linux/drivers/parisc/eisa_eeprom.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* 
   3 *    EISA "eeprom" support routines
   4 *
   5 *    Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/init.h>
  10#include <linux/kernel.h>
  11#include <linux/miscdevice.h>
  12#include <linux/slab.h>
  13#include <linux/fs.h>
  14#include <asm/io.h>
  15#include <linux/uaccess.h>
  16#include <asm/eisa_eeprom.h>
  17
  18#define         EISA_EEPROM_MINOR 241
  19
  20static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin)
  21{
  22        return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH);
  23}
  24
  25static ssize_t eisa_eeprom_read(struct file * file,
  26                              char __user *buf, size_t count, loff_t *ppos )
  27{
  28        unsigned char *tmp;
  29        ssize_t ret;
  30        int i;
  31        
  32        if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH)
  33                return 0;
  34        
  35        count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos;
  36        tmp = kmalloc(count, GFP_KERNEL);
  37        if (tmp) {
  38                for (i = 0; i < count; i++)
  39                        tmp[i] = readb(eisa_eeprom_addr+(*ppos)++);
  40
  41                if (copy_to_user (buf, tmp, count))
  42                        ret = -EFAULT;
  43                else
  44                        ret = count;
  45                kfree (tmp);
  46        } else
  47                ret = -ENOMEM;
  48        
  49        return ret;
  50}
  51
  52static int eisa_eeprom_open(struct inode *inode, struct file *file)
  53{
  54        if (file->f_mode & FMODE_WRITE)
  55                return -EINVAL;
  56   
  57        return 0;
  58}
  59
  60static int eisa_eeprom_release(struct inode *inode, struct file *file)
  61{
  62        return 0;
  63}
  64
  65/*
  66 *      The various file operations we support.
  67 */
  68static const struct file_operations eisa_eeprom_fops = {
  69        .owner =        THIS_MODULE,
  70        .llseek =       eisa_eeprom_llseek,
  71        .read =         eisa_eeprom_read,
  72        .open =         eisa_eeprom_open,
  73        .release =      eisa_eeprom_release,
  74};
  75
  76static struct miscdevice eisa_eeprom_dev = {
  77        EISA_EEPROM_MINOR,
  78        "eisa_eeprom",
  79        &eisa_eeprom_fops
  80};
  81
  82static int __init eisa_eeprom_init(void)
  83{
  84        int retval;
  85
  86        if (!eisa_eeprom_addr)
  87                return -ENODEV;
  88
  89        retval = misc_register(&eisa_eeprom_dev);
  90        if (retval < 0) {
  91                printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n");
  92                return retval;
  93        }
  94
  95        printk(KERN_INFO "EISA EEPROM at 0x%px\n", eisa_eeprom_addr);
  96        return 0;
  97}
  98
  99MODULE_LICENSE("GPL");
 100
 101module_init(eisa_eeprom_init);
 102