/* * Generic /dev/nvram driver for architectures providing some * "generic" hooks, that is : * * nvram_read_byte, nvram_write_byte, nvram_sync * * Note that an additional hook is supported for PowerMac only * for getting the nvram "partition" informations * */ #define NVRAM_VERSION "1.1" #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/init.h> #include <linux/smp_lock.h> #include <asm/uaccess.h> #include <asm/nvram.h> #ifdef CONFIG_PPC_PMAC #include <asm/machdep.h> #endif #define NVRAM_SIZE 8192 static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) { lock_kernel(); switch (origin) { case 1: offset += file->f_pos; break; case 2: offset += NVRAM_SIZE; break; } if (offset < 0) { unlock_kernel(); return -EINVAL; } file->f_pos = offset; unlock_kernel(); return file->f_pos; } static ssize_t read_nvram(struct file *file, char __user *buf, size_t count, loff_t *ppos) { unsigned int i; char __user *p = buf; if (!access_ok(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 __user *buf, size_t count, loff_t *ppos) { unsigned int i; const char __user *p = buf; char c; if (!access_ok(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_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { switch(cmd) { #ifdef CONFIG_PPC_PMAC case OBSOLETE_PMAC_NVRAM_GET_OFFSET: printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); case IOC_NVRAM_GET_OFFSET: { int part, offset; if (!machine_is(powermac)) return -EINVAL; if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) return -EFAULT; if (part < pmac_nvram_OF || part > pmac_nvram_NR) return -EINVAL; offset = pmac_get_partition(part); if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) return -EFAULT; break; } #endif /* CONFIG_PPC_PMAC */ case IOC_NVRAM_SYNC: nvram_sync(); break; default: return -EINVAL; } return 0; } const struct file_operations nvram_fops = { .owner = THIS_MODULE, .llseek = nvram_llseek, .read = read_nvram, .write = write_nvram, .ioctl = nvram_ioctl, }; static struct miscdevice nvram_dev = { NVRAM_MINOR, "nvram", &nvram_fops }; int __init nvram_init(void) { printk(KERN_INFO "Generic non-volatile memory driver v%s\n", NVRAM_VERSION); return misc_register(&nvram_dev); } void __exit nvram_cleanup(void) { misc_deregister( &nvram_dev ); } module_init(nvram_init); module_exit(nvram_cleanup); MODULE_LICENSE("GPL");