[deliverable/linux.git] / drivers / mtd / devices / phram.c

/**
 * $Id: phram.c,v 1.16 2005/11/07 11:14:25 gleixner Exp $
 *
 * Copyright (c) ????		Jochen Schäuble <psionic@psionic.de>
 * Copyright (c) 2003-2004	Joern Engel <joern@wh.fh-wedel.de>
 *
 * Usage:
 *
 * one commend line parameter per device, each in the form:
 *   phram=<name>,<start>,<len>
 * <name> may be up to 63 characters.
 * <start> and <len> can be octal, decimal or hexadecimal.  If followed
 * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
 * gigabytes.
 *
 * Example:
 *	phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
 */
#include <asm/io.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>

#define ERROR(fmt, args...) printk(KERN_ERR "phram: " fmt , ## args)

struct phram_mtd_list {
	struct mtd_info mtd;
	struct list_head list;
};

static LIST_HEAD(phram_list);


static int phram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	u_char *start = mtd->priv;

	if (instr->addr + instr->len > mtd->size)
		return -EINVAL;

	memset(start + instr->addr, 0xff, instr->len);

	/* This'll catch a few races. Free the thing before returning :)
	 * I don't feel at all ashamed. This kind of thing is possible anyway
	 * with flash, but unlikely.
	 */

	instr->state = MTD_ERASE_DONE;

	mtd_erase_callback(instr);

	return 0;
}

static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, void **virt, resource_size_t *phys)
{
	if (from + len > mtd->size)
		return -EINVAL;

	/* can we return a physical address with this driver? */
	if (phys)
		return -EINVAL;

	*virt = mtd->priv + from;
	*retlen = len;
	return 0;
}

static void phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
}

static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, u_char *buf)
{
	u_char *start = mtd->priv;

	if (from >= mtd->size)
		return -EINVAL;

	if (len > mtd->size - from)
		len = mtd->size - from;

	memcpy(buf, start + from, len);

	*retlen = len;
	return 0;
}

static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	u_char *start = mtd->priv;

	if (to >= mtd->size)
		return -EINVAL;

	if (len > mtd->size - to)
		len = mtd->size - to;

	memcpy(start + to, buf, len);

	*retlen = len;
	return 0;
}


static void unregister_devices(void)
{
	struct phram_mtd_list *this, *safe;

	list_for_each_entry_safe(this, safe, &phram_list, list) {
		del_mtd_device(&this->mtd);
		iounmap(this->mtd.priv);
		kfree(this);
	}
}

static int register_device(char *name, unsigned long start, unsigned long len)
{
	struct phram_mtd_list *new;
	int ret = -ENOMEM;

	new = kzalloc(sizeof(*new), GFP_KERNEL);
	if (!new)
		goto out0;

	ret = -EIO;
	new->mtd.priv = ioremap(start, len);
	if (!new->mtd.priv) {
		ERROR("ioremap failed\n");
		goto out1;
	}


	new->mtd.name = name;
	new->mtd.size = len;
	new->mtd.flags = MTD_CAP_RAM;
        new->mtd.erase = phram_erase;
	new->mtd.point = phram_point;
	new->mtd.unpoint = phram_unpoint;
	new->mtd.read = phram_read;
	new->mtd.write = phram_write;
	new->mtd.owner = THIS_MODULE;
	new->mtd.type = MTD_RAM;
	new->mtd.erasesize = PAGE_SIZE;
	new->mtd.writesize = 1;

	ret = -EAGAIN;
	if (add_mtd_device(&new->mtd)) {
		ERROR("Failed to register new device\n");
		goto out2;
	}

	list_add_tail(&new->list, &phram_list);
	return 0;

out2:
	iounmap(new->mtd.priv);
out1:
	kfree(new);
out0:
	return ret;
}

static int ustrtoul(const char *cp, char **endp, unsigned int base)
{
	unsigned long result = simple_strtoul(cp, endp, base);

	switch (**endp) {
	case 'G':
		result *= 1024;
	case 'M':
		result *= 1024;
	case 'k':
		result *= 1024;
	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
		if ((*endp)[1] == 'i')
			(*endp) += 2;
	}
	return result;
}

static int parse_num32(uint32_t *num32, const char *token)
{
	char *endp;
	unsigned long n;

	n = ustrtoul(token, &endp, 0);
	if (*endp)
		return -EINVAL;

