1/* 2 * /dev/nvram driver for Power Macintosh. 3 */ 4 5#define NVRAM_VERSION "1.0" 6 7#include <linux/module.h> 8 9#include <linux/types.h> 10#include <linux/errno.h> 11#include <linux/fs.h> 12#include <linux/miscdevice.h> 13#include <linux/fcntl.h> 14#include <linux/nvram.h> 15#include <linux/init.h> 16#include <asm/uaccess.h> 17#include <asm/nvram.h> 18 19#define NVRAM_SIZE 8192 20 21static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) 22{ 23 switch (origin) { 24 case 0: 25 break; 26 case 1: 27 offset += file->f_pos; 28 break; 29 case 2: 30 offset += NVRAM_SIZE; 31 break; 32 default: 33 offset = -1; 34 } 35 if (offset < 0) 36 return -EINVAL; 37 38 file->f_pos = offset; 39 return file->f_pos; 40} 41 42static ssize_t read_nvram(struct file *file, char __user *buf, 43 size_t count, loff_t *ppos) 44{ 45 unsigned int i; 46 char __user *p = buf; 47 48 if (!access_ok(VERIFY_WRITE, buf, count)) 49 return -EFAULT; 50 if (*ppos >= NVRAM_SIZE) 51 return 0; 52 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) 53 if (__put_user(nvram_read_byte(i), p)) 54 return -EFAULT; 55 *ppos = i; 56 return p - buf; 57} 58 59static ssize_t write_nvram(struct file *file, const char __user *buf, 60 size_t count, loff_t *ppos) 61{ 62 unsigned int i; 63 const char __user *p = buf; 64 char c; 65 66 if (!access_ok(VERIFY_READ, buf, count)) 67 return -EFAULT; 68 if (*ppos >= NVRAM_SIZE) 69 return 0; 70 for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) { 71 if (__get_user(c, p)) 72 return -EFAULT; 73 nvram_write_byte(c, i); 74 } 75 *ppos = i; 76 return p - buf; 77} 78 79static long nvram_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 80{ 81 switch(cmd) { 82 case PMAC_NVRAM_GET_OFFSET: 83 { 84 int part, offset; 85 if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) 86 return -EFAULT; 87 if (part < pmac_nvram_OF || part > pmac_nvram_NR) 88 return -EINVAL; 89 offset = pmac_get_partition(part); 90 if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) 91 return -EFAULT; 92 break; 93 } 94 95 default: 96 return -EINVAL; 97 } 98 99 return 0; 100} 101 102const struct file_operations nvram_fops = { 103 .owner = THIS_MODULE, 104 .llseek = nvram_llseek, 105 .read = read_nvram, 106 .write = write_nvram, 107 .unlocked_ioctl = nvram_ioctl, 108}; 109 110static struct miscdevice nvram_dev = { 111 NVRAM_MINOR, 112 "nvram", 113 &nvram_fops 114}; 115 116int __init nvram_init(void) 117{ 118 printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n", 119 NVRAM_VERSION); 120 return misc_register(&nvram_dev); 121} 122 123void __exit nvram_cleanup(void) 124{ 125 misc_deregister( &nvram_dev ); 126} 127 128module_init(nvram_init); 129module_exit(nvram_cleanup); 130MODULE_LICENSE("GPL"); 131