
+[[example]]
+name = "hal"
+required-features = ["ram_access_1x16"]
diff --git a/examples/hal.rs b/examples/hal.rs
new file mode 100644
index 0000000..e76e97f
--- /dev/null
+++ b/examples/hal.rs
@@ -0,0 +1,49 @@
+//! USB peripheral
+
+use stm32f1xx_hal::pac::{USB, RCC};
+use stm32_usbd::UsbPeripheral;
+
+use stm32f1xx_hal::gpio::gpioa::{PA11, PA12};
+use stm32f1xx_hal::gpio::{Floating, Input};
+pub use stm32_usbd::UsbBus;
+
+pub struct Peripheral {
+    pub usb: USB,
+    pub pin_dm: PA11<Input<Floating>>,
+    pub pin_dp: PA12<Input<Floating>>,
+}
+
+unsafe impl Sync for Peripheral {}
+
+unsafe impl UsbPeripheral for Peripheral {
+    const REGISTERS: *const () = USB::ptr() as *const ();
+    const DP_PULL_UP_FEATURE: bool = false;
+    const EP_MEMORY: *const () = 0x4000_6000 as _;
+    const EP_MEMORY_SIZE: usize = 512;
+
+    fn enable() {
+        let rcc = unsafe { (&*RCC::ptr()) };
+
+        cortex_m::interrupt::free(|_| {
+            // Enable USB peripheral
+            rcc.apb1enr.modify(|_, w| w.usben().set_bit());
+
+            // Reset USB peripheral
+            rcc.apb1rstr.modify(|_, w| w.usbrst().set_bit());
+            rcc.apb1rstr.modify(|_, w| w.usbrst().clear_bit());
+        });
+    }
+
+    fn startup_delay() {
+        // There is a chip specific startup delay. For STM32F103xx it's 1µs and this should wait for
+        // at least that long.
+        cortex_m::asm::delay(72);
+    }
+}
+
+pub type UsbBusType = UsbBus<Peripheral>;
+
+
+fn main() -> ! {
+    loop {}
+}

From aa5d5eef3f609d05bc935da486577b15082fae59 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Mon, 11 Nov 2019 18:21:25 +0300
Subject: [PATCH 22/25] Update README

---
 README.md | 55 ++++++++-----------------------------------------------
 1 file changed, 8 insertions(+), 47 deletions(-)

diff --git a/README.md b/README.md
index 607b01f..bbf6647 100644
--- a/README.md
+++ b/README.md
@@ -21,57 +21,18 @@ This repository is a fork of the [mvirkkunen/stm32f103xx-usb](https://github.com
 * `STM32L4x2xx`
 * And others...
 
-## Feature flags
+## Usage
 
-To use this crate you need to set proper feature flags.
-All the feature flags are listed in `Cargo.toml` under different sections.
-
-If your target MCU matches one of the feature flags listed under the
-`Known devices` section of `Cargo.toml`, you can use just that feature flag. For example:
-
-```toml
-[dependencies]
-stm32-usbd = { version = "0.3", features = ["stm32f103xx"] }
-```
-
-For other cases, you have to figure out different properties
-of your MCU and USB peripheral implemented in it.
-Each property has a corresponding feature flag that you should
-set to indicate that property.
-
-Device family:
-* `stm32f0`
-* `stm32f1`
-* `stm32f3`
-* `stm32l0`
-* `stm32l4`
-
-Size of dedicated packet buffer memory SRAM:
-* `ram_size_512`
-* `ram_size_1024`
-
-Dedicated packet buffer memory SRAM access scheme:
+This driver is intended for use through a device hal library.
+Such hal library should implement `UsbPeripheral` for the corresponding USB peripheral object.
+This trait declares all the peripheral properties that may vary from one device family to the other.
+Additionally, hal should pass `ram_access_1x16` of `ram_access_2x16` feature to the `stm32-usbd` library to
+define endpoint memory access scheme:
 * `ram_access_1x16` - for "1x16 bits/word" access scheme
 * `ram_access_2x16` - for "2x16 bits/word" access scheme
 
