[mirror_ubuntu-zesty-kernel.git] / arch / mips / bcm47xx / nvram.c

/*
 * BCM947xx nvram variable access
 *
 * Copyright (C) 2005 Broadcom Corporation
 * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
 * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
 *
 * This program is free software; you can redistribute	it and/or modify it
 * under  the terms of	the GNU General	 Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <linux/io.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/mtd/mtd.h>
#include <linux/bcm47xx_nvram.h>

#define NVRAM_MAGIC			0x48534C46	/* 'FLSH' */
#define NVRAM_SPACE			0x10000
#define NVRAM_MAX_GPIO_ENTRIES		32
#define NVRAM_MAX_GPIO_VALUE_LEN	30

#define FLASH_MIN		0x00020000	/* Minimum flash size */

struct nvram_header {
	u32 magic;
	u32 len;
	u32 crc_ver_init;	/* 0:7 crc, 8:15 ver, 16:31 sdram_init */
	u32 config_refresh;	/* 0:15 sdram_config, 16:31 sdram_refresh */
	u32 config_ncdl;	/* ncdl values for memc */
};

static char nvram_buf[NVRAM_SPACE];
static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};

static u32 find_nvram_size(void __iomem *end)
{
	struct nvram_header __iomem *header;
	int i;

	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
		header = (struct nvram_header *)(end - nvram_sizes[i]);
		if (header->magic == NVRAM_MAGIC)
			return nvram_sizes[i];
	}

	return 0;
}

/* Probe for NVRAM header */
static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
{
	struct nvram_header __iomem *header;
	int i;
	u32 off;
	u32 *src, *dst;
	u32 size;

	if (nvram_buf[0]) {
		pr_warn("nvram already initialized\n");
		return -EEXIST;
	}

	/* TODO: when nvram is on nand flash check for bad blocks first. */
	off = FLASH_MIN;
	while (off <= lim) {
		/* Windowed flash access */
		size = find_nvram_size(iobase + off);
		if (size) {
			header = (struct nvram_header *)(iobase + off - size);
			goto found;
		}
		off <<= 1;
	}

	/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
	header = (struct nvram_header *)(iobase + 4096);
	if (header->magic == NVRAM_MAGIC) {
		size = NVRAM_SPACE;
		goto found;
	}

	header = (struct nvram_header *)(iobase + 1024);
	if (header->magic == NVRAM_MAGIC) {
		size = NVRAM_SPACE;
		goto found;
	}

	pr_err("no nvram found\n");
	return -ENXIO;

found:
	src = (u32 *)header;
	dst = (u32 *)nvram_buf;
	for (i = 0; i < sizeof(struct nvram_header); i += 4)
		*dst++ = __raw_readl(src++);
	header = (struct nvram_header *)nvram_buf;
	if (header->len > size) {
		pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
		header->len = size;
	}
	if (header->len >= NVRAM_SPACE) {
		pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
		       header->len, NVRAM_SPACE - 1);
		header->len = NVRAM_SPACE - 1;
	}
	/* proceed reading data after header */
	for (; i < header->len; i += 4)
		*dst++ = readl(src++);
	nvram_buf[NVRAM_SPACE - 1] = '\0';

	return 0;
}

/*
 * On bcm47xx we need access to the NVRAM very early, so we can't use mtd
 * subsystem to access flash. We can't even use platform device / driver to
 * store memory offset.
 * To handle this we provide following symbol. It's supposed to be called as
 * soon as we get info about flash device, before any NVRAM entry is needed.
 */
int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)
{
	void __iomem *iobase;
	int err;

	iobase = ioremap_nocache(base, lim);
	if (!iobase)
		return -ENOMEM;

	err = nvram_find_and_copy(iobase, lim);

	iounmap(iobase);

	return err;
}

static int nvram_init(void)
{
#ifdef CONFIG_MTD
	struct mtd_info *mtd;
	struct nvram_header header;
	struct nvram_header *pheader;
	size_t bytes_read;
	int err;

	mtd = get_mtd_device_nm("nvram");
	if (IS_ERR(mtd))
		return -ENODEV;

	err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header);
	if (!err && header.magic == NVRAM_MAGIC &&
	    header.len > sizeof(header)) {
		if (header.len >= NVRAM_SPACE) {
			pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
				header.len, NVRAM_SPACE);
			header.len = NVRAM_SPACE - 1;
		}

