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
cci_read(struct regmap * map,u32 reg,u64 * val,int * err)19 int cci_read(struct regmap *map, u32 reg, u64 *val, int *err)
20 {
21 unsigned int len;
22 u8 buf[8];
23 int ret;
24
25 if (err && *err)
26 return *err;
27
28 len = FIELD_GET(CCI_REG_WIDTH_MASK, reg);
29 reg = FIELD_GET(CCI_REG_ADDR_MASK, reg);
30
31 ret = regmap_bulk_read(map, reg, buf, len);
32 if (ret) {
33 dev_err(regmap_get_device(map), "Error reading reg 0x%4x: %d\n",
34 reg, ret);
35 goto out;
36 }
37
38 switch (len) {
39 case 1:
40 *val = buf[0];
41 break;
42 case 2:
43 *val = get_unaligned_be16(buf);
44 break;
45 case 3:
46 *val = get_unaligned_be24(buf);
47 break;
48 case 4:
49 *val = get_unaligned_be32(buf);
50 break;
51 case 8:
52 *val = get_unaligned_be64(buf);
53 break;
54 default:
55 dev_err(regmap_get_device(map), "Error invalid reg-width %u for reg 0x%04x\n",
56 len, reg);
57 ret = -EINVAL;
58 break;
59 }
60
61 out:
62 if (ret && err)
63 *err = ret;
64
65 return ret;
66 }
67 EXPORT_SYMBOL_GPL(cci_read);
68
cci_write(struct regmap * map,u32 reg,u64 val,int * err)69 int cci_write(struct regmap *map, u32 reg, u64 val, int *err)
70 {
71 unsigned int len;
72 u8 buf[8];
73 int ret;
74
75 if (err && *err)
76 return *err;
77
78 len = FIELD_GET(CCI_REG_WIDTH_MASK, reg);
79 reg = FIELD_GET(CCI_REG_ADDR_MASK, reg);
80
81 switch (len) {
82 case 1:
83 buf[0] = val;
84 break;
85 case 2:
86 put_unaligned_be16(val, buf);
87 break;
88 case 3:
89 put_unaligned_be24(val, buf);
90 break;
91 case 4:
92 put_unaligned_be32(val, buf);
93 break;
94 case 8:
95 put_unaligned_be64(val, buf);
96 break;
97 default:
98 dev_err(regmap_get_device(map), "Error invalid reg-width %u for reg 0x%04x\n",
99 len, reg);
100 ret = -EINVAL;
101 goto out;
102 }
103
104 ret = regmap_bulk_write(map, reg, buf, len);
105 if (ret)
106 dev_err(regmap_get_device(map), "Error writing reg 0x%4x: %d\n",
107 reg, ret);
108
109 out:
110 if (ret && err)
111 *err = ret;
112
113 return ret;
114 }
115 EXPORT_SYMBOL_GPL(cci_write);
116
cci_update_bits(struct regmap * map,u32 reg,u64 mask,u64 val,int * err)117 int cci_update_bits(struct regmap *map, u32 reg, u64 mask, u64 val, int *err)
118 {
119 u64 readval;
120 int ret;
121
122 ret = cci_read(map, reg, &readval, err);
123 if (ret)
124 return ret;
125
126 val = (readval & ~mask) | (val & mask);
127
128 return cci_write(map, reg, val, err);
129 }
130 EXPORT_SYMBOL_GPL(cci_update_bits);
131
cci_multi_reg_write(struct regmap * map,const struct cci_reg_sequence * regs,unsigned int num_regs,int * err)132 int cci_multi_reg_write(struct regmap *map, const struct cci_reg_sequence *regs,
133 unsigned int num_regs, int *err)
134 {
135 unsigned int i;
136 int ret;
137
138 for (i = 0; i < num_regs; i++) {
139 ret = cci_write(map, regs[i].reg, regs[i].val, err);
140 if (ret)
141 return ret;
142 }
143
144 return 0;
145 }
146 EXPORT_SYMBOL_GPL(cci_multi_reg_write);
147
148 #if IS_ENABLED(CONFIG_V4L2_CCI_I2C)
devm_cci_regmap_init_i2c(struct i2c_client * client,int reg_addr_bits)149 struct regmap *devm_cci_regmap_init_i2c(struct i2c_client *client,
150 int reg_addr_bits)
151 {
152 struct regmap_config config = {
153 .reg_bits = reg_addr_bits,
154 .val_bits = 8,
155 .reg_format_endian = REGMAP_ENDIAN_BIG,
156 .disable_locking = true,
157 };
158
159 return devm_regmap_init_i2c(client, &config);
160 }
161 EXPORT_SYMBOL_GPL(devm_cci_regmap_init_i2c);
162 #endif
163
164 MODULE_LICENSE("GPL");
165 MODULE_AUTHOR("Hans de Goede <hansg@kernel.org>");
166 MODULE_DESCRIPTION("MIPI Camera Control Interface (CCI) support");
167
