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