	*num32 = n;
	return 0;
}

static int parse_name(char **pname, const char *token)
{
	size_t len;
	char *name;

	len = strlen(token) + 1;
	if (len > 64)
		return -ENOSPC;

	name = kmalloc(len, GFP_KERNEL);
	if (!name)
		return -ENOMEM;

	strcpy(name, token);

	*pname = name;
	return 0;
}


static inline void kill_final_newline(char *str)
{
	char *newline = strrchr(str, '\n');
	if (newline && !newline[1])
		*newline = 0;
}


#define parse_err(fmt, args...) do {	\
	ERROR(fmt , ## args);	\
	return 0;		\
} while (0)

static int phram_setup(const char *val, struct kernel_param *kp)
{
	char buf[64+12+12], *str = buf;
	char *token[3];
	char *name;
	uint32_t start;
	uint32_t len;
	int i, ret;

	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
		parse_err("parameter too long\n");

	strcpy(str, val);
	kill_final_newline(str);

	for (i=0; i<3; i++)
		token[i] = strsep(&str, ",");

	if (str)
		parse_err("too many arguments\n");

	if (!token[2])
		parse_err("not enough arguments\n");

	ret = parse_name(&name, token[0]);
	if (ret == -ENOMEM)
		parse_err("out of memory\n");
	if (ret == -ENOSPC)
		parse_err("name too long\n");
	if (ret)
		return 0;

	ret = parse_num32(&start, token[1]);
	if (ret) {
		kfree(name);
		parse_err("illegal start address\n");
	}

	ret = parse_num32(&len, token[2]);
	if (ret) {
		kfree(name);
		parse_err("illegal device length\n");
	}

	register_device(name, start, len);

	return 0;
}

module_param_call(phram, phram_setup, NULL, NULL, 000);
MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>\"");


