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 20 static 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 25 static 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 52 static 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 60 static 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 */ 68 static 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 76 static struct miscdevice eisa_eeprom_dev = { 77 EISA_EEPROM_MINOR, 78 "eisa_eeprom", 79 &eisa_eeprom_fops 80 }; 81 82 static 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 99 MODULE_LICENSE("GPL"); 100 101 module_init(eisa_eeprom_init); 102