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(indio_dev: iio_dev);
43
44 return regmap_update_bits(map: 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(map: hw->regmap, HTS221_REG_STATUS_ADDR, val: &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(trig: 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(indio_dev: iio_dev);
79 struct st_sensors_platform_data *pdata = dev_get_platdata(dev: 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(d: irq_get_irq_data(irq: 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(map: 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(dev: hw->dev, propname: "drive-open-drain") ||
110 (pdata && pdata->open_drain)) {
111 irq_type |= IRQF_SHARED;
112 open_drain = true;
113 }
114
115 err = regmap_update_bits(map: 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(dev: hw->dev, irq: hw->irq, NULL,
123 thread_fn: hts221_trigger_handler_thread,
124 irqflags: irq_type | IRQF_ONESHOT,
125 devname: hw->name, dev_id: 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(trig: hw->trig, data: iio_dev);
138 hw->trig->ops = &hts221_trigger_ops;
139
140 err = devm_iio_trigger_register(dev: hw->dev, trig_info: hw->trig);
141
142 iio_dev->trig = iio_trigger_get(trig: hw->trig);
143
144 return err;
145}
146
147static int hts221_buffer_preenable(struct iio_dev *iio_dev)
148{
149 return hts221_set_enable(hw: iio_priv(indio_dev: iio_dev), enable: true);
150}
151
152static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
153{
154 return hts221_set_enable(hw: iio_priv(indio_dev: iio_dev), enable: 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(indio_dev: 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(map: hw->regmap, reg: ch->address,
173 val: &hw->scan.channels[0],
174 val_count: 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(map: hw->regmap, reg: ch->address,
181 val: &hw->scan.channels[1],
182 val_count: sizeof(hw->scan.channels[1]));
183 if (err < 0)
184 goto out;
185
186 iio_push_to_buffers_with_timestamp(indio_dev: iio_dev, data: &hw->scan,
187 timestamp: iio_get_time_ns(indio_dev: iio_dev));
188
189out:
190 iio_trigger_notify_done(trig: 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(indio_dev: 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

source code of linux/drivers/iio/humidity/hts221_buffer.c