static int __init init_phram(void)
{
	return 0;
}

static void __exit cleanup_phram(void)
{
	unregister_devices();
}

module_init(init_phram);
module_exit(cleanup_phram);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
MODULE_DESCRIPTION("MTD driver for physical RAM");
Commit	Line	Data
1da177e4	1	/**
e5580fbe	2	* $Id: phram.c,v 1.16 2005/11/07 11:14:25 gleixner Exp $
1da177e4	3	*
151e7659	4	* Copyright (c) ???? Jochen Schäuble <psionic@psionic.de>
2b54aaef	5	* Copyright (c) 2003-2004 Joern Engel <joern@wh.fh-wedel.de>
1da177e4 LT	6	*
	7	* Usage:
	8	*
	9	* one commend line parameter per device, each in the form:
	10	* phram=<name>,<start>,<len>
	11	* <name> may be up to 63 characters.
	12	* <start> and <len> can be octal, decimal or hexadecimal. If followed
	13	* by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
	14	* gigabytes.
	15	*
	16	* Example:
	17	* phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
1da177e4	18	*/
1da177e4 LT	19	#include <asm/io.h>
	20	#include <linux/init.h>
	21	#include <linux/kernel.h>
	22	#include <linux/list.h>
	23	#include <linux/module.h>
	24	#include <linux/moduleparam.h>
4e57b681	25	#include <linux/slab.h>
1da177e4 LT	26	#include <linux/mtd/mtd.h>
	27
	28	#define ERROR(fmt, args...) printk(KERN_ERR "phram: " fmt , ## args)
	29
	30	struct phram_mtd_list {
	31	struct mtd_info mtd;
	32	struct list_head list;
	33	};
	34
	35	static LIST_HEAD(phram_list);
	36
	37
1da177e4 LT	38	static int phram_erase(struct mtd_info mtd, struct erase_info instr)
	39	{
	40	u_char *start = mtd->priv;
	41
	42	if (instr->addr + instr->len > mtd->size)
	43	return -EINVAL;
e5580fbe	44
1da177e4 LT	45	memset(start + instr->addr, 0xff, instr->len);
1da177e4 LT	46
e5580fbe	47	/* This'll catch a few races. Free the thing before returning :)
1da177e4 LT	48	* I don't feel at all ashamed. This kind of thing is possible anyway
	49	* with flash, but unlikely.
	50	*/
	51
	52	instr->state = MTD_ERASE_DONE;
	53
	54	mtd_erase_callback(instr);
	55
	56	return 0;
	57	}
	58
	59	static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
a98889f3	60	size_t retlen, void virt, resource_size_t phys)
1da177e4	61	{
1da177e4 LT	62	if (from + len > mtd->size)
1da177e4 LT	63	return -EINVAL;
e5580fbe	64
a98889f3 JH	65	/* can we return a physical address with this driver? */
	66	if (phys)
	67	return -EINVAL;
	68
	69	*virt = mtd->priv + from;
1da177e4 LT	70	*retlen = len;
	71	return 0;
	72	}
	73
a98889f3	74	static void phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1da177e4 LT	75	{
	76	}
	77
	78	static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
	79	size_t retlen, u_char buf)
	80	{
	81	u_char *start = mtd->priv;
	82
663259a4	83	if (from >= mtd->size)
1da177e4	84	return -EINVAL;
663259a4 JE	85
	86	if (len > mtd->size - from)
	87	len = mtd->size - from;
e5580fbe	88
1da177e4 LT	89	memcpy(buf, start + from, len);
	90
	91	*retlen = len;
	92	return 0;
	93	}
	94
	95	static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
	96	size_t retlen, const u_char buf)
	97	{
	98	u_char *start = mtd->priv;
	99
663259a4	100	if (to >= mtd->size)
1da177e4	101	return -EINVAL;
663259a4 JE	102
	103	if (len > mtd->size - to)
	104	len = mtd->size - to;
e5580fbe	105
1da177e4 LT	106	memcpy(start + to, buf, len);
	107
	108	*retlen = len;
	109	return 0;
	110	}
	111
	112
	113
	114	static void unregister_devices(void)
	115	{
d30f11d2	116	struct phram_mtd_list this, safe;
1da177e4	117
d30f11d2	118	list_for_each_entry_safe(this, safe, &phram_list, list) {
1da177e4 LT	119	del_mtd_device(&this->mtd);
	120	iounmap(this->mtd.priv);
	121	kfree(this);
	122	}
	123	}
	124
	125	static int register_device(char *name, unsigned long start, unsigned long len)
	126	{
	127	struct phram_mtd_list *new;
	128	int ret = -ENOMEM;
	129
95b93a0c	130	new = kzalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	131	if (!new)
	132	goto out0;
	133
1da177e4 LT	134	ret = -EIO;
	135	new->mtd.priv = ioremap(start, len);
