109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2a9540d34SDavid S. Miller /* flash.c: Allow mmap access to the OBP Flash, for OBP updates. 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) 51da177e4SLinus Torvalds */ 61da177e4SLinus Torvalds 71da177e4SLinus Torvalds #include <linux/module.h> 81da177e4SLinus Torvalds #include <linux/types.h> 91da177e4SLinus Torvalds #include <linux/errno.h> 101da177e4SLinus Torvalds #include <linux/miscdevice.h> 111da177e4SLinus Torvalds #include <linux/fcntl.h> 121da177e4SLinus Torvalds #include <linux/poll.h> 13a3108ca2SArnd Bergmann #include <linux/mutex.h> 141da177e4SLinus Torvalds #include <linux/spinlock.h> 158a73709eSHorst H. von Brand #include <linux/mm.h> 16a9540d34SDavid S. Miller #include <linux/of.h> 17a9540d34SDavid S. Miller #include <linux/of_device.h> 181da177e4SLinus Torvalds 197c0f6ba6SLinus Torvalds #include <linux/uaccess.h> 201da177e4SLinus Torvalds #include <asm/pgtable.h> 211da177e4SLinus Torvalds #include <asm/io.h> 221da177e4SLinus Torvalds #include <asm/upa.h> 231da177e4SLinus Torvalds 24a3108ca2SArnd Bergmann static DEFINE_MUTEX(flash_mutex); 251da177e4SLinus Torvalds static DEFINE_SPINLOCK(flash_lock); 261da177e4SLinus Torvalds static struct { 271da177e4SLinus Torvalds unsigned long read_base; /* Physical read address */ 281da177e4SLinus Torvalds unsigned long write_base; /* Physical write address */ 291da177e4SLinus Torvalds unsigned long read_size; /* Size of read area */ 301da177e4SLinus Torvalds unsigned long write_size; /* Size of write area */ 311da177e4SLinus Torvalds unsigned long busy; /* In use? */ 321da177e4SLinus Torvalds } flash; 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds static int 351da177e4SLinus Torvalds flash_mmap(struct file *file, struct vm_area_struct *vma) 361da177e4SLinus Torvalds { 371da177e4SLinus Torvalds unsigned long addr; 381da177e4SLinus Torvalds unsigned long size; 391da177e4SLinus Torvalds 401da177e4SLinus Torvalds spin_lock(&flash_lock); 411da177e4SLinus Torvalds if (flash.read_base == flash.write_base) { 421da177e4SLinus Torvalds addr = flash.read_base; 431da177e4SLinus Torvalds size = flash.read_size; 441da177e4SLinus Torvalds } else { 451da177e4SLinus Torvalds if ((vma->vm_flags & VM_READ) && 461da177e4SLinus Torvalds (vma->vm_flags & VM_WRITE)) { 471da177e4SLinus Torvalds spin_unlock(&flash_lock); 481da177e4SLinus Torvalds return -EINVAL; 491da177e4SLinus Torvalds } 501da177e4SLinus Torvalds if (vma->vm_flags & VM_READ) { 511da177e4SLinus Torvalds addr = flash.read_base; 521da177e4SLinus Torvalds size = flash.read_size; 531da177e4SLinus Torvalds } else if (vma->vm_flags & VM_WRITE) { 541da177e4SLinus Torvalds addr = flash.write_base; 551da177e4SLinus Torvalds size = flash.write_size; 561da177e4SLinus Torvalds } else { 571da177e4SLinus Torvalds spin_unlock(&flash_lock); 581da177e4SLinus Torvalds return -ENXIO; 591da177e4SLinus Torvalds } 601da177e4SLinus Torvalds } 611da177e4SLinus Torvalds spin_unlock(&flash_lock); 621da177e4SLinus Torvalds 631da177e4SLinus Torvalds if ((vma->vm_pgoff << PAGE_SHIFT) > size) 641da177e4SLinus Torvalds return -ENXIO; 651da177e4SLinus Torvalds addr = vma->vm_pgoff + (addr >> PAGE_SHIFT); 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size) 681da177e4SLinus Torvalds size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)); 691da177e4SLinus Torvalds 7014778d90SDavid S. Miller vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 711da177e4SLinus Torvalds 721da177e4SLinus Torvalds if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot)) 731da177e4SLinus Torvalds return -EAGAIN; 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds return 0; 761da177e4SLinus Torvalds } 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds static long long 791da177e4SLinus Torvalds flash_llseek(struct file *file, long long offset, int origin) 801da177e4SLinus Torvalds { 81a3108ca2SArnd Bergmann mutex_lock(&flash_mutex); 821da177e4SLinus Torvalds switch (origin) { 831da177e4SLinus Torvalds case 0: 841da177e4SLinus Torvalds file->f_pos = offset; 851da177e4SLinus Torvalds break; 861da177e4SLinus Torvalds case 1: 871da177e4SLinus Torvalds file->f_pos += offset; 881da177e4SLinus Torvalds if (file->f_pos > flash.read_size) 891da177e4SLinus Torvalds file->f_pos = flash.read_size; 901da177e4SLinus Torvalds break; 911da177e4SLinus Torvalds case 2: 921da177e4SLinus Torvalds file->f_pos = flash.read_size; 931da177e4SLinus Torvalds break; 941da177e4SLinus Torvalds default: 95a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex); 961da177e4SLinus Torvalds return -EINVAL; 971da177e4SLinus Torvalds } 98a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex); 991da177e4SLinus Torvalds return file->f_pos; 1001da177e4SLinus Torvalds } 1011da177e4SLinus Torvalds 1021da177e4SLinus Torvalds static ssize_t 1031da177e4SLinus Torvalds flash_read(struct file * file, char __user * buf, 1041da177e4SLinus Torvalds size_t count, loff_t *ppos) 1051da177e4SLinus Torvalds { 106be94bbb5SJan Blunck loff_t p = *ppos; 1071da177e4SLinus Torvalds int i; 1081da177e4SLinus Torvalds 1091da177e4SLinus Torvalds if (count > flash.read_size - p) 1101da177e4SLinus Torvalds count = flash.read_size - p; 1111da177e4SLinus Torvalds 1121da177e4SLinus Torvalds for (i = 0; i < count; i++) { 1131da177e4SLinus Torvalds u8 data = upa_readb(flash.read_base + p + i); 1141da177e4SLinus Torvalds if (put_user(data, buf)) 1151da177e4SLinus Torvalds return -EFAULT; 1161da177e4SLinus Torvalds buf++; 1171da177e4SLinus Torvalds } 1181da177e4SLinus Torvalds 119be94bbb5SJan Blunck *ppos += count; 1201da177e4SLinus Torvalds return count; 1211da177e4SLinus Torvalds } 1221da177e4SLinus Torvalds 1231da177e4SLinus Torvalds static int 1241da177e4SLinus Torvalds flash_open(struct inode *inode, struct file *file) 1251da177e4SLinus Torvalds { 126a3108ca2SArnd Bergmann mutex_lock(&flash_mutex); 12778abb6acSArnd Bergmann if (test_and_set_bit(0, (void *)&flash.busy) != 0) { 128a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex); 1291da177e4SLinus Torvalds return -EBUSY; 13078abb6acSArnd Bergmann } 1311da177e4SLinus Torvalds 132a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex); 1331da177e4SLinus Torvalds return 0; 1341da177e4SLinus Torvalds } 1351da177e4SLinus Torvalds 1361da177e4SLinus Torvalds static int 1371da177e4SLinus Torvalds flash_release(struct inode *inode, struct file *file) 1381da177e4SLinus Torvalds { 1391da177e4SLinus Torvalds spin_lock(&flash_lock); 1401da177e4SLinus Torvalds flash.busy = 0; 1411da177e4SLinus Torvalds spin_unlock(&flash_lock); 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds return 0; 1441da177e4SLinus Torvalds } 1451da177e4SLinus Torvalds 14600977a59SArjan van de Ven static const struct file_operations flash_fops = { 1471da177e4SLinus Torvalds /* no write to the Flash, use mmap 1481da177e4SLinus Torvalds * and play flash dependent tricks. 