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#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/semaphore.h>
#include "mod.h"
#include "dev.h"
#include "debug.h"
#include "sysfs.h"
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Suren A. Chilingaryan <csa@suren.me>");
MODULE_DESCRIPTION("Testing module");
MODULE_VERSION("0.0.1");
int test_minors = TEST_MINORS;
module_param(test_minors, int, S_IRUGO);
static dev_t test_devno; /**< major number */
static test_dev_t **test_devs = NULL; /**< per-device context */
static DEFINE_SEMAPHORE(test_devs_mtx); /**< mutex protecting creation/destruction of devices */
static struct class *test_class; /**< device class */
static void test_module_destroy_cdev(test_dev_t *test)
{
if (test->dev) {
test_sysfs_free(test);
device_destroy(test_class, test->devno);
}
cdev_del(&test->cdev);
kfree(test);
}
static int test_module_setup_cdev(void)
{
int i;
int err = 0;
dev_t devno;
test_dev_t *test;
test = kmalloc(sizeof(test_dev_t), GFP_KERNEL);
if (!test) {
mod_info("Couldn't allocate memory. Device is not created.\n");
return -ENOMEM;
}
cdev_init(&test->cdev, test_get_fops());
test->cdev.owner = THIS_MODULE;
test->cdev.ops = test_get_fops();
down(&test_devs_mtx);
for (i = 0; i < test_minors; i++) {
if (!test_devs[i])
break;
}
if (i == test_minors) {
mod_info("No free minor numbers left");
err = -EBUSY;
goto fail;
}
devno = MKDEV(MAJOR(test_devno), MINOR(test_devno) + i);
test->devno = devno;
err = cdev_add(&test->cdev, devno, 1);
if (err) {
mod_info("Error %d adding device kmm%d", err, i);
goto fail;
}
test->dev = device_create(test_class, NULL, devno, test, TEST_NODE_FMT, MINOR(test_devno) + i);
if (!test->dev) {
mod_info("Error creating /dev/%s%d\n", TEST_NODE, MINOR(test_devno) + i);
goto fail;
}
dev_set_drvdata(test->dev, test);
test_devs[i] = test;
up(&test_devs_mtx);
err = test_sysfs_init(test);
if (err) goto fail_sysfs;
mod_info("Device /dev/%s%d added\n", TEST_NODE, MINOR(test_devno) + i);
return 0;
fail:
up(&test_devs_mtx);
fail_sysfs:
test_module_destroy_cdev(test);
return err;
}
static void test_module_cleanup(void)
{
int i;
if (test_devs) {
for (i = 0; i < test_minors; i++) {
if (test_devs[i])
test_module_destroy_cdev(test_devs[i]);
}
kfree(test_devs);
}
if (test_class)
class_destroy(test_class);
unregister_chrdev_region(test_devno, test_minors);
}
static int __init test_module_init(void)
{
int err;
if ((err = alloc_chrdev_region(&test_devno, 0, test_minors, TEST_NODE))) {
mod_info("Couldn't allocate chrdev region. Module not loaded.\n");
goto alloc_chrdev_fail;
}
test_class = class_create(THIS_MODULE, TEST_NODE);
if (IS_ERR(test_class)) {
mod_info("No sysfs support. Module not loaded.\n");
goto fail;
}
test_devs = kmalloc(test_minors * sizeof(test_dev_t*), GFP_KERNEL);
if (!test_devs) {
mod_info("Couldn't allocate memory. Module not loaded.\n");
err = -ENOMEM;
}
memset(test_devs, 0, test_minors * sizeof(test_dev_t*));
mod_info("Major %d allocated to node '%s'\n", MAJOR(test_devno), TEST_NODE);
err = test_module_setup_cdev();
if (err) goto fail;
return 0;
fail:
test_module_cleanup();
alloc_chrdev_fail:
return err;
}
static void __exit test_module_exit(void)
{
test_module_cleanup();
}
module_init(test_module_init);
module_exit(test_module_exit);
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