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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | /* * /dev/nvram driver for Power Macintosh. */ #define NVRAM_VERSION "1.0" #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/nvram.h> #include <linux/init.h> #include <asm/uaccess.h> #define NVRAM_SIZE 8192 static long long nvram_llseek(struct file *file, loff_t offset, int origin) { switch (origin) { case 1: offset += file->f_pos; break; case 2: offset += NVRAM_SIZE; break; } if (offset < 0) return -EINVAL; file->f_pos = offset; return file->f_pos; } static ssize_t read_nvram(struct file *file, char *buf, size_t count, loff_t *ppos) { unsigned int i; char *p = buf; if (verify_area(VERIFY_WRITE, buf, count)) return -EFAULT; if (*ppos >= NVRAM_SIZE) return 0; for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++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 *buf, size_t count, loff_t *ppos) { unsigned int i; const char *p = buf; char c; if (verify_area(VERIFY_READ, buf, count)) return -EFAULT; if (*ppos >= NVRAM_SIZE) return 0; for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) { if (__get_user(c, p)) return -EFAULT; nvram_write_byte(c, i); } *ppos = i; return p - buf; } static int nvram_open(struct inode *inode, struct file *file) { MOD_INC_USE_COUNT; return 0; } static int nvram_release(struct inode *inode, struct file *file) { MOD_DEC_USE_COUNT; return 0; } struct file_operations nvram_fops = { nvram_llseek, read_nvram, write_nvram, NULL, /* nvram_readdir */ NULL, /* nvram_select */ NULL, /* nvram_ioctl */ NULL, /* nvram_mmap */ nvram_open, NULL, /* flush */ nvram_release, NULL /* fsync */ }; static struct miscdevice nvram_dev = { NVRAM_MINOR, "nvram", &nvram_fops }; int nvram_init(void) { printk(KERN_INFO "Macintosh non-volatile memory driver v%s\n", NVRAM_VERSION); misc_register(&nvram_dev); return 0; } #ifdef MODULE int init_module (void) { return( nvram_init() ); } void cleanup_module (void) { misc_deregister( &nvram_dev ); } #endif |