[deliverable/linux.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;

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

static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
	return 0;
}

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;

	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;

	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) {
		mtd_device_unregister(&this->mtd);
		iounmap(this->mtd.priv);
		kfree(this->mtd.name);
		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 (mtd_device_register(&new->mtd, NULL, 0)) {
		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)

/*
 * This shall contain the module parameter if any. It is of the form:
 * - phram=<device>,<address>,<size> for module case
 * - phram.phram=<device>,<address>,<size> for built-in case
 * We leave 64 bytes for the device name, 12 for the address and 12 for the
 * size.
 * Example: phram.phram=rootfs,0xa0000000,512Mi
 */
static __initdata char phram_paramline[64+12+12];

static int __init phram_setup(const char *val)
{
	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);
	else
		kfree(name);

	return ret;
}

static int __init phram_param_call(const char *val, struct kernel_param *kp)
{
	/*
	 * This function is always called before 'init_phram()', whether
	 * built-in or module.
	 */
	if (strlen(val) >= sizeof(phram_paramline))
		return -ENOSPC;
	strcpy(phram_paramline, val);

	return 0;
}

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


static int __init init_phram(void)
{
	if (phram_paramline[0])
		return phram_setup(phram_paramline);

	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
1da177e4 LT	36	static int phram_erase(struct mtd_info mtd, struct erase_info instr)
	37	{
	38	u_char *start = mtd->priv;
	39
1da177e4 LT	40	memset(start + instr->addr, 0xff, instr->len);
1da177e4 LT	41
b2a2a84d HF	42	/*
b2a2a84d HF	43	* This'll catch a few races. Free the thing before returning :)
1da177e4 LT	44	* I don't feel at all ashamed. This kind of thing is possible anyway
	45	* with flash, but unlikely.
	46	*/
1da177e4	47	instr->state = MTD_ERASE_DONE;
1da177e4	48	mtd_erase_callback(instr);
1da177e4 LT	49	return 0;
	50	}
	51
	52	static int phram_point(struct mtd_info *mtd, loff_t from, size_t len,
a98889f3	53	size_t retlen, void virt, resource_size_t phys)
1da177e4	54	{
a98889f3	55	*virt = mtd->priv + from;
1da177e4 LT	56	*retlen = len;
	57	return 0;
	58	}
	59
5e4e6e3f	60	static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1da177e4	61	{
5e4e6e3f	62	return 0;
1da177e4 LT	63	}
	64
	65	static int phram_read(struct mtd_info *mtd, loff_t from, size_t len,
	66	size_t retlen, u_char buf)
	67	{
	68	u_char *start = mtd->priv;
	69
1da177e4	70	memcpy(buf, start + from, len);
1da177e4 LT	71	*retlen = len;
	72	return 0;
	73	}
	74
	75	static int phram_write(struct mtd_info *mtd, loff_t to, size_t len,
	76	size_t retlen, const u_char buf)
	77	{
	78	u_char *start = mtd->priv;
	79
1da177e4	80	memcpy(start + to, buf, len);
1da177e4 LT	81	*retlen = len;
	82	return 0;
	83	}
	84
1da177e4 LT	85	static void unregister_devices(void)
1da177e4 LT	86	{
d30f11d2	87	struct phram_mtd_list this, safe;
1da177e4	88
d30f11d2	89	list_for_each_entry_safe(this, safe, &phram_list, list) {
ee0e87b1	90	mtd_device_unregister(&this->mtd);
1da177e4	91	iounmap(this->mtd.priv);
f17f12ce	92	kfree(this->mtd.name);
1da177e4 LT	93	kfree(this);
	94	}
	95	}
	96
	97	static int register_device(char *name, unsigned long start, unsigned long len)
	98	{
	99	struct phram_mtd_list *new;
	100	int ret = -ENOMEM;
	101
95b93a0c	102	new = kzalloc(sizeof(*new), GFP_KERNEL);
1da177e4 LT	103	if (!new)
	104	goto out0;
	105
1da177e4 LT	106	ret = -EIO;
	107	new->mtd.priv = ioremap(start, len);
	108	if (!new->mtd.priv) {
64da392a	109	pr_err("ioremap failed\n");
1da177e4 LT	110	goto out1;
	111	}
	112
	113
	114	new->mtd.name = name;
	115	new->mtd.size = len;
a6c591ed	116	new->mtd.flags = MTD_CAP_RAM;
3c3c10bb AB	117	new->mtd._erase = phram_erase;
	118	new->mtd._point = phram_point;
	119	new->mtd._unpoint = phram_unpoint;
	120	new->mtd._read = phram_read;
	121	new->mtd._write = phram_write;
1da177e4	122	new->mtd.owner = THIS_MODULE;
21c8db9e	123	new->mtd.type = MTD_RAM;
663259a4	124	new->mtd.erasesize = PAGE_SIZE;
17ffc7ba	125	new->mtd.writesize = 1;
1da177e4 LT	126
1da177e4 LT	127	ret = -EAGAIN;
ee0e87b1	128	if (mtd_device_register(&new->mtd, NULL, 0)) {
