1 /* $Id: flash.c,v 1.25 2001/12/21 04:56:16 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/slab.h> 13 #include <linux/fcntl.h> 14 #include <linux/poll.h> 15 #include <linux/init.h> 16 #include <linux/smp_lock.h> 17 #include <linux/spinlock.h> 18 19 #include <asm/system.h> 20 #include <asm/uaccess.h> 21 #include <asm/pgtable.h> 22 #include <asm/io.h> 23 #include <asm/sbus.h> 24 #include <asm/ebus.h> 25 #include <asm/upa.h> 26 27 static DEFINE_SPINLOCK(flash_lock); 28 static struct { 29 unsigned long read_base; /* Physical read address */ 30 unsigned long write_base; /* Physical write address */ 31 unsigned long read_size; /* Size of read area */ 32 unsigned long write_size; /* Size of write area */ 33 unsigned long busy; /* In use? */ 34 } flash; 35 36 #define FLASH_MINOR 152 37 38 static int 39 flash_mmap(struct file *file, struct vm_area_struct *vma) 40 { 41 unsigned long addr; 42 unsigned long size; 43 44 spin_lock(&flash_lock); 45 if (flash.read_base == flash.write_base) { 46 addr = flash.read_base; 47 size = flash.read_size; 48 } else { 49 if ((vma->vm_flags & VM_READ) && 50 (vma->vm_flags & VM_WRITE)) { 51 spin_unlock(&flash_lock); 52 return -EINVAL; 53 } 54 if (vma->vm_flags & VM_READ) { 55 addr = flash.read_base; 56 size = flash.read_size; 57 } else if (vma->vm_flags & VM_WRITE) { 58 addr = flash.write_base; 59 size = flash.write_size; 60 } else { 61 spin_unlock(&flash_lock); 62 return -ENXIO; 63 } 64 } 65 spin_unlock(&flash_lock); 66 67 if ((vma->vm_pgoff << PAGE_SHIFT) > size) 68 return -ENXIO; 69 addr = vma->vm_pgoff + (addr >> PAGE_SHIFT); 70 71 if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size) 72 size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)); 73 74 vma->vm_flags |= (VM_SHM | VM_LOCKED); 75 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 76 77 if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot)) 78 return -EAGAIN; 79 80 return 0; 81 } 82 83 static long long 84 flash_llseek(struct file *file, long long offset, int origin) 85 { 86 lock_kernel(); 87 switch (origin) { 88 case 0: 89 file->f_pos = offset; 90 break; 91 case 1: 92 file->f_pos += offset; 93 if (file->f_pos > flash.read_size) 94 file->f_pos = flash.read_size; 95 break; 96 case 2: 97 file->f_pos = flash.read_size; 98 break; 99 default: 100 unlock_kernel(); 101 return -EINVAL; 102 } 103 unlock_kernel(); 104 return file->f_pos; 105 } 106 107 static ssize_t 108 flash_read(struct file * file, char __user * buf, 109 size_t count, loff_t *ppos) 110 { 111 unsigned long p = file->f_pos; 112 int i; 113 114 if (count > flash.read_size - p) 115 count = flash.read_size - p; 116 117 for (i = 0; i < count; i++) { 118 u8 data = upa_readb(flash.read_base + p + i); 119 if (put_user(data, buf)) 120 return -EFAULT; 121 buf++; 122 } 123 124 file->f_pos += count; 125 return count; 126 } 127 128 static int 129 flash_open(struct inode *inode, struct file *file) 130 { 131 if (test_and_set_bit(0, (void *)&flash.busy) != 0) 132 return -EBUSY; 133 134 return 0; 135 } 136 137 static int 138 flash_release(struct inode *inode, struct file *file) 139 { 140 spin_lock(&flash_lock); 141 flash.busy = 0; 142 spin_unlock(&flash_lock); 143 144 return 0; 145 } 146 147 static struct file_operations flash_fops = { 148 /* no write to the Flash, use mmap 149 * and play flash dependent tricks. 150 */ 151 .owner = THIS_MODULE, 152 .llseek = flash_llseek, 153 .read = flash_read, 154 .mmap = flash_mmap, 155 .open = flash_open, 156 .release = flash_release, 157 }; 158 159 static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops }; 160 161 static int __init flash_init(void) 162 { 163 struct sbus_bus *sbus; 164 struct sbus_dev *sdev = NULL; 165 #ifdef CONFIG_PCI 166 struct linux_ebus *ebus; 167 struct linux_ebus_device *edev = NULL; 168 struct linux_prom_registers regs[2]; 169 int len, nregs; 170 #endif 171 int err; 172 173 for_all_sbusdev(sdev, sbus) { 174 if (!strcmp(sdev->prom_name, "flashprom")) { 175 if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) { 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 = flash.read_base; 180 flash.write_size = flash.read_size; 181 } else { 182 flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) | 183 (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL); 184 flash.read_size = sdev->reg_addrs[0].reg_size; 185 flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) | 186 (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL); 187 flash.write_size = sdev->reg_addrs[1].reg_size; 188 } 189 flash.busy = 0; 190 break; 191 } 192 } 193 if (!sdev) { 194 #ifdef CONFIG_PCI 195 for_each_ebus(ebus) { 196 for_each_ebusdev(edev, ebus) { 197 if (!strcmp(edev->prom_name, "flashprom")) 198 goto ebus_done; 199 } 200 } 201 ebus_done: 202 if (!edev) 203 return -ENODEV; 204 205 len = prom_getproperty(edev->prom_node, "reg", (void *)regs, sizeof(regs)); 206 if ((len % sizeof(regs[0])) != 0) { 207 printk("flash: Strange reg property size %d\n", len); 208 return -ENODEV; 209 } 210 211 nregs = len / sizeof(regs[0]); 212 213 flash.read_base = edev->resource[0].start; 214 flash.read_size = regs[0].reg_size; 215 216 if (nregs == 1) { 217 flash.write_base = edev->resource[0].start; 218 flash.write_size = regs[0].reg_size; 219 } else if (nregs == 2) { 220 flash.write_base = edev->resource[1].start; 221 flash.write_size = regs[1].reg_size; 222 } else { 223 printk("flash: Strange number of regs %d\n", nregs); 224 return -ENODEV; 225 } 226 227 flash.busy = 0; 228 229 #else 230 return -ENODEV; 231 #endif 232 } 233 234 printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n", 235 flash.read_base, flash.read_size, 236 flash.write_base, flash.write_size); 237 238 err = misc_register(&flash_dev); 239 if (err) { 240 printk(KERN_ERR "flash: unable to get misc minor\n"); 241 return err; 242 } 243 244 return 0; 245 } 246 247 static void __exit flash_cleanup(void) 248 { 249 misc_deregister(&flash_dev); 250 } 251 252 module_init(flash_init); 253 module_exit(flash_cleanup); 254 MODULE_LICENSE("GPL"); 255