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>
17*878f2774SRob Herring #include <linux/platform_device.h>
181da177e4SLinus Torvalds
197c0f6ba6SLinus Torvalds #include <linux/uaccess.h>
201da177e4SLinus Torvalds #include <asm/io.h>
211da177e4SLinus Torvalds #include <asm/upa.h>
221da177e4SLinus Torvalds
23a3108ca2SArnd Bergmann static DEFINE_MUTEX(flash_mutex);
241da177e4SLinus Torvalds static DEFINE_SPINLOCK(flash_lock);
251da177e4SLinus Torvalds static struct {
261da177e4SLinus Torvalds unsigned long read_base; /* Physical read address */
271da177e4SLinus Torvalds unsigned long write_base; /* Physical write address */
281da177e4SLinus Torvalds unsigned long read_size; /* Size of read area */
291da177e4SLinus Torvalds unsigned long write_size; /* Size of write area */
301da177e4SLinus Torvalds unsigned long busy; /* In use? */
311da177e4SLinus Torvalds } flash;
321da177e4SLinus Torvalds
331da177e4SLinus Torvalds static int
flash_mmap(struct file * file,struct vm_area_struct * vma)341da177e4SLinus Torvalds flash_mmap(struct file *file, struct vm_area_struct *vma)
351da177e4SLinus Torvalds {
361da177e4SLinus Torvalds unsigned long addr;
371da177e4SLinus Torvalds unsigned long size;
381da177e4SLinus Torvalds
391da177e4SLinus Torvalds spin_lock(&flash_lock);
401da177e4SLinus Torvalds if (flash.read_base == flash.write_base) {
411da177e4SLinus Torvalds addr = flash.read_base;
421da177e4SLinus Torvalds size = flash.read_size;
431da177e4SLinus Torvalds } else {
441da177e4SLinus Torvalds if ((vma->vm_flags & VM_READ) &&
451da177e4SLinus Torvalds (vma->vm_flags & VM_WRITE)) {
461da177e4SLinus Torvalds spin_unlock(&flash_lock);
471da177e4SLinus Torvalds return -EINVAL;
481da177e4SLinus Torvalds }
491da177e4SLinus Torvalds if (vma->vm_flags & VM_READ) {
501da177e4SLinus Torvalds addr = flash.read_base;
511da177e4SLinus Torvalds size = flash.read_size;
521da177e4SLinus Torvalds } else if (vma->vm_flags & VM_WRITE) {
531da177e4SLinus Torvalds addr = flash.write_base;
541da177e4SLinus Torvalds size = flash.write_size;
551da177e4SLinus Torvalds } else {
561da177e4SLinus Torvalds spin_unlock(&flash_lock);
571da177e4SLinus Torvalds return -ENXIO;
581da177e4SLinus Torvalds }
591da177e4SLinus Torvalds }
601da177e4SLinus Torvalds spin_unlock(&flash_lock);
611da177e4SLinus Torvalds
621da177e4SLinus Torvalds if ((vma->vm_pgoff << PAGE_SHIFT) > size)
631da177e4SLinus Torvalds return -ENXIO;
641da177e4SLinus Torvalds addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
651da177e4SLinus Torvalds
661da177e4SLinus Torvalds if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
671da177e4SLinus Torvalds size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
681da177e4SLinus Torvalds
6914778d90SDavid S. Miller vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
701da177e4SLinus Torvalds
711da177e4SLinus Torvalds if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
721da177e4SLinus Torvalds return -EAGAIN;
731da177e4SLinus Torvalds
741da177e4SLinus Torvalds return 0;
751da177e4SLinus Torvalds }
761da177e4SLinus Torvalds
771da177e4SLinus Torvalds static long long
flash_llseek(struct file * file,long long offset,int origin)781da177e4SLinus Torvalds flash_llseek(struct file *file, long long offset, int origin)
