[linux-block.git] / include / linux / nvmem-provider.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * nvmem framework provider.
 *
 * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
 * Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
 */

#ifndef _LINUX_NVMEM_PROVIDER_H
#define _LINUX_NVMEM_PROVIDER_H

#include <linux/device/driver.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>

struct nvmem_device;
typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
				void *val, size_t bytes);
typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
				 void *val, size_t bytes);
/* used for vendor specific post processing of cell data */
typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id, int index,
					 unsigned int offset, void *buf,
					 size_t bytes);

enum nvmem_type {
	NVMEM_TYPE_UNKNOWN = 0,
	NVMEM_TYPE_EEPROM,
	NVMEM_TYPE_OTP,
	NVMEM_TYPE_BATTERY_BACKED,
	NVMEM_TYPE_FRAM,
};

#define NVMEM_DEVID_NONE	(-1)
#define NVMEM_DEVID_AUTO	(-2)

/**
 * struct nvmem_keepout - NVMEM register keepout range.
 *
 * @start:	The first byte offset to avoid.
 * @end:	One beyond the last byte offset to avoid.
 * @value:	The byte to fill reads with for this region.
 */
struct nvmem_keepout {
	unsigned int start;
	unsigned int end;
	unsigned char value;
};

/**
 * struct nvmem_cell_info - NVMEM cell description
 * @name:	Name.
 * @offset:	Offset within the NVMEM device.
 * @raw_len:	Length of raw data (without post processing).
 * @bytes:	Length of the cell.
 * @bit_offset:	Bit offset if cell is smaller than a byte.
 * @nbits:	Number of bits.
 * @np:		Optional device_node pointer.
 * @read_post_process:	Callback for optional post processing of cell data
 *			on reads.
 * @priv:	Opaque data passed to the read_post_process hook.
 */
struct nvmem_cell_info {
	const char		*name;
	unsigned int		offset;
	size_t			raw_len;
	unsigned int		bytes;
	unsigned int		bit_offset;
	unsigned int		nbits;
	struct device_node	*np;
	nvmem_cell_post_process_t read_post_process;
	void			*priv;
};

/**
 * struct nvmem_config - NVMEM device configuration
 *
 * @dev:	Parent device.
 * @name:	Optional name.
 * @id:		Optional device ID used in full name. Ignored if name is NULL.
 * @owner:	Pointer to exporter module. Used for refcounting.
 * @cells:	Optional array of pre-defined NVMEM cells.
 * @ncells:	Number of elements in cells.
 * @keepout:	Optional array of keepout ranges (sorted ascending by start).
 * @nkeepout:	Number of elements in the keepout array.
 * @type:	Type of the nvmem storage
 * @read_only:	Device is read-only.
 * @root_only:	Device is accessibly to root only.
 * @of_node:	If given, this will be used instead of the parent's of_node.
 * @no_of_node:	Device should not use the parent's of_node even if it's !NULL.
 * @reg_read:	Callback to read data.
 * @reg_write:	Callback to write data.
 * @size:	Device size.
 * @word_size:	Minimum read/write access granularity.
 * @stride:	Minimum read/write access stride.
 * @priv:	User context passed to read/write callbacks.
 * @ignore_wp:  Write Protect pin is managed by the provider.
 * @layout:	Fixed layout associated with this nvmem device.
 *
 * Note: A default "nvmem<id>" name will be assigned to the device if
 * no name is specified in its configuration. In such case "<id>" is
 * generated with ida_simple_get() and provided id field is ignored.
 *
 * Note: Specifying name and setting id to -1 implies a unique device
 * whose name is provided as-is (kept unaltered).
 */
struct nvmem_config {
	struct device		*dev;
	const char		*name;
	int			id;
	struct module		*owner;
	const struct nvmem_cell_info	*cells;
	int			ncells;
	const struct nvmem_keepout *keepout;
	unsigned int		nkeepout;
	enum nvmem_type		type;
	bool			read_only;
	bool			root_only;
	bool			ignore_wp;
	struct nvmem_layout	*layout;
	struct device_node	*of_node;
	bool			no_of_node;
	nvmem_reg_read_t	reg_read;
	nvmem_reg_write_t	reg_write;
	int	size;
	int	word_size;
	int	stride;
	void	*priv;
	/* To be only used by old driver/misc/eeprom drivers */
	bool			compat;
	struct device		*base_dev;
};

/**
 * struct nvmem_cell_table - NVMEM cell definitions for given provider
 *
 * @nvmem_name:		Provider name.
 * @cells:		Array of cell definitions.
 * @ncells:		Number of cell definitions in the array.
 * @node:		List node.
 *
 * This structure together with related helper functions is provided for users
 * that don't can't access the nvmem provided structure but wish to register
 * cell definitions for it e.g. board files registering an EEPROM device.
 */
struct nvmem_cell_table {
	const char		*nvmem_name;
	const struct nvmem_cell_info	*cells;
	size_t			ncells;
	struct list_head	node;
};

