1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * I2C register access helpers for Omnivision OVxxxx image sensors which expect
4 * a 16 bit register address in big-endian format and which have 1-3 byte
5 * wide registers, in big-endian format (for the higher width registers).
6 *
7 * Based on the register helpers from drivers/media/i2c/ov2680.c which is:
8 * Copyright (C) 2018 Linaro Ltd
9 */
10 #ifndef __OV_16BIT_ADDR_REG_HELPERS_H
11 #define __OV_16BIT_ADDR_REG_HELPERS_H
12
13 #include <asm/unaligned.h>
14 #include <linux/dev_printk.h>
15 #include <linux/i2c.h>
16
ov_read_reg(struct i2c_client * client,u16 reg,unsigned int len,u32 * val)17 static inline int ov_read_reg(struct i2c_client *client, u16 reg,
18 unsigned int len, u32 *val)
19 {
20 u8 addr_buf[2], data_buf[4] = { };
21 struct i2c_msg msgs[2];
22 int ret;
23
24 if (len > 4)
25 return -EINVAL;
26
27 put_unaligned_be16(reg, addr_buf);
28
29 msgs[0].addr = client->addr;
30 msgs[0].flags = 0;
31 msgs[0].len = ARRAY_SIZE(addr_buf);
32 msgs[0].buf = addr_buf;
33
34 msgs[1].addr = client->addr;
35 msgs[1].flags = I2C_M_RD;
36 msgs[1].len = len;
37 msgs[1].buf = &data_buf[4 - len];
38
39 ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
40 if (ret != ARRAY_SIZE(msgs)) {
41 dev_err(&client->dev, "read error: reg=0x%4x: %d\n", reg, ret);
42 return -EIO;
43 }
44
45 *val = get_unaligned_be32(data_buf);
46
47 return 0;
48 }
49
50 #define ov_read_reg8(s, r, v) ov_read_reg(s, r, 1, v)
51 #define ov_read_reg16(s, r, v) ov_read_reg(s, r, 2, v)
52 #define ov_read_reg24(s, r, v) ov_read_reg(s, r, 3, v)
53
ov_write_reg(struct i2c_client * client,u16 reg,unsigned int len,u32 val)54 static inline int ov_write_reg(struct i2c_client *client, u16 reg,
55 unsigned int len, u32 val)
56 {
57 u8 buf[6];
58 int ret;
59
60 if (len > 4)
61 return -EINVAL;
62
63 put_unaligned_be16(reg, buf);
64 put_unaligned_be32(val << (8 * (4 - len)), buf + 2);
65 ret = i2c_master_send(client, buf, len + 2);
66 if (ret != len + 2) {
67 dev_err(&client->dev, "write error: reg=0x%4x: %d\n", reg, ret);
68 return -EIO;
69 }
70
71 return 0;
72 }
73
74 #define ov_write_reg8(s, r, v) ov_write_reg(s, r, 1, v)
75 #define ov_write_reg16(s, r, v) ov_write_reg(s, r, 2, v)
76 #define ov_write_reg24(s, r, v) ov_write_reg(s, r, 3, v)
77
ov_update_reg(struct i2c_client * client,u16 reg,u8 mask,u8 val)78 static inline int ov_update_reg(struct i2c_client *client, u16 reg, u8 mask, u8 val)
79 {
80 u32 readval;
81 int ret;
82
83 ret = ov_read_reg8(client, reg, &readval);
84 if (ret < 0)
85 return ret;
86
87 val = (readval & ~mask) | (val & mask);
88
89 return ov_write_reg8(client, reg, val);
90 }
91
92 #endif
93