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
itg3200_read_all_channels(struct i2c_client * i2c,__be16 * buf)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(i2c->adapter, msg, 2);
42 }
43
itg3200_trigger_handler(int irq,void * p)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(st->i2c, scan.buf);
59 if (ret < 0)
60 goto error_ret;
61
62 iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);
63
64 error_ret:
65 iio_trigger_notify_done(indio_dev->trig);
66
67 return IRQ_HANDLED;
68 }
69
itg3200_buffer_configure(struct iio_dev * indio_dev)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
itg3200_buffer_unconfigure(struct iio_dev * indio_dev)76 void itg3200_buffer_unconfigure(struct iio_dev *indio_dev)
77 {
78 iio_triggered_buffer_cleanup(indio_dev);
79 }
80
81
itg3200_data_rdy_trigger_set_state(struct iio_trigger * trig,bool state)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, &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, 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
itg3200_probe_trigger(struct iio_dev * indio_dev)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(st->i2c->irq,
122 &iio_trigger_generic_data_rdy_poll,
123 IRQF_TRIGGER_RISING,
124 "itg3200_data_rdy",
125 st->trig);
126 if (ret)
127 goto error_free_trig;
128
129
130 st->trig->ops = &itg3200_trigger_ops;
131 iio_trigger_set_drvdata(st->trig, indio_dev);
132 ret = iio_trigger_register(st->trig);
133 if (ret)
134 goto error_free_irq;
135
136 /* select default trigger */
137 indio_dev->trig = iio_trigger_get(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(st->trig);
145 return ret;
146 }
147
itg3200_remove_trigger(struct iio_dev * indio_dev)148 void itg3200_remove_trigger(struct iio_dev *indio_dev)
149 {
150 struct itg3200 *st = iio_priv(indio_dev);
151
152 iio_trigger_unregister(st->trig);
153 free_irq(st->i2c->irq, st->trig);
154 iio_trigger_free(st->trig);
155 }
156