1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 TDK-InvenSense, Inc.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/delay.h>
#include "inv_mpu_aux.h"
#include "inv_mpu_iio.h"
/*
* i2c master auxiliary bus transfer function.
* Requires the i2c operations to be correctly setup before.
*/
static int inv_mpu_i2c_master_xfer(const struct inv_mpu6050_state *st)
{
/* use 50hz frequency for xfer */
const unsigned int freq = 50;
const unsigned int period_ms = 1000 / freq;
uint8_t d;
unsigned int user_ctrl;
int ret;
/* set sample rate */
d = INV_MPU6050_FIFO_RATE_TO_DIVIDER(freq);
ret = regmap_write(st->map, st->reg->sample_rate_div, d);
if (ret)
return ret;
/* start i2c master */
user_ctrl = st->chip_config.user_ctrl | INV_MPU6050_BIT_I2C_MST_EN;
ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
if (ret)
goto error_restore_rate;
/* wait for xfer: 1 period + half-period margin */
msleep(period_ms + period_ms / 2);
/* stop i2c master */
user_ctrl = st->chip_config.user_ctrl;
ret = regmap_write(st->map, st->reg->user_ctrl, user_ctrl);
if (ret)
goto error_stop_i2c;
/* restore sample rate */
d = st->chip_config.divider;
ret = regmap_write(st->map, st->reg->sample_rate_div, d);
if (ret)
goto error_restore_rate;
return 0;
error_stop_i2c:
regmap_write(st->map, st->reg->user_ctrl, st->chip_config.user_ctrl);
error_restore_rate:
regmap_write(st->map, st->reg->sample_rate_div, st->chip_config.divider);
return ret;
}
/**
* inv_mpu_aux_init() - init i2c auxiliary bus
* @st: driver internal state
*
* Returns 0 on success, a negative error code otherwise.
*/
int inv_mpu_aux_init(const struct inv_mpu6050_state *st)
{
unsigned int val;
int ret;
/* configure i2c master */
val = INV_MPU6050_BITS_I2C_MST_CLK_400KHZ |
INV_MPU6050_BIT_WAIT_FOR_ES;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_MST_CTRL, val);
if (ret)
return ret;
/* configure i2c master delay */
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV4_CTRL, 0);
if (ret)
return ret;
val = INV_MPU6050_BIT_I2C_SLV0_DLY_EN |
INV_MPU6050_BIT_I2C_SLV1_DLY_EN |
INV_MPU6050_BIT_I2C_SLV2_DLY_EN |
INV_MPU6050_BIT_I2C_SLV3_DLY_EN |
INV_MPU6050_BIT_DELAY_ES_SHADOW;
return regmap_write(st->map, INV_MPU6050_REG_I2C_MST_DELAY_CTRL, val);
}
/**
* inv_mpu_aux_read() - read register function for i2c auxiliary bus
* @st: driver internal state.
* @addr: chip i2c Address
* @reg: chip register address
* @val: buffer for storing read bytes
* @size: number of bytes to read
*
* Returns 0 on success, a negative error code otherwise.
*/
int inv_mpu_aux_read(const struct inv_mpu6050_state *st, uint8_t addr,
uint8_t reg, uint8_t *val, size_t size)
{
unsigned int status;
int ret;
if (size > 0x0F)
return -EINVAL;
/* setup i2c SLV0 control: i2c addr, register, enable + size */
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0),
INV_MPU6050_BIT_I2C_SLV_RNW | addr);
if (ret)
return ret;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0), reg);
if (ret)
return ret;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0),
INV_MPU6050_BIT_SLV_EN | size);
if (ret)
return ret;
/* do i2c xfer */
ret = inv_mpu_i2c_master_xfer(st);
if (ret)
goto error_disable_i2c;
/* disable i2c slave */
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
if (ret)
goto error_disable_i2c;
/* check i2c status */
ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status);
if (ret)
return ret;
if (status & INV_MPU6050_BIT_I2C_SLV0_NACK)
return -EIO;
/* read data in registers */
return regmap_bulk_read(st->map, INV_MPU6050_REG_EXT_SENS_DATA,
val, size);
error_disable_i2c:
regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
return ret;
}
/**
* inv_mpu_aux_write() - write register function for i2c auxiliary bus
* @st: driver internal state.
* @addr: chip i2c Address
* @reg: chip register address
* @val: 1 byte value to write
*
* Returns 0 on success, a negative error code otherwise.
*/
int inv_mpu_aux_write(const struct inv_mpu6050_state *st, uint8_t addr,
uint8_t reg, uint8_t val)
{
unsigned int status;
int ret;
/* setup i2c SLV0 control: i2c addr, register, value, enable + size */
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(0), addr);
if (ret)
return ret;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(0), reg);
if (ret)
return ret;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_DO(0), val);
if (ret)
return ret;
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0),
INV_MPU6050_BIT_SLV_EN | 1);
if (ret)
return ret;
/* do i2c xfer */
ret = inv_mpu_i2c_master_xfer(st);
if (ret)
goto error_disable_i2c;
/* disable i2c slave */
ret = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
if (ret)
goto error_disable_i2c;
/* check i2c status */
ret = regmap_read(st->map, INV_MPU6050_REG_I2C_MST_STATUS, &status);
if (ret)
return ret;
if (status & INV_MPU6050_BIT_I2C_SLV0_NACK)
return -EIO;
return 0;
error_disable_i2c:
regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(0), 0);
return ret;
}
|
