fpga config: included into lib

examples/fpga_config.rs

@@ -17,6 +17,8 @@ use cortex_m_rt::entry;
 use core::ptr;
 use nb::block;
 
+use firmware::flash::flash_ice40_fpga;
+
 #[path = "util/logger.rs"]
 mod logger;
 
@@ -74,65 +76,10 @@ fn main() -> ! {
 		&ccdr.clocks,
 	);
 
-	// Data buffer setup
-	let mut dummy_byte :[u8; 1] = [0x00];
-	let mut dummy_13_bytes :[u8; 13] = [0x00; 13];
-
-	// Drive CRESET_B low
-	fpga_creset.set_low().unwrap();
-
-	// Drive SPI_SS_B low
-	fpga_ss.set_low().unwrap();
-
-	// Wait at least 200ns
-	delay.delay_us(1_u16);
-
-	// Drive CRESET_B high
-	fpga_creset.set_high().unwrap();
-
-	// Wait at least another 1200us to clear internal config memory
-	delay.delay_us(1200_u16);
-
-	// Before data transmission starts, check if C_DONE is truly dine
-	match fpga_cdone.is_high() {
-		Ok(false)	=> debug!("Reset successful!"),
-		Ok(_) 		=> debug!("Reset unsuccessful!"),
-		Err(_) 		=> debug!("Reset error!"),
-	};
-
-	// Set SPI_SS_B high
-	fpga_ss.set_high().unwrap();
-
-	// Send 8 dummy clock, effectively 1 byte of 0x00
-	fpga_cfg_spi.transfer(&mut dummy_byte).unwrap();
-
-	// Drive SPI_SS_B low
-	fpga_ss.set_low().unwrap();
-
-	// Send the whole image without interruption
+	// Pre-load the configuration bytes
 	let config_data = include_bytes!("../build/top.bin");
 
-	for byte in config_data.into_iter() {
-		block!(fpga_cfg_spi.send(*byte)).unwrap();
-		block!(fpga_cfg_spi.read()).unwrap();
-	}
-
-	// Drive SPI_SS_B high
-	fpga_ss.set_high().unwrap();
-
-	// Send at another 100 dummy clocks (choosing 13 bytes)
-	fpga_cfg_spi.transfer(&mut dummy_13_bytes).unwrap();
-
-	// Check the CDONE output from FPGA
-	if !(fpga_cdone.is_high().unwrap()) {
-		debug!("ERROR!");
-	}
-	else {
-		debug!("Configuration successful!");
-		// Send at least another 49 clock cycles to activate IO pins (choosing same 13 bytes)
-		fpga_cfg_spi.transfer(&mut dummy_13_bytes).unwrap();
-		debug!("User I/O pins activated.");
-	}
+	flash_ice40_fpga(fpga_cfg_spi, fpga_ss, fpga_creset, fpga_cdone, delay, config_data)?;
 
 	loop {
 		nop();

src/flash.rs

@@ -0,0 +1,99 @@
+use embedded_hal::{
+	digital::v2::{OutputPin, InputPin},
+    blocking::spi::Transfer,
+    blocking::delay::{DelayMs, DelayUs},
+};
+
+use cortex_m;
+use cortex_m::asm::nop;
+use cortex_m_rt::entry;
+
+use core::ptr;
+use nb::block;
+
+use log::{warn, debug};
+
+pub enum FPGAFlashError {
+    SPICommunicationError,
+    NegotiationError,
+    ResetStatusError,
+}
+
+// A public method to flash iCE40 FPGA on Humpback
+pub fn flash_ice40_fpga<SPI: Transfer<u8>,
+                        SS: OutputPin,
+                        RST: OutputPin,
+                        DELAY: DelayUs<u32>,
+                        DONE: InputPin>
+    (mut spi: SPI, mut ss: SS, mut creset: RST, cdone: DONE, mut delay: DELAY, data: &[u8]) -> Result<(), FPGAFlashError>
+{
+	// Data buffer setup
+	let mut dummy_byte :[u8; 1] = [0x00];
+	let mut dummy_13_bytes :[u8; 13] = [0x00; 13];
+
+	// Drive CRESET_B low
+    creset.set_low()
+            .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Drive SPI_SS_B low
+    ss.set_low()
+        .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Wait at least 200ns
+	delay.delay_us(1_u32);
+
+	// Drive CRESET_B high
+    creset.set_high()
+            .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Wait at least another 1200us to clear internal config memory
+	delay.delay_us(1200_u32);
+
+    // Before data transmission starts, check if C_DONE is truly low
+    // If C_DONE is high, the FPGA reset procedure is unsuccessful
+	match cdone.is_low() {
+        Ok(true) => {},
+        _ => return Err(FPGAFlashError::ResetStatusError),
+    };
+
+	// Set SPI_SS_B high
+    ss.set_high()
+        .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Send 8 dummy clock, effectively 1 byte of 0x00
+    spi.transfer(&mut dummy_byte)
+        .map_err(|_| FPGAFlashError::SPICommunicationError)?;
+
+	// Drive SPI_SS_B low
+    ss.set_low()
+        .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Send the whole image without interruption
+	for byte in data.into_iter() {
+        let mut single_byte_slice = [*byte];
+        spi.transfer(&mut single_byte_slice)
+            .map_err(|_| FPGAFlashError::SPICommunicationError)?;
+	}
+
+	// Drive SPI_SS_B high
+    ss.set_high()
+        .map_err(|_| FPGAFlashError::NegotiationError)?;
+
+	// Send at another 100 dummy clocks (choosing 13 bytes)
+    spi.transfer(&mut dummy_13_bytes)
+        .map_err(|_| FPGAFlashError::SPICommunicationError)?;
+
+    // Check the CDONE output from FPGA
+    // CDONE needs to be high
+	match cdone.is_high() {
+        Ok(true) => {},
+        _ => return Err(FPGAFlashError::ResetStatusError),
+    };
+
+    debug!("Configuration successful!");
+    // Send at least another 49 clock cycles to activate IO pins (choosing same 13 bytes)
+    spi.transfer(&mut dummy_13_bytes).map_err(|_| FPGAFlashError::SPICommunicationError)?;
+    debug!("User I/O pins activated.");
+    Ok(())
+
+}