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
hts221_trig_set_state(struct iio_trigger * trig,bool state)39 static 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
49 static const struct iio_trigger_ops hts221_trigger_ops = {
50 .set_trigger_state = hts221_trig_set_state,
51 };
52
hts221_trigger_handler_thread(int irq,void * private)53 static 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
hts221_allocate_trigger(struct iio_dev * iio_dev)76 int 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
hts221_buffer_preenable(struct iio_dev * iio_dev)147 static int hts221_buffer_preenable(struct iio_dev *iio_dev)
148 {
149 return hts221_set_enable(iio_priv(iio_dev), true);
150 }
151
hts221_buffer_postdisable(struct iio_dev * iio_dev)152 static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
153 {
154 return hts221_set_enable(iio_priv(iio_dev), false);
155 }
156
157 static const struct iio_buffer_setup_ops hts221_buffer_ops = {
158 .preenable = hts221_buffer_preenable,
159 .postdisable = hts221_buffer_postdisable,
160 };
161
hts221_buffer_handler_thread(int irq,void * p)162 static 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
189 out:
190 iio_trigger_notify_done(hw->trig);
191
192 return IRQ_HANDLED;
193 }
194
hts221_allocate_buffers(struct iio_dev * iio_dev)195 int 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
203 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
204 MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
205 MODULE_LICENSE("GPL v2");
206