[linux-2.6-block.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, u_char **mtdbuf)
{
	u_char *start = mtd->priv;

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

	*mtdbuf = start + from;
	*retlen = len;
	return 0;
}

static void phram_unpoint(struct mtd_info *mtd, u_char *addr, 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. \"map=<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,
	60	size_t retlen, u_char *mtdbuf)
	61	{
	62	u_char *start = mtd->priv;
	63
	64	if (from + len > mtd->size)
	65	return -EINVAL;
e5580fbe	66
1da177e4 LT	67	*mtdbuf = start + from;
	68	*retlen = len;
	69	return 0;
	70	}
	71
663259a4 JE	72	static void phram_unpoint(struct mtd_info mtd, u_char addr, loff_t from,
663259a4 JE	73	size_t len)
1da177e4 LT	74	{
	75	}
	76
	77	static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
	78	size_t retlen, u_char buf)
	79	{
	80	u_char *start = mtd->priv;
	81
663259a4	82	if (from >= mtd->size)
1da177e4	83	return -EINVAL;
663259a4 JE	84
	85	if (len > mtd->size - from)
	86	len = mtd->size - from;
e5580fbe	87
1da177e4 LT	88	memcpy(buf, start + from, len);
	89
	90	*retlen = len;
	91	return 0;
	92	}
	93
	94	static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
	95	size_t retlen, const u_char buf)
	96	{
	97	u_char *start = mtd->priv;
	98
663259a4	99	if (to >= mtd->size)
1da177e4	100	return -EINVAL;
663259a4 JE	101
	102	if (len > mtd->size - to)
	103	len = mtd->size - to;
e5580fbe	104
1da177e4 LT	105	memcpy(start + to, buf, len);
	106
	107	*retlen = len;
	108	return 0;
	109	}
	110
	111
	112
	113	static void unregister_devices(void)
	114	{
d30f11d2	115	struct phram_mtd_list this, safe;
1da177e4	116
d30f11d2	117	list_for_each_entry_safe(this, safe, &phram_list, list) {
1da177e4 LT	118	del_mtd_device(&this->mtd);
	119	iounmap(this->mtd.priv);
	120	kfree(this);
	121	}
	122	}
	123
	124	static int register_device(char *name, unsigned long start, unsigned long len)
	125	{
	126	struct phram_mtd_list *new;
	127	int ret = -ENOMEM;
	128
95b93a0c	129	new = kzalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	130	if (!new)
	131	goto out0;
	132
1da177e4 LT	133	ret = -EIO;
	134	new->mtd.priv = ioremap(start, len);
	135	if (!new->mtd.priv) {
	136	ERROR("ioremap failed\n");
	137	goto out1;
	138	}
	139
	140
	141	new->mtd.name = name;
	142	new->mtd.size = len;
a6c591ed	143	new->mtd.flags = MTD_CAP_RAM;
1da177e4 LT	144	new->mtd.erase = phram_erase;
	145	new->mtd.point = phram_point;
	146	new->mtd.unpoint = phram_unpoint;
	147	new->mtd.read = phram_read;
	148	new->mtd.write = phram_write;
	149	new->mtd.owner = THIS_MODULE;
21c8db9e	150	new->mtd.type = MTD_RAM;
663259a4	151	new->mtd.erasesize = PAGE_SIZE;
17ffc7ba	152	new->mtd.writesize = 1;
1da177e4 LT	153
	154	ret = -EAGAIN;
	155	if (add_mtd_device(&new->mtd)) {
	156	ERROR("Failed to register new device\n");
	157	goto out2;
	158	}
	159
	160	list_add_tail(&new->list, &phram_list);
e5580fbe	161	return 0;
1da177e4 LT	162
	163	out2:
	164	iounmap(new->mtd.priv);
	165	out1:
	166	kfree(new);
	167	out0:
	168	return ret;
	169	}
	170
	171	static int ustrtoul(const char cp, char *endp, unsigned int base)
	172	{
	173	unsigned long result = simple_strtoul(cp, endp, base);
	174
	175	switch (**endp) {
	176	case 'G':
	177	result *= 1024;
	178	case 'M':
	179	result *= 1024;
	180	case 'k':
	181	result *= 1024;
	182	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
	183	if ((*endp)[1] == 'i')
	184	(*endp) += 2;
	185	}
	186	return result;
	187	}
	188
	189	static int parse_num32(uint32_t num32, const char token)
	190	{
	191	char *endp;
	192	unsigned long n;
	193
	194	n = ustrtoul(token, &endp, 0);
	195	if (*endp)
	196	return -EINVAL;
	197
	198	*num32 = n;
	199	return 0;
	200	}
	201
	202	static int parse_name(char *pname, const char token)
	203	{
	204	size_t len;
	205	char *name;
	206
	207	len = strlen(token) + 1;
	208	if (len > 64)
	209	return -ENOSPC;
	210
	211	name = kmalloc(len, GFP_KERNEL);
	212	if (!name)
	213	return -ENOMEM;
	214
	215	strcpy(name, token);
	216
	217	*pname = name;
	218	return 0;
	219	}
	220
663259a4 JE	221
	222	static inline void kill_final_newline(char *str)
	223	{
	224	char *newline = strrchr(str, '\n');
	225	if (newline && !newline[1])
	226	*newline = 0;
	227	}
	228
	229
1da177e4 LT	230	#define parse_err(fmt, args...) do { \
	231	ERROR(fmt , ## args); \
	232	return 0; \
	233	} while (0)
	234
	235	static int phram_setup(const char val, struct kernel_param kp)
	236	{
	237	char buf[64+12+12], *str = buf;
	238	char *token[3];
	239	char *name;
	240	uint32_t start;
	241	uint32_t len;
	242	int i, ret;
	243
	244	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
	245	parse_err("parameter too long\n");
	246
	247	strcpy(str, val);
663259a4	248	kill_final_newline(str);
1da177e4 LT	249
	250	for (i=0; i<3; i++)
	251	token[i] = strsep(&str, ",");
	252
	253	if (str)
	254	parse_err("too many arguments\n");
	255
	256	if (!token[2])
	257	parse_err("not enough arguments\n");
	258
	259	ret = parse_name(&name, token[0]);
	260	if (ret == -ENOMEM)
	261	parse_err("out of memory\n");
	262	if (ret == -ENOSPC)
	263	parse_err("name too long\n");
	264	if (ret)
	265	return 0;
	266
	267	ret = parse_num32(&start, token[1]);
4f678a58 JJ	268	if (ret) {
4f678a58 JJ	269	kfree(name);
1da177e4	270	parse_err("illegal start address\n");
4f678a58	271	}
1da177e4 LT	272
1da177e4 LT	273	ret = parse_num32(&len, token[2]);
4f678a58 JJ	274	if (ret) {
4f678a58 JJ	275	kfree(name);
1da177e4	276	parse_err("illegal device length\n");
4f678a58	277	}
1da177e4 LT	278
	279	register_device(name, start, len);
	280
	281	return 0;
	282	}
	283
	284	module_param_call(phram, phram_setup, NULL, NULL, 000);
	285	MODULE_PARM_DESC(phram,"Memory region to map. \"map=<name>,<start>,<length>\"");
	286
	287
	288	static int __init init_phram(void)
	289	{
	290	return 0;
	291	}
	292
	293	static void __exit cleanup_phram(void)
	294	{
	295	unregister_devices();
	296	}
	297
	298	module_init(init_phram);
	299	module_exit(cleanup_phram);
	300
	301	MODULE_LICENSE("GPL");
2b54aaef	302	MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
1da177e4	303	MODULE_DESCRIPTION("MTD driver for physical RAM");