		err = mtd_read(mtd, 0, header.len, &bytes_read,
			       (u8 *)nvram_buf);
		if (err)
			return err;

		pheader = (struct nvram_header *)nvram_buf;
		pheader->len = header.len;
		return 0;
	}
#endif

	return -ENXIO;
}

int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len)
{
	char *var, *value, *end, *eq;
	int err;

	if (!name)
		return -EINVAL;

	if (!nvram_buf[0]) {
		err = nvram_init();
		if (err)
			return err;
	}

	/* Look for name=value and return value */
	var = &nvram_buf[sizeof(struct nvram_header)];
	end = nvram_buf + sizeof(nvram_buf);
	while (var < end && *var) {
		eq = strchr(var, '=');
		if (!eq)
			break;
		value = eq + 1;
		if (eq - var == strlen(name) &&
		    strncmp(var, name, eq - var) == 0)
			return snprintf(val, val_len, "%s", value);
		var = value + strlen(value) + 1;
	}
	return -ENOENT;
}
EXPORT_SYMBOL(bcm47xx_nvram_getenv);

int bcm47xx_nvram_gpio_pin(const char *name)
{
	int i, err;
	char nvram_var[] = "gpioXX";
	char buf[NVRAM_MAX_GPIO_VALUE_LEN];

	/* TODO: Optimize it to don't call getenv so many times */
	for (i = 0; i < NVRAM_MAX_GPIO_ENTRIES; i++) {
		err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
		if (err <= 0)
			continue;
		err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
		if (err <= 0)
			continue;
		if (!strcmp(name, buf))
			return i;
	}
	return -ENOENT;
}
EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);

char *bcm47xx_nvram_get_contents(size_t *nvram_size)
{
	int err;
	char *nvram;
	struct nvram_header *header;

	if (!nvram_buf[0]) {
		err = nvram_init();
		if (err)
			return NULL;
	}

	header = (struct nvram_header *)nvram_buf;
	*nvram_size = header->len - sizeof(struct nvram_header);
	nvram = vmalloc(*nvram_size);
	if (!nvram)
		return NULL;
	memcpy(nvram, &nvram_buf[sizeof(struct nvram_header)], *nvram_size);

