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 
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 
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_chained(hw->trig);
72 
73 	return IRQ_HANDLED;
74 }
75 
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 
147 static int hts221_buffer_preenable(struct iio_dev *iio_dev)
148 {
149 	return hts221_set_enable(iio_priv(iio_dev), true);
150 }
151 
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 
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 
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