791da177e4SLinus Torvalds {
80a3108ca2SArnd Bergmann mutex_lock(&flash_mutex);
811da177e4SLinus Torvalds switch (origin) {
821da177e4SLinus Torvalds case 0:
831da177e4SLinus Torvalds file->f_pos = offset;
841da177e4SLinus Torvalds break;
851da177e4SLinus Torvalds case 1:
861da177e4SLinus Torvalds file->f_pos += offset;
871da177e4SLinus Torvalds if (file->f_pos > flash.read_size)
881da177e4SLinus Torvalds file->f_pos = flash.read_size;
891da177e4SLinus Torvalds break;
901da177e4SLinus Torvalds case 2:
911da177e4SLinus Torvalds file->f_pos = flash.read_size;
921da177e4SLinus Torvalds break;
931da177e4SLinus Torvalds default:
94a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex);
951da177e4SLinus Torvalds return -EINVAL;
961da177e4SLinus Torvalds }
97a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex);
981da177e4SLinus Torvalds return file->f_pos;
991da177e4SLinus Torvalds }
1001da177e4SLinus Torvalds
1011da177e4SLinus Torvalds static ssize_t
flash_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1021da177e4SLinus Torvalds flash_read(struct file * file, char __user * buf,
1031da177e4SLinus Torvalds size_t count, loff_t *ppos)
1041da177e4SLinus Torvalds {
105be94bbb5SJan Blunck loff_t p = *ppos;
1061da177e4SLinus Torvalds int i;
1071da177e4SLinus Torvalds
1081da177e4SLinus Torvalds if (count > flash.read_size - p)
1091da177e4SLinus Torvalds count = flash.read_size - p;
1101da177e4SLinus Torvalds
1111da177e4SLinus Torvalds for (i = 0; i < count; i++) {
1121da177e4SLinus Torvalds u8 data = upa_readb(flash.read_base + p + i);
1131da177e4SLinus Torvalds if (put_user(data, buf))
1141da177e4SLinus Torvalds return -EFAULT;
1151da177e4SLinus Torvalds buf++;
1161da177e4SLinus Torvalds }
1171da177e4SLinus Torvalds
118be94bbb5SJan Blunck *ppos += count;
1191da177e4SLinus Torvalds return count;
1201da177e4SLinus Torvalds }
1211da177e4SLinus Torvalds
1221da177e4SLinus Torvalds static int
flash_open(struct inode * inode,struct file * file)1231da177e4SLinus Torvalds flash_open(struct inode *inode, struct file *file)
1241da177e4SLinus Torvalds {
125a3108ca2SArnd Bergmann mutex_lock(&flash_mutex);
12678abb6acSArnd Bergmann if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
127a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex);
1281da177e4SLinus Torvalds return -EBUSY;
12978abb6acSArnd Bergmann }
1301da177e4SLinus Torvalds
131a3108ca2SArnd Bergmann mutex_unlock(&flash_mutex);
1321da177e4SLinus Torvalds return 0;
1331da177e4SLinus Torvalds }
1341da177e4SLinus Torvalds
1351da177e4SLinus Torvalds static int
flash_release(struct inode * inode,struct file * file)1361da177e4SLinus Torvalds flash_release(struct inode *inode, struct file *file)
1371da177e4SLinus Torvalds {
1381da177e4SLinus Torvalds spin_lock(&flash_lock);
1391da177e4SLinus Torvalds flash.busy = 0;
1401da177e4SLinus Torvalds spin_unlock(&flash_lock);
1411da177e4SLinus Torvalds
1421da177e4SLinus Torvalds return 0;
1431da177e4SLinus Torvalds }
1441da177e4SLinus Torvalds
14500977a59SArjan van de Ven static const struct file_operations flash_fops = {
1461da177e4SLinus Torvalds /* no write to the Flash, use mmap
1471da177e4SLinus Torvalds * and play flash dependent tricks.
