/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Counter interface
 * Copyright (C) 2018 William Breathitt Gray
 */
#ifndef _COUNTER_H_
#define _COUNTER_H_

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/types.h>

struct counter_device;
struct counter_count;
struct counter_synapse;
struct counter_signal;

enum counter_comp_type {
	COUNTER_COMP_U8,
	COUNTER_COMP_U64,
	COUNTER_COMP_BOOL,
	COUNTER_COMP_SIGNAL_LEVEL,
	COUNTER_COMP_FUNCTION,
	COUNTER_COMP_SYNAPSE_ACTION,
	COUNTER_COMP_ENUM,
	COUNTER_COMP_COUNT_DIRECTION,
	COUNTER_COMP_COUNT_MODE,
};

enum counter_scope {
	COUNTER_SCOPE_DEVICE,
	COUNTER_SCOPE_SIGNAL,
	COUNTER_SCOPE_COUNT,
};

enum counter_count_direction {
	COUNTER_COUNT_DIRECTION_FORWARD,
	COUNTER_COUNT_DIRECTION_BACKWARD,
};

enum counter_count_mode {
	COUNTER_COUNT_MODE_NORMAL,
	COUNTER_COUNT_MODE_RANGE_LIMIT,
	COUNTER_COUNT_MODE_NON_RECYCLE,
	COUNTER_COUNT_MODE_MODULO_N,
};

enum counter_function {
	COUNTER_FUNCTION_INCREASE,
	COUNTER_FUNCTION_DECREASE,
	COUNTER_FUNCTION_PULSE_DIRECTION,
	COUNTER_FUNCTION_QUADRATURE_X1_A,
	COUNTER_FUNCTION_QUADRATURE_X1_B,
	COUNTER_FUNCTION_QUADRATURE_X2_A,
	COUNTER_FUNCTION_QUADRATURE_X2_B,
	COUNTER_FUNCTION_QUADRATURE_X4,
};

enum counter_signal_level {
	COUNTER_SIGNAL_LEVEL_LOW,
	COUNTER_SIGNAL_LEVEL_HIGH,
};

enum counter_synapse_action {
	COUNTER_SYNAPSE_ACTION_NONE,
	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
	COUNTER_SYNAPSE_ACTION_FALLING_EDGE,
	COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
};