/**
 * struct nvmem_layout - NVMEM layout definitions
 *
 * @name:		Layout name.
 * @of_match_table:	Open firmware match table.
 * @add_cells:		Will be called if a nvmem device is found which
 *			has this layout. The function will add layout
 *			specific cells with nvmem_add_one_cell().
 * @fixup_cell_info:	Will be called before a cell is added. Can be
 *			used to modify the nvmem_cell_info.
 * @owner:		Pointer to struct module.
 * @node:		List node.
 *
 * A nvmem device can hold a well defined structure which can just be
 * evaluated during runtime. For example a TLV list, or a list of "name=val"
 * pairs. A nvmem layout can parse the nvmem device and add appropriate
 * cells.
 */
struct nvmem_layout {
	const char *name;
	const struct of_device_id *of_match_table;
	int (*add_cells)(struct device *dev, struct nvmem_device *nvmem,
			 struct nvmem_layout *layout);
	void (*fixup_cell_info)(struct nvmem_device *nvmem,
				struct nvmem_layout *layout,
				struct nvmem_cell_info *cell);

	/* private */
	struct module *owner;
	struct list_head node;
};

#if IS_ENABLED(CONFIG_NVMEM)

struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
void nvmem_unregister(struct nvmem_device *nvmem);

struct nvmem_device *devm_nvmem_register(struct device *dev,
					 const struct nvmem_config *cfg);

void nvmem_add_cell_table(struct nvmem_cell_table *table);
void nvmem_del_cell_table(struct nvmem_cell_table *table);

int nvmem_add_one_cell(struct nvmem_device *nvmem,
		       const struct nvmem_cell_info *info);

int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner);
#define nvmem_layout_register(layout) \
	__nvmem_layout_register(layout, THIS_MODULE)
void nvmem_layout_unregister(struct nvmem_layout *layout);

const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
					struct nvmem_layout *layout);

#else

static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
{
	return ERR_PTR(-EOPNOTSUPP);
}

static inline void nvmem_unregister(struct nvmem_device *nvmem) {}

static inline struct nvmem_device *
devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
{
	return nvmem_register(c);
}

static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
static inline int nvmem_add_one_cell(struct nvmem_device *nvmem,
				     const struct nvmem_cell_info *info)
{
	return -EOPNOTSUPP;
}

static inline int nvmem_layout_register(struct nvmem_layout *layout)
{
	return -EOPNOTSUPP;
}

static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {}

static inline const void *
nvmem_layout_get_match_data(struct nvmem_device *nvmem,
			    struct nvmem_layout *layout)
{
	return NULL;
}

#endif /* CONFIG_NVMEM */

#define module_nvmem_layout_driver(__layout_driver)		\
	module_driver(__layout_driver, nvmem_layout_register,	\
		      nvmem_layout_unregister)

