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
8#include <linux/bitfield.h>
9#include <linux/delay.h>
10#include <linux/dev_printk.h>
11#include <linux/module.h>
12#include <linux/regmap.h>
13#include <linux/types.h>
14
15#include <asm/unaligned.h>
16
17#include <media/v4l2-cci.h>
18
19int cci_read(struct regmap *map, u32 reg, u64 *val, int *err)
20{
21 bool little_endian;
22 unsigned int len;
23 u8 buf[8];
24 int ret;
25
26 if (err && *err)
27 return *err;
28
29 little_endian = reg & CCI_REG_LE;
30 len = CCI_REG_WIDTH_BYTES(reg);
31 reg = CCI_REG_ADDR(reg);
32
33 ret = regmap_bulk_read(map, reg, val: buf, val_count: len);
34 if (ret) {
35 dev_err(regmap_get_device(map), "Error reading reg 0x%04x: %d\n",
36 reg, ret);
37 goto out;
38 }
39
40 switch (len) {
41 case 1:
42 *val = buf[0];
43 break;
44 case 2:
45 if (little_endian)
46 *val = get_unaligned_le16(p: buf);
47 else
48 *val = get_unaligned_be16(p: buf);
49 break;
50 case 3:
51 if (little_endian)
52 *val = get_unaligned_le24(p: buf);
53 else
54 *val = get_unaligned_be24(p: buf);
55 break;
56 case 4:
57 if (little_endian)
58 *val = get_unaligned_le32(p: buf);
59 else
60 *val = get_unaligned_be32(p: buf);
61 break;
62 case 8:
63 if (little_endian)
64 *val = get_unaligned_le64(p: buf);
65 else
66 *val = get_unaligned_be64(p: buf);
67 break;
68 default:
69 dev_err(regmap_get_device(map), "Error invalid reg-width %u for reg 0x%04x\n",
70 len, reg);
71 ret = -EINVAL;
72 break;
73 }
74
75out:
76 if (ret && err)
77 *err = ret;
78
79 return ret;
80}
81EXPORT_SYMBOL_GPL(cci_read);
82
83int cci_write(struct regmap *map, u32 reg, u64 val, int *err)
84{
85 bool little_endian;
86 unsigned int len;
87 u8 buf[8];
88 int ret;
89
90 if (err && *err)
91 return *err;
92
93 little_endian = reg & CCI_REG_LE;
94 len = CCI_REG_WIDTH_BYTES(reg);
95 reg = CCI_REG_ADDR(reg);
96
97 switch (len) {
98 case 1:
99 buf[0] = val;
100 break;
101 case 2:
102 if (little_endian)
103 put_unaligned_le16(val, p: buf);
104 else
105 put_unaligned_be16(val, p: buf);
106 break;
107 case 3:
108 if (little_endian)
109 put_unaligned_le24(val, p: buf);
110 else
111 put_unaligned_be24(val, p: buf);
112 break;
113 case 4:
114 if (little_endian)
115 put_unaligned_le32(val, p: buf);
116 else
117 put_unaligned_be32(val, p: buf);
118 break;
119 case 8:
120 if (little_endian)
121 put_unaligned_le64(val, p: buf);
122 else
123 put_unaligned_be64(val, p: buf);
124 break;
125 default:
126 dev_err(regmap_get_device(map), "Error invalid reg-width %u for reg 0x%04x\n",
127 len, reg);
128 ret = -EINVAL;
129 goto out;
130 }
131
132 ret = regmap_bulk_write(map, reg, val: buf, val_count: len);
133 if (ret)
134 dev_err(regmap_get_device(map), "Error writing reg 0x%04x: %d\n",
135 reg, ret);
136
137out:
138 if (ret && err)
139 *err = ret;
140
141 return ret;
142}
143EXPORT_SYMBOL_GPL(cci_write);
144
145int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err)
146{
147 u64 readval;
148 int ret;
149
150 ret = cci_read(map, reg, &readval, err);
151 if (ret)
152 return ret;
153
154 val = (readval & ~mask) | (val & mask);
155
156 return cci_write(map, reg, val, err);
157}
158EXPORT_SYMBOL_GPL(cci_update_bits);
159
160int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs,
161 unsigned int num_regs, int *err)
162{
163 unsigned int i;
164 int ret;
165
166 for (i = 0; i < num_regs; i++) {
167 ret = cci_write(map, regs[i].reg, regs[i].val, err);
168 if (ret)
169 return ret;
170 }
171
172 return 0;
173}
174EXPORT_SYMBOL_GPL(cci_multi_reg_write);
175
176#if IS_ENABLED(CONFIG_V4L2_CCI_I2C)
177struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client,
178 int reg_addr_bits)
179{
180 struct regmap_config config = {
181 .reg_bits = reg_addr_bits,
182 .val_bits = 8,
183 .reg_format_endian = REGMAP_ENDIAN_BIG,
184 .disable_locking = true,
185 };
186
187 return devm_regmap_init_i2c(client, &config);
188}
189EXPORT_SYMBOL_GPL(devm_cci_regmap_init_i2c);
190#endif
191
192MODULE_LICENSE("GPL");
193MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
194MODULE_DESCRIPTION("MIPI Camera Control Interface (CCI) support");
195

source code of linux/drivers/media/v4l2-core/v4l2-cci.c