/**
 * struct counter_comp - Counter component node
 * @type:		Counter component data type
 * @name:		device-specific component name
 * @priv:		component-relevant data
 * @action_read:		Synapse action mode read callback. The read value of the
 *			respective Synapse action mode should be passed back via
 *			the action parameter.
 * @device_u8_read:		Device u8 component read callback. The read value of the
 *			respective Device u8 component should be passed back via
 *			the val parameter.
 * @count_u8_read:		Count u8 component read callback. The read value of the
 *			respective Count u8 component should be passed back via
 *			the val parameter.
 * @signal_u8_read:		Signal u8 component read callback. The read value of the
 *			respective Signal u8 component should be passed back via
 *			the val parameter.
 * @device_u32_read:		Device u32 component read callback. The read value of
 *			the respective Device u32 component should be passed
 *			back via the val parameter.
 * @count_u32_read:		Count u32 component read callback. The read value of the
 *			respective Count u32 component should be passed back via
 *			the val parameter.
 * @signal_u32_read:		Signal u32 component read callback. The read value of
 *			the respective Signal u32 component should be passed
 *			back via the val parameter.
 * @device_u64_read:		Device u64 component read callback. The read value of
 *			the respective Device u64 component should be passed
 *			back via the val parameter.
 * @count_u64_read:		Count u64 component read callback. The read value of the
 *			respective Count u64 component should be passed back via
 *			the val parameter.
 * @signal_u64_read:		Signal u64 component read callback. The read value of
 *			the respective Signal u64 component should be passed
 *			back via the val parameter.
 * @action_write:		Synapse action mode write callback. The write value of
 *			the respective Synapse action mode is passed via the
 *			action parameter.
 * @device_u8_write:		Device u8 component write callback. The write value of
 *			the respective Device u8 component is passed via the val
 *			parameter.
 * @count_u8_write:		Count u8 component write callback. The write value of
 *			the respective Count u8 component is passed via the val
 *			parameter.
 * @signal_u8_write:		Signal u8 component write callback. The write value of
 *			the respective Signal u8 component is passed via the val
 *			parameter.
 * @device_u32_write:		Device u32 component write callback. The write value of
 *			the respective Device u32 component is passed via the
 *			val parameter.
 * @count_u32_write:		Count u32 component write callback. The write value of
 *			the respective Count u32 component is passed via the val
 *			parameter.
 * @signal_u32_write:		Signal u32 component write callback. The write value of
 *			the respective Signal u32 component is passed via the
 *			val parameter.
 * @device_u64_write:		Device u64 component write callback. The write value of
 *			the respective Device u64 component is passed via the
 *			val parameter.
 * @count_u64_write:		Count u64 component write callback. The write value of
 *			the respective Count u64 component is passed via the val
 *			parameter.
 * @signal_u64_write:		Signal u64 component write callback. The write value of
 *			the respective Signal u64 component is passed via the
 *			val parameter.
 */
struct counter_comp {
	enum counter_comp_type type;
	const char *name;
	void *priv;
	union {
		int (*action_read)(struct counter_device *counter,
				   struct counter_count *count,
				   struct counter_synapse *synapse,
				   enum counter_synapse_action *action);
		int (*device_u8_read)(struct counter_device *counter, u8 *val);
		int (*count_u8_read)(struct counter_device *counter,
				     struct counter_count *count, u8 *val);
		int (*signal_u8_read)(struct counter_device *counter,
				      struct counter_signal *signal, u8 *val);
		int (*device_u32_read)(struct counter_device *counter,
				       u32 *val);
		int (*count_u32_read)(struct counter_device *counter,
				      struct counter_count *count, u32 *val);
		int (*signal_u32_read)(struct counter_device *counter,
				       struct counter_signal *signal, u32 *val);
		int (*device_u64_read)(struct counter_device *counter,
				       u64 *val);
		int (*count_u64_read)(struct counter_device *counter,
				      struct counter_count *count, u64 *val);
		int (*signal_u64_read)(struct counter_device *counter,
				       struct counter_signal *signal, u64 *val);
	};
	union {
		int (*action_write)(struct counter_device *counter,
				    struct counter_count *count,
				    struct counter_synapse *synapse,
				    enum counter_synapse_action action);
		int (*device_u8_write)(struct counter_device *counter, u8 val);
		int (*count_u8_write)(struct counter_device *counter,
				      struct counter_count *count, u8 val);
		int (*signal_u8_write)(struct counter_device *counter,
				       struct counter_signal *signal, u8 val);
		int (*device_u32_write)(struct counter_device *counter,
					u32 val);
		int (*count_u32_write)(struct counter_device *counter,
				       struct counter_count *count, u32 val);
		int (*signal_u32_write)(struct counter_device *counter,
					struct counter_signal *signal, u32 val);
		int (*device_u64_write)(struct counter_device *counter,
					u64 val);
		int (*count_u64_write)(struct counter_device *counter,
				       struct counter_count *count, u64 val);
		int (*signal_u64_write)(struct counter_device *counter,
					struct counter_signal *signal, u64 val);
	};
};

/**
 * struct counter_signal - Counter Signal node
 * @id:		unique ID used to identify signal
 * @name:	device-specific Signal name; ideally, this should match the name
 *		as it appears in the datasheet documentation
 * @ext:	optional array of Counter Signal extensions
 * @num_ext:	number of Counter Signal extensions specified in @ext
 */
struct counter_signal {
	int id;
	const char *name;

	struct counter_comp *ext;
	size_t num_ext;
};

/**
 * struct counter_synapse - Counter Synapse node
 * @actions_list:	array of available action modes
 * @num_actions:	number of action modes specified in @actions_list
 * @signal:		pointer to associated signal
 */
struct counter_synapse {
	const enum counter_synapse_action *actions_list;
	size_t num_actions;

	struct counter_signal *signal;
};

