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#include <linux/cdev.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include "fopdrv.h"
#include "config.h"
int one = 0;
module_param(one, int, 0400);
MODULE_PARM_DESC(one, "first parameter, only printed on init");
int not_named_two = 0;
module_param_named(two, not_named_two, int, 0400);
MODULE_PARM_DESC(not_named_two, "second parameter, only printed on init");
struct cdev *cdev;
struct device *dev;
struct class *class;
dev_t node;
struct file_operations fops = {
.read = fop_read,
.write = fop_write,
.open = fop_open,
.release = fop_release,
};
static int mod_init(void) {
int err;
err = alloc_chrdev_region(&node, 0, 1, DRV_NAME);
if (err < 0) {
printk(KERN_ERR "alloc_chrdev_region error %d\n", err);
goto return_err;
}
class = class_create(DRV_NAME);
if (IS_ERR_OR_NULL(class)) {
err = PTR_ERR(class);
printk(KERN_ERR "class_create error %d\n", err);
goto free_class;
}
cdev = cdev_alloc();
if (!cdev) {
err = ENOMEM;
goto free_cdev;
}
cdev->ops = &fops;
cdev_init(cdev, &fops);
err = cdev_add(cdev, node, 1);
if (err < 0) {
printk(KERN_ERR "cdev_add error %d\n", err);
goto free_cdev;
}
dev = device_create(class, NULL, node, NULL, DRV_NAME);
if (IS_ERR_OR_NULL(dev)) {
err = PTR_ERR(dev);
printk(KERN_ERR "device_create error %d\n", err);
goto free_device;
}
// configure gpio mux
uint32_t* conf_gpmc_a3 = ioremap(TI_AM335X_CM_GPMC_A3_ADDR, sizeof(ti_am335x_word_t));
if (conf_gpmc_a3 == NULL)
return -EINVAL;
barrier();
uint32_t val = ioread32(conf_gpmc_a3); rmb();
val &= ~0x7;
val |= 0x7;
iowrite32(val, conf_gpmc_a3); wmb();
iounmap(conf_gpmc_a3);
// configure output pin
ti_am335x_word_t* gpio1 = ioremap(TI_AM335X_GPIO1_ADDR, GPIO_REG_SIZE);
barrier();
ti_am335x_word_t oe_reg = ioread32(gpio1 + GPIO_OE); rmb();
oe_reg &= ~(1<<PIN); // 0=output
iowrite32(oe_reg, gpio1 + GPIO_OE); wmb();
iounmap(gpio1);
// printk("%s() -> 0 (%d:%d)\n", __PRETTY_FUNCTION__, MAJOR(node), MINOR(node));
// printk("one = %d, two = %d\n", one, not_named_two);
return 0;
free_device:
device_destroy(class, node);
free_cdev:
cdev_del(cdev);
free_class:
class_destroy(class);
return_err:
// printk("%s() -> %d\n", __PRETTY_FUNCTION__, err);
return err;
}
static void mod_exit(void) {
device_destroy(class, node);
cdev_del(cdev);
class_destroy(class);
// printk("%s()\n", __PRETTY_FUNCTION__);
}
module_init(mod_init);
module_exit(mod_exit);
MODULE_LICENSE("Dual MIT/GPL");
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