160 lines
3.3 KiB
C
160 lines
3.3 KiB
C
/*
|
|
* Generic /dev/nvram driver for architectures providing some
|
|
* "generic" hooks, that is :
|
|
*
|
|
* nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size
|
|
*
|
|
* Note that an additional hook is supported for PowerMac only
|
|
* for getting the nvram "partition" informations
|
|
*
|
|
*/
|
|
|
|
#define NVRAM_VERSION "1.1"
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/init.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/pagemap.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/nvram.h>
|
|
#ifdef CONFIG_PPC_PMAC
|
|
#include <asm/machdep.h>
|
|
#endif
|
|
|
|
#define NVRAM_SIZE 8192
|
|
|
|
static DEFINE_MUTEX(nvram_mutex);
|
|
static ssize_t nvram_len;
|
|
|
|
static loff_t nvram_llseek(struct file *file, loff_t offset, int origin)
|
|
{
|
|
return generic_file_llseek_size(file, offset, origin,
|
|
MAX_LFS_FILESIZE, nvram_len);
|
|
}
|
|
|
|
static ssize_t read_nvram(struct file *file, char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned int i;
|
|
char __user *p = buf;
|
|
|
|
if (!access_ok(VERIFY_WRITE, buf, count))
|
|
return -EFAULT;
|
|
if (*ppos >= nvram_len)
|
|
return 0;
|
|
for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count)
|
|
if (__put_user(nvram_read_byte(i), p))
|
|
return -EFAULT;
|
|
*ppos = i;
|
|
return p - buf;
|
|
}
|
|
|
|
static ssize_t write_nvram(struct file *file, const char __user *buf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned int i;
|
|
const char __user *p = buf;
|
|
char c;
|
|
|
|
if (!access_ok(VERIFY_READ, buf, count))
|
|
return -EFAULT;
|
|
if (*ppos >= nvram_len)
|
|
return 0;
|
|
for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) {
|
|
if (__get_user(c, p))
|
|
return -EFAULT;
|
|
nvram_write_byte(c, i);
|
|
}
|
|
*ppos = i;
|
|
return p - buf;
|
|
}
|
|
|
|
static int nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
switch(cmd) {
|
|
#ifdef CONFIG_PPC_PMAC
|
|
case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
|
|
printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
|
|
case IOC_NVRAM_GET_OFFSET: {
|
|
int part, offset;
|
|
|
|
if (!machine_is(powermac))
|
|
return -EINVAL;
|
|
if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0)
|
|
return -EFAULT;
|
|
if (part < pmac_nvram_OF || part > pmac_nvram_NR)
|
|
return -EINVAL;
|
|
offset = pmac_get_partition(part);
|
|
if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0)
|
|
return -EFAULT;
|
|
break;
|
|
}
|
|
#endif /* CONFIG_PPC_PMAC */
|
|
case IOC_NVRAM_SYNC:
|
|
nvram_sync();
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static long nvram_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&nvram_mutex);
|
|
ret = nvram_ioctl(file, cmd, arg);
|
|
mutex_unlock(&nvram_mutex);
|
|
|
|
return ret;
|
|
}
|
|
|
|
const struct file_operations nvram_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = nvram_llseek,
|
|
.read = read_nvram,
|
|
.write = write_nvram,
|
|
.unlocked_ioctl = nvram_unlocked_ioctl,
|
|
};
|
|
|
|
static struct miscdevice nvram_dev = {
|
|
NVRAM_MINOR,
|
|
"nvram",
|
|
&nvram_fops
|
|
};
|
|
|
|
int __init nvram_init(void)
|
|
{
|
|
int ret = 0;
|
|
|
|
printk(KERN_INFO "Generic non-volatile memory driver v%s\n",
|
|
NVRAM_VERSION);
|
|
ret = misc_register(&nvram_dev);
|
|
if (ret != 0)
|
|
goto out;
|
|
|
|
nvram_len = nvram_get_size();
|
|
if (nvram_len < 0)
|
|
nvram_len = NVRAM_SIZE;
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
void __exit nvram_cleanup(void)
|
|
{
|
|
misc_deregister( &nvram_dev );
|
|
}
|
|
|
|
module_init(nvram_init);
|
|
module_exit(nvram_cleanup);
|
|
MODULE_LICENSE("GPL");
|