1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * itg3200_buffer.c -- support InvenSense ITG3200 |
4 | * Digital 3-Axis Gyroscope driver |
5 | * |
6 | * Copyright (c) 2011 Christian Strobel <christian.strobel@iis.fraunhofer.de> |
7 | * Copyright (c) 2011 Manuel Stahl <manuel.stahl@iis.fraunhofer.de> |
8 | * Copyright (c) 2012 Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de> |
9 | */ |
10 | |
11 | #include <linux/slab.h> |
12 | #include <linux/i2c.h> |
13 | #include <linux/interrupt.h> |
14 | |
15 | #include <linux/iio/iio.h> |
16 | #include <linux/iio/buffer.h> |
17 | #include <linux/iio/trigger.h> |
18 | #include <linux/iio/trigger_consumer.h> |
19 | #include <linux/iio/triggered_buffer.h> |
20 | #include <linux/iio/gyro/itg3200.h> |
21 | |
22 | |
23 | static int itg3200_read_all_channels(struct i2c_client *i2c, __be16 *buf) |
24 | { |
25 | u8 tx = 0x80 | ITG3200_REG_TEMP_OUT_H; |
26 | struct i2c_msg msg[2] = { |
27 | { |
28 | .addr = i2c->addr, |
29 | .flags = i2c->flags, |
30 | .len = 1, |
31 | .buf = &tx, |
32 | }, |
33 | { |
34 | .addr = i2c->addr, |
35 | .flags = i2c->flags | I2C_M_RD, |
36 | .len = ITG3200_SCAN_ELEMENTS * sizeof(s16), |
37 | .buf = (char *)&buf, |
38 | }, |
39 | }; |
40 | |
41 | return i2c_transfer(adap: i2c->adapter, msgs: msg, num: 2); |
42 | } |
43 | |
44 | static irqreturn_t itg3200_trigger_handler(int irq, void *p) |
45 | { |
46 | struct iio_poll_func *pf = p; |
47 | struct iio_dev *indio_dev = pf->indio_dev; |
48 | struct itg3200 *st = iio_priv(indio_dev); |
49 | /* |
50 | * Ensure correct alignment and padding including for the |
51 | * timestamp that may be inserted. |
52 | */ |
53 | struct { |
54 | __be16 buf[ITG3200_SCAN_ELEMENTS]; |
55 | s64 ts __aligned(8); |
56 | } scan; |
57 | |
58 | int ret = itg3200_read_all_channels(i2c: st->i2c, buf: scan.buf); |
59 | if (ret < 0) |
60 | goto error_ret; |
61 | |
62 | iio_push_to_buffers_with_timestamp(indio_dev, data: &scan, timestamp: pf->timestamp); |
63 | |
64 | error_ret: |
65 | iio_trigger_notify_done(trig: indio_dev->trig); |
66 | |
67 | return IRQ_HANDLED; |
68 | } |
69 | |
70 | int itg3200_buffer_configure(struct iio_dev *indio_dev) |
71 | { |
72 | return iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, |
73 | itg3200_trigger_handler, NULL); |
74 | } |
75 | |
76 | void itg3200_buffer_unconfigure(struct iio_dev *indio_dev) |
77 | { |
78 | iio_triggered_buffer_cleanup(indio_dev); |
79 | } |
80 | |
81 | |
82 | static int itg3200_data_rdy_trigger_set_state(struct iio_trigger *trig, |
83 | bool state) |
84 | { |
85 | struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig); |
86 | int ret; |
87 | u8 msc; |
88 | |
89 | ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, val: &msc); |
90 | if (ret) |
91 | goto error_ret; |
92 | |
93 | if (state) |
94 | msc |= ITG3200_IRQ_DATA_RDY_ENABLE; |
95 | else |
96 | msc &= ~ITG3200_IRQ_DATA_RDY_ENABLE; |
97 | |
98 | ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_IRQ_CONFIG, val: msc); |
99 | if (ret) |
100 | goto error_ret; |
101 | |
102 | error_ret: |
103 | return ret; |
104 | |
105 | } |
106 | |
107 | static const struct iio_trigger_ops itg3200_trigger_ops = { |
108 | .set_trigger_state = &itg3200_data_rdy_trigger_set_state, |
109 | }; |
110 | |
111 | int itg3200_probe_trigger(struct iio_dev *indio_dev) |
112 | { |
113 | int ret; |
114 | struct itg3200 *st = iio_priv(indio_dev); |
115 | |
116 | st->trig = iio_trigger_alloc(&st->i2c->dev, "%s-dev%d" , indio_dev->name, |
117 | iio_device_id(indio_dev)); |
118 | if (!st->trig) |
119 | return -ENOMEM; |
120 | |
121 | ret = request_irq(irq: st->i2c->irq, |
122 | handler: &iio_trigger_generic_data_rdy_poll, |
123 | IRQF_TRIGGER_RISING, |
124 | name: "itg3200_data_rdy" , |
125 | dev: st->trig); |
126 | if (ret) |
127 | goto error_free_trig; |
128 | |
129 | |
130 | st->trig->ops = &itg3200_trigger_ops; |
131 | iio_trigger_set_drvdata(trig: st->trig, data: indio_dev); |
132 | ret = iio_trigger_register(trig_info: st->trig); |
133 | if (ret) |
134 | goto error_free_irq; |
135 | |
136 | /* select default trigger */ |
137 | indio_dev->trig = iio_trigger_get(trig: st->trig); |
138 | |
139 | return 0; |
140 | |
141 | error_free_irq: |
142 | free_irq(st->i2c->irq, st->trig); |
143 | error_free_trig: |
144 | iio_trigger_free(trig: st->trig); |
145 | return ret; |
146 | } |
147 | |
148 | void itg3200_remove_trigger(struct iio_dev *indio_dev) |
149 | { |
150 | struct itg3200 *st = iio_priv(indio_dev); |
151 | |
152 | iio_trigger_unregister(trig_info: st->trig); |
153 | free_irq(st->i2c->irq, st->trig); |
154 | iio_trigger_free(trig: st->trig); |
155 | } |
156 | |