64da392a	129	pr_err("Failed to register new device\n");
1da177e4 LT	130	goto out2;
	131	}
	132
	133	list_add_tail(&new->list, &phram_list);
e5580fbe	134	return 0;
1da177e4 LT	135
	136	out2:
	137	iounmap(new->mtd.priv);
	138	out1:
	139	kfree(new);
	140	out0:
	141	return ret;
	142	}
	143
	144	static int ustrtoul(const char cp, char *endp, unsigned int base)
	145	{
	146	unsigned long result = simple_strtoul(cp, endp, base);
	147
	148	switch (**endp) {
	149	case 'G':
	150	result *= 1024;
	151	case 'M':
	152	result *= 1024;
	153	case 'k':
	154	result *= 1024;
	155	/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
	156	if ((*endp)[1] == 'i')
	157	(*endp) += 2;
	158	}
	159	return result;
	160	}
	161
	162	static int parse_num32(uint32_t num32, const char token)
	163	{
	164	char *endp;
	165	unsigned long n;
	166
	167	n = ustrtoul(token, &endp, 0);
	168	if (*endp)
	169	return -EINVAL;
	170
	171	*num32 = n;
	172	return 0;
	173	}
	174
	175	static int parse_name(char *pname, const char token)
	176	{
	177	size_t len;
	178	char *name;
	179
	180	len = strlen(token) + 1;
	181	if (len > 64)
	182	return -ENOSPC;
	183
	184	name = kmalloc(len, GFP_KERNEL);
	185	if (!name)
	186	return -ENOMEM;
	187
	188	strcpy(name, token);
	189
	190	*pname = name;
	191	return 0;
	192	}
	193
663259a4 JE	194
	195	static inline void kill_final_newline(char *str)
	196	{
	197	char *newline = strrchr(str, '\n');
	198	if (newline && !newline[1])
	199	*newline = 0;
	200	}
	201
	202
1da177e4	203	#define parse_err(fmt, args...) do { \
64da392a MF	204	pr_err(fmt , ## args); \
64da392a MF	205	return 1; \
1da177e4 LT	206	} while (0)
1da177e4 LT	207
b2a2a84d HF	208	/*
	209	* This shall contain the module parameter if any. It is of the form:
	210	* - phram=<device>,<address>,<size> for module case
	211	* - phram.phram=<device>,<address>,<size> for built-in case
	212	* We leave 64 bytes for the device name, 12 for the address and 12 for the
	213	* size.
	214	* Example: phram.phram=rootfs,0xa0000000,512Mi
	215	*/
	216	static __initdata char phram_paramline[64+12+12];
	217
b11ec57f	218	static int __init phram_setup(const char *val)
1da177e4 LT	219	{
	220	char buf[64+12+12], *str = buf;
	221	char *token[3];
	222	char *name;
	223	uint32_t start;
	224	uint32_t len;
	225	int i, ret;
	226
	227	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
	228	parse_err("parameter too long\n");
	229
	230	strcpy(str, val);
663259a4	231	kill_final_newline(str);
1da177e4 LT	232
	233	for (i=0; i<3; i++)
	234	token[i] = strsep(&str, ",");
	235
	236	if (str)
	237	parse_err("too many arguments\n");
	238
	239	if (!token[2])
	240	parse_err("not enough arguments\n");
	241
	242	ret = parse_name(&name, token[0]);
1da177e4	243	if (ret)
64da392a	244	return ret;
1da177e4 LT	245
1da177e4 LT	246	ret = parse_num32(&start, token[1]);
4f678a58 JJ	247	if (ret) {
4f678a58 JJ	248	kfree(name);
1da177e4	249	parse_err("illegal start address\n");
4f678a58	250	}
1da177e4 LT	251
1da177e4 LT	252	ret = parse_num32(&len, token[2]);
4f678a58 JJ	253	if (ret) {
4f678a58 JJ	254	kfree(name);
1da177e4	255	parse_err("illegal device length\n");
4f678a58	256	}
1da177e4	257
64da392a MF	258	ret = register_device(name, start, len);
	259	if (!ret)
	260	pr_info("%s device: %#x at %#x\n", name, len, start);
f17f12ce MK	261	else
f17f12ce MK	262	kfree(name);
1da177e4	263
64da392a	264	return ret;
1da177e4 LT	265	}
1da177e4 LT	266
b2a2a84d HF	267	static int __init phram_param_call(const char val, struct kernel_param kp)
	268	{
	269	/*
	270	* This function is always called before 'init_phram()', whether
	271	* built-in or module.
	272	*/
	273	if (strlen(val) >= sizeof(phram_paramline))
	274	return -ENOSPC;
	275	strcpy(phram_paramline, val);
	276
	277	return 0;
	278	}
	279
	280	module_param_call(phram, phram_param_call, NULL, NULL, 000);
f72561cf	281	MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>\"");
1da177e4 LT	282
	283
	284	static int __init init_phram(void)
	285	{
b2a2a84d HF	286	if (phram_paramline[0])
	287	return phram_setup(phram_paramline);
	288
1da177e4 LT	289	return 0;
	290	}
	291
	292	static void __exit cleanup_phram(void)
	293	{
	294	unregister_devices();
	295	}
	296
	297	module_init(init_phram);
	298	module_exit(cleanup_phram);
	299
	300	MODULE_LICENSE("GPL");
2b54aaef	301	MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>");
1da177e4	302	MODULE_DESCRIPTION("MTD driver for physical RAM");