iio: imu: mpu6050: fix possible NULL dereferences
[deliverable/linux.git] / drivers / iio / imu / inv_mpu6050 / inv_mpu_trigger.c
1 /*
2 * Copyright (C) 2012 Invensense, Inc.
3 *
4 * This software is licensed under the terms of the GNU General Public
5 * License version 2, as published by the Free Software Foundation, and
6 * may be copied, distributed, and modified under those terms.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 */
13
14 #include "inv_mpu_iio.h"
15
16 static void inv_scan_query(struct iio_dev *indio_dev)
17 {
18 struct inv_mpu6050_state *st = iio_priv(indio_dev);
19
20 st->chip_config.gyro_fifo_enable =
21 test_bit(INV_MPU6050_SCAN_GYRO_X,
22 indio_dev->active_scan_mask) ||
23 test_bit(INV_MPU6050_SCAN_GYRO_Y,
24 indio_dev->active_scan_mask) ||
25 test_bit(INV_MPU6050_SCAN_GYRO_Z,
26 indio_dev->active_scan_mask);
27
28 st->chip_config.accl_fifo_enable =
29 test_bit(INV_MPU6050_SCAN_ACCL_X,
30 indio_dev->active_scan_mask) ||
31 test_bit(INV_MPU6050_SCAN_ACCL_Y,
32 indio_dev->active_scan_mask) ||
33 test_bit(INV_MPU6050_SCAN_ACCL_Z,
34 indio_dev->active_scan_mask);
35 }
36
37 /**
38 * inv_mpu6050_set_enable() - enable chip functions.
39 * @indio_dev: Device driver instance.
40 * @enable: enable/disable
41 */
42 static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
43 {
44 struct inv_mpu6050_state *st = iio_priv(indio_dev);
45 int result;
46
47 if (enable) {
48 result = inv_mpu6050_set_power_itg(st, true);
49 if (result)
50 return result;
51 inv_scan_query(indio_dev);
52 if (st->chip_config.gyro_fifo_enable) {
53 result = inv_mpu6050_switch_engine(st, true,
54 INV_MPU6050_BIT_PWR_GYRO_STBY);
55 if (result)
56 return result;
57 }
58 if (st->chip_config.accl_fifo_enable) {
59 result = inv_mpu6050_switch_engine(st, true,
60 INV_MPU6050_BIT_PWR_ACCL_STBY);
61 if (result)
62 return result;
63 }
64 result = inv_reset_fifo(indio_dev);
65 if (result)
66 return result;
67 } else {
68 result = regmap_write(st->map, st->reg->fifo_en, 0);
69 if (result)
70 return result;
71
72 result = regmap_write(st->map, st->reg->int_enable, 0);
73 if (result)
74 return result;
75
76 result = regmap_write(st->map, st->reg->user_ctrl, 0);
77 if (result)
78 return result;
79
80 result = inv_mpu6050_switch_engine(st, false,
81 INV_MPU6050_BIT_PWR_GYRO_STBY);
82 if (result)
83 return result;
84
85 result = inv_mpu6050_switch_engine(st, false,
86 INV_MPU6050_BIT_PWR_ACCL_STBY);
87 if (result)
88 return result;
89 result = inv_mpu6050_set_power_itg(st, false);
90 if (result)
91 return result;
92 }
93 st->chip_config.enable = enable;
94
95 return 0;
96 }
97
98 /**
99 * inv_mpu_data_rdy_trigger_set_state() - set data ready interrupt state
100 * @trig: Trigger instance
101 * @state: Desired trigger state
102 */
103 static int inv_mpu_data_rdy_trigger_set_state(struct iio_trigger *trig,
104 bool state)
105 {
106 return inv_mpu6050_set_enable(iio_trigger_get_drvdata(trig), state);
107 }
108
109 static const struct iio_trigger_ops inv_mpu_trigger_ops = {
110 .owner = THIS_MODULE,
111 .set_trigger_state = &inv_mpu_data_rdy_trigger_set_state,
112 };
113
114 int inv_mpu6050_probe_trigger(struct iio_dev *indio_dev)
115 {
116 int ret;
117 struct inv_mpu6050_state *st = iio_priv(indio_dev);
118
119 st->trig = devm_iio_trigger_alloc(&indio_dev->dev,
120 "%s-dev%d",
121 indio_dev->name,
122 indio_dev->id);
123 if (!st->trig)
124 return -ENOMEM;
125
126 ret = devm_request_irq(&indio_dev->dev, st->irq,
127 &iio_trigger_generic_data_rdy_poll,
128 IRQF_TRIGGER_RISING,
129 "inv_mpu",
130 st->trig);
131 if (ret)
132 return ret;
133
134 st->trig->dev.parent = regmap_get_device(st->map);
135 st->trig->ops = &inv_mpu_trigger_ops;
136 iio_trigger_set_drvdata(st->trig, indio_dev);
137
138 ret = iio_trigger_register(st->trig);
139 if (ret)
140 return ret;
141
142 indio_dev->trig = iio_trigger_get(st->trig);
143
144 return 0;
145 }
146
147 void inv_mpu6050_remove_trigger(struct inv_mpu6050_state *st)
148 {
149 iio_trigger_unregister(st->trig);
150 }
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