-USB peripheral features:
-* `lpm_support` - USB 2.0 Link Power Management (LPM) support
-* `bcd_support` - Battery Charging Detection (BCD) support
-* `dp_pull_up_support` - Embedded pull-up resistor on USB_DP line
-
-Various hacks:
-* `ram_addr_40006c00` if dedicated SRAM address is equal to `0x4000_6c00`
-instead of `0x4000_6000`
-
-```toml
-[dependencies]
-# An example feature set for STM32F303CB MCU
-stm32-usbd = { version = "0.3", features = ["stm32f3", "ram_size_512", "ram_access_1x16"] }
-stm32f3xx-hal = { version = "0.1.4", features = ["rt", "stm32f3xx-hal/stm32f303"] }
-```
-
-Note that you also need to set the device feature for `stm32*-hal` crate.
-
 ## Examples
 
 See the [stm32-usbd-examples](https://github.com/stm32-rs/stm32-usbd-examples) repo for different device-specific examples.
+
+See the `hal` example for the reference hal implementation.

From 5ee7e3019402b5d687a61425dc8ca2d027d7b867 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Mon, 11 Nov 2019 18:32:36 +0300
Subject: [PATCH 23/25] Update CI rules

---
 ci/script.sh | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/ci/script.sh b/ci/script.sh
index 20869be..83d549a 100755
--- a/ci/script.sh
+++ b/ci/script.sh
@@ -2,11 +2,6 @@
 
 set -euxo pipefail
 
-cargo check --no-default-features --features stm32f042xx
-#cargo check --no-default-features --features stm32f048xx
-#cargo check --no-default-features --features stm32f072xx
-#cargo check --no-default-features --features stm32f078xx
-cargo check --no-default-features --features stm32f103xx
-cargo check --no-default-features --features stm32f303xc
-cargo check --no-default-features --features stm32l0x2xx
-cargo check --no-default-features --features stm32l4x2xx
+cargo check --features ram_access_1x16
+cargo check --features ram_access_2x16
+cargo check --example hal --features ram_access_1x16

From 7c3d4cd39c9e528e7f8447bce7674f1b5daec490 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Mon, 11 Nov 2019 18:45:59 +0300
Subject: [PATCH 24/25] rustfmt

---
 examples/hal.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/examples/hal.rs b/examples/hal.rs
index e76e97f..833cb8a 100644
--- a/examples/hal.rs
+++ b/examples/hal.rs
@@ -1,11 +1,11 @@
 //! USB peripheral
 
-use stm32f1xx_hal::pac::{USB, RCC};
 use stm32_usbd::UsbPeripheral;
+use stm32f1xx_hal::pac::{RCC, USB};
 
+pub use stm32_usbd::UsbBus;
 use stm32f1xx_hal::gpio::gpioa::{PA11, PA12};
 use stm32f1xx_hal::gpio::{Floating, Input};
-pub use stm32_usbd::UsbBus;
 
 pub struct Peripheral {
     pub usb: USB,
@@ -43,7 +43,6 @@ unsafe impl UsbPeripheral for Peripheral {
 
 pub type UsbBusType = UsbBus<Peripheral>;
 
-
 fn main() -> ! {
     loop {}
 }

From b802384432cb3be843fa746d5c77de8bf0bfbbb7 Mon Sep 17 00:00:00 2001
From: Vadim Kaushan <admin@disasm.info>
Date: Tue, 12 Nov 2019 18:38:11 +0300
Subject: [PATCH 25/25] Fix comment

---
 src/registers.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/registers.rs b/src/registers.rs
index 51b2bc7..5df40c9 100644
--- a/src/registers.rs
+++ b/src/registers.rs
@@ -2,7 +2,7 @@ use crate::pac::usb::{RegisterBlock, EPR};
 use crate::UsbPeripheral;
 use core::marker::PhantomData;
 
-/// Wrapper around device-specific peripheral that provides unified register interface
+/// A proxy type that provides unified register interface
 pub struct UsbRegisters<USB> {
     _marker: PhantomData<USB>,
 }