#endif  /* ifndef _LINUX_NVMEM_PROVIDER_H */
Commit	Line	Data
b1c1db98	1	/* SPDX-License-Identifier: GPL-2.0 */
eace75cf SK	2	/*
	3	* nvmem framework provider.
	4	*
	5	* Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
	6	* Copyright (C) 2013 Maxime Ripard <maxime.ripard@free-electrons.com>
eace75cf SK	7	*/
	8
	9	#ifndef _LINUX_NVMEM_PROVIDER_H
	10	#define _LINUX_NVMEM_PROVIDER_H
	11
814c978f	12	#include <linux/device/driver.h>
42a6e099 AB	13	#include <linux/err.h>
42a6e099 AB	14	#include <linux/errno.h>
2a127da4	15	#include <linux/gpio/consumer.h>
42a6e099	16
eace75cf	17	struct nvmem_device;
795ddd18 SK	18	typedef int (nvmem_reg_read_t)(void priv, unsigned int offset,
	19	void *val, size_t bytes);
	20	typedef int (nvmem_reg_write_t)(void priv, unsigned int offset,
	21	void *val, size_t bytes);
5008062f	22	/* used for vendor specific post processing of cell data */
5d8e6e6c	23	typedef int (nvmem_cell_post_process_t)(void priv, const char *id, int index,
8a134fd9 MW	24	unsigned int offset, void *buf,
8a134fd9 MW	25	size_t bytes);
eace75cf	26
16688453 AB	27	enum nvmem_type {
	28	NVMEM_TYPE_UNKNOWN = 0,
	29	NVMEM_TYPE_EEPROM,
	30	NVMEM_TYPE_OTP,
	31	NVMEM_TYPE_BATTERY_BACKED,
fd307a4a	32	NVMEM_TYPE_FRAM,
16688453 AB	33	};
16688453 AB	34
731aa3fa SK	35	#define NVMEM_DEVID_NONE (-1)
	36	#define NVMEM_DEVID_AUTO (-2)
	37
fd3bb8f5 EG	38	/**
	39	* struct nvmem_keepout - NVMEM register keepout range.
	40	*
	41	* @start: The first byte offset to avoid.
	42	* @end: One beyond the last byte offset to avoid.
	43	* @value: The byte to fill reads with for this region.
	44	*/
	45	struct nvmem_keepout {
	46	unsigned int start;
	47	unsigned int end;
	48	unsigned char value;
	49	};
	50
fbd03d27 MW	51	/**
	52	* struct nvmem_cell_info - NVMEM cell description
	53	* @name: Name.
	54	* @offset: Offset within the NVMEM device.
55d4980c	55	* @raw_len: Length of raw data (without post processing).
fbd03d27 MW	56	* @bytes: Length of the cell.
	57	* @bit_offset: Bit offset if cell is smaller than a byte.
	58	* @nbits: Number of bits.
	59	* @np: Optional device_node pointer.
345ec382 MW	60	* @read_post_process: Callback for optional post processing of cell data
345ec382 MW	61	* on reads.
8a134fd9	62	* @priv: Opaque data passed to the read_post_process hook.
fbd03d27 MW	63	*/
	64	struct nvmem_cell_info {
	65	const char *name;
	66	unsigned int offset;
55d4980c	67	size_t raw_len;
fbd03d27 MW	68	unsigned int bytes;
	69	unsigned int bit_offset;
	70	unsigned int nbits;
	71	struct device_node *np;
345ec382	72	nvmem_cell_post_process_t read_post_process;
8a134fd9	73	void *priv;
fbd03d27 MW	74	};
fbd03d27 MW	75
0b2ed745 AS	76	/**
	77	* struct nvmem_config - NVMEM device configuration
	78	*
	79	* @dev: Parent device.
	80	* @name: Optional name.
	81	* @id: Optional device ID used in full name. Ignored if name is NULL.
	82	* @owner: Pointer to exporter module. Used for refcounting.
	83	* @cells: Optional array of pre-defined NVMEM cells.
	84	* @ncells: Number of elements in cells.
fd3bb8f5 EG	85	* @keepout: Optional array of keepout ranges (sorted ascending by start).
fd3bb8f5 EG	86	* @nkeepout: Number of elements in the keepout array.
16688453	87	* @type: Type of the nvmem storage
0b2ed745 AS	88	* @read_only: Device is read-only.
0b2ed745 AS	89	* @root_only: Device is accessibly to root only.
1333a677	90	* @of_node: If given, this will be used instead of the parent's of_node.
517f14d9	91	* @no_of_node: Device should not use the parent's of_node even if it's !NULL.
0b2ed745 AS	92	* @reg_read: Callback to read data.
	93	* @reg_write: Callback to write data.
	94	* @size: Device size.
	95	* @word_size: Minimum read/write access granularity.
	96	* @stride: Minimum read/write access stride.
	97	* @priv: User context passed to read/write callbacks.
f6c052af	98	* @ignore_wp: Write Protect pin is managed by the provider.
266570f4	99	* @layout: Fixed layout associated with this nvmem device.
0b2ed745 AS	100	*
	101	* Note: A default "nvmem<id>" name will be assigned to the device if
	102	* no name is specified in its configuration. In such case "<id>" is
	103	* generated with ida_simple_get() and provided id field is ignored.
fd0f4906 AS	104	*
	105	* Note: Specifying name and setting id to -1 implies a unique device
	106	* whose name is provided as-is (kept unaltered).
0b2ed745	107	*/
eace75cf SK	108	struct nvmem_config {
	109	struct device *dev;
	110	const char *name;
	111	int id;
	112	struct module *owner;
	113	const struct nvmem_cell_info *cells;
	114	int ncells;
fd3bb8f5 EG	115	const struct nvmem_keepout *keepout;
fd3bb8f5 EG	116	unsigned int nkeepout;
16688453	117	enum nvmem_type type;
eace75cf	118	bool read_only;
811b0d65	119	bool root_only;
f6c052af	120	bool ignore_wp;
