[mirror_ubuntu-eoan-kernel.git] / drivers / sbus / char / flash.c

/* 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/init.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/system.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 __devinit 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 __devexit 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",
		.owner = THIS_MODULE,
		.of_match_table = flash_match,
	},
	.probe		= flash_probe,
	.remove		= __devexit_p(flash_remove),
};

module_platform_driver(flash_driver);

MODULE_LICENSE("GPL");
Commit	Line	Data
a9540d34	1	/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
1da177e4 LT	2	*
	3	* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
	4	*/
	5
1da177e4 LT	6	#include <linux/module.h>
	7	#include <linux/types.h>
	8	#include <linux/errno.h>
	9	#include <linux/miscdevice.h>
1da177e4 LT	10	#include <linux/fcntl.h>
	11	#include <linux/poll.h>
	12	#include <linux/init.h>
a3108ca2	13	#include <linux/mutex.h>
1da177e4	14	#include <linux/spinlock.h>
8a73709e	15	#include <linux/mm.h>
a9540d34 DM	16	#include <linux/of.h>
a9540d34 DM	17	#include <linux/of_device.h>
1da177e4 LT	18
	19	#include <asm/system.h>
	20	#include <asm/uaccess.h>
	21	#include <asm/pgtable.h>
	22	#include <asm/io.h>
1da177e4 LT	23	#include <asm/upa.h>
1da177e4 LT	24
a3108ca2	25	static DEFINE_MUTEX(flash_mutex);
1da177e4 LT	26	static DEFINE_SPINLOCK(flash_lock);
	27	static struct {
	28	unsigned long read_base; /* Physical read address */
	29	unsigned long write_base; /* Physical write address */
	30	unsigned long read_size; /* Size of read area */
	31	unsigned long write_size; /* Size of write area */
	32	unsigned long busy; /* In use? */
	33	} flash;
	34
	35	#define FLASH_MINOR 152
	36
	37	static int
	38	flash_mmap(struct file file, struct vm_area_struct vma)
	39	{
	40	unsigned long addr;
	41	unsigned long size;
	42
	43	spin_lock(&flash_lock);
	44	if (flash.read_base == flash.write_base) {
	45	addr = flash.read_base;
	46	size = flash.read_size;
	47	} else {
	48	if ((vma->vm_flags & VM_READ) &&
	49	(vma->vm_flags & VM_WRITE)) {
	50	spin_unlock(&flash_lock);
	51	return -EINVAL;
	52	}
	53	if (vma->vm_flags & VM_READ) {
	54	addr = flash.read_base;
	55	size = flash.read_size;
	56	} else if (vma->vm_flags & VM_WRITE) {
	57	addr = flash.write_base;
	58	size = flash.write_size;
	59	} else {
	60	spin_unlock(&flash_lock);
	61	return -ENXIO;
	62	}
	63	}
	64	spin_unlock(&flash_lock);
	65
	66	if ((vma->vm_pgoff << PAGE_SHIFT) > size)
	67	return -ENXIO;
	68	addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
	69
	70	if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
	71	size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
	72
14778d90	73	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1da177e4 LT	74
	75	if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
	76	return -EAGAIN;
	77
	78	return 0;
	79	}
	80
	81	static long long
	82	flash_llseek(struct file *file, long long offset, int origin)
	83	{
a3108ca2	84	mutex_lock(&flash_mutex);
1da177e4 LT	85	switch (origin) {
	86	case 0:
	87	file->f_pos = offset;
	88	break;
	89	case 1:
	90	file->f_pos += offset;
	91	if (file->f_pos > flash.read_size)
	92	file->f_pos = flash.read_size;
	93	break;
	94	case 2:
	95	file->f_pos = flash.read_size;
	96	break;
	97	default:
a3108ca2	98	mutex_unlock(&flash_mutex);
1da177e4 LT	99	return -EINVAL;
1da177e4 LT	100	}
