[mirror_ubuntu-zesty-kernel.git] / drivers / firmware / broadcom / 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 size_t nvram_len;
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;
	u32 off;
	u32 size;

	if (nvram_len) {
		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:
	__ioread32_copy(nvram_buf, header, sizeof(*header) / 4);
	nvram_len = ((struct nvram_header *)(nvram_buf))->len;
	if (nvram_len > size) {
		pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
		nvram_len = size;
	}
	if (nvram_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",
		       nvram_len, NVRAM_SPACE - 1);
		nvram_len = NVRAM_SPACE - 1;
	}
	/* proceed reading data after header */
	__ioread32_copy(nvram_buf + sizeof(*header), header + 1,
			DIV_ROUND_UP(nvram_len, 4));
	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;
	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)) {
		nvram_len = header.len;
		if (nvram_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);
			nvram_len = NVRAM_SPACE - 1;
		}

		err = mtd_read(mtd, 0, nvram_len, &nvram_len,
			       (u8 *)nvram_buf);
		return err;
	}
#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_len) {
		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;

	if (!nvram_len) {
		err = nvram_init();
		if (err)
			return NULL;
	}

	*nvram_size = nvram_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);

MODULE_LICENSE("GPL v2");
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];
94a0535b	38	static size_t nvram_len;
f4c4d589	39	static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
121915c4	40
8d602dd0	41	static u32 find_nvram_size(void __iomem *end)
f36738dd	42	{
8d602dd0	43	struct nvram_header __iomem *header;
f36738dd HM	44	int i;
	45
	46	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
8d602dd0	47	header = (struct nvram_header *)(end - nvram_sizes[i]);
341097f1	48	if (header->magic == NVRAM_MAGIC)
f36738dd HM	49	return nvram_sizes[i];
	50	}
	51
	52	return 0;
	53	}
	54
121915c4	55	/* Probe for NVRAM header */
8d602dd0	56	static int nvram_find_and_copy(void __iomem *iobase, u32 lim)
121915c4	57	{
8d602dd0	58	struct nvram_header __iomem *header;
08ccf572	59	u32 off;
f36738dd	60	u32 size;
121915c4	61
94a0535b	62	if (nvram_len) {
8d602dd0 RM	63	pr_warn("nvram already initialized\n");
	64	return -EEXIST;
	65	}
	66
c4485671	67	/* TODO: when nvram is on nand flash check for bad blocks first. */
121915c4 WB	68	off = FLASH_MIN;
	69	while (off <= lim) {
	70	/* Windowed flash access */
8d602dd0	71	size = find_nvram_size(iobase + off);
f36738dd	72	if (size) {
8d602dd0	73	header = (struct nvram_header *)(iobase + off - size);
121915c4	74	goto found;
f36738dd	75	}
121915c4 WB	76	off <<= 1;
	77	}
	78
	79	/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
8d602dd0	80	header = (struct nvram_header *)(iobase + 4096);
341097f1	81	if (header->magic == NVRAM_MAGIC) {
f36738dd	82	size = NVRAM_SPACE;
121915c4	83	goto found;
f36738dd	84	}
121915c4	85
8d602dd0	86	header = (struct nvram_header *)(iobase + 1024);
341097f1	87	if (header->magic == NVRAM_MAGIC) {
f36738dd	88	size = NVRAM_SPACE;
121915c4	89	goto found;
f36738dd	90	}
121915c4	91
f36738dd	92	pr_err("no nvram found\n");
cc4403e0	93	return -ENXIO;
121915c4 WB	94
121915c4 WB	95	found:
1f330c32	96	__ioread32_copy(nvram_buf, header, sizeof(*header) / 4);
4c11e554	97	nvram_len = ((struct nvram_header *)(nvram_buf))->len;
94a0535b	98	if (nvram_len > size) {
55cab93b	99	pr_err("The nvram size according to the header seems to be bigger than the partition on flash\n");
94a0535b	100	nvram_len = size;
55cab93b	101	}
94a0535b	102	if (nvram_len >= NVRAM_SPACE) {
55cab93b	103	pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
4c11e554	104	nvram_len, NVRAM_SPACE - 1);
94a0535b	105	nvram_len = NVRAM_SPACE - 1;
55cab93b HM	106	}
55cab93b HM	107	/* proceed reading data after header */
1f330c32 SB	108	__ioread32_copy(nvram_buf + sizeof(*header), header + 1,
1f330c32 SB	109	DIV_ROUND_UP(nvram_len, 4));
d28c9a55	110	nvram_buf[NVRAM_SPACE - 1] = '\0';
cc4403e0 HM	111
