[RFC v1 07/10] iio: light: opt3001: add roadtest

[Vincent Whitchurch <vincent.whitchurch@axis.com>]

Add a regression test for the problem fixed by the following patch,
which would require specific environmental conditions to be able to be
reproduced and regression-tested on real hardware:

 iio: light: opt3001: Fixed timeout error when 0 lux
 https://lore.kernel.org/lkml/20210920125351.6569-1-valek@2n.cz/

No other aspects of the driver are tested.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
 .../roadtest/roadtest/tests/iio/__init__.py   |  0
 .../roadtest/roadtest/tests/iio/config        |  1 +
 .../roadtest/tests/iio/light/__init__.py      |  0
 .../roadtest/roadtest/tests/iio/light/config  |  1 +
 .../roadtest/tests/iio/light/test_opt3001.py  | 95 +++++++++++++++++++
 5 files changed, 97 insertions(+)
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py

diff --git a/tools/testing/roadtest/roadtest/tests/iio/__init__.py b/tools/testing/roadtest/roadtest/tests/iio/__init__.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/tools/testing/roadtest/roadtest/tests/iio/config b/tools/testing/roadtest/roadtest/tests/iio/config
new file mode 100644
index 000000000000..a08d9e23ce38
--- /dev/null
+++ b/tools/testing/roadtest/roadtest/tests/iio/config
@@ -0,0 +1 @@
+CONFIG_IIO=y
diff --git a/tools/testing/roadtest/roadtest/tests/iio/light/__init__.py b/tools/testing/roadtest/roadtest/tests/iio/light/__init__.py
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/tools/testing/roadtest/roadtest/tests/iio/light/config b/tools/testing/roadtest/roadtest/tests/iio/light/config
new file mode 100644
index 000000000000..b9753f2d0728
--- /dev/null
+++ b/tools/testing/roadtest/roadtest/tests/iio/light/config
@@ -0,0 +1 @@
+CONFIG_OPT3001=m
diff --git a/tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py b/tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py
new file mode 100644
index 000000000000..abf20b8f3516
--- /dev/null
+++ b/tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright Axis Communications AB
+
+from typing import Any, Final
+
+from roadtest.backend.i2c import SMBusModel
+from roadtest.core.devicetree import DtFragment, DtVar
+from roadtest.core.hardware import Hardware
+from roadtest.core.modules import insmod, rmmod
+from roadtest.core.suite import UMLTestCase
+from roadtest.core.sysfs import I2CDriver, read_float
+
+REG_RESULT: Final = 0x00
+REG_CONFIGURATION: Final = 0x01
+REG_LOW_LIMIT: Final = 0x02
+REG_HIGH_LIMIT: Final = 0x03
+REG_MANUFACTURER_ID: Final = 0x7E
+REG_DEVICE_ID: Final = 0x7F
+
+REG_CONFIGURATION_CRF: Final = 1 << 7
+
+
+class OPT3001(SMBusModel):
+    def __init__(self, **kwargs: Any) -> None:
+        super().__init__(regbytes=2, byteorder="big", **kwargs)
+        # Reset values from datasheet
+        self.regs = {
+            REG_RESULT: 0x0000,
+            REG_CONFIGURATION: 0xC810,
+            REG_LOW_LIMIT: 0xC000,
+            REG_HIGH_LIMIT: 0xBFFF,
+            REG_MANUFACTURER_ID: 0x5449,
+            REG_DEVICE_ID: 0x3001,
+        }
+
+    def reg_read(self, addr: int) -> int:
+        val = self.regs[addr]
+
+        if addr == REG_CONFIGURATION:
+            # Always indicate that the conversion is ready.  This is good
+            # enough for our current purposes.
+            val |= REG_CONFIGURATION_CRF
+
+        return val
+
+    def reg_write(self, addr: int, val: int) -> None:
+        assert addr in self.regs
+        self.regs[addr] = val
+
+
+class TestOPT3001(UMLTestCase):
+    dts = DtFragment(
+        src="""
+&i2c {
+    light-sensor@$addr$ {
+        compatible = "ti,opt3001";
+        reg = <0x$addr$>;
+    };
+};
+        """,
+        variables={
+            "addr": DtVar.I2C_ADDR,
+        },
+    )
+
+    @classmethod
+    def setUpClass(cls) -> None:
+        insmod("opt3001")
+
+    @classmethod
+    def tearDownClass(cls) -> None:
+        rmmod("opt3001")
+
+    def setUp(self) -> None:
+        self.driver = I2CDriver("opt3001")
+        self.hw = Hardware("i2c")
+        self.hw.load_model(OPT3001)
+
+    def tearDown(self) -> None:
+        self.hw.close()
+
+    def test_illuminance(self) -> None:
+        data = [
+            # Some values from datasheet, and 0
+            (0b_0000_0000_0000_0000, 0),
+            (0b_0000_0000_0000_0001, 0.01),
+            (0b_0011_0100_0101_0110, 88.80),
+            (0b_0111_1000_1001_1010, 2818.56),
+        ]
+        with self.driver.bind(self.dts["addr"]) as dev:
+            luxfile = dev.path / "iio:device0/in_illuminance_input"
+
+            for regval, lux in data:
+                self.hw.reg_write(REG_RESULT, regval)
+                self.assertEqual(read_float(luxfile), lux)
-- 
2.34.1