applet.radio.sx1276: new applet. (WIP)

Co-authored-by: elena <[email protected]>

software/glasgow/applet/radio/sx1276/__init__.py

@@ -0,0 +1,141 @@
+# Ref: SX1276/77/78/79 - 137 MHz to 1020 MHz Low Power Long Range Transceiver Datasheet
+# Ref: https://www.semtech.com/products/wireless-rf/lora-connect/sx1276#documentation
+# Accession: G00086
+
+import math
+import asyncio
+import logging
+from amaranth import *
+
+from ....support.logging import *
+from ....arch.sx1276 import *
+from ...interface.spi_controller import SPIControllerSubtarget, SPIControllerInterface
+from ... import *
+
+
+class RadioSX1276Error(GlasgowAppletError):
+    pass
+
+
+class RadioSX1276Subtarget(Elaboratable):
+    def __init__(self, spi_subtarget, reset_t, dut_reset):
+        self.spi_subtarget = spi_subtarget
+        self.reset_t = reset_t
+        self.dut_reset = dut_reset
+
+    def elaborate(self, platform):
+        m = Module()
+
+        m.submodules.spi_subtarget = self.spi_subtarget
+
+        m.d.comb += [
+            self.reset_t.o.eq(~self.dut_reset),
+            self.reset_t.oe.eq(1),
+        ]
+
+        return m
+
+
+class RadioSX1276Interface:
+    def __init__(self, interface, logger, device, addr_dut_reset):
+        self.lower   = interface
+        self._logger = logger
+        self._level  = logging.DEBUG if self._logger.name == __name__ else logging.TRACE
+        self._device = device
+        self._addr_dut_reset = addr_dut_reset
+
+    def _log(self, message, *args) -> None:
+        self._logger.log(self._level, "SX1276: " + message, *args)
+
+    async def _set_reset(self, reset) -> None:
+        await self._device.write_register(self._addr_dut_reset, int(reset))
+
+    async def reset(self) -> None:
+        self._log("reset")
+        await self.lower.synchronize()
+        await self._set_reset(True)
+        await self.lower.delay_us(100) # TODO: reference DS
+        await self.lower.synchronize()
+        await self._set_reset(False)
+        await self.lower.delay_us(500) # TODO: reference DS
+        await self.lower.synchronize()
+
+    async def read_register(self, address: int, *, length=1) -> int:
+        assert address in range(0x7f) and length >= 1
+        await self.lower.write([(0<<7)|address], hold_ss=True)
+        value = int.from_bytes(await self.lower.read(length), byteorder="big")
+        self._log("read register [%02x]=<%.*x>", address, length * 2, value)
+        return value
+
+    async def write_register(self, address: int, value: int, *, length=1) -> None:
+        assert address in range(0x7f) and isinstance(value, int) and length >= 1
+        self._log("write register [%02x]=<%.*x>", address, length * 2, value)
+        await self.lower.write([(1<<7)|address, *value.to_bytes(length)])
+
+    async def identify(self):
+        version = await self.read_register(Addr.RegVersion)
+        self._log("version=%02x", version)
+        if version != Version.ProductionRevision:
+            raise RadioSX1276Error(f"incorrect version {version:#x} returned by device")
+        return version
+
+
+class RadioSX1276Applet(GlasgowApplet):
+    logger = logging.getLogger(__name__)
+    help = "transmit and receive using SX1276/7/8/9 RF PHYs"
+    description = """
+    Transmit and receive packets using the SX1276/7/8/9 RF PHYs. SX1276 is the base device, while
+    SX1277/8/9 are the lower cost, reduced functionality, interface compatible versions of the same.
+
+    [TODO: expand]
+    """
+
+    __pins = ("cs", "sck", "copi", "cipo", "reset", "dio0")
+
+    @classmethod
+    def add_build_arguments(cls, parser, access):
+        access.add_build_arguments(parser)
+
+        access.add_pin_argument(parser, "cs",    required=True, default=True)
+        access.add_pin_argument(parser, "sck",   required=True, default=True)
+        access.add_pin_argument(parser, "copi",  required=True, default=True)
+        access.add_pin_argument(parser, "cipo",  required=True, default=True)
+        access.add_pin_argument(parser, "reset", required=False, default=True)
+        access.add_pin_argument(parser, "dio0",  required=False, default=True) # currently unused
+
+        parser.add_argument(
+            "-f", "--frequency", metavar="FREQ", type=int, default=1000,
+            help="set SPI frequency to FREQ kHz (default: %(default)s)")
+
+    def build(self, target, args):
+        dut_reset, self.__addr_dut_reset = target.registers.add_rw(1)
+
+        self.mux_interface = iface = target.multiplexer.claim_interface(self, args)
+        pads = iface.get_pads(args, pins=self.__pins)
+
+        spi_subtarget = SPIControllerSubtarget(
+            pads=pads,
+            out_fifo=iface.get_out_fifo(),
+            in_fifo=iface.get_in_fifo(),
+            period_cyc=math.ceil(target.sys_clk_freq / (args.frequency * 1000)),
+            delay_cyc=math.ceil(target.sys_clk_freq / 1e6),
+            sck_idle=0,
+            sck_edge="rising",
+            cs_active=0,
+        )
+        sx1276_subtarget = RadioSX1276Subtarget(spi_subtarget, pads.reset_t, dut_reset)
+        return iface.add_subtarget(sx1276_subtarget)
+
+    async def run(self, device, args):
+        iface = await device.demultiplexer.claim_interface(self, self.mux_interface, args)
+        spi_iface = SPIControllerInterface(iface, self.logger)
+        sx1276_iface = RadioSX1276Interface(spi_iface, self.logger, device,
+                                                   self.__addr_dut_reset)
+        return sx1276_iface
+
+# -------------------------------------------------------------------------------------------------
+
+class RadioSX1276AppletTestCase(GlasgowAppletTestCase, applet=RadioSX1276Applet):
+    @synthesis_test
+    def test_build(self):
+        self.assertBuilds()