1491da177e4SLinus Torvalds */ 1501da177e4SLinus Torvalds .owner = THIS_MODULE, 1511da177e4SLinus Torvalds .llseek = flash_llseek, 1521da177e4SLinus Torvalds .read = flash_read, 1531da177e4SLinus Torvalds .mmap = flash_mmap, 1541da177e4SLinus Torvalds .open = flash_open, 1551da177e4SLinus Torvalds .release = flash_release, 1561da177e4SLinus Torvalds }; 1571da177e4SLinus Torvalds 1582668dba6SZhenzhong Duan static struct miscdevice flash_dev = { SBUS_FLASH_MINOR, "flash", &flash_fops }; 1591da177e4SLinus Torvalds 160082a2004SGreg Kroah-Hartman static int flash_probe(struct platform_device *op) 1611da177e4SLinus Torvalds { 16261c7a080SGrant Likely struct device_node *dp = op->dev.of_node; 163a9540d34SDavid S. Miller struct device_node *parent; 1641da177e4SLinus Torvalds 165a9540d34SDavid S. Miller parent = dp->parent; 166a9540d34SDavid S. Miller 16791abe6b2SRob Herring if (!of_node_name_eq(parent, "sbus") && 16891abe6b2SRob Herring !of_node_name_eq(parent, "sbi") && 16991abe6b2SRob Herring !of_node_name_eq(parent, "ebus")) 170a9540d34SDavid S. Miller return -ENODEV; 171a9540d34SDavid S. Miller 172a9540d34SDavid S. Miller flash.read_base = op->resource[0].start; 173a9540d34SDavid S. Miller flash.read_size = resource_size(&op->resource[0]); 174a9540d34SDavid S. Miller if (op->resource[1].flags) { 175a9540d34SDavid S. Miller flash.write_base = op->resource[1].start; 176a9540d34SDavid S. Miller flash.write_size = resource_size(&op->resource[1]); 1771da177e4SLinus Torvalds } else { 178a9540d34SDavid S. Miller flash.write_base = op->resource[0].start; 179a9540d34SDavid S. Miller flash.write_size = resource_size(&op->resource[0]); 1801da177e4SLinus Torvalds } 1811da177e4SLinus Torvalds flash.busy = 0; 182690c8fd3SDavid S. Miller 1838cd3ec51SRob Herring printk(KERN_INFO "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n", 1848cd3ec51SRob Herring op->dev.of_node, 1851da177e4SLinus Torvalds flash.read_base, flash.read_size, 1861da177e4SLinus Torvalds flash.write_base, flash.write_size); 1871da177e4SLinus Torvalds 188a9540d34SDavid S. Miller return misc_register(&flash_dev); 1891da177e4SLinus Torvalds } 1901da177e4SLinus Torvalds 191082a2004SGreg Kroah-Hartman static int flash_remove(struct platform_device *op) 192a9540d34SDavid S. Miller { 193a9540d34SDavid S. Miller misc_deregister(&flash_dev); 194a9540d34SDavid S. Miller 1951da177e4SLinus Torvalds return 0; 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds 198fd098316SDavid S. Miller static const struct of_device_id flash_match[] = { 199a9540d34SDavid S. Miller { 200a9540d34SDavid S. Miller .name = "flashprom", 201a9540d34SDavid S. Miller }, 202a9540d34SDavid S. Miller {}, 203a9540d34SDavid S. Miller }; 204a9540d34SDavid S. Miller MODULE_DEVICE_TABLE(of, flash_match); 205a9540d34SDavid S. Miller 2064ebb24f7SGrant Likely static struct platform_driver flash_driver = { 2074018294bSGrant Likely .driver = { 208a9540d34SDavid S. Miller .name = "flash", 2094018294bSGrant Likely .of_match_table = flash_match, 2104018294bSGrant Likely }, 211a9540d34SDavid S. Miller .probe = flash_probe, 212082a2004SGreg Kroah-Hartman .remove = flash_remove, 213a9540d34SDavid S. Miller }; 214a9540d34SDavid S. Miller 215dbf2b92dSAxel Lin module_platform_driver(flash_driver); 216a9540d34SDavid S. Miller 2171da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 218