Day26 - Sensor Core and Bus Layer Refactor

🎯 Objective

Transform a single-file I2C driver into:

• Bus-agnostic core
• Separate I2C transport layer

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🧩 Steps

Step 1 - Introduce bus abstraction

Replace direct I2C calls:

i2c_smbus_read_byte_data(...)

With:

mysensor_hw_read_reg(...)

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Step 2 - Extract core logic

Move to mysensor_core.c:

• cache handling
• update logic
• polling / IRQ
• sysfs / hwmon

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Step 3 - Create I2C glue layer

File: mysensor_i2c.c

Contains:

• i2c_driver
• probe/remove
• bus_ops implementation

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Step 4 - Modify probe flow

mysensor_i2c_probe()
    ↓
mysensor_core_probe()

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Step 5 - Update Makefile

obj-m += myi2c_sensor.o
myi2c_sensor-objs := mysensor_core.o mysensor_i2c.o

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✅ Validation Checklist

• Module loads successfully
• hwmon interface works
• IRQ mode works
• Polling mode works
• Hybrid mode works
• Cooldown logic works
• debug_status is correct

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🔍 Verification Commands

dmesg | tail
cat /sys/class/hwmon/hwmonX/temp1_input
cat /sys/class/hwmon/hwmonX/device/debug_status

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