drivers/sbus/char/flash.c

   1 /* $Id: flash.c,v 1.13 1999/08/31 06:58:06 davem Exp $
   2  * flash.c: Allow mmap access to the OBP Flash, for OBP updates.
   3  *
   4  * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
   5  */
   6
   7 #include <linux/config.h>
   8 #include <linux/module.h>
   9 #include <linux/types.h>
  10 #include <linux/errno.h>
  11 #include <linux/miscdevice.h>
  12 #include <linux/malloc.h>
  13 #include <linux/fcntl.h>
  14 #include <linux/poll.h>
  15 #include <linux/init.h>
  16
  17 #include <asm/system.h>
  18 #include <asm/uaccess.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/io.h>
  21 #include <asm/sbus.h>
  22 #include <asm/ebus.h>
  23
  24 static struct {
  25         unsigned long read_base;        /* Physical read address */
  26         unsigned long write_base;       /* Physical write address */
  27         unsigned long read_size;        /* Size of read area */
  28         unsigned long write_size;       /* Size of write area */
  29         unsigned long busy;             /* In use? */
  30 } flash;
  31
  32 #define FLASH_MINOR     152
  33
  34 static int
  35 flash_mmap(struct file *file, struct vm_area_struct *vma)
  36 {
  37         unsigned long addr;
  38         unsigned long size;
  39
  40         if (vma->vm_offset & ~(PAGE_MASK))
  41                 return -ENXIO;
  42
  43         if (flash.read_base == flash.write_base) {
  44                 addr = flash.read_base;
  45                 size = flash.read_size;
  46         } else {
  47                 if ((vma->vm_flags & VM_READ) &&
  48                     (vma->vm_flags & VM_WRITE))
  49                         return -EINVAL;
  50
  51                 if (vma->vm_flags & VM_READ) {
  52                         addr = flash.read_base;
  53                         size = flash.read_size;
  54                 } else if (vma->vm_flags & VM_WRITE) {
  55                         addr = flash.write_base;
  56                         size = flash.write_size;
  57                 } else
  58                         return -ENXIO;
  59         }
  60
  61         if (vma->vm_offset > size)
  62                 return -ENXIO;
  63         addr += vma->vm_offset;
  64
  65         if (vma->vm_end - (vma->vm_start + vma->vm_offset) > size)
  66                 size = vma->vm_end - (vma->vm_start + vma->vm_offset);
  67
  68         pgprot_val(vma->vm_page_prot) &= ~(_PAGE_CACHE);
  69         pgprot_val(vma->vm_page_prot) |= _PAGE_E;
  70         vma->vm_flags |= (VM_SHM | VM_LOCKED);
  71
  72         if (remap_page_range(vma->vm_start, addr, size, vma->vm_page_prot))
  73                 return -EAGAIN;
  74
  75         return 0;
  76 }
  77
  78 static long long
  79 flash_llseek(struct file *file, long long offset, int origin)
  80 {
  81         switch (origin) {
  82                 case 0:
  83                         file->f_pos = offset;
  84                         break;
  85                 case 1:
  86                         file->f_pos += offset;
  87                         if (file->f_pos > flash.read_size)
  88                                 file->f_pos = flash.read_size;
  89                         break;
  90                 case 2:
  91                         file->f_pos = flash.read_size;
  92                         break;
  93                 default:
  94                         return -EINVAL;
  95         }
  96         return file->f_pos;
  97 }
  98
  99 static ssize_t
 100 flash_read(struct file * file, char * buf,
 101            size_t count, loff_t *ppos)
 102 {
 103         unsigned long p = file->f_pos;
 104
 105         if (count > flash.read_size - p)
 106                 count = flash.read_size - p;
 107
 108         if (copy_to_user(buf, flash.read_base + p, count) < 0)
 109                 return -EFAULT;
 110
 111         file->f_pos += count;
 112         return count;
 113 }
 114
 115 static int
 116 flash_open(struct inode *inode, struct file *file)
 117 {
 118         if (test_and_set_bit(0, (void *)&flash.busy) != 0)
 119                 return -EBUSY;
 120
 121         MOD_INC_USE_COUNT;
 122         return 0;
 123 }
 124
 125 static int
 126 flash_release(struct inode *inode, struct file *file)
 127 {
 128         MOD_DEC_USE_COUNT;
 129         flash.busy = 0;
 130         return 0;
 131 }
 132
 133 static struct file_operations flash_fops = {
 134         flash_llseek,
 135         flash_read,
 136         NULL,           /* no write to the Flash, use mmap
 137                          * and play flash dependent tricks.
