Clean up spi

Remove uncommented spi::Write implementation

Author: Sh3Rm4n

src/spi.rs

@@ -610,44 +610,3 @@ hal! {
     SPI3: (spi3, APB1, spi3en, spi3rst, pclk1),
     SPI4: (spi4, APB2, spi4en, spi4rst, pclk2),
 }
-
-// FIXME not working
-// TODO measure if this actually faster than the default implementation
-// impl ::hal::blocking::spi::Write<u8> for Spi {
-//     type Error = Error;
-
-//     fn write(&mut self, bytes: &[u8]) -> Result<(), Error> {
-//         for byte in bytes {
-//             'l: loop {
-//                 let sr = self.spi.sr.read();
-
-//                 // ignore overruns because we don't care about the incoming data
-//                 // if sr.ovr().bit_is_set() {
-//                 // Err(nb::Error::Other(Error::Overrun))
-//                 // } else
-//                 if sr.modf().bit_is_set() {
-//                     return Err(Error::ModeFault);
-//                 } else if sr.crcerr().bit_is_set() {
-//                     return Err(Error::Crc);
-//                 } else if sr.txe().bit_is_set() {
-//                     // NOTE(write_volatile) see note above
-//                     unsafe { ptr::write_volatile(&self.spi.dr as *const _ as *mut u8, *byte) }
-//                     break 'l;
-//                 } else {
-//                     // try again
-//                 }
-//             }
-//         }
-
-//         // wait until the transmission of the last byte is done
-//         while self.spi.sr.read().bsy().bit_is_set() {}
-
-//         // clear OVR flag
-//         unsafe {
-//             ptr::read_volatile(&self.spi.dr as *const _ as *const u8);
-//         }
-//         self.spi.sr.read();
-
-//         Ok(())
-//     }
-// }