Finishing and testing the driver

projects/clusterctrl/src/python/clusterctrl/driver.py

@@ -1,4 +1,4 @@
-"""An I2C driver for the ClusterCTRL/ClusterHAT device(s)."""
+"""An I2C driver for the ClusterCTRL/ClusterHAT family of device(s)."""
 
 from enum import Enum
 from itertools import chain, repeat
@@ -10,8 +10,14 @@ from typing import NamedTuple, Union
 
 log = logging.getLogger(__name__)
 
-
+# Variable source import "smbus"
+#  - smbus can come from i2c-dev (host package, c ext.)
+#  - smbus2 is a PyPi hosted pure Python implementation
+#
+# In order to support reasonable packaging and deployment, we want to prefer
+# smbus and fall back to smbus2 if it isn't available.
 smbus = None
+
 if not smbus:
     try:
         import smbus
@@ -51,11 +57,12 @@ I2C_ADDRESS = 0x20
 
 class BoardType(Enum):
     DA = 0x00      # Unknown, presunably a prototype
+    SINGLE = 0x01  # Do the 'single' and 'triple' really use the same board ID?
+    TRIPLE = 0x01  # ???
+    PHAT = 0x02    # The ClusterHAT boards
+    CTRL = 0x02    # The ClusterCTRL boards
     A6 = 0x03      # https://clusterctrl.com/p/aplus6
     STACK = 0x04   # https://shop.pimoroni.com/products/clusterctrl-stack
-    SINGLE = 0x01  # Do the 'single' and 'triple' really use the same board ID?
-    TRIPLE = 0x01
-    PHAT = 0x02
 
 
 class Status(Enum):
@@ -113,12 +120,12 @@ class Cmd(Enum):
     GET_USTATUS = 0x14  # Get Px USBBOOT status (data0=x)
     SET_ORDER = 0x15  # Set order (data0=order)
     SAVE = 0xF0  # Save current PWR/P1-LED/P2-LED/P1/P2/Order/Mode to EEPROM
-    SAVEDEFAULTS = 0xF1  # Save factory defaults
+    SAVE_DEFAULTS = 0xF1  # Save factory defaults
     GET_DATA = 0xF2  # Get DATA (Temps/ADC/etc.)
     SAVE_ORDER = 0xF3  # Save order to EEPROM
     SAVE_USBBOOT = 0xF4  # Save usbboot status to EEPROM
     SAVE_POS = 0xF5  # Save Power On State to EEPROM
-    SAVE_LED = 0xF6  # Save LED to EEPROM
+    SAVE_LEDS = 0xF6  # Save LED to EEPROM
     NOP = 0x90  # Do nothing
 
 
@@ -133,21 +140,25 @@ class Data(Enum):
     FANSTATUS = 0x04  # Read fan status
 
 
-class PiID(NamedTuple):
+class PiRef(NamedTuple):
-    """Represent Pi IDs as something somewhat unique; a CTRL/HAT id and the Pi ID.
+    """An ID for a specific Pi/PiZero controlled by a Cluster{CTRL,HAT}.
 
     These IDs are expected to be unique at the host level; not at the cluster level.
 
     """
-    ctrl_id: int
+    controller_id: int
     pi_id: int
 
     def __repr__(self) -> str:
-        return f"<PiID {self.ctrl_id:03d}-{self.pi_id:02d}>"
+        return f"<PiRef {self.controller_id:d}-{self.pi_id:d}>"
 
 
 class ClusterCTRLv2Driver(object):
-    def __init__(self, bus: smbus2.SMBus, address: int = I2C_ADDRESS, delay: int = 0, clear = False):
+    def __init__(self,
+                 bus: smbus.SMBus,
+                 address: int = I2C_ADDRESS,
+                 delay: int = 0,
+                 clear: bool = False):
         """Initialize a ClusterCTRL/ClusterHAT driver instance for a given bus device."""
         self._bus = bus
         self._address = address
@@ -160,8 +171,11 @@ class ClusterCTRLv2Driver(object):
         except:
             raise ValueError("Cannot communicate with a ClusterCTRL/ClusterHAT on the given bus")
 
+        self._post_init()
+
+    def _post_init(self):
         # This is a firmware default value indicating an uninitialized board.
-        # Randomize it if present.
+        # Randomize it if present and the user hasn't told us not to.
         if self.get_order() == 20:
             v = 20
             r = SystemRandom()
@@ -231,32 +245,42 @@ class ClusterCTRLv2Driver(object):
         # Return the (mostly) meaningful return code
         return self._read(Reg.DATA0)
 
