tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * STMicroelectronics hts221 sensor driver
3 *
4 * Copyright 2016 STMicroelectronics Inc.
5 *
6 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
7 *
8 * Licensed under the GPL-2.
9 */
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/device.h>
13#include <linux/interrupt.h>
14#include <linux/irqreturn.h>
15
16#include <linux/iio/iio.h>
17#include <linux/iio/trigger.h>
18#include <linux/iio/events.h>
19#include <linux/iio/trigger_consumer.h>
20#include <linux/iio/triggered_buffer.h>
21#include <linux/iio/buffer.h>
22
23#include "hts221.h"
24
25#define HTS221_REG_STATUS_ADDR 0x27
26#define HTS221_RH_DRDY_MASK BIT(1)
27#define HTS221_TEMP_DRDY_MASK BIT(0)
28
29static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
30{
31 struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
32 struct hts221_hw *hw = iio_priv(iio_dev);
33
34 return hts221_config_drdy(hw, state);
35}
36
37static const struct iio_trigger_ops hts221_trigger_ops = {
38 .owner = THIS_MODULE,
39 .set_trigger_state = hts221_trig_set_state,
40};
41
42static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
43{
44 struct hts221_hw *hw = private;
45 u8 status;
46 int err;
47
48 err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
49 &status);
50 if (err < 0)
51 return IRQ_HANDLED;
52
53 /*
54 * H_DA bit (humidity data available) is routed to DRDY line.
55 * Humidity sample is computed after temperature one.
56 * Here we can assume data channels are both available if H_DA bit
57 * is set in status register
58 */
59 if (!(status & HTS221_RH_DRDY_MASK))
60 return IRQ_NONE;
61
62 iio_trigger_poll_chained(hw->trig);
63
64 return IRQ_HANDLED;
65}
66
67int hts221_allocate_trigger(struct hts221_hw *hw)
68{
69 struct iio_dev *iio_dev = iio_priv_to_dev(hw);
70 unsigned long irq_type;
71 int err;
72
73 irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
74
75 switch (irq_type) {
76 case IRQF_TRIGGER_HIGH:
77 case IRQF_TRIGGER_RISING:
78 break;
79 default:
80 dev_info(hw->dev,
81 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
82 irq_type);
83 irq_type = IRQF_TRIGGER_RISING;
84 break;
85 }
86
87 err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
88 hts221_trigger_handler_thread,
89 irq_type | IRQF_ONESHOT,
90 hw->name, hw);
91 if (err) {
92 dev_err(hw->dev, "failed to request trigger irq %d\n",
93 hw->irq);
94 return err;
95 }
96
97 hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
98 iio_dev->name);
99 if (!hw->trig)
100 return -ENOMEM;
101
102 iio_trigger_set_drvdata(hw->trig, iio_dev);
103 hw->trig->ops = &hts221_trigger_ops;
104 hw->trig->dev.parent = hw->dev;
105 iio_dev->trig = iio_trigger_get(hw->trig);
106
107 return devm_iio_trigger_register(hw->dev, hw->trig);
108}
109
110static int hts221_buffer_preenable(struct iio_dev *iio_dev)
111{
112 return hts221_power_on(iio_priv(iio_dev));
113}
114
115static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
116{
117 return hts221_power_off(iio_priv(iio_dev));
118}
119
120static const struct iio_buffer_setup_ops hts221_buffer_ops = {
121 .preenable = hts221_buffer_preenable,
122 .postenable = iio_triggered_buffer_postenable,
123 .predisable = iio_triggered_buffer_predisable,
124 .postdisable = hts221_buffer_postdisable,
125};
126
127static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
128{
129 u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)];
130 struct iio_poll_func *pf = p;
131 struct iio_dev *iio_dev = pf->indio_dev;
132 struct hts221_hw *hw = iio_priv(iio_dev);
133 struct iio_chan_spec const *ch;
134 int err;
135
136 /* humidity data */
137 ch = &iio_dev->channels[HTS221_SENSOR_H];
138 err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
139 buffer);
140 if (err < 0)
141 goto out;
142
143 /* temperature data */
144 ch = &iio_dev->channels[HTS221_SENSOR_T];
145 err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
146 buffer + HTS221_DATA_SIZE);
147 if (err < 0)
148 goto out;
149
150 iio_push_to_buffers_with_timestamp(iio_dev, buffer,
151 iio_get_time_ns(iio_dev));
152
153out:
154 iio_trigger_notify_done(hw->trig);
155
156 return IRQ_HANDLED;
157}
158
159int hts221_allocate_buffers(struct hts221_hw *hw)
160{
161 return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
162 NULL, hts221_buffer_handler_thread,
163 &hts221_buffer_ops);
164}
165
166MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
167MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
168MODULE_LICENSE("GPL v2");