[net-next-2.6.git] / drivers / mtd / devices / phram.c

/**
 * 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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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>

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) {
		pr_err("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)) {
		pr_err("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 {	\
	pr_err(fmt , ## args);	\
	return 1;		\
} 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)
		return ret;

	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");
	}

	ret = register_device(name, start, len);
	if (!ret)
		pr_info("%s device: %#x at %#x\n", name, len, start);

	return ret;
}

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	/**
151e7659	2	* Copyright (c) ???? Jochen Schäuble <psionic@psionic.de>
2b54aaef	3	* Copyright (c) 2003-2004 Joern Engel <joern@wh.fh-wedel.de>
1da177e4 LT	4	*
	5	* Usage:
	6	*
	7	* one commend line parameter per device, each in the form:
	8	* phram=<name>,<start>,<len>
	9	* <name> may be up to 63 characters.
	10	* <start> and <len> can be octal, decimal or hexadecimal. If followed
	11	* by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or
	12	* gigabytes.
	13	*
	14	* Example:
	15	* phram=swap,64Mi,128Mi phram=test,900Mi,1Mi
1da177e4	16	*/
64da392a	17
1cd844fe	18	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
64da392a	19
1da177e4 LT	20	#include <asm/io.h>
	21	#include <linux/init.h>
	22	#include <linux/kernel.h>
	23	#include <linux/list.h>
	24	#include <linux/module.h>
	25	#include <linux/moduleparam.h>
4e57b681	26	#include <linux/slab.h>
1da177e4 LT	27	#include <linux/mtd/mtd.h>
1da177e4 LT	28
1da177e4 LT	29	struct phram_mtd_list {
	30	struct mtd_info mtd;
	31	struct list_head list;
	32	};
	33
	34	static LIST_HEAD(phram_list);
	35
	36
1da177e4 LT	37	static int phram_erase(struct mtd_info mtd, struct erase_info instr)
	38	{
	39	u_char *start = mtd->priv;
	40
	41	if (instr->addr + instr->len > mtd->size)
	42	return -EINVAL;
e5580fbe	43
1da177e4 LT	44	memset(start + instr->addr, 0xff, instr->len);
1da177e4 LT	45
e5580fbe	46	/* This'll catch a few races. Free the thing before returning :)
1da177e4 LT	47	* I don't feel at all ashamed. This kind of thing is possible anyway
	48	* with flash, but unlikely.
	49	*/
	50
	51	instr->state = MTD_ERASE_DONE;
	52
	53	mtd_erase_callback(instr);
	54
	55	return 0;
	56	}
	57
	58	static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
a98889f3	59	size_t retlen, void virt, resource_size_t phys)
1da177e4	60	{
1da177e4 LT	61	if (from + len > mtd->size)
1da177e4 LT	62	return -EINVAL;
e5580fbe	63
a98889f3 JH	64	/* can we return a physical address with this driver? */
	65	if (phys)
	66	return -EINVAL;
	67
	68	*virt = mtd->priv + from;
1da177e4 LT	69	*retlen = len;
	70	return 0;
	71	}
	72
a98889f3	73	static void phram_unpoint(struct mtd_info *mtd, loff_t from, 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) {
64da392a	136	pr_err("ioremap failed\n");
1da177e4 LT	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)) {
64da392a	156	pr_err("Failed to register new device\n");
1da177e4 LT	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	230	#define parse_err(fmt, args...) do { \
64da392a MF	231	pr_err(fmt , ## args); \
64da392a MF	232	return 1; \
1da177e4 LT	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]);
1da177e4	260	if (ret)
64da392a	261	return ret;
1da177e4 LT	262
1da177e4 LT	263	ret = parse_num32(&start, token[1]);
4f678a58 JJ	264	if (ret) {
4f678a58 JJ	265	kfree(name);
1da177e4	266	parse_err("illegal start address\n");
4f678a58	267	}
1da177e4 LT	268
1da177e4 LT	269	ret = parse_num32(&len, token[2]);
4f678a58 JJ	270	if (ret) {
4f678a58 JJ	271	kfree(name);
1da177e4	272	parse_err("illegal device length\n");
4f678a58	273	}
1da177e4	274
64da392a MF	275	ret = register_device(name, start, len);
	276	if (!ret)
	277	pr_info("%s device: %#x at %#x\n", name, len, start);
1da177e4	278
64da392a	279	return ret;
1da177e4 LT	280	}
	281
	282	module_param_call(phram, phram_setup, NULL, NULL, 000);
f72561cf	283	MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>\"");
1da177e4 LT	284
	285
	286	static int __init init_phram(void)
	287	{
	288	return 0;
	289	}
	290
	291	static void __exit cleanup_phram(void)
	292	{
	293	unregister_devices();
	294	}
	295
	296	module_init(init_phram);
	297	module_exit(cleanup_phram);
	298
	299	MODULE_LICENSE("GPL");
2b54aaef	300	MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
1da177e4	301	MODULE_DESCRIPTION("MTD driver for physical RAM");