1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * STMicroelectronics hts221 sensor driver
4 *
5 * Copyright 2016 STMicroelectronics Inc.
6 *
7 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
8 */
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/device.h>
12#include <linux/interrupt.h>
13#include <linux/irqreturn.h>
14#include <linux/property.h>
15#include <linux/regmap.h>
16#include <linux/bitfield.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/trigger.h>
20#include <linux/iio/events.h>
21#include <linux/iio/trigger_consumer.h>
22#include <linux/iio/triggered_buffer.h>
23#include <linux/iio/buffer.h>
24
25#include <linux/platform_data/st_sensors_pdata.h>
26
27#include "hts221.h"
28
29#define HTS221_REG_DRDY_HL_ADDR		0x22
30#define HTS221_REG_DRDY_HL_MASK		BIT(7)
31#define HTS221_REG_DRDY_PP_OD_ADDR	0x22
32#define HTS221_REG_DRDY_PP_OD_MASK	BIT(6)
33#define HTS221_REG_DRDY_EN_ADDR		0x22
34#define HTS221_REG_DRDY_EN_MASK		BIT(2)
35#define HTS221_REG_STATUS_ADDR		0x27
36#define HTS221_RH_DRDY_MASK		BIT(1)
37#define HTS221_TEMP_DRDY_MASK		BIT(0)
38
39static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
40{
41	struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
42	struct hts221_hw *hw = iio_priv(iio_dev);
43
44	return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR,
45				  HTS221_REG_DRDY_EN_MASK,
46				  FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state));
47}
48
49static const struct iio_trigger_ops hts221_trigger_ops = {
50	.set_trigger_state = hts221_trig_set_state,
51};
52
53static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
54{
55	struct hts221_hw *hw = private;
56	int err, status;
57
58	err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status);
59	if (err < 0)
60		return IRQ_HANDLED;
61
62	/*
63	 * H_DA bit (humidity data available) is routed to DRDY line.
64	 * Humidity sample is computed after temperature one.
65	 * Here we can assume data channels are both available if H_DA bit
66	 * is set in status register
67	 */
68	if (!(status & HTS221_RH_DRDY_MASK))
69		return IRQ_NONE;
70
71	iio_trigger_poll_nested(hw->trig);
72
73	return IRQ_HANDLED;
74}
75
76int hts221_allocate_trigger(struct iio_dev *iio_dev)
77{
78	struct hts221_hw *hw = iio_priv(iio_dev);
79	struct st_sensors_platform_data *pdata = dev_get_platdata(hw->dev);
80	bool irq_active_low = false, open_drain = false;
81	unsigned long irq_type;
82	int err;
83
84	irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
85
86	switch (irq_type) {
87	case IRQF_TRIGGER_HIGH:
88	case IRQF_TRIGGER_RISING:
89		break;
90	case IRQF_TRIGGER_LOW:
91	case IRQF_TRIGGER_FALLING:
92		irq_active_low = true;
93		break;
94	default:
95		dev_info(hw->dev,
96			 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
97			 irq_type);
98		irq_type = IRQF_TRIGGER_RISING;
99		break;
100	}
101
102	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR,
103				 HTS221_REG_DRDY_HL_MASK,
104				 FIELD_PREP(HTS221_REG_DRDY_HL_MASK,
105					    irq_active_low));
106	if (err < 0)
107		return err;
108
109	if (device_property_read_bool(hw->dev, "drive-open-drain") ||
110	    (pdata && pdata->open_drain)) {
111		irq_type |= IRQF_SHARED;
112		open_drain = true;
113	}
114
115	err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR,
116				 HTS221_REG_DRDY_PP_OD_MASK,
117				 FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK,
118					    open_drain));
119	if (err < 0)
120		return err;
121
122	err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
123					hts221_trigger_handler_thread,
124					irq_type | IRQF_ONESHOT,
125					hw->name, hw);
126	if (err) {
127		dev_err(hw->dev, "failed to request trigger irq %d\n",
128			hw->irq);
129		return err;
130	}
131
132	hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
133					  iio_dev->name);
134	if (!hw->trig)
135		return -ENOMEM;
136
137	iio_trigger_set_drvdata(hw->trig, iio_dev);
138	hw->trig->ops = &hts221_trigger_ops;
139
140	err = devm_iio_trigger_register(hw->dev, hw->trig);
141
142	iio_dev->trig = iio_trigger_get(hw->trig);
143
144	return err;
145}
146
147static int hts221_buffer_preenable(struct iio_dev *iio_dev)
148{
149	return hts221_set_enable(iio_priv(iio_dev), true);
150}
151
152static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
153{
154	return hts221_set_enable(iio_priv(iio_dev), false);
155}
156
157static const struct iio_buffer_setup_ops hts221_buffer_ops = {
158	.preenable = hts221_buffer_preenable,
159	.postdisable = hts221_buffer_postdisable,
160};
161
162static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
163{
164	struct iio_poll_func *pf = p;
165	struct iio_dev *iio_dev = pf->indio_dev;
166	struct hts221_hw *hw = iio_priv(iio_dev);
167	struct iio_chan_spec const *ch;
168	int err;
169
170	/* humidity data */
171	ch = &iio_dev->channels[HTS221_SENSOR_H];
172	err = regmap_bulk_read(hw->regmap, ch->address,
173			       &hw->scan.channels[0],
174			       sizeof(hw->scan.channels[0]));
175	if (err < 0)
176		goto out;
177
178	/* temperature data */
179	ch = &iio_dev->channels[HTS221_SENSOR_T];
180	err = regmap_bulk_read(hw->regmap, ch->address,
181			       &hw->scan.channels[1],
182			       sizeof(hw->scan.channels[1]));
183	if (err < 0)
184		goto out;
185
186	iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
187					   iio_get_time_ns(iio_dev));
188
189out:
190	iio_trigger_notify_done(hw->trig);
191
192	return IRQ_HANDLED;
193}
194
195int hts221_allocate_buffers(struct iio_dev *iio_dev)
196{
197	struct hts221_hw *hw = iio_priv(iio_dev);
198	return devm_iio_triggered_buffer_setup(hw->dev, iio_dev,
199					NULL, hts221_buffer_handler_thread,
200					&hts221_buffer_ops);
201}
202
203MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
204MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
205MODULE_LICENSE("GPL v2");
206