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/bitfield.h> 11 #include <linux/bits.h> 12 #include <linux/types.h> 13 14 struct i2c_client; 15 struct regmap; 16 17 /** 18 * struct cci_reg_sequence - An individual write from a sequence of CCI writes 19 * 20 * @reg: Register address, use CCI_REG#() macros to encode reg width 21 * @val: Register value 22 * 23 * Register/value pairs for sequences of writes. 24 */ 25 struct cci_reg_sequence { 26 u32 reg; 27 u64 val; 28 }; 29 30 /* 31 * Macros to define register address with the register width encoded 32 * into the higher bits. 33 */ 34 #define CCI_REG_ADDR_MASK GENMASK(15, 0) 35 #define CCI_REG_WIDTH_SHIFT 16 36 #define CCI_REG_WIDTH_MASK GENMASK(19, 16) 37 38 #define CCI_REG_WIDTH_BYTES(x) FIELD_GET(CCI_REG_WIDTH_MASK, x) 39 #define CCI_REG_WIDTH(x) (CCI_REG_WIDTH_BYTES(x) << 3) 40 #define CCI_REG_ADDR(x) FIELD_GET(CCI_REG_ADDR_MASK, x) 41 #define CCI_REG_LE BIT(20) 42 43 #define CCI_REG8(x) ((1 << CCI_REG_WIDTH_SHIFT) | (x)) 44 #define CCI_REG16(x) ((2 << CCI_REG_WIDTH_SHIFT) | (x)) 45 #define CCI_REG24(x) ((3 << CCI_REG_WIDTH_SHIFT) | (x)) 46 #define CCI_REG32(x) ((4 << CCI_REG_WIDTH_SHIFT) | (x)) 47 #define CCI_REG64(x) ((8 << CCI_REG_WIDTH_SHIFT) | (x)) 48 #define CCI_REG16_LE(x) (CCI_REG_LE | (2U << CCI_REG_WIDTH_SHIFT) | (x)) 49 #define CCI_REG24_LE(x) (CCI_REG_LE | (3U << CCI_REG_WIDTH_SHIFT) | (x)) 50 #define CCI_REG32_LE(x) (CCI_REG_LE | (4U << CCI_REG_WIDTH_SHIFT) | (x)) 51 #define CCI_REG64_LE(x) (CCI_REG_LE | (8U << CCI_REG_WIDTH_SHIFT) | (x)) 52 53 /** 54 * cci_read() - Read a value from a single CCI register 55 * 56 * @map: Register map to read from 57 * @reg: Register address to read, use CCI_REG#() macros to encode reg width 58 * @val: Pointer to store read value 59 * @err: Optional pointer to store errors, if a previous error is set 60 * then the read will be skipped 61 * 62 * Return: %0 on success or a negative error code on failure. 63 */ 64 int cci_read(struct regmap *map, u32 reg, u64 *val, int *err); 65 66 /** 67 * cci_write() - Write a value to a single CCI register 68 * 69 * @map: Register map to write to 70 * @reg: Register address to write, use CCI_REG#() macros to encode reg width 71 * @val: Value to be written 72 * @err: Optional pointer to store errors, if a previous error is set 73 * then the write will be skipped 74 * 75 * Return: %0 on success or a negative error code on failure. 76 */ 77 int cci_write(struct regmap *map, u32 reg, u64 val, int *err); 78 79 /** 80 * cci_update_bits() - Perform a read/modify/write cycle on 81 * a single CCI register 82 * 83 * @map: Register map to update 84 * @reg: Register address to update, use CCI_REG#() macros to encode reg width 85 * @mask: Bitmask to change 86 * @val: New value for bitmask 87 * @err: Optional pointer to store errors, if a previous error is set 88 * then the update will be skipped 89 * 90 * Note this uses read-modify-write to update the bits, atomicity with regards 91 * to other cci_*() register access functions is NOT guaranteed. 92 * 93 * Return: %0 on success or a negative error code on failure. 94 */ 95 int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err); 96 97 /** 98 * cci_multi_reg_write() - Write multiple registers to the device 99 * 100 * @map: Register map to write to 101 * @regs: Array of structures containing register-address, -value pairs to be 102 * written, register-addresses use CCI_REG#() macros to encode reg width 103 * @num_regs: Number of registers to write 104 * @err: Optional pointer to store errors, if a previous error is set 105 * then the write will be skipped 106 * 107 * Write multiple registers to the device where the set of register, value 108 * pairs are supplied in any order, possibly not all in a single range. 109 * 110 * Use of the CCI_REG#() macros to encode reg width is mandatory. 111 * 112 * For raw lists of register-address, -value pairs with only 8 bit 113 * wide writes regmap_multi_reg_write() can be used instead. 114 * 115 * Return: %0 on success or a negative error code on failure. 116 */ 117 int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs, 118 unsigned int num_regs, int *err); 119 120 #if IS_ENABLED(CONFIG_V4L2_CCI_I2C) 121 /** 122 * devm_cci_regmap_init_i2c() - Create regmap to use with cci_*() register 123 * access functions 124 * 125 * @client: i2c_client to create the regmap for 126 * @reg_addr_bits: register address width to use (8 or 16) 127 * 128 * Note the memory for the created regmap is devm() managed, tied to the client. 129 * 130 * Return: %0 on success or a negative error code on failure. 131 */ 132 struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client, 133 int reg_addr_bits); 134 #endif 135 136 #endif 137