/**
 * struct counter_count - Counter Count node
 * @id:			unique ID used to identify Count
 * @name:		device-specific Count name; ideally, this should match
 *			the name as it appears in the datasheet documentation
 * @functions_list:	array available function modes
 * @num_functions:	number of function modes specified in @functions_list
 * @synapses:		array of synapses for initialization
 * @num_synapses:	number of synapses specified in @synapses
 * @ext:		optional array of Counter Count extensions
 * @num_ext:		number of Counter Count extensions specified in @ext
 */
struct counter_count {
	int id;
	const char *name;

	const enum counter_function *functions_list;
	size_t num_functions;

	struct counter_synapse *synapses;
	size_t num_synapses;

	struct counter_comp *ext;
	size_t num_ext;
};

/**
 * struct counter_ops - Callbacks from driver
 * @signal_read:	optional read callback for Signal attribute. The read
 *			level of the respective Signal should be passed back via
 *			the level parameter.
 * @count_read:		optional read callback for Count attribute. The read
 *			value of the respective Count should be passed back via
 *			the val parameter.
 * @count_write:	optional write callback for Count attribute. The write
 *			value for the respective Count is passed in via the val
 *			parameter.
 * @function_read:	read callback the Count function modes. The read
 *			function mode of the respective Count should be passed
 *			back via the function parameter.
 * @function_write:	write callback for Count function modes. The function
 *			mode to write for the respective Count is passed in via
 *			the function parameter.
 * @action_read:	read callback the Synapse action modes. The read action
 *			mode of the respective Synapse should be passed back via
 *			the action parameter.
 * @action_write:	write callback for Synapse action modes. The action mode
 *			to write for the respective Synapse is passed in via the
 *			action parameter.
 */
struct counter_ops {
	int (*signal_read)(struct counter_device *counter,
			   struct counter_signal *signal,
			   enum counter_signal_level *level);
	int (*count_read)(struct counter_device *counter,
			  struct counter_count *count, u64 *value);
	int (*count_write)(struct counter_device *counter,
			   struct counter_count *count, u64 value);
	int (*function_read)(struct counter_device *counter,
			     struct counter_count *count,
			     enum counter_function *function);
	int (*function_write)(struct counter_device *counter,
			      struct counter_count *count,
			      enum counter_function function);
	int (*action_read)(struct counter_device *counter,
			   struct counter_count *count,
			   struct counter_synapse *synapse,
			   enum counter_synapse_action *action);
	int (*action_write)(struct counter_device *counter,
			    struct counter_count *count,
			    struct counter_synapse *synapse,
			    enum counter_synapse_action action);
};

/**
 * struct counter_device - Counter data structure
 * @name:		name of the device as it appears in the datasheet
 * @parent:		optional parent device providing the counters
 * @ops:		callbacks from driver
 * @signals:		array of Signals
 * @num_signals:	number of Signals specified in @signals
 * @counts:		array of Counts
 * @num_counts:		number of Counts specified in @counts
 * @ext:		optional array of Counter device extensions
 * @num_ext:		number of Counter device extensions specified in @ext
 * @priv:		optional private data supplied by driver
 * @dev:		internal device structure
 */
struct counter_device {
	const char *name;
	struct device *parent;

	const struct counter_ops *ops;

	struct counter_signal *signals;
	size_t num_signals;
	struct counter_count *counts;
	size_t num_counts;

	struct counter_comp *ext;
	size_t num_ext;

	void *priv;

	struct device dev;
};

int counter_register(struct counter_device *const counter);
void counter_unregister(struct counter_device *const counter);
int devm_counter_register(struct device *dev,
			  struct counter_device *const counter);

#define COUNTER_COMP_DEVICE_U8(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U8, \
	.name = (_name), \
	.device_u8_read = (_read), \
	.device_u8_write = (_write), \
}
#define COUNTER_COMP_COUNT_U8(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U8, \
	.name = (_name), \
	.count_u8_read = (_read), \
	.count_u8_write = (_write), \
}
#define COUNTER_COMP_SIGNAL_U8(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U8, \
	.name = (_name), \
	.signal_u8_read = (_read), \
	.signal_u8_write = (_write), \
}