1481da177e4SLinus Torvalds */
1491da177e4SLinus Torvalds .owner = THIS_MODULE,
1501da177e4SLinus Torvalds .llseek = flash_llseek,
1511da177e4SLinus Torvalds .read = flash_read,
1521da177e4SLinus Torvalds .mmap = flash_mmap,
1531da177e4SLinus Torvalds .open = flash_open,
1541da177e4SLinus Torvalds .release = flash_release,
1551da177e4SLinus Torvalds };
1561da177e4SLinus Torvalds
1572668dba6SZhenzhong Duan static struct miscdevice flash_dev = { SBUS_FLASH_MINOR, "flash", &flash_fops };
1581da177e4SLinus Torvalds
flash_probe(struct platform_device * op)159082a2004SGreg Kroah-Hartman static int flash_probe(struct platform_device *op)
1601da177e4SLinus Torvalds {
16161c7a080SGrant Likely struct device_node *dp = op->dev.of_node;
162a9540d34SDavid S. Miller struct device_node *parent;
1631da177e4SLinus Torvalds
164a9540d34SDavid S. Miller parent = dp->parent;
165a9540d34SDavid S. Miller
16691abe6b2SRob Herring if (!of_node_name_eq(parent, "sbus") &&
16791abe6b2SRob Herring !of_node_name_eq(parent, "sbi") &&
16891abe6b2SRob Herring !of_node_name_eq(parent, "ebus"))
169a9540d34SDavid S. Miller return -ENODEV;
170a9540d34SDavid S. Miller
171a9540d34SDavid S. Miller flash.read_base = op->resource[0].start;
172a9540d34SDavid S. Miller flash.read_size = resource_size(&op->resource[0]);
173a9540d34SDavid S. Miller if (op->resource[1].flags) {
174a9540d34SDavid S. Miller flash.write_base = op->resource[1].start;
175a9540d34SDavid S. Miller flash.write_size = resource_size(&op->resource[1]);
1761da177e4SLinus Torvalds } else {
177a9540d34SDavid S. Miller flash.write_base = op->resource[0].start;
178a9540d34SDavid S. Miller flash.write_size = resource_size(&op->resource[0]);
1791da177e4SLinus Torvalds }
1801da177e4SLinus Torvalds flash.busy = 0;
181690c8fd3SDavid S. Miller
1828cd3ec51SRob Herring printk(KERN_INFO "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
1838cd3ec51SRob Herring op->dev.of_node,
1841da177e4SLinus Torvalds flash.read_base, flash.read_size,
1851da177e4SLinus Torvalds flash.write_base, flash.write_size);
1861da177e4SLinus Torvalds
187a9540d34SDavid S. Miller return misc_register(&flash_dev);
1881da177e4SLinus Torvalds }
1891da177e4SLinus Torvalds
flash_remove(struct platform_device * op)190082a2004SGreg Kroah-Hartman static int flash_remove(struct platform_device *op)
191a9540d34SDavid S. Miller {
192a9540d34SDavid S. Miller misc_deregister(&flash_dev);
193a9540d34SDavid S. Miller
1941da177e4SLinus Torvalds return 0;
1951da177e4SLinus Torvalds }
1961da177e4SLinus Torvalds
197fd098316SDavid S. Miller static const struct of_device_id flash_match[] = {
198a9540d34SDavid S. Miller {
199a9540d34SDavid S. Miller .name = "flashprom",
200a9540d34SDavid S. Miller },
201a9540d34SDavid S. Miller {},
202a9540d34SDavid S. Miller };
203a9540d34SDavid S. Miller MODULE_DEVICE_TABLE(of, flash_match);
204a9540d34SDavid S. Miller
2054ebb24f7SGrant Likely static struct platform_driver flash_driver = {
2064018294bSGrant Likely .driver = {
207a9540d34SDavid S. Miller .name = "flash",
2084018294bSGrant Likely .of_match_table = flash_match,
2094018294bSGrant Likely },
210a9540d34SDavid S. Miller .probe = flash_probe,
211082a2004SGreg Kroah-Hartman .remove = flash_remove,
212a9540d34SDavid S. Miller };
213a9540d34SDavid S. Miller
214dbf2b92dSAxel Lin module_platform_driver(flash_driver);
215a9540d34SDavid S. Miller
2161da177e4SLinus Torvalds MODULE_LICENSE("GPL");
217