-    def _id(self, id: PiID) -> int:
+    def _id(self, id: Union[PiRef, int]) -> int:
-        """Validate a logical ID and convert it to a numeric one."""
+        """Validate a user-provided ID and convert it to a numeric one."""
-        assert self.min_pi <= id <= self.max_pi
+
-        assert self.get_order() == id.ctrl_id
+        if isinstance(id, PiRef):
-        return id.pi_id
+            # Yes this is backwards, but its' most convenient for sharing validation
+            assert self.get_order() == id.controller_id
+            id = id.pi_id
+        elif isinstance(id, int):
+            pass
+        else:
+            raise ValueError(f"Expected an int or PiRef, got {type(id)}")
+
+        maxpi = self._read(Reg.MAXPI)
+        if 0 <= id <= maxpi:
+           return id
+        else:
+            raise ValueError("Expected an id in [0,{maxpi:d}], got {id:d}")
 
-    @property
     def min_pi(self):
         """Get the minimum supported Pi ID on this controller."""
 
-        return PiID(self.get_order(), 1)
+        return PiRef(self.get_order(), 1)
 
-    @property
     @once
     def max_pi(self):
         """Get the maximum supported Pi ID on this controller."""
 
-        return PiID(self.get_order(), self._read(Reg.MAXPI))
+        return PiRef(self.get_order(), self._read(Reg.MAXPI))
 
-    @property
+    def pis(self):
-    def pi_ids(self):
         """Iterate over the IDs of Pis which could be connected to this controller."""
 
         order = self.get_order()
-        for i in range(1, 6):
+        maxpi = self._read(Reg.MAXPI)
-            yield PiID(order, i)
+        for i in range(1, maxpi + 1):
+            yield PiRef(order, i)
 
     @property
     def type(self) -> BoardType:
@@ -287,7 +311,7 @@ class ClusterCTRLv2Driver(object):
     def eeprom_reset(self):
         """Reset EEPROM to factory/firmware default value(s)."""
 
-        return self._call(Cmd.SAVEDEFAULTS)
+        return self._call(Cmd.SAVE_DEFAULTS)
 
     def eeprom_save_powerstate(self):
         """Persist the current power state to EEPROM."""
@@ -297,7 +321,7 @@ class ClusterCTRLv2Driver(object):
     def eeprom_save_leds(self):
         """Persist the current LED state to EEPROM."""
 
-        return self._call(Cmd.SAVE_LED)
+        return self._call(Cmd.SAVE_LEDS)
 
     def eeprom_save_order(self):
         """Persist the current order value to EEPROM."""
@@ -307,7 +331,7 @@ class ClusterCTRLv2Driver(object):
     def eeprom_save_usbboot(self):
         """Persist USB booting settings to EEPROM."""
 
-        return self._call(Cmd.SAVEUSBBOOT)
+        return self._call(Cmd.SAVE_USBBOOT)
 
     ####################################################################################################
     # USB hub management
@@ -320,11 +344,11 @@ class ClusterCTRLv2Driver(object):
     def hub_off(self):
         """Turn off the USB hub."""
 
-        return self._call(Cmd.HUB_ON)
+        return self._call(Cmd.HUB_OFF)
 
     # FIXME: Is hub_status unsupported in the firmware?
 
-    def reset_hub(self, delay: int = 0):
+    def hub_reset(self, delay: int = 0):
         """[Power] cycle the Controller hub for `delay` x 10ms."""
 
         return self._call(Cmd.HUB_CYCLE, delay)
@@ -332,19 +356,19 @@ class ClusterCTRLv2Driver(object):
     ####################################################################################################
     # Power management
     ####################################################################################################
-    def power_on(self, id: PiID):
+    def power_on(self, id: Union[PiRef, int]):
         """Power on a given slot by ID."""
 
         id = self._id(id)
         return self._call(Cmd.ON, id)
 
-    def power_off(self, id: PiID):
+    def power_off(self, id: Union[PiRef, int]):
         """Power off a given slot by ID."""
 
         id = self._id(id)
         return self._call(Cmd.OFF, id)
 
-    def power_status(self, id: PiID):
+    def power_status(self, id: Union[PiRef, int]):
         """Read the status of a given slot by ID."""
 
         id = self._id(id)
@@ -353,14 +377,13 @@ class ClusterCTRLv2Driver(object):
     def power_all_on(self):
         """Power on all slots in this Controller."""
 
-        for id in self.pi_ids:
+        for id in self.pis():
-            if not self.power_status(id):
             self.power_on(id)
 
     def power_all_off(self):
         """Power off all slots in this Controller."""
 