#define COUNTER_COMP_DEVICE_U64(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U64, \
	.name = (_name), \
	.device_u64_read = (_read), \
	.device_u64_write = (_write), \
}
#define COUNTER_COMP_COUNT_U64(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U64, \
	.name = (_name), \
	.count_u64_read = (_read), \
	.count_u64_write = (_write), \
}
#define COUNTER_COMP_SIGNAL_U64(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_U64, \
	.name = (_name), \
	.signal_u64_read = (_read), \
	.signal_u64_write = (_write), \
}

#define COUNTER_COMP_DEVICE_BOOL(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_BOOL, \
	.name = (_name), \
	.device_u8_read = (_read), \
	.device_u8_write = (_write), \
}
#define COUNTER_COMP_COUNT_BOOL(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_BOOL, \
	.name = (_name), \
	.count_u8_read = (_read), \
	.count_u8_write = (_write), \
}
#define COUNTER_COMP_SIGNAL_BOOL(_name, _read, _write) \
{ \
	.type = COUNTER_COMP_BOOL, \
	.name = (_name), \
	.signal_u8_read = (_read), \
	.signal_u8_write = (_write), \
}

struct counter_available {
	union {
		const u32 *enums;
		const char *const *strs;
	};
	size_t num_items;
};

#define DEFINE_COUNTER_AVAILABLE(_name, _enums) \
	struct counter_available _name = { \
		.enums = (_enums), \
		.num_items = ARRAY_SIZE(_enums), \
	}

#define DEFINE_COUNTER_ENUM(_name, _strs) \
	struct counter_available _name = { \
		.strs = (_strs), \
		.num_items = ARRAY_SIZE(_strs), \
	}

#define COUNTER_COMP_DEVICE_ENUM(_name, _get, _set, _available) \
{ \
	.type = COUNTER_COMP_ENUM, \
	.name = (_name), \
	.device_u32_read = (_get), \
	.device_u32_write = (_set), \
	.priv = &(_available), \
}
#define COUNTER_COMP_COUNT_ENUM(_name, _get, _set, _available) \
{ \
	.type = COUNTER_COMP_ENUM, \
	.name = (_name), \
	.count_u32_read = (_get), \
	.count_u32_write = (_set), \
	.priv = &(_available), \
}
#define COUNTER_COMP_SIGNAL_ENUM(_name, _get, _set, _available) \
{ \
	.type = COUNTER_COMP_ENUM, \
	.name = (_name), \
	.signal_u32_read = (_get), \
	.signal_u32_write = (_set), \
	.priv = &(_available), \
}

#define COUNTER_COMP_CEILING(_read, _write) \
	COUNTER_COMP_COUNT_U64("ceiling", _read, _write)

#define COUNTER_COMP_COUNT_MODE(_read, _write, _available) \
{ \
	.type = COUNTER_COMP_COUNT_MODE, \
	.name = "count_mode", \
	.count_u32_read = (_read), \
	.count_u32_write = (_write), \
	.priv = &(_available), \
}

#define COUNTER_COMP_DIRECTION(_read) \
{ \
	.type = COUNTER_COMP_COUNT_DIRECTION, \
	.name = "direction", \
	.count_u32_read = (_read), \
}

#define COUNTER_COMP_ENABLE(_read, _write) \
	COUNTER_COMP_COUNT_BOOL("enable", _read, _write)

#define COUNTER_COMP_FLOOR(_read, _write) \
	COUNTER_COMP_COUNT_U64("floor", _read, _write)

#define COUNTER_COMP_PRESET(_read, _write) \
	COUNTER_COMP_COUNT_U64("preset", _read, _write)

#define COUNTER_COMP_PRESET_ENABLE(_read, _write) \
	COUNTER_COMP_COUNT_BOOL("preset_enable", _read, _write)

#endif /* _COUNTER_H_ */