a3108ca2	101	mutex_unlock(&flash_mutex);
1da177e4 LT	102	return file->f_pos;
	103	}
	104
	105	static ssize_t
	106	flash_read(struct file * file, char __user * buf,
	107	size_t count, loff_t *ppos)
	108	{
be94bbb5	109	loff_t p = *ppos;
1da177e4	110	int i;
be94bbb5	111
1da177e4 LT	112	if (count > flash.read_size - p)
	113	count = flash.read_size - p;
	114
	115	for (i = 0; i < count; i++) {
	116	u8 data = upa_readb(flash.read_base + p + i);
	117	if (put_user(data, buf))
	118	return -EFAULT;
	119	buf++;
	120	}
	121
be94bbb5	122	*ppos += count;
1da177e4 LT	123	return count;
	124	}
	125
	126	static int
	127	flash_open(struct inode inode, struct file file)
	128	{
a3108ca2	129	mutex_lock(&flash_mutex);
78abb6ac	130	if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
a3108ca2	131	mutex_unlock(&flash_mutex);
1da177e4	132	return -EBUSY;
78abb6ac	133	}
1da177e4	134
a3108ca2	135	mutex_unlock(&flash_mutex);
1da177e4 LT	136	return 0;
	137	}
	138
	139	static int
	140	flash_release(struct inode inode, struct file file)
	141	{
	142	spin_lock(&flash_lock);
	143	flash.busy = 0;
	144	spin_unlock(&flash_lock);
	145
	146	return 0;
	147	}
	148
00977a59	149	static const struct file_operations flash_fops = {
1da177e4 LT	150	/* no write to the Flash, use mmap
	151	* and play flash dependent tricks.
	152	*/
	153	.owner = THIS_MODULE,
	154	.llseek = flash_llseek,
	155	.read = flash_read,
	156	.mmap = flash_mmap,
	157	.open = flash_open,
	158	.release = flash_release,
	159	};
	160
	161	static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
	162
4ebb24f7	163	static int __devinit flash_probe(struct platform_device *op)
1da177e4	164	{
61c7a080	165	struct device_node *dp = op->dev.of_node;
a9540d34	166	struct device_node *parent;
1da177e4	167
a9540d34	168	parent = dp->parent;
1da177e4	169
a9540d34 DM	170	if (strcmp(parent->name, "sbus") &&
	171	strcmp(parent->name, "sbi") &&
	172	strcmp(parent->name, "ebus"))
1da177e4	173	return -ENODEV;
a9540d34 DM	174
	175	flash.read_base = op->resource[0].start;
	176	flash.read_size = resource_size(&op->resource[0]);
	177	if (op->resource[1].flags) {
	178	flash.write_base = op->resource[1].start;
	179	flash.write_size = resource_size(&op->resource[1]);
	180	} else {
	181	flash.write_base = op->resource[0].start;
	182	flash.write_size = resource_size(&op->resource[0]);
1da177e4	183	}
a9540d34	184	flash.busy = 0;
1da177e4	185
a9540d34	186	printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
61c7a080	187	op->dev.of_node->full_name,
1da177e4 LT	188	flash.read_base, flash.read_size,
	189	flash.write_base, flash.write_size);
	190
a9540d34 DM	191	return misc_register(&flash_dev);
	192	}
	193
2dc11581	194	static int __devexit flash_remove(struct platform_device *op)
a9540d34 DM	195	{
a9540d34 DM	196	misc_deregister(&flash_dev);
1da177e4 LT	197
	198	return 0;
	199	}
	200
fd098316	201	static const struct of_device_id flash_match[] = {
a9540d34 DM	202	{
	203	.name = "flashprom",
	204	},
	205	{},
	206	};
	207	MODULE_DEVICE_TABLE(of, flash_match);
	208
4ebb24f7	209	static struct platform_driver flash_driver = {
4018294b GL	210	.driver = {
	211	.name = "flash",
	212	.owner = THIS_MODULE,
	213	.of_match_table = flash_match,
	214	},
a9540d34 DM	215	.probe = flash_probe,
	216	.remove = __devexit_p(flash_remove),
	217	};
	218
dbf2b92d	219	module_platform_driver(flash_driver);
1da177e4	220
1da177e4	221	MODULE_LICENSE("GPL");