266570f4	121	struct nvmem_layout *layout;
1333a677	122	struct device_node *of_node;
517f14d9	123	bool no_of_node;
795ddd18 SK	124	nvmem_reg_read_t reg_read;
	125	nvmem_reg_write_t reg_write;
	126	int size;
	127	int word_size;
	128	int stride;
	129	void *priv;
b6c217ab AL	130	/* To be only used by old driver/misc/eeprom drivers */
	131	bool compat;
	132	struct device *base_dev;
eace75cf SK	133	};
eace75cf SK	134
b985f4cb BG	135	/**
	136	* struct nvmem_cell_table - NVMEM cell definitions for given provider
	137	*
	138	* @nvmem_name: Provider name.
	139	* @cells: Array of cell definitions.
	140	* @ncells: Number of cell definitions in the array.
	141	* @node: List node.
	142	*
	143	* This structure together with related helper functions is provided for users
	144	* that don't can't access the nvmem provided structure but wish to register
	145	* cell definitions for it e.g. board files registering an EEPROM device.
	146	*/
	147	struct nvmem_cell_table {
	148	const char *nvmem_name;
	149	const struct nvmem_cell_info *cells;
	150	size_t ncells;
	151	struct list_head node;
	152	};
	153
266570f4 MW	154	/**
	155	* struct nvmem_layout - NVMEM layout definitions
	156	*
	157	* @name: Layout name.
	158	* @of_match_table: Open firmware match table.
	159	* @add_cells: Will be called if a nvmem device is found which
	160	* has this layout. The function will add layout
	161	* specific cells with nvmem_add_one_cell().
de12c969 MW	162	* @fixup_cell_info: Will be called before a cell is added. Can be
de12c969 MW	163	* used to modify the nvmem_cell_info.
266570f4 MW	164	* @owner: Pointer to struct module.
	165	* @node: List node.
	166	*
	167	* A nvmem device can hold a well defined structure which can just be
	168	* evaluated during runtime. For example a TLV list, or a list of "name=val"
	169	* pairs. A nvmem layout can parse the nvmem device and add appropriate
	170	* cells.
	171	*/
	172	struct nvmem_layout {
	173	const char *name;
	174	const struct of_device_id *of_match_table;
	175	int (add_cells)(struct device dev, struct nvmem_device *nvmem,
	176	struct nvmem_layout *layout);
de12c969 MW	177	void (fixup_cell_info)(struct nvmem_device nvmem,
	178	struct nvmem_layout *layout,
	179	struct nvmem_cell_info *cell);
266570f4 MW	180
	181	/* private */
	182	struct module *owner;
	183	struct list_head node;
	184	};
	185
eace75cf SK	186	#if IS_ENABLED(CONFIG_NVMEM)
	187
	188	struct nvmem_device nvmem_register(const struct nvmem_config cfg);
bf58e882	189	void nvmem_unregister(struct nvmem_device *nvmem);
eace75cf	190
f1f50eca AS	191	struct nvmem_device devm_nvmem_register(struct device dev,
	192	const struct nvmem_config *cfg);
	193
b985f4cb BG	194	void nvmem_add_cell_table(struct nvmem_cell_table *table);
	195	void nvmem_del_cell_table(struct nvmem_cell_table *table);
	196
2ded6830 MW	197	int nvmem_add_one_cell(struct nvmem_device *nvmem,
	198	const struct nvmem_cell_info *info);
	199
266570f4 MW	200	int __nvmem_layout_register(struct nvmem_layout layout, struct module owner);
	201	#define nvmem_layout_register(layout) \
	202	__nvmem_layout_register(layout, THIS_MODULE)
	203	void nvmem_layout_unregister(struct nvmem_layout *layout);
	204
	205	const void nvmem_layout_get_match_data(struct nvmem_device nvmem,
	206	struct nvmem_layout *layout);
	207
eace75cf SK	208	#else
	209
	210	static inline struct nvmem_device nvmem_register(const struct nvmem_config c)
	211	{
20167b70	212	return ERR_PTR(-EOPNOTSUPP);
eace75cf SK	213	}
eace75cf SK	214
bf58e882	215	static inline void nvmem_unregister(struct nvmem_device *nvmem) {}
eace75cf	216
f1f50eca AS	217	static inline struct nvmem_device *
	218	devm_nvmem_register(struct device dev, const struct nvmem_config c)
	219	{
	220	return nvmem_register(c);
	221	}
	222
b985f4cb BG	223	static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
b985f4cb BG	224	static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
2ded6830 MW	225	static inline int nvmem_add_one_cell(struct nvmem_device *nvmem,
	226	const struct nvmem_cell_info *info)
	227	{
	228	return -EOPNOTSUPP;
	229	}
f1f50eca	230
266570f4 MW	231	static inline int nvmem_layout_register(struct nvmem_layout *layout)
	232	{
	233	return -EOPNOTSUPP;
	234	}
	235
	236	static inline void nvmem_layout_unregister(struct nvmem_layout *layout) {}
	237
	238	static inline const void *
	239	nvmem_layout_get_match_data(struct nvmem_device *nvmem,
	240	struct nvmem_layout *layout)
	241	{
	242	return NULL;
	243	}
	244
eace75cf	245	#endif /* CONFIG_NVMEM */
814c978f MR	246
	247	#define module_nvmem_layout_driver(__layout_driver) \
	248	module_driver(__layout_driver, nvmem_layout_register, \
	249	nvmem_layout_unregister)
	250
eace75cf	251	#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */