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 * Private CCI register flags, for the use of drivers. 39 */ 40 #define CCI_REG_PRIVATE_SHIFT 28U 41 #define CCI_REG_PRIVATE_MASK GENMASK(31U, CCI_REG_PRIVATE_SHIFT) 42 43 #define CCI_REG_WIDTH_BYTES(x) FIELD_GET(CCI_REG_WIDTH_MASK, x) 44 #define CCI_REG_WIDTH(x) (CCI_REG_WIDTH_BYTES(x) << 3) 45 #define CCI_REG_ADDR(x) FIELD_GET(CCI_REG_ADDR_MASK, x) 46 #define CCI_REG_LE BIT(20) 47 48 #define CCI_REG8(x) ((1 << CCI_REG_WIDTH_SHIFT) | (x)) 49 #define CCI_REG16(x) ((2 << CCI_REG_WIDTH_SHIFT) | (x)) 50 #define CCI_REG24(x) ((3 << CCI_REG_WIDTH_SHIFT) | (x)) 51 #define CCI_REG32(x) ((4 << CCI_REG_WIDTH_SHIFT) | (x)) 52 #define CCI_REG64(x) ((8 << CCI_REG_WIDTH_SHIFT) | (x)) 53 #define CCI_REG16_LE(x) (CCI_REG_LE | (2U << CCI_REG_WIDTH_SHIFT) | (x)) 54 #define CCI_REG24_LE(x) (CCI_REG_LE | (3U << CCI_REG_WIDTH_SHIFT) | (x)) 55 #define CCI_REG32_LE(x) (CCI_REG_LE | (4U << CCI_REG_WIDTH_SHIFT) | (x)) 56 #define CCI_REG64_LE(x) (CCI_REG_LE | (8U << CCI_REG_WIDTH_SHIFT) | (x)) 57 58 /** 59 * cci_read() - Read a value from a single CCI register 60 * 61 * @map: Register map to read from 62 * @reg: Register address to read, use CCI_REG#() macros to encode reg width 63 * @val: Pointer to store read value 64 * @err: Optional pointer to store errors, if a previous error is set 65 * then the read will be skipped 66 * 67 * Return: %0 on success or a negative error code on failure. 68 */ 69 int cci_read(struct regmap *map, u32 reg, u64 *val, int *err); 70 71 /** 72 * cci_write() - Write a value to a single CCI register 73 * 74 * @map: Register map to write to 75 * @reg: Register address to write, use CCI_REG#() macros to encode reg width 76 * @val: Value to be written 77 * @err: Optional pointer to store errors, if a previous error is set 78 * then the write will be skipped 79 * 80 * Return: %0 on success or a negative error code on failure. 81 */ 82 int cci_write(struct regmap *map, u32 reg, u64 val, int *err); 83 84 /** 85 * cci_update_bits() - Perform a read/modify/write cycle on 86 * a single CCI register 87 * 88 * @map: Register map to update 89 * @reg: Register address to update, use CCI_REG#() macros to encode reg width 90 * @mask: Bitmask to change 91 * @val: New value for bitmask 92 * @err: Optional pointer to store errors, if a previous error is set 93 * then the update will be skipped 94 * 95 * Note this uses read-modify-write to update the bits, atomicity with regards 96 * to other cci_*() register access functions is NOT guaranteed. 97 * 98 * Return: %0 on success or a negative error code on failure. 99 */ 100 int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err); 101 102 /** 103 * cci_multi_reg_write() - Write multiple registers to the device 104 * 105 * @map: Register map to write to 106 * @regs: Array of structures containing register-address, -value pairs to be 107 * written, register-addresses use CCI_REG#() macros to encode reg width 108 * @num_regs: Number of registers to write 109 * @err: Optional pointer to store errors, if a previous error is set 110 * then the write will be skipped 111 * 112 * Write multiple registers to the device where the set of register, value 113 * pairs are supplied in any order, possibly not all in a single range. 114 * 115 * Use of the CCI_REG#() macros to encode reg width is mandatory. 116 * 117 * For raw lists of register-address, -value pairs with only 8 bit 118 * wide writes regmap_multi_reg_write() can be used instead. 119 * 120 * Return: %0 on success or a negative error code on failure. 121 */ 122 int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs, 123 unsigned int num_regs, int *err); 124 125 #if IS_ENABLED(CONFIG_V4L2_CCI_I2C) 126 /** 127 * devm_cci_regmap_init_i2c() - Create regmap to use with cci_*() register 128 * access functions 129 * 130 * @client: i2c_client to create the regmap for 131 * @reg_addr_bits: register address width to use (8 or 16) 132 * 133 * Note the memory for the created regmap is devm() managed, tied to the client. 134 * 135 * Return: %0 on success or a negative error code on failure. 136 */ 137 struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client, 138 int reg_addr_bits); 139 #endif 140 141 #endif 142