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 static loff_t eisa_eeprom_llseek(struct file *file, loff_t offset, int origin) 19 { 20 return fixed_size_llseek(file, offset, origin, HPEE_MAX_LENGTH); 21 } 22 23 static ssize_t eisa_eeprom_read(struct file * file, 24 char __user *buf, size_t count, loff_t *ppos ) 25 { 26 unsigned char *tmp; 27 ssize_t ret; 28 int i; 29 30 if (*ppos < 0 || *ppos >= HPEE_MAX_LENGTH) 31 return 0; 32 33 count = *ppos + count < HPEE_MAX_LENGTH ? count : HPEE_MAX_LENGTH - *ppos; 34 tmp = kmalloc(count, GFP_KERNEL); 35 if (tmp) { 36 for (i = 0; i < count; i++) 37 tmp[i] = readb(eisa_eeprom_addr+(*ppos)++); 38 39 if (copy_to_user (buf, tmp, count)) 40 ret = -EFAULT; 41 else 42 ret = count; 43 kfree (tmp); 44 } else 45 ret = -ENOMEM; 46 47 return ret; 48 } 49 50 static int eisa_eeprom_open(struct inode *inode, struct file *file) 51 { 52 if (file->f_mode & FMODE_WRITE) 53 return -EINVAL; 54 55 return 0; 56 } 57 58 static int eisa_eeprom_release(struct inode *inode, struct file *file) 59 { 60 return 0; 61 } 62 63 /* 64 * The various file operations we support. 65 */ 66 static const struct file_operations eisa_eeprom_fops = { 67 .owner = THIS_MODULE, 68 .llseek = eisa_eeprom_llseek, 69 .read = eisa_eeprom_read, 70 .open = eisa_eeprom_open, 71 .release = eisa_eeprom_release, 72 }; 73 74 static struct miscdevice eisa_eeprom_dev = { 75 EISA_EEPROM_MINOR, 76 "eisa_eeprom", 77 &eisa_eeprom_fops 78 }; 79 80 static int __init eisa_eeprom_init(void) 81 { 82 int retval; 83 84 if (!eisa_eeprom_addr) 85 return -ENODEV; 86 87 retval = misc_register(&eisa_eeprom_dev); 88 if (retval < 0) { 89 printk(KERN_ERR "EISA EEPROM: cannot register misc device.\n"); 90 return retval; 91 } 92 93 printk(KERN_INFO "EISA EEPROM at 0x%px\n", eisa_eeprom_addr); 94 return 0; 95 } 96 97 MODULE_LICENSE("GPL"); 98 99 module_init(eisa_eeprom_init); 100