 138                          */
 139         NULL,           /* readdir */
 140         NULL,           /* poll */
 141         NULL,           /* ioctl */
 142         flash_mmap,
 143         flash_open,
 144         NULL,           /* flush */
 145         flash_release
 146 };
 147
 148 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
 149
 150 EXPORT_NO_SYMBOLS;
 151
 152 #ifdef MODULE
 153 int init_module(void)
 154 #else
 155 int __init flash_init(void)
 156 #endif
 157 {
 158         struct linux_sbus *sbus;
 159         struct linux_sbus_device *sdev = 0;
 160         struct linux_ebus *ebus;
 161         struct linux_ebus_device *edev = 0;
 162         struct linux_prom_registers regs[2];
 163         int len, err, nregs;
 164
 165         for_all_sbusdev(sdev, sbus) {
 166                 if (!strcmp(sdev->prom_name, "flashprom")) {
 167                         prom_apply_sbus_ranges(sdev->my_bus, &sdev->reg_addrs[0],
 168                                                sdev->num_registers, sdev);
 169                         if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) {
 170                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
 171                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
 172                                 flash.read_size = sdev->reg_addrs[0].reg_size;
 173                                 flash.write_base = flash.read_base;
 174                                 flash.write_size = flash.read_size;
 175                         } else {
 176                                 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) |
 177                                         (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL);
 178                                 flash.read_size = sdev->reg_addrs[0].reg_size;
 179                                 flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) |
 180                                         (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL);
 181                                 flash.write_size = sdev->reg_addrs[1].reg_size;
 182                         }
 183                         flash.busy = 0;
 184                         break;
 185                 }
 186         }
 187         if (!sdev) {
 188 #ifdef CONFIG_PCI
 189                 for_each_ebus(ebus) {
 190                         for_each_ebusdev(edev, ebus) {
 191                                 if (!strcmp(edev->prom_name, "flashprom"))
 192                                         goto ebus_done;
 193                         }
 194                 }
 195         ebus_done:
 196                 if (!edev)
 197                         return -ENODEV;
 198
 199                 len = prom_getproperty(edev->prom_node, "reg", (void *)regs, sizeof(regs));
 200                 if ((len % sizeof(regs[0])) != 0) {
 201                         printk("flash: Strange reg property size %d\n", len);
 202                         return -ENODEV;
 203                 }
 204
 205                 nregs = len / sizeof(regs[0]);
 206
 207                 flash.read_base = edev->resource[0].start;
 208                 flash.read_size = regs[0].reg_size;
 209
 210                 if (nregs == 1) {
 211                         flash.write_base = edev->resource[0].start;
 212                         flash.write_size = regs[0].reg_size;
 213                 } else if (nregs == 2) {
 214                         flash.write_base = edev->resource[1].start;
 215                         flash.write_size = regs[1].reg_size;
 216                 } else {
 217                         printk("flash: Strange number of regs %d\n", nregs);
 218                         return -ENODEV;
 219                 }
 220
 221                 flash.busy = 0;
 222
 223 #else
 224                 return -ENODEV;
 225 #endif
 226         }
 227
 228         printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n",
 229                flash.read_base, flash.read_size,
 230                flash.write_base, flash.write_size);
 231
 232         err = misc_register(&flash_dev);
 233         if (err) {
 234                 printk(KERN_ERR "flash: unable to get misc minor\n");
 235                 return err;
 236         }
 237
 238         return 0;
 239 }
 240
 241 #ifdef MODULE
 242 void cleanup_module(void)
 243 {
 244         misc_deregister(&flash_dev);
 245 }
 246 #endif