-        for id in self.pi_ids:
+        for id in self.pis():
             self.power_off(id)
 
     ####################################################################################################
@@ -412,19 +435,19 @@ class ClusterCTRLv2Driver(object):
     ####################################################################################################
     # USB booting
     ####################################################################################################
-    def usbboot_on(self, id: PiID):
+    def usbboot_on(self, id: Union[PiRef, int]):
         """Enable USB booting for the given Pi."""
 
         id = self._id(id)
         return self._call(Cmd.USBBOOT_EN, id)
 
-    def usbboot_off(self, id: PiID):
+    def usbboot_off(self, id: Union[PiRef, int]):
         """Disable USB booting for the given Pi."""
 
         id = self._id(id)
         return self._call(Cmd.USBBOOT_DIS, id)
 
-    def usbboot_status(self, id: PiID):
+    def usbboot_status(self, id: Union[PiRef, int]):
         """Get the current USB booting status for the given Pi."""
 
         id = self._id(id)
@@ -442,9 +465,8 @@ class ClusterCTRLv2Driver(object):
     def adc_ids(self):
         return range(1, self.max_adc + 1)
 
-    def read_adc(self, id: PiID):
+    def read_adc(self, adc_id: int):
-        id = self._id(id)
+        self._call(Cmd.GET_DATA, Data.ADC_READ.value, adc_id)
-        self._call(Cmd.GET_DATA, Data.ADC_READ.value, id)
         # Now this is screwy.
         # DATA0 gets set to 0 or 1, indicating the voldage type
         # DATA1 and DATA2 are a 16bi number that need to be reassembled.
@@ -474,14 +496,16 @@ class ClusterCTRLv2Driver(object):
     ####################################################################################################
     # Operations with inconsistent platform support
     ####################################################################################################
-    def led_on(self, id: PiID):
+    def led_on(self, id: Union[PiRef, int]):
         """Turn on an LED by ID."""
 
         id = self._id(id)
         return self._call(Cmd.LED_EN, id)
 
-    def led_off(self, id: PiID):
+    def led_off(self, id: Union[PiRef, int]):
         """Turn off an LED by ID."""
 
         id = self._id(id)
         return self._call(Cmd.LED_DIS, id)
+
+    # FIXME: LED status?

