🧰 I2C Device Driver Tutorial: Part 4 - Developing a Basic I2C Device Driver 🧰

In the fourth part of our tutorial series on I2C device drivers, we'll dive into the development of a basic I2C device driver in the Linux kernel. Building upon the knowledge gained in previous parts, we'll implement the necessary functions to initialize the device, perform data transfers, and handle errors effectively. By following this step-by-step guide, gives practical experience in developing I2C device drivers for Linux systems.

Developing a Basic I2C Device Driver:

Below is an example of a basic I2C device driver implementation:

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/i2c.h>

#include <linux/fs.h>

#define DEVICE_NAME "my_i2c_device"

static struct i2c_client *my_i2c_client;

static int my_i2c_probe(struct i2c_client client, const struct i2c_device_id id)

{

 // Perform device initialization

 printk(KERN_INFO "I2C Device Detected\n");

 my_i2c_client = client;

 return 0; // Success

}

static int my_i2c_remove(struct i2c_client *client)

{

 // Perform device cleanup

 printk(KERN_INFO "I2C Device Removed\n");

 return 0;

}

static const struct i2c_device_id my_i2c_id[] = {

 { DEVICE_NAME, 0 },

 { }

};

MODULE_DEVICE_TABLE(i2c, my_i2c_id);

static struct i2c_driver my_i2c_driver = {

 .probe = my_i2c_probe,

 .remove = my_i2c_remove,

 .id_table = my_i2c_id,

 .driver = {

 .name = DEVICE_NAME,

 .owner = THIS_MODULE,

 },

};

static int __init my_i2c_init(void)

{

 return i2c_add_driver(&my_i2c_driver);

}

static void __exit my_i2c_exit(void)

{

 i2c_del_driver(&my_i2c_driver);

}

module_init(my_i2c_init);

module_exit(my_i2c_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("LinuxLovers");

MODULE_DESCRIPTION("Basic I2C Device Driver");

.

.

.

Explanation:

- This code defines an I2C device driver module that initializes when a compatible I2C device is detected and cleans up when the device is removed.

- The `my_i2c_probe` function is called when the driver detects a compatible device, and it initializes the device and registers it with the I2C subsystem.

- The `my_i2c_remove` function is called when the device is removed, and it performs any necessary cleanup operations.

- The module uses the `i2c_driver` structure to define the driver's probe and remove functions, as well as the device ID table.

This example provides a basic framework for an I2C device driver. In the next part of the tutorial, we'll expand upon this foundation and add support for data transfer operations.

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