	return nvram;
}
EXPORT_SYMBOL(bcm47xx_nvram_get_contents);
Commit	Line	Data
121915c4 WB	1	/*
	2	* BCM947xx nvram variable access
	3	*
	4	* Copyright (C) 2005 Broadcom Corporation
	5	* Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
f36738dd	6	* Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
121915c4	7	*
70342287 RB	8	* This program is free software; you can redistribute it and/or modify it
70342287 RB	9	* under the terms of the GNU General Public License as published by the
121915c4 WB	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*/
	13
50c97910	14	#include <linux/io.h>
121915c4 WB	15	#include <linux/types.h>
121915c4 WB	16	#include <linux/module.h>
121915c4 WB	17	#include <linux/kernel.h>
121915c4 WB	18	#include <linux/string.h>
9d1d0864	19	#include <linux/mtd/mtd.h>
138173d4	20	#include <linux/bcm47xx_nvram.h>
121915c4	21
d548ca6b	22	#define NVRAM_MAGIC 0x48534C46 /* 'FLSH' */
6ab7c290	23	#define NVRAM_SPACE 0x10000
d548ca6b RM	24	#define NVRAM_MAX_GPIO_ENTRIES 32
d548ca6b RM	25	#define NVRAM_MAX_GPIO_VALUE_LEN 30
341097f1 RM	26
	27	#define FLASH_MIN 0x00020000 /* Minimum flash size */
	28
	29	struct nvram_header {
	30	u32 magic;
	31	u32 len;
	32	u32 crc_ver_init; /* 0:7 crc, 8:15 ver, 16:31 sdram_init */
	33	u32 config_refresh; /* 0:15 sdram_config, 16:31 sdram_refresh */
	34	u32 config_ncdl; /* ncdl values for memc */
	35	};
	36
121915c4	37	static char nvram_buf[NVRAM_SPACE];
f4c4d589	38	static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
121915c4	39
8d602dd0	40	static u32 find_nvram_size(void __iomem *end)
f36738dd	41	{
8d602dd0	42	struct nvram_header __iomem *header;
f36738dd HM	43	int i;
	44
	45	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
8d602dd0	46	header = (struct nvram_header *)(end - nvram_sizes[i]);
341097f1	47	if (header->magic == NVRAM_MAGIC)
f36738dd HM	48	return nvram_sizes[i];
	49	}
	50
	51	return 0;
	52	}
	53
121915c4	54	/* Probe for NVRAM header */
8d602dd0	55	static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
121915c4	56	{
8d602dd0	57	struct nvram_header __iomem *header;
121915c4	58	int i;
08ccf572	59	u32 off;
121915c4	60	u32 src, dst;
f36738dd	61	u32 size;
121915c4	62
8d602dd0 RM	63	if (nvram_buf[0]) {
	64	pr_warn("nvram already initialized\n");
	65	return -EEXIST;
	66	}
	67
c4485671	68	/* TODO: when nvram is on nand flash check for bad blocks first. */
121915c4 WB	69	off = FLASH_MIN;
	70	while (off <= lim) {
	71	/* Windowed flash access */
8d602dd0	72	size = find_nvram_size(iobase + off);
f36738dd	73	if (size) {
8d602dd0	74	header = (struct nvram_header *)(iobase + off - size);
121915c4	75	goto found;
f36738dd	76	}
121915c4 WB	77	off <<= 1;
	78	}
	79
	80	/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
8d602dd0	81	header = (struct nvram_header *)(iobase + 4096);
341097f1	82	if (header->magic == NVRAM_MAGIC) {
f36738dd	83	size = NVRAM_SPACE;
121915c4	84	goto found;
f36738dd	85	}
121915c4	86
8d602dd0	87	header = (struct nvram_header *)(iobase + 1024);
341097f1	88	if (header->magic == NVRAM_MAGIC) {
f36738dd	89	size = NVRAM_SPACE;
121915c4	90	goto found;
f36738dd	91	}
121915c4	92
f36738dd	93	pr_err("no nvram found\n");
cc4403e0	94	return -ENXIO;
121915c4 WB	95
121915c4 WB	96	found:
d548ca6b RM	97	src = (u32 *)header;
d548ca6b RM	98	dst = (u32 *)nvram_buf;
121915c4	99	for (i = 0; i < sizeof(struct nvram_header); i += 4)
23d2bc42	100	*dst++ = __raw_readl(src++);
55cab93b HM	101	header = (struct nvram_header *)nvram_buf;
	102	if (header->len > size) {
	103	pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
	104	header->len = size;
	105	}
	106	if (header->len >= NVRAM_SPACE) {
	107	pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
	108	header->len, NVRAM_SPACE - 1);
	109	header->len = NVRAM_SPACE - 1;
	110	}
	111	/* proceed reading data after header */
	112	for (; i < header->len; i += 4)
23d2bc42	113	*dst++ = readl(src++);
d28c9a55	114	nvram_buf[NVRAM_SPACE - 1] = '\0';
cc4403e0 HM	115
cc4403e0 HM	116	return 0;
121915c4 WB	117	}
121915c4 WB	118
21400f25 RM	119	/*