projects/clusterctrl/test/python/test_driver.py

@@ -0,0 +1,265 @@
+"""Tests covering the v2 ClusterCTRL driver."""
+
+from clusterctrl.driver import (
+    BoardType,
+    ClusterCTRLv2Driver,
+    Cmd,
+    Data,
+    Reg,
+)
+import pytest
+
+
+class MockSMBus(object):
+    """An object that looks like smbus[2].SMBus.
+
+    This object builds an append/mock log of all i2c calls performed, allowing a
+    user to assert that a specific sequence of reads and writes was issued.
+
+    """
+
+    def __init__(self, regs={}):
+        self._log = []
+        self._regs = regs
+        self._retvals = []
+
+    def read_byte_data(self, bus_addr, memory_addr) -> int:
+        self._log.append(["read", bus_addr, memory_addr])
+        return self._regs[memory_addr]
+
+    def write_byte_data(self, bus_addr, memory_addr, value) -> None:
+        self._regs[memory_addr] = value
+        self._log.append(["write", bus_addr, memory_addr, value])
+
+        # Minimum viable call/return mocking
+        if memory_addr == Reg.CMD.value:
+            # Clear data registers after a "call"
+            for r in range(Reg.DATA7.value, Reg.CMD.value):
+                self._regs[r] = 0
+
+            if self._retvals:
+                self._regs[Reg.DATA0.value] = self._retvals.pop()
+
+    def read_block_data(self, bus_addr, memory_addr, block_size) -> int:
+        raise NotImplemented
+
+
+@pytest.fixture
+def bus():
+    """An SMBus-alike object."""
+
+    regs = {x: 0 for x in range(0, 16)}
+    regs[Reg.ORDER.value] = 13  # (un)lucky 13
+    regs[Reg.VERSION.value] = 2
+    regs[Reg.MAXPI.value] = 5
+    return MockSMBus(regs)
+
+
+@pytest.fixture
+def driver(bus):
+    """The driver under test atop a mocked bus."""
+
+    driver = ClusterCTRLv2Driver(bus)
+    bus._log.clear()  # The driver has startup behavior, so flush the log
+    return driver
+
+
+def sublist(l1, l2):
+    """Naive but adequate sublist testing."""
+
+    for i in range(len(l1)):
+        if l1[i] == l2[0]:
+            for j in range(len(l2)):
+                try:
+                    if l1[i + j] != l2[j]:
+                        break
+                except IndexError:
+                    break
+            else:
+                return True
+    return False
+
+
+def assert_log(bus, log):
+    def simplify(e):
+        if hasattr(e, "value"):
+            return e.value
+        else:
+            return e
+
+    log = [[simplify(e) for e in cmd] for cmd in log]
+
+    assert sublist(bus._log, log), "\n".join(
+        ["Failed to find expected sublog", "log:"] + [f"- {e}" for e in bus._log] + ["expected:"] + [f"- {e}" for e in log]
+    )
+
+
+def test_get_order(bus, driver):
+    """Check that get_order sends the appropriate command sequence."""
+
+    assert driver.get_order() == 13
+    assert_log(bus,
+               [["read", 0x20, Reg.ORDER]])
+
+
+def test_set_order(bus, driver):
+    """Check that set_order sends the appropriate command sequence."""
+
+    driver.set_order(14)
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, 14],
+                ["write", 0x20, Reg.CMD, Cmd.SET_ORDER]])
+
+
+def test_type(bus, driver):
+    assert isinstance(driver.type, BoardType)
+    assert_log(bus,
+               [["read", 0x20, Reg.TYPE]])
+
+
+def test_version(bus, driver):
+    assert driver.fw_version
+    # Invoke "read version"
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, Data.VERSION],
+                ["write", 0x20, Reg.CMD, Cmd.GET_DATA]])
+    # Read the two relevant registers
+    assert_log(bus,
+               [["read", 0x20, Reg.DATA1],
+                ["read", 0x20, Reg.DATA0]])
+
+
+def test_reset(bus, driver):
+    driver.reset_all()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.RESET]])
+
+
+def test_eeprom_save_all(bus, driver):
+    driver.eeprom_save_all()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE]])
+
+
+def test_eeprom_reset(bus, driver):
+    driver.eeprom_reset()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE_DEFAULTS]])
+
+
+def test_eeprom_save_powerstate(bus, driver):
+    driver.eeprom_save_powerstate()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE_POS]])
+
+
+def test_eeprom_save_leds(bus, driver):
+    driver.eeprom_save_leds()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE_LEDS]])
+
+
+def test_eeprom_save_order(bus, driver):
+    driver.eeprom_save_order()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE_ORDER]])
+
+
+def test_eeprom_save_ussbboot(bus, driver):
+    driver.eeprom_save_usbboot()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.SAVE_USBBOOT]])
+
+
+def test_hub_on(bus, driver):
+    driver.hub_on()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.HUB_ON]])
+
+
+def test_hub_off(bus, driver):
+    driver.hub_off()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.HUB_OFF]])
+
+
+def test_hub_reset(bus, driver):
+    driver.hub_reset()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.HUB_CYCLE]])
+
+
+def test_power_status(bus, driver):
+    bus._retvals.append(1)  # Set a mocked return code.
+    assert driver.power_status(1) == 1
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, 1],
+                ["write", 0x20, Reg.CMD, Cmd.GET_PSTATUS]])
+
+
+def test_pis(bus, driver):
+    assert len(list(driver.pis())) == 5
+
+
+def test_power_all_on(bus, driver):
+    driver.power_all_on()
+
+    for pi in driver.pis():
+        assert_log(bus,
+                   [["write", 0x20, Reg.DATA0, pi.pi_id],
+                    ["write", 0x20, Reg.CMD, Cmd.ON]])
+
+
+def test_power_all_off(bus, driver):
+    driver.power_all_off()
+
+    for pi in driver.pis():
+        assert_log(bus,
+                   [["write", 0x20, Reg.DATA0, pi.pi_id],
+                    ["write", 0x20, Reg.CMD, Cmd.OFF]])
+
+
+def test_alert_on(bus, driver):
+    driver.alert_on()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.ALERT_ON]])
+
+
+def test_alert_off(bus, driver):
+    driver.alert_off()
+    assert_log(bus,
+               [["write", 0x20, Reg.CMD, Cmd.ALERT_OFF]])
+
+
+def test_fan_on(bus, driver):
+    driver.fan_on()
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, 1],
+                ["write", 0x20, Reg.CMD, Cmd.FAN]])
+
+
+def test_fan_off(bus, driver):
+    driver.fan_off()
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, 0],
+                ["write", 0x20, Reg.CMD, Cmd.FAN]])
+
+
+def test_fan_status(bus, driver):
+    driver.fan_status()
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, Data.FANSTATUS],
+                ["write", 0x20, Reg.CMD, Cmd.GET_DATA]])
+
+
+def test_get_order(bus, driver):
+    driver.get_order()
+    assert_log(bus,
+               [["read", 0x20, Reg.ORDER]])
+
+
+def test_set_order(bus, driver):
+    driver.set_order(253)
+    assert_log(bus,
+               [["write", 0x20, Reg.DATA0, 253],
+                ["write", 0x20, Reg.CMD, Cmd.SET_ORDER]])