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/* SPDX-License-Identifier: GPL-2.0 */
/*
* MIPI Camera Control Interface (CCI) register access helpers.
*
* Copyright (C) 2023 Hans de Goede <hansg@kernel.org>
*/
#ifndef _V4L2_CCI_H
#define _V4L2_CCI_H
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/types.h>
struct i2c_client;
struct regmap;
/**
* struct cci_reg_sequence - An individual write from a sequence of CCI writes
*
* @reg: Register address, use CCI_REG#() macros to encode reg width
* @val: Register value
*
* Register/value pairs for sequences of writes.
*/
struct cci_reg_sequence {
u32 reg;
u64 val;
};
/*
* Macros to define register address with the register width encoded
* into the higher bits.
*/
#define CCI_REG_ADDR_MASK GENMASK(15, 0)
#define CCI_REG_WIDTH_SHIFT 16
#define CCI_REG_WIDTH_MASK GENMASK(19, 16)
/*
* Private CCI register flags, for the use of drivers.
*/
#define CCI_REG_PRIVATE_SHIFT 28U
#define CCI_REG_PRIVATE_MASK GENMASK(31U, CCI_REG_PRIVATE_SHIFT)
#define CCI_REG_WIDTH_BYTES(x) FIELD_GET(CCI_REG_WIDTH_MASK, x)
#define CCI_REG_WIDTH(x) (CCI_REG_WIDTH_BYTES(x) << 3)
#define CCI_REG_ADDR(x) FIELD_GET(CCI_REG_ADDR_MASK, x)
#define CCI_REG_LE BIT(20)
#define CCI_REG8(x) ((1 << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG16(x) ((2 << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG24(x) ((3 << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG32(x) ((4 << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG64(x) ((8 << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG16_LE(x) (CCI_REG_LE | (2U << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG24_LE(x) (CCI_REG_LE | (3U << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG32_LE(x) (CCI_REG_LE | (4U << CCI_REG_WIDTH_SHIFT) | (x))
#define CCI_REG64_LE(x) (CCI_REG_LE | (8U << CCI_REG_WIDTH_SHIFT) | (x))
/**
* cci_read() - Read a value from a single CCI register
*
* @map: Register map to read from
* @reg: Register address to read, use CCI_REG#() macros to encode reg width
* @val: Pointer to store read value
* @err: Optional pointer to store errors, if a previous error is set
* then the read will be skipped
*
* Return: %0 on success or a negative error code on failure.
*/
int cci_read(struct regmap *map, u32 reg, u64 *val, int *err);
/**
* cci_write() - Write a value to a single CCI register
*
* @map: Register map to write to
* @reg: Register address to write, use CCI_REG#() macros to encode reg width
* @val: Value to be written
* @err: Optional pointer to store errors, if a previous error is set
* then the write will be skipped
*
* Return: %0 on success or a negative error code on failure.
*/
int cci_write(struct regmap *map, u32 reg, u64 val, int *err);
/**
* cci_update_bits() - Perform a read/modify/write cycle on
* a single CCI register
*
* @map: Register map to update
* @reg: Register address to update, use CCI_REG#() macros to encode reg width
* @mask: Bitmask to change
* @val: New value for bitmask
* @err: Optional pointer to store errors, if a previous error is set
* then the update will be skipped
*
* Note this uses read-modify-write to update the bits, atomicity with regards
* to other cci_*() register access functions is NOT guaranteed.
*
* Return: %0 on success or a negative error code on failure.
*/
int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err);
/**
* cci_multi_reg_write() - Write multiple registers to the device
*
* @map: Register map to write to
* @regs: Array of structures containing register-address, -value pairs to be
* written, register-addresses use CCI_REG#() macros to encode reg width
* @num_regs: Number of registers to write
* @err: Optional pointer to store errors, if a previous error is set
* then the write will be skipped
*
* Write multiple registers to the device where the set of register, value
* pairs are supplied in any order, possibly not all in a single range.
*
* Use of the CCI_REG#() macros to encode reg width is mandatory.
*
* For raw lists of register-address, -value pairs with only 8 bit
* wide writes regmap_multi_reg_write() can be used instead.
*
* Return: %0 on success or a negative error code on failure.
*/
int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs,
unsigned int num_regs, int *err);
#if IS_ENABLED(CONFIG_V4L2_CCI_I2C)
/**
* devm_cci_regmap_init_i2c() - Create regmap to use with cci_*() register
* access functions
*
* @client: i2c_client to create the regmap for
* @reg_addr_bits: register address width to use (8 or 16)
*
* Note the memory for the created regmap is devm() managed, tied to the client.
*
* Return: %0 on success or a negative error code on failure.
*/
struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client,
int reg_addr_bits);
#endif
#endif