	120	* On bcm47xx we need access to the NVRAM very early, so we can't use mtd
	121	* subsystem to access flash. We can't even use platform device / driver to
	122	* store memory offset.
	123	* To handle this we provide following symbol. It's supposed to be called as
	124	* soon as we get info about flash device, before any NVRAM entry is needed.
	125	*/
	126	int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)
8d602dd0 RM	127	{
	128	void __iomem *iobase;
	129	int err;
	130
	131	iobase = ioremap_nocache(base, lim);
	132	if (!iobase)
	133	return -ENOMEM;
	134
	135	err = nvram_find_and_copy(iobase, lim);
	136
	137	iounmap(iobase);
	138
	139	return err;
	140	}
	141
e58da16f	142	static int nvram_init(void)
bb765632	143	{
9d1d0864 RM	144	#ifdef CONFIG_MTD
	145	struct mtd_info *mtd;
	146	struct nvram_header header;
55cab93b	147	struct nvram_header *pheader;
9d1d0864	148	size_t bytes_read;
40d12172	149	int err;
9d1d0864 RM	150
	151	mtd = get_mtd_device_nm("nvram");
	152	if (IS_ERR(mtd))
	153	return -ENODEV;
	154
40d12172	155	err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header);
55cab93b HM	156	if (!err && header.magic == NVRAM_MAGIC &&
	157	header.len > sizeof(header)) {
	158	if (header.len >= NVRAM_SPACE) {
40d12172	159	pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
55cab93b HM	160	header.len, NVRAM_SPACE);
55cab93b HM	161	header.len = NVRAM_SPACE - 1;
40d12172	162	}
9d1d0864	163
55cab93b HM	164	err = mtd_read(mtd, 0, header.len, &bytes_read,
55cab93b HM	165	(u8 *)nvram_buf);
40d12172 RM	166	if (err)
40d12172 RM	167	return err;
9d1d0864	168
55cab93b HM	169	pheader = (struct nvram_header *)nvram_buf;
55cab93b HM	170	pheader->len = header.len;
40d12172	171	return 0;
9d1d0864 RM	172	}
9d1d0864 RM	173	#endif
7177efc5	174
cc4403e0	175	return -ENXIO;
bb765632 RM	176	}
bb765632 RM	177
341097f1	178	int bcm47xx_nvram_getenv(const char name, char val, size_t val_len)
121915c4 WB	179	{
121915c4 WB	180	char var, value, end, eq;
5bfad4ee	181	int err;
121915c4 WB	182
121915c4 WB	183	if (!name)
ee7e2f3c	184	return -EINVAL;
121915c4	185
cc4403e0	186	if (!nvram_buf[0]) {
e58da16f	187	err = nvram_init();
cc4403e0 HM	188	if (err)
	189	return err;
	190	}
121915c4 WB	191
	192	/* Look for name=value and return value */
	193	var = &nvram_buf[sizeof(struct nvram_header)];
5bfad4ee RM	194	end = nvram_buf + sizeof(nvram_buf);
	195	while (var < end && *var) {
	196	eq = strchr(var, '=');
121915c4 WB	197	if (!eq)
	198	break;
	199	value = eq + 1;
d548ca6b RM	200	if (eq - var == strlen(name) &&
d548ca6b RM	201	strncmp(var, name, eq - var) == 0)
44d4b2ae	202	return snprintf(val, val_len, "%s", value);
5bfad4ee	203	var = value + strlen(value) + 1;
50c97910	204	}
ee7e2f3c	205	return -ENOENT;
121915c4	206	}
111bd981	207	EXPORT_SYMBOL(bcm47xx_nvram_getenv);
62cf3bc0 HM	208
	209	int bcm47xx_nvram_gpio_pin(const char *name)
	210	{
	211	int i, err;
d548ca6b RM	212	char nvram_var[] = "gpioXX";
d548ca6b RM	213	char buf[NVRAM_MAX_GPIO_VALUE_LEN];
62cf3bc0	214
d548ca6b RM	215	/* TODO: Optimize it to don't call getenv so many times */
d548ca6b RM	216	for (i = 0; i < NVRAM_MAX_GPIO_ENTRIES; i++) {
62cf3bc0 HM	217	err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
	218	if (err <= 0)
	219	continue;
	220	err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
	221	if (err <= 0)
	222	continue;
	223	if (!strcmp(name, buf))
	224	return i;
	225	}
	226	return -ENOENT;
	227	}
	228	EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);
55cab93b HM	229
	230	char bcm47xx_nvram_get_contents(size_t nvram_size)
	231	{
	232	int err;
	233	char *nvram;
	234	struct nvram_header *header;
	235
	236	if (!nvram_buf[0]) {
	237	err = nvram_init();
	238	if (err)
	239	return NULL;
	240	}
	241
	242	header = (struct nvram_header *)nvram_buf;
	243	*nvram_size = header->len - sizeof(struct nvram_header);
	244	nvram = vmalloc(*nvram_size);
	245	if (!nvram)
	246	return NULL;
	247	memcpy(nvram, &nvram_buf[sizeof(struct nvram_header)], *nvram_size);
	248
	249	return nvram;
	250	}
	251	EXPORT_SYMBOL(bcm47xx_nvram_get_contents);