summaryrefslogtreecommitdiffstats
path: root/drivers/iio/humidity/hts221_buffer.c
blob: 2a4107a796622521582c1b7512ba4e62702546ed (plain)
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
205
// SPDX-License-Identifier: GPL-2.0-only
/*
 * STMicroelectronics hts221 sensor driver
 *
 * Copyright 2016 STMicroelectronics Inc.
 *
 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/bitfield.h>

#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/buffer.h>

#include <linux/platform_data/st_sensors_pdata.h>

#include "hts221.h"

#define HTS221_REG_DRDY_HL_ADDR		0x22
#define HTS221_REG_DRDY_HL_MASK		BIT(7)
#define HTS221_REG_DRDY_PP_OD_ADDR	0x22
#define HTS221_REG_DRDY_PP_OD_MASK	BIT(6)
#define HTS221_REG_DRDY_EN_ADDR		0x22
#define HTS221_REG_DRDY_EN_MASK		BIT(2)
#define HTS221_REG_STATUS_ADDR		0x27
#define HTS221_RH_DRDY_MASK		BIT(1)
#define HTS221_TEMP_DRDY_MASK		BIT(0)

static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
{
	struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
	struct hts221_hw *hw = iio_priv(iio_dev);

	return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR,
				  HTS221_REG_DRDY_EN_MASK,
				  FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state));
}

static const struct iio_trigger_ops hts221_trigger_ops = {
	.set_trigger_state = hts221_trig_set_state,
};

static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
{
	struct hts221_hw *hw = private;
	int err, status;

	err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status);
	if (err < 0)
		return IRQ_HANDLED;

	/*
	 * H_DA bit (humidity data available) is routed to DRDY line.
	 * Humidity sample is computed after temperature one.
	 * Here we can assume data channels are both available if H_DA bit
	 * is set in status register
	 */
	if (!(status & HTS221_RH_DRDY_MASK))
		return IRQ_NONE;

	iio_trigger_poll_chained(hw->trig);

	return IRQ_HANDLED;
}

int hts221_allocate_trigger(struct iio_dev *iio_dev)
{
	struct hts221_hw *hw = iio_priv(iio_dev);
	struct st_sensors_platform_data *pdata = dev_get_platdata(hw->dev);
	bool irq_active_low = false, open_drain = false;
	unsigned long irq_type;
	int err;

	irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));

	switch (irq_type) {
	case IRQF_TRIGGER_HIGH:
	case IRQF_TRIGGER_RISING:
		break;
	case IRQF_TRIGGER_LOW:
	case IRQF_TRIGGER_FALLING:
		irq_active_low = true;
		break;
	default:
		dev_info(hw->dev,
			 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
			 irq_type);
		irq_type = IRQF_TRIGGER_RISING;
		break;
	}

	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR,
				 HTS221_REG_DRDY_HL_MASK,
				 FIELD_PREP(HTS221_REG_DRDY_HL_MASK,
					    irq_active_low));
	if (err < 0)
		return err;

	if (device_property_read_bool(hw->dev, "drive-open-drain") ||
	    (pdata && pdata->open_drain)) {
		irq_type |= IRQF_SHARED;
		open_drain = true;
	}

	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR,
				 HTS221_REG_DRDY_PP_OD_MASK,
				 FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK,
					    open_drain));
	if (err < 0)
		return err;

	err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
					hts221_trigger_handler_thread,
					irq_type | IRQF_ONESHOT,
					hw->name, hw);
	if (err) {
		dev_err(hw->dev, "failed to request trigger irq %d\n",
			hw->irq);
		return err;
	}

	hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
					  iio_dev->name);
	if (!hw->trig)
		return -ENOMEM;

	iio_trigger_set_drvdata(hw->trig, iio_dev);
	hw->trig->ops = &hts221_trigger_ops;

	err = devm_iio_trigger_register(hw->dev, hw->trig);

	iio_dev->trig = iio_trigger_get(hw->trig);

	return err;
}

static int hts221_buffer_preenable(struct iio_dev *iio_dev)
{
	return hts221_set_enable(iio_priv(iio_dev), true);
}

static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
{
	return hts221_set_enable(iio_priv(iio_dev), false);
}

static const struct iio_buffer_setup_ops hts221_buffer_ops = {
	.preenable = hts221_buffer_preenable,
	.postdisable = hts221_buffer_postdisable,
};

static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *iio_dev = pf->indio_dev;
	struct hts221_hw *hw = iio_priv(iio_dev);
	struct iio_chan_spec const *ch;
	int err;

	/* humidity data */
	ch = &iio_dev->channels[HTS221_SENSOR_H];
	err = regmap_bulk_read(hw->regmap, ch->address,
			       &hw->scan.channels[0],
			       sizeof(hw->scan.channels[0]));
	if (err < 0)
		goto out;

	/* temperature data */
	ch = &iio_dev->channels[HTS221_SENSOR_T];
	err = regmap_bulk_read(hw->regmap, ch->address,
			       &hw->scan.channels[1],
			       sizeof(hw->scan.channels[1]));
	if (err < 0)
		goto out;

	iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
					   iio_get_time_ns(iio_dev));

out:
	iio_trigger_notify_done(hw->trig);

	return IRQ_HANDLED;
}

int hts221_allocate_buffers(struct iio_dev *iio_dev)
{
	struct hts221_hw *hw = iio_priv(iio_dev);
	return devm_iio_triggered_buffer_setup(hw->dev, iio_dev,
					NULL, hts221_buffer_handler_thread,
					&hts221_buffer_ops);
}

MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
MODULE_LICENSE("GPL v2");