cc4403e0 HM	112	return 0;
121915c4 WB	113	}
121915c4 WB	114
21400f25 RM	115	/*
	116	* On bcm47xx we need access to the NVRAM very early, so we can't use mtd
	117	* subsystem to access flash. We can't even use platform device / driver to
	118	* store memory offset.
	119	* To handle this we provide following symbol. It's supposed to be called as
	120	* soon as we get info about flash device, before any NVRAM entry is needed.
	121	*/
	122	int bcm47xx_nvram_init_from_mem(u32 base, u32 lim)
8d602dd0 RM	123	{
	124	void __iomem *iobase;
	125	int err;
	126
	127	iobase = ioremap_nocache(base, lim);
	128	if (!iobase)
	129	return -ENOMEM;
	130
	131	err = nvram_find_and_copy(iobase, lim);
	132
	133	iounmap(iobase);
	134
	135	return err;
	136	}
	137
e58da16f	138	static int nvram_init(void)
bb765632	139	{
9d1d0864 RM	140	#ifdef CONFIG_MTD
	141	struct mtd_info *mtd;
	142	struct nvram_header header;
	143	size_t bytes_read;
40d12172	144	int err;
9d1d0864 RM	145
	146	mtd = get_mtd_device_nm("nvram");
	147	if (IS_ERR(mtd))
	148	return -ENODEV;
	149
40d12172	150	err = mtd_read(mtd, 0, sizeof(header), &bytes_read, (uint8_t *)&header);
55cab93b HM	151	if (!err && header.magic == NVRAM_MAGIC &&
55cab93b HM	152	header.len > sizeof(header)) {
94a0535b RM	153	nvram_len = header.len;
94a0535b RM	154	if (nvram_len >= NVRAM_SPACE) {
40d12172	155	pr_err("nvram on flash (%i bytes) is bigger than the reserved space in memory, will just copy the first %i bytes\n",
55cab93b	156	header.len, NVRAM_SPACE);
94a0535b	157	nvram_len = NVRAM_SPACE - 1;
40d12172	158	}
9d1d0864	159
94a0535b	160	err = mtd_read(mtd, 0, nvram_len, &nvram_len,
55cab93b	161	(u8 *)nvram_buf);
94a0535b	162	return err;
9d1d0864 RM	163	}
9d1d0864 RM	164	#endif
7177efc5	165
cc4403e0	166	return -ENXIO;
bb765632 RM	167	}
bb765632 RM	168
341097f1	169	int bcm47xx_nvram_getenv(const char name, char val, size_t val_len)
121915c4 WB	170	{
121915c4 WB	171	char var, value, end, eq;
5bfad4ee	172	int err;
121915c4 WB	173
121915c4 WB	174	if (!name)
ee7e2f3c	175	return -EINVAL;
121915c4	176
94a0535b	177	if (!nvram_len) {
e58da16f	178	err = nvram_init();
cc4403e0 HM	179	if (err)
	180	return err;
	181	}
121915c4 WB	182
	183	/* Look for name=value and return value */
	184	var = &nvram_buf[sizeof(struct nvram_header)];
5bfad4ee RM	185	end = nvram_buf + sizeof(nvram_buf);
	186	while (var < end && *var) {
	187	eq = strchr(var, '=');
121915c4 WB	188	if (!eq)
	189	break;
	190	value = eq + 1;
d548ca6b RM	191	if (eq - var == strlen(name) &&
d548ca6b RM	192	strncmp(var, name, eq - var) == 0)
44d4b2ae	193	return snprintf(val, val_len, "%s", value);
5bfad4ee	194	var = value + strlen(value) + 1;
50c97910	195	}
ee7e2f3c	196	return -ENOENT;
121915c4	197	}
111bd981	198	EXPORT_SYMBOL(bcm47xx_nvram_getenv);
62cf3bc0 HM	199
	200	int bcm47xx_nvram_gpio_pin(const char *name)
	201	{
	202	int i, err;
d548ca6b RM	203	char nvram_var[] = "gpioXX";
d548ca6b RM	204	char buf[NVRAM_MAX_GPIO_VALUE_LEN];
62cf3bc0	205
d548ca6b RM	206	/* TODO: Optimize it to don't call getenv so many times */
d548ca6b RM	207	for (i = 0; i < NVRAM_MAX_GPIO_ENTRIES; i++) {
62cf3bc0 HM	208	err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
	209	if (err <= 0)
	210	continue;
	211	err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
	212	if (err <= 0)
	213	continue;
	214	if (!strcmp(name, buf))
	215	return i;
	216	}
	217	return -ENOENT;
	218	}
	219	EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);
55cab93b HM	220
	221	char bcm47xx_nvram_get_contents(size_t nvram_size)
	222	{
	223	int err;
	224	char *nvram;
55cab93b	225
94a0535b	226	if (!nvram_len) {
55cab93b HM	227	err = nvram_init();
	228	if (err)
	229	return NULL;
	230	}
	231
94a0535b	232	*nvram_size = nvram_len - sizeof(struct nvram_header);
55cab93b HM	233	nvram = vmalloc(*nvram_size);
	234	if (!nvram)
	235	return NULL;
	236	memcpy(nvram, &nvram_buf[sizeof(struct nvram_header)], *nvram_size);
	237
	238	return nvram;
	239	}
	240	EXPORT_SYMBOL(bcm47xx_nvram_get_contents);
f6e734a8	241
72ccc89e	242	MODULE_LICENSE("GPL v2");