1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * MIPI Camera Control Interface (CCI) register access helpers. 4 * 5 * Copyright (C) 2023 Hans de Goede <hansg@kernel.org> 6 */ 7 #ifndef _V4L2_CCI_H 8 #define _V4L2_CCI_H 9 10 #include <linux/types.h> 11 12 struct i2c_client; 13 struct regmap; 14 15 /** 16 * struct cci_reg_sequence - An individual write from a sequence of CCI writes 17 * 18 * @reg: Register address, use CCI_REG#() macros to encode reg width 19 * @val: Register value 20 * 21 * Register/value pairs for sequences of writes. 22 */ 23 struct cci_reg_sequence { 24 u32 reg; 25 u64 val; 26 }; 27 28 /* 29 * Macros to define register address with the register width encoded 30 * into the higher bits. 31 */ 32 #define CCI_REG_ADDR_MASK GENMASK(15, 0) 33 #define CCI_REG_WIDTH_SHIFT 16 34 #define CCI_REG_WIDTH_MASK GENMASK(19, 16) 35 36 #define CCI_REG8(x) ((1 << CCI_REG_WIDTH_SHIFT) | (x)) 37 #define CCI_REG16(x) ((2 << CCI_REG_WIDTH_SHIFT) | (x)) 38 #define CCI_REG24(x) ((3 << CCI_REG_WIDTH_SHIFT) | (x)) 39 #define CCI_REG32(x) ((4 << CCI_REG_WIDTH_SHIFT) | (x)) 40 #define CCI_REG64(x) ((8 << CCI_REG_WIDTH_SHIFT) | (x)) 41 42 /** 43 * cci_read() - Read a value from a single CCI register 44 * 45 * @map: Register map to read from 46 * @reg: Register address to read, use CCI_REG#() macros to encode reg width 47 * @val: Pointer to store read value 48 * @err: Optional pointer to store errors, if a previous error is set 49 * then the read will be skipped 50 * 51 * Return: %0 on success or a negative error code on failure. 52 */ 53 int cci_read(struct regmap *map, u32 reg, u64 *val, int *err); 54 55 /** 56 * cci_write() - Write a value to a single CCI register 57 * 58 * @map: Register map to write to 59 * @reg: Register address to write, use CCI_REG#() macros to encode reg width 60 * @val: Value to be written 61 * @err: Optional pointer to store errors, if a previous error is set 62 * then the write will be skipped 63 * 64 * Return: %0 on success or a negative error code on failure. 65 */ 66 int cci_write(struct regmap *map, u32 reg, u64 val, int *err); 67 68 /** 69 * cci_update_bits() - Perform a read/modify/write cycle on 70 * a single CCI register 71 * 72 * @map: Register map to update 73 * @reg: Register address to update, use CCI_REG#() macros to encode reg width 74 * @mask: Bitmask to change 75 * @val: New value for bitmask 76 * @err: Optional pointer to store errors, if a previous error is set 77 * then the update will be skipped 78 * 79 * Note this uses read-modify-write to update the bits, atomicity with regards 80 * to other cci_*() register access functions is NOT guaranteed. 81 * 82 * Return: %0 on success or a negative error code on failure. 83 */ 84 int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err); 85 86 /** 87 * cci_multi_reg_write() - Write multiple registers to the device 88 * 89 * @map: Register map to write to 90 * @regs: Array of structures containing register-address, -value pairs to be 91 * written, register-addresses use CCI_REG#() macros to encode reg width 92 * @num_regs: Number of registers to write 93 * @err: Optional pointer to store errors, if a previous error is set 94 * then the write will be skipped 95 * 96 * Write multiple registers to the device where the set of register, value 97 * pairs are supplied in any order, possibly not all in a single range. 98 * 99 * Use of the CCI_REG#() macros to encode reg width is mandatory. 100 * 101 * For raw lists of register-address, -value pairs with only 8 bit 102 * wide writes regmap_multi_reg_write() can be used instead. 103 * 104 * Return: %0 on success or a negative error code on failure. 105 */ 106 int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs, 107 unsigned int num_regs, int *err); 108 109 #if IS_ENABLED(CONFIG_V4L2_CCI_I2C) 110 /** 111 * devm_cci_regmap_init_i2c() - Create regmap to use with cci_*() register 112 * access functions 113 * 114 * @client: i2c_client to create the regmap for 115 * @reg_addr_bits: register address width to use (8 or 16) 116 * 117 * Note the memory for the created regmap is devm() managed, tied to the client. 118 * 119 * Return: %0 on success or a negative error code on failure. 120 */ 121 struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client, 122 int reg_addr_bits); 123 #endif 124 125 #endif 126