--- /dev/null
+/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
+ *
+ * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+#include <linux/poll.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#include <asm/upa.h>
+
+static DEFINE_MUTEX(flash_mutex);
+static DEFINE_SPINLOCK(flash_lock);
+static struct {
+ unsigned long read_base; /* Physical read address */
+ unsigned long write_base; /* Physical write address */
+ unsigned long read_size; /* Size of read area */
+ unsigned long write_size; /* Size of write area */
+ unsigned long busy; /* In use? */
+} flash;
+
+#define FLASH_MINOR 152
+
+static int
+flash_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ unsigned long addr;
+ unsigned long size;
+
+ spin_lock(&flash_lock);
+ if (flash.read_base == flash.write_base) {
+ addr = flash.read_base;
+ size = flash.read_size;
+ } else {
+ if ((vma->vm_flags & VM_READ) &&
+ (vma->vm_flags & VM_WRITE)) {
+ spin_unlock(&flash_lock);
+ return -EINVAL;
+ }
+ if (vma->vm_flags & VM_READ) {
+ addr = flash.read_base;
+ size = flash.read_size;
+ } else if (vma->vm_flags & VM_WRITE) {
+ addr = flash.write_base;
+ size = flash.write_size;
+ } else {
+ spin_unlock(&flash_lock);
+ return -ENXIO;
+ }
+ }
+ spin_unlock(&flash_lock);
+
+ if ((vma->vm_pgoff << PAGE_SHIFT) > size)
+ return -ENXIO;
+ addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
+
+ if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
+ size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
+
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+ if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
+ return -EAGAIN;
+
+ return 0;
+}
+
+static long long
+flash_llseek(struct file *file, long long offset, int origin)
+{
+ mutex_lock(&flash_mutex);
+ switch (origin) {
+ case 0:
+ file->f_pos = offset;
+ break;
+ case 1:
+ file->f_pos += offset;
+ if (file->f_pos > flash.read_size)
+ file->f_pos = flash.read_size;
+ break;
+ case 2:
+ file->f_pos = flash.read_size;
+ break;
+ default:
+ mutex_unlock(&flash_mutex);
+ return -EINVAL;
+ }
+ mutex_unlock(&flash_mutex);
+ return file->f_pos;
+}
+
+static ssize_t
+flash_read(struct file * file, char __user * buf,
+ size_t count, loff_t *ppos)
+{
+ loff_t p = *ppos;
+ int i;
+
+ if (count > flash.read_size - p)
+ count = flash.read_size - p;
+
+ for (i = 0; i < count; i++) {
+ u8 data = upa_readb(flash.read_base + p + i);
+ if (put_user(data, buf))
+ return -EFAULT;
+ buf++;
+ }
+
+ *ppos += count;
+ return count;
+}
+
+static int
+flash_open(struct inode *inode, struct file *file)
+{
+ mutex_lock(&flash_mutex);
+ if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
+ mutex_unlock(&flash_mutex);
+ return -EBUSY;
+ }
+
+ mutex_unlock(&flash_mutex);
+ return 0;
+}
+
+static int
+flash_release(struct inode *inode, struct file *file)
+{
+ spin_lock(&flash_lock);
+ flash.busy = 0;
+ spin_unlock(&flash_lock);
+
+ return 0;
+}
+
+static const struct file_operations flash_fops = {
+ /* no write to the Flash, use mmap
+ * and play flash dependent tricks.
+ */
+ .owner = THIS_MODULE,
+ .llseek = flash_llseek,
+ .read = flash_read,
+ .mmap = flash_mmap,
+ .open = flash_open,
+ .release = flash_release,
+};
+
+static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
+
+static int flash_probe(struct platform_device *op)
+{
+ struct device_node *dp = op->dev.of_node;
+ struct device_node *parent;
+
+ parent = dp->parent;
+
+ if (strcmp(parent->name, "sbus") &&
+ strcmp(parent->name, "sbi") &&
+ strcmp(parent->name, "ebus"))
+ return -ENODEV;
+
+ flash.read_base = op->resource[0].start;
+ flash.read_size = resource_size(&op->resource[0]);
+ if (op->resource[1].flags) {
+ flash.write_base = op->resource[1].start;
+ flash.write_size = resource_size(&op->resource[1]);
+ } else {
+ flash.write_base = op->resource[0].start;
+ flash.write_size = resource_size(&op->resource[0]);
+ }
+ flash.busy = 0;
+
+ printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
+ op->dev.of_node->full_name,
+ flash.read_base, flash.read_size,
+ flash.write_base, flash.write_size);
+
+ return misc_register(&flash_dev);
+}
+
+static int flash_remove(struct platform_device *op)
+{
+ misc_deregister(&flash_dev);
+
+ return 0;
+}
+
+static const struct of_device_id flash_match[] = {
+ {
+ .name = "flashprom",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, flash_match);
+
+static struct platform_driver flash_driver = {
+ .driver = {
+ .name = "flash",
+ .of_match_table = flash_match,
+ },
+ .probe = flash_probe,
+ .remove = flash_remove,
+};
+
+module_platform_driver(flash_driver);
+
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff