diff options
Diffstat (limited to 'drivers/sbus/char/flash.c')
| -rw-r--r-- | drivers/sbus/char/flash.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/sbus/char/flash.c b/drivers/sbus/char/flash.c new file mode 100644 index 000000000000..6bdd768b731d --- /dev/null +++ b/drivers/sbus/char/flash.c @@ -0,0 +1,255 @@ +/* $Id: flash.c,v 1.25 2001/12/21 04:56:16 davem Exp $ + * flash.c: Allow mmap access to the OBP Flash, for OBP updates. + * + * Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be) + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/miscdevice.h> +#include <linux/slab.h> +#include <linux/fcntl.h> +#include <linux/poll.h> +#include <linux/init.h> +#include <linux/smp_lock.h> +#include <linux/spinlock.h> + +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/pgtable.h> +#include <asm/io.h> +#include <asm/sbus.h> +#include <asm/ebus.h> +#include <asm/upa.h> + +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)); + + pgprot_val(vma->vm_page_prot) &= ~(_PAGE_CACHE); + pgprot_val(vma->vm_page_prot) |= _PAGE_E; + vma->vm_flags |= (VM_SHM | VM_LOCKED); + + 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) +{ + lock_kernel(); + 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: + unlock_kernel(); + return -EINVAL; + } + unlock_kernel(); + return file->f_pos; +} + +static ssize_t +flash_read(struct file * file, char __user * buf, + size_t count, loff_t *ppos) +{ + unsigned long p = file->f_pos; + 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++; + } + + file->f_pos += count; + return count; +} + +static int +flash_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, (void *)&flash.busy) != 0) + return -EBUSY; + + 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 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 __init flash_init(void) +{ + struct sbus_bus *sbus; + struct sbus_dev *sdev = NULL; +#ifdef CONFIG_PCI + struct linux_ebus *ebus; + struct linux_ebus_device *edev = NULL; + struct linux_prom_registers regs[2]; + int len, nregs; +#endif + int err; + + for_all_sbusdev(sdev, sbus) { + if (!strcmp(sdev->prom_name, "flashprom")) { + if (sdev->reg_addrs[0].phys_addr == sdev->reg_addrs[1].phys_addr) { + flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) | + (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL); + flash.read_size = sdev->reg_addrs[0].reg_size; + flash.write_base = flash.read_base; + flash.write_size = flash.read_size; + } else { + flash.read_base = ((unsigned long)sdev->reg_addrs[0].phys_addr) | + (((unsigned long)sdev->reg_addrs[0].which_io)<<32UL); + flash.read_size = sdev->reg_addrs[0].reg_size; + flash.write_base = ((unsigned long)sdev->reg_addrs[1].phys_addr) | + (((unsigned long)sdev->reg_addrs[1].which_io)<<32UL); + flash.write_size = sdev->reg_addrs[1].reg_size; + } + flash.busy = 0; + break; + } + } + if (!sdev) { +#ifdef CONFIG_PCI + for_each_ebus(ebus) { + for_each_ebusdev(edev, ebus) { + if (!strcmp(edev->prom_name, "flashprom")) + goto ebus_done; + } + } + ebus_done: + if (!edev) + return -ENODEV; + + len = prom_getproperty(edev->prom_node, "reg", (void *)regs, sizeof(regs)); + if ((len % sizeof(regs[0])) != 0) { + printk("flash: Strange reg property size %d\n", len); + return -ENODEV; + } + + nregs = len / sizeof(regs[0]); + + flash.read_base = edev->resource[0].start; + flash.read_size = regs[0].reg_size; + + if (nregs == 1) { + flash.write_base = edev->resource[0].start; + flash.write_size = regs[0].reg_size; + } else if (nregs == 2) { + flash.write_base = edev->resource[1].start; + flash.write_size = regs[1].reg_size; + } else { + printk("flash: Strange number of regs %d\n", nregs); + return -ENODEV; + } + + flash.busy = 0; + +#else + return -ENODEV; +#endif + } + + printk("OBP Flash: RD %lx[%lx] WR %lx[%lx]\n", + flash.read_base, flash.read_size, + flash.write_base, flash.write_size); + + err = misc_register(&flash_dev); + if (err) { + printk(KERN_ERR "flash: unable to get misc minor\n"); + return err; + } + + return 0; +} + +static void __exit flash_cleanup(void) +{ + misc_deregister(&flash_dev); +} + +module_init(flash_init); +module_exit(flash_cleanup); +MODULE_LICENSE("GPL"); |