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 | |