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| #include <linux/cdev.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#define TESTDEV_NAME "test"
struct test_dev {
dev_t devid;
struct cdev cdev;
struct class *class;
struct device *device;
struct gpio_desc *gpiod;
};
static int test_open(struct inode *inode, struct file *file)
{
struct test_dev *led;
led = container_of(inode->i_cdev, struct test_dev, cdev);
file->private_data = led;
return 0;
}
static ssize_t test_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct test_dev *led = file->private_data;
char kbuf[16];
size_t len;
int ret, value;
if (!count)
return 0;
len = min(count, sizeof(kbuf) - 1);
if (copy_from_user(kbuf, buf, len))
return -EFAULT;
kbuf[len] = '\0';
ret = kstrtoint(kbuf, 0, &value);
if (ret)
return ret;
gpiod_set_value_cansleep(led->gpiod, !!value);
return count;
}
static const struct file_operations test_fops = {
.owner = THIS_MODULE,
.open = test_open,
.write = test_write,
};
static int test_probe(struct platform_device *pdev)
{
struct test_dev *led;
int ret;
led = devm_kzalloc(&pdev->dev, sizeof(*led), GFP_KERNEL);
if (!led)
return -ENOMEM;
led->gpiod = devm_gpiod_get(&pdev->dev, "led", GPIOD_OUT_HIGH);
if (IS_ERR(led->gpiod)) {
dev_err(&pdev->dev, "failed to get led gpio\n");
return PTR_ERR(led->gpiod);
}
ret = alloc_chrdev_region(&led->devid, 0, 1, TESTDEV_NAME);
if (ret)
return ret;
cdev_init(&led->cdev, &test_fops);
led->cdev.owner = THIS_MODULE;
ret = cdev_add(&led->cdev, led->devid, 1);
if (ret)
goto err_unregister_chrdev;
led->class = class_create(THIS_MODULE, TESTDEV_NAME);
if (IS_ERR(led->class)) {
ret = PTR_ERR(led->class);
goto err_cdev_del;
}
led->device = device_create(led->class, NULL, led->devid, NULL,
TESTDEV_NAME);
if (IS_ERR(led->device)) {
ret = PTR_ERR(led->device);
goto err_class_destroy;
}
platform_set_drvdata(pdev, led);
dev_info(&pdev->dev, "test probe ok\n");
return 0;
err_class_destroy:
class_destroy(led->class);
err_cdev_del:
cdev_del(&led->cdev);
err_unregister_chrdev:
unregister_chrdev_region(led->devid, 1);
return ret;
}
static int test_remove(struct platform_device *pdev)
{
struct test_dev *led = platform_get_drvdata(pdev);
device_destroy(led->class, led->devid);
class_destroy(led->class);
cdev_del(&led->cdev);
unregister_chrdev_region(led->devid, 1);
return 0;
}
static const struct of_device_id test_of_match[] = {
{ .compatible = "atk,test" },
{ }
};
MODULE_DEVICE_TABLE(of, test_of_match);
static struct platform_driver test_driver = {
.probe = test_probe,
.remove = test_remove,
.driver = {
.name = TESTDEV_NAME,
.of_match_table = test_of_match,
},
};
module_platform_driver(test_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jvle");
MODULE_DESCRIPTION("GPIO descriptor based test driver");
|
