projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 5b50c166 MJ |
1 | /* |
| 2 | * FRAM driver for MIMC200 board | |
| 3 | * | |
| 4 | * Copyright 2008 Mark Jackson <mpfj@mimc.co.uk> | |
| 5 | * | |
| 6 | * This module adds *very* simply support for the system's FRAM device. | |
| 7 | * At the moment, this is hard-coded to the MIMC200 platform, and only | |
| 8 | * supports mmap(). | |
| 9 | */ | |
| 10 | ||
| 11 | #define FRAM_VERSION "1.0" | |
| 12 | ||
| 13 | #include <linux/miscdevice.h> | |
| 5745d6a4 | 14 | #include <linux/module.h> |
| 5b50c166 MJ |
15 | #include <linux/proc_fs.h> |
| 16 | #include <linux/mm.h> | |
| 17 | #include <linux/io.h> | |
| 18 | ||
| 19 | #define FRAM_BASE 0xac000000 | |
| 20 | #define FRAM_SIZE 0x20000 | |
| 21 | ||
| 22 | /* | |
| 23 | * The are the file operation function for user access to /dev/fram | |
| 24 | */ | |
| 25 | ||
| 26 | static int fram_mmap(struct file *filp, struct vm_area_struct *vma) | |
| 27 | { | |
| 28 | int ret; | |
| 29 | ||
| 30 | ret = remap_pfn_range(vma, | |
| 31 | vma->vm_start, | |
| 32 | virt_to_phys((void *)((unsigned long)FRAM_BASE)) >> PAGE_SHIFT, | |
| 33 | vma->vm_end-vma->vm_start, | |
| 34 | PAGE_SHARED); | |
| 35 | ||
| 36 | if (ret != 0) | |
| 37 | return -EAGAIN; | |
| 38 | ||
| 39 | return 0; | |
| 40 | } | |
| 41 | ||
| 42 | static const struct file_operations fram_fops = { | |
| 43 | .owner = THIS_MODULE, | |
| 44 | .mmap = fram_mmap, | |
| 6038f373 | 45 | .llseek = noop_llseek, |
| 5b50c166 MJ |
46 | }; |
| 47 | ||
| 48 | #define FRAM_MINOR 0 | |
| 49 | ||
| 50 | static struct miscdevice fram_dev = { | |
| 51 | FRAM_MINOR, | |
| 52 | "fram", | |
| 53 | &fram_fops | |
| 54 | }; | |
| 55 | ||
| 56 | static int __init | |
| 57 | fram_init(void) | |
| 58 | { | |
| 59 | int ret; | |
| 60 | ||
| 61 | ret = misc_register(&fram_dev); | |
| 62 | if (ret) { | |
| 63 | printk(KERN_ERR "fram: can't misc_register on minor=%d\n", | |
| 64 | FRAM_MINOR); | |
| 65 | return ret; | |
| 66 | } | |
| 67 | printk(KERN_INFO "FRAM memory driver v" FRAM_VERSION "\n"); | |
| 68 | return 0; | |
| 69 | } | |
| 70 | ||
| 71 | static void __exit | |
| 72 | fram_cleanup_module(void) | |
| 73 | { | |
| 74 | misc_deregister(&fram_dev); | |
| 75 | } | |
| 76 | ||
| 77 | module_init(fram_init); | |
| 78 | module_exit(fram_cleanup_module); | |
| 79 | ||
| 80 | MODULE_LICENSE("GPL"); | |
| 81 | ||
| 82 | MODULE_ALIAS_MISCDEV(FRAM_MINOR); |