	136	if (!new->mtd.priv) {
	137	ERROR("ioremap failed\n");
	138	goto out1;
	139	}
	140
	141
	142	new->mtd.name = name;
	143	new->mtd.size = len;
a6c591ed	144	new->mtd.flags = MTD_CAP_RAM;
1da177e4 LT	145	new->mtd.erase = phram_erase;
	146	new->mtd.point = phram_point;
	147	new->mtd.unpoint = phram_unpoint;
	148	new->mtd.read = phram_read;
	149	new->mtd.write = phram_write;
	150	new->mtd.owner = THIS_MODULE;
21c8db9e	151	new->mtd.type = MTD_RAM;
663259a4	152	new->mtd.erasesize = PAGE_SIZE;
17ffc7ba	153	new->mtd.writesize = 1;
1da177e4 LT	154
	155	ret = -EAGAIN;
	156	if (add_mtd_device(&new->mtd)) {
	157	ERROR("Failed to register new device\n");
	158	goto out2;
	159	}
	160
	161	list_add_tail(&new->list, &phram_list);
e5580fbe	162	return 0;
1da177e4 LT	163
	164	out2:
	165	iounmap(new->mtd.priv);
	166	out1:
	167	kfree(new);
	168	out0:
	169	return ret;
	170	}
	171
	172	static int ustrtoul(const char cp, char *endp, unsigned int base)
	173	{
	174	unsigned long result = simple_strtoul(cp, endp, base);
	175
	176	switch (**endp) {
	177	case 'G':
	178	result *= 1024;
	179	case 'M':
	180	result *= 1024;
	181	case 'k':
	182	result *= 1024;
	183	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
	184	if ((*endp)[1] == 'i')
	185	(*endp) += 2;
	186	}
	187	return result;
	188	}
	189
	190	static int parse_num32(uint32_t num32, const char token)
	191	{
	192	char *endp;
	193	unsigned long n;
	194
	195	n = ustrtoul(token, &endp, 0);
	196	if (*endp)
	197	return -EINVAL;
	198
	199	*num32 = n;
	200	return 0;
	201	}
	202
	203	static int parse_name(char *pname, const char token)
	204	{
	205	size_t len;
	206	char *name;
	207
	208	len = strlen(token) + 1;
	209	if (len > 64)
	210	return -ENOSPC;
	211
	212	name = kmalloc(len, GFP_KERNEL);
	213	if (!name)
	214	return -ENOMEM;
	215
	216	strcpy(name, token);
	217
	218	*pname = name;
	219	return 0;
	220	}
	221
663259a4 JE	222
	223	static inline void kill_final_newline(char *str)
	224	{
	225	char *newline = strrchr(str, '\n');
	226	if (newline && !newline[1])
	227	*newline = 0;
	228	}
	229
	230
1da177e4 LT	231	#define parse_err(fmt, args...) do { \
	232	ERROR(fmt , ## args); \
	233	return 0; \
	234	} while (0)
	235
	236	static int phram_setup(const char val, struct kernel_param kp)
	237	{
	238	char buf[64+12+12], *str = buf;
	239	char *token[3];
	240	char *name;
	241	uint32_t start;
	242	uint32_t len;
	243	int i, ret;
	244
	245	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
	246	parse_err("parameter too long\n");
	247
	248	strcpy(str, val);
663259a4	249	kill_final_newline(str);
1da177e4 LT	250
	251	for (i=0; i<3; i++)
	252	token[i] = strsep(&str, ",");
	253
	254	if (str)
	255	parse_err("too many arguments\n");
	256
	257	if (!token[2])
	258	parse_err("not enough arguments\n");
	259
	260	ret = parse_name(&name, token[0]);
	261	if (ret == -ENOMEM)
	262	parse_err("out of memory\n");
	263	if (ret == -ENOSPC)
	264	parse_err("name too long\n");
	265	if (ret)
	266	return 0;
	267
	268	ret = parse_num32(&start, token[1]);
4f678a58 JJ	269	if (ret) {
4f678a58 JJ	270	kfree(name);
1da177e4	271	parse_err("illegal start address\n");
4f678a58	272	}
1da177e4 LT	273
1da177e4 LT	274	ret = parse_num32(&len, token[2]);
4f678a58 JJ	275	if (ret) {
4f678a58 JJ	276	kfree(name);
1da177e4	277	parse_err("illegal device length\n");
4f678a58	278	}
1da177e4 LT	279
	280	register_device(name, start, len);
	281
	282	return 0;
	283	}
	284
	285	module_param_call(phram, phram_setup, NULL, NULL, 000);
f72561cf	286	MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>\"");
1da177e4 LT	287
	288
	289	static int __init init_phram(void)
	290	{
	291	return 0;
	292	}
	293
	294	static void __exit cleanup_phram(void)
	295	{
	296	unregister_devices();
	297	}
	298
	299	module_init(init_phram);
	300	module_exit(cleanup_phram);
	301
	302	MODULE_LICENSE("GPL");
2b54aaef	303	MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
1da177e4	304	MODULE_DESCRIPTION("MTD driver for physical RAM");