[mirror_ubuntu-artful-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/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <linux/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 "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
	       op->dev.of_node,
	       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");
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>
1da177e4 LT	11	#include <linux/poll.h>
a3108ca2	12	#include <linux/mutex.h>
1da177e4	13	#include <linux/spinlock.h>
8a73709e	14	#include <linux/mm.h>
a9540d34 DM	15	#include <linux/of.h>
a9540d34 DM	16	#include <linux/of_device.h>
1da177e4	17
7c0f6ba6	18	#include <linux/uaccess.h>
1da177e4 LT	19	#include <asm/pgtable.h>
1da177e4 LT	20	#include <asm/io.h>
1da177e4 LT	21	#include <asm/upa.h>
1da177e4 LT	22
a3108ca2	23	static DEFINE_MUTEX(flash_mutex);
1da177e4 LT	24	static DEFINE_SPINLOCK(flash_lock);
	25	static struct {
	26	unsigned long read_base; /* Physical read address */
	27	unsigned long write_base; /* Physical write address */
	28	unsigned long read_size; /* Size of read area */
	29	unsigned long write_size; /* Size of write area */
	30	unsigned long busy; /* In use? */
	31	} flash;
	32
	33	#define FLASH_MINOR 152
	34
	35	static int
	36	flash_mmap(struct file file, struct vm_area_struct vma)
	37	{
	38	unsigned long addr;
	39	unsigned long size;
	40
	41	spin_lock(&flash_lock);
	42	if (flash.read_base == flash.write_base) {
	43	addr = flash.read_base;
	44	size = flash.read_size;
	45	} else {
	46	if ((vma->vm_flags & VM_READ) &&
	47	(vma->vm_flags & VM_WRITE)) {
	48	spin_unlock(&flash_lock);
	49	return -EINVAL;
	50	}
	51	if (vma->vm_flags & VM_READ) {
	52	addr = flash.read_base;
	53	size = flash.read_size;
	54	} else if (vma->vm_flags & VM_WRITE) {
	55	addr = flash.write_base;
	56	size = flash.write_size;
	57	} else {
	58	spin_unlock(&flash_lock);
	59	return -ENXIO;
	60	}
	61	}
	62	spin_unlock(&flash_lock);
	63
	64	if ((vma->vm_pgoff << PAGE_SHIFT) > size)
	65	return -ENXIO;
	66	addr = vma->vm_pgoff + (addr >> PAGE_SHIFT);
	67
	68	if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size)
	69	size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT));
	70
14778d90	71	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1da177e4 LT	72
	73	if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot))
	74	return -EAGAIN;
	75
	76	return 0;
	77	}
	78
	79	static long long
	80	flash_llseek(struct file *file, long long offset, int origin)
	81	{
a3108ca2	82	mutex_lock(&flash_mutex);
1da177e4 LT	83	switch (origin) {
	84	case 0:
	85	file->f_pos = offset;
	86	break;
	87	case 1:
	88	file->f_pos += offset;
	89	if (file->f_pos > flash.read_size)
	90	file->f_pos = flash.read_size;
	91	break;
	92	case 2:
	93	file->f_pos = flash.read_size;
	94	break;
	95	default:
a3108ca2	96	mutex_unlock(&flash_mutex);
1da177e4 LT	97	return -EINVAL;
1da177e4 LT	98	}
a3108ca2	99	mutex_unlock(&flash_mutex);
1da177e4 LT	100	return file->f_pos;
	101	}
	102
	103	static ssize_t
	104	flash_read(struct file * file, char __user * buf,
	105	size_t count, loff_t *ppos)
	106	{
be94bbb5	107	loff_t p = *ppos;
1da177e4	108	int i;
be94bbb5	109
1da177e4 LT	110	if (count > flash.read_size - p)
	111	count = flash.read_size - p;
	112
	113	for (i = 0; i < count; i++) {
	114	u8 data = upa_readb(flash.read_base + p + i);
	115	if (put_user(data, buf))
	116	return -EFAULT;
	117	buf++;
	118	}
	119
be94bbb5	120	*ppos += count;
1da177e4 LT	121	return count;
	122	}
	123
	124	static int
	125	flash_open(struct inode inode, struct file file)
	126	{
a3108ca2	127	mutex_lock(&flash_mutex);
78abb6ac	128	if (test_and_set_bit(0, (void *)&flash.busy) != 0) {
a3108ca2	129	mutex_unlock(&flash_mutex);
1da177e4	130	return -EBUSY;
78abb6ac	131	}
1da177e4	132
a3108ca2	133	mutex_unlock(&flash_mutex);
1da177e4 LT	134	return 0;
	135	}
	136
	137	static int
	138	flash_release(struct inode inode, struct file file)
	139	{
	140	spin_lock(&flash_lock);
	141	flash.busy = 0;
	142	spin_unlock(&flash_lock);
	143
	144	return 0;
	145	}
	146
00977a59	147	static const struct file_operations flash_fops = {
1da177e4 LT	148	/* no write to the Flash, use mmap
	149	* and play flash dependent tricks.
	150	*/
	151	.owner = THIS_MODULE,
	152	.llseek = flash_llseek,
	153	.read = flash_read,
	154	.mmap = flash_mmap,
	155	.open = flash_open,
	156	.release = flash_release,
	157	};
	158
	159	static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
	160
082a2004	161	static int flash_probe(struct platform_device *op)
1da177e4	162	{
61c7a080	163	struct device_node *dp = op->dev.of_node;
a9540d34	164	struct device_node *parent;
1da177e4	165
a9540d34	166	parent = dp->parent;
1da177e4	167
a9540d34 DM	168	if (strcmp(parent->name, "sbus") &&
	169	strcmp(parent->name, "sbi") &&
	170	strcmp(parent->name, "ebus"))
1da177e4	171	return -ENODEV;
a9540d34 DM	172
	173	flash.read_base = op->resource[0].start;
	174	flash.read_size = resource_size(&op->resource[0]);
	175	if (op->resource[1].flags) {
	176	flash.write_base = op->resource[1].start;
	177	flash.write_size = resource_size(&op->resource[1]);
	178	} else {
	179	flash.write_base = op->resource[0].start;
	180	flash.write_size = resource_size(&op->resource[0]);
1da177e4	181	}
a9540d34	182	flash.busy = 0;
1da177e4	183
8cd3ec51 RH	184	printk(KERN_INFO "%pOF: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n",
8cd3ec51 RH	185	op->dev.of_node,
1da177e4 LT	186	flash.read_base, flash.read_size,
	187	flash.write_base, flash.write_size);
	188
a9540d34 DM	189	return misc_register(&flash_dev);
	190	}
	191
082a2004	192	static int flash_remove(struct platform_device *op)
a9540d34 DM	193	{
a9540d34 DM	194	misc_deregister(&flash_dev);
1da177e4 LT	195
	196	return 0;
	197	}
	198
fd098316	199	static const struct of_device_id flash_match[] = {
a9540d34 DM	200	{
	201	.name = "flashprom",
	202	},
	203	{},
	204	};
	205	MODULE_DEVICE_TABLE(of, flash_match);
	206
4ebb24f7	207	static struct platform_driver flash_driver = {
4018294b GL	208	.driver = {
4018294b GL	209	.name = "flash",
4018294b GL	210	.of_match_table = flash_match,
4018294b GL	211	},
a9540d34	212	.probe = flash_probe,
082a2004	213	.remove = flash_remove,
a9540d34 DM	214	};
a9540d34 DM	215
dbf2b92d	216	module_platform_driver(flash_driver);
1da177e4	217
1da177e4	218	MODULE_LICENSE("GPL");