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| #include <linux/init.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/cdev.h>
#include <linux/property.h>
#include <linux/gpio/consumer.h>
#include <linux/device.h>
#define DEVICE_NAME "my_i2c_device"
#define CLASS_NAME "my_i2c_class"
static int major;
static struct class *i2c_class = NULL;
static struct device *i2c_device = NULL;
static struct i2c_client *global_client = NULL;
static int my_i2c_read(struct i2c_client *client, char *buf, int count) {
struct i2c_msg msgs[1];
msgs[0].addr = client->addr;
msgs[0].flags = I2C_M_RD;
msgs[0].len = count;
msgs[0].buf = buf;
return (i2c_transfer(client->adapter, msgs, 1) == 1) ? 0 : -EIO;
}
static int my_i2c_write(struct i2c_client *client, const char *buf, int count) {
struct i2c_msg msgs[1];
msgs[0].addr = client->addr;
msgs[0].flags = 0;
msgs[0].len = count;
msgs[0].buf = (char *)buf;
return (i2c_transfer(client->adapter, msgs, 1) == 1) ? 0 : -EIO;
}
static ssize_t dev_read(struct file *file, char __user *buf, size_t count, loff_t *offset) {
char kbuf[64];
int ret;
if (count > 64) count = 64;
ret = my_i2c_read(global_client, kbuf, count);
if (ret < 0) return ret;
if (copy_to_user(buf, kbuf, count)) return -EFAULT;
return count;
}
static ssize_t dev_write(struct file *file, const char __user *buf, size_t count, loff_t *offset) {
char kbuf[64];
if (count > 64) count = 64;
if (copy_from_user(kbuf, buf, count)) return -EFAULT;
if (my_i2c_write(global_client, kbuf, count) < 0) return -EIO;
return count;
}
static struct file_operations fops = {
.owner = THIS_MODULE,
.read = dev_read,
.write = dev_write,
};
static int my_i2c_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
u32 val32, array[4];
const char *str;
bool gesture_enabled;
global_client = client;
if (!device_property_read_u32(dev, "max-x", &val32))
dev_info(dev, "DTS Max X: %u\n", val32);
if (!device_property_read_string(dev, "vendor-name", &str))
dev_info(dev, "DTS Vendor: %s\n", str);
gesture_enabled = device_property_read_bool(dev, "enable-gesture");
dev_info(dev, "DTS Gesture: %s\n", gesture_enabled ? "Yes" : "No");
if (!device_property_read_u32_array(dev, "touch-thresholds", array, 4))
dev_info(dev, "DTS Thresholds: %u, %u, %u, %u\n", array[0], array[1], array[2], array[3]);
struct gpio_desc *ts_gpio = devm_gpiod_get_optional(dev, "touch", GPIOD_IN);
if (!IS_ERR(ts_gpio) && ts_gpio)
dev_info(dev, "DTS Touch GPIO obtained!\n");
if (client->irq > 0)
dev_info(dev, "DTS IRQ Number: %d\n", client->irq);
major = register_chrdev(0, DEVICE_NAME, &fops);
if (major < 0) return major;
i2c_class = class_create(THIS_MODULE, CLASS_NAME);
if (IS_ERR(i2c_class)) {
unregister_chrdev(major, DEVICE_NAME);
return PTR_ERR(i2c_class);
}
i2c_device = device_create(i2c_class, NULL, MKDEV(major, 0), NULL, DEVICE_NAME);
if (IS_ERR(i2c_device)) {
class_destroy(i2c_class);
unregister_chrdev(major, DEVICE_NAME);
return PTR_ERR(i2c_device);
}
dev_info(dev, "Device /dev/%s created successfully\n", DEVICE_NAME);
return 0;
}
static void my_i2c_remove(struct i2c_client *client) {
device_destroy(i2c_class, MKDEV(major, 0));
class_destroy(i2c_class);
unregister_chrdev(major, DEVICE_NAME);
dev_info(&client->dev, "I2C Device Removed\n");
}
static const struct of_device_id my_i2c_of_match[] = {
{ .compatible = "myvendor,mysensor" },
{ }
};
MODULE_DEVICE_TABLE(of, my_i2c_of_match);
static struct i2c_driver my_driver = {
.driver = {
.name = "my_custom_i2c_driver",
.of_match_table = my_i2c_of_match,
},
.probe = my_i2c_probe,
.remove = my_i2c_remove,
};
module_i2c_driver(my_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jvle");
|
