1 /*
2 * STMicroelectronics hts221 sensor driver
3 *
4 * Copyright 2016 STMicroelectronics Inc.
5 *
6 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
7 *
8 * Licensed under the GPL-2.
9 */
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/interrupt.h>
14 #include <linux/irqreturn.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_chained(hw->trig);
72
73 return IRQ_HANDLED;
74 }
75
hts221_allocate_trigger(struct hts221_hw * hw)76 int hts221_allocate_trigger(struct hts221_hw *hw)
77 {
78 struct iio_dev *iio_dev = iio_priv_to_dev(hw);
79 bool irq_active_low = false, open_drain = false;
80 struct device_node *np = hw->dev->of_node;
81 struct st_sensors_platform_data *pdata;
82 unsigned long irq_type;
83 int err;
84
85 irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
86
87 switch (irq_type) {
88 case IRQF_TRIGGER_HIGH:
89 case IRQF_TRIGGER_RISING:
90 break;
91 case IRQF_TRIGGER_LOW:
92 case IRQF_TRIGGER_FALLING:
93 irq_active_low = true;
94 break;
95 default:
96 dev_info(hw->dev,
97 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
98 irq_type);
99 irq_type = IRQF_TRIGGER_RISING;
100 break;
101 }
102
103 err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_HL_ADDR,
104 HTS221_REG_DRDY_HL_MASK,
105 FIELD_PREP(HTS221_REG_DRDY_HL_MASK,
106 irq_active_low));
107 if (err < 0)
108 return err;
109
110 pdata = (struct st_sensors_platform_data *)hw->dev->platform_data;
111 if ((np && of_property_read_bool(np, "drive-open-drain")) ||
112 (pdata && pdata->open_drain)) {
113 irq_type |= IRQF_SHARED;
114 open_drain = true;
115 }
116
117 err = regmap_update_bits(hw->regmap, HTS221_REG_DRDY_PP_OD_ADDR,
118 HTS221_REG_DRDY_PP_OD_MASK,
119 FIELD_PREP(HTS221_REG_DRDY_PP_OD_MASK,
120 open_drain));
121 if (err < 0)
122 return err;
123
124 err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
125 hts221_trigger_handler_thread,
126 irq_type | IRQF_ONESHOT,
127 hw->name, hw);
128 if (err) {
129 dev_err(hw->dev, "failed to request trigger irq %d\n",
130 hw->irq);
131 return err;
132 }
133
134 hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
135 iio_dev->name);
136 if (!hw->trig)
137 return -ENOMEM;
138
139 iio_trigger_set_drvdata(hw->trig, iio_dev);
140 hw->trig->ops = &hts221_trigger_ops;
141 hw->trig->dev.parent = hw->dev;
142 iio_dev->trig = iio_trigger_get(hw->trig);
143
144 return devm_iio_trigger_register(hw->dev, hw->trig);
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 .postenable = iio_triggered_buffer_postenable,
160 .predisable = iio_triggered_buffer_predisable,
161 .postdisable = hts221_buffer_postdisable,
162 };
163
hts221_buffer_handler_thread(int irq,void * p)164 static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
165 {
166 struct iio_poll_func *pf = p;
167 struct iio_dev *iio_dev = pf->indio_dev;
168 struct hts221_hw *hw = iio_priv(iio_dev);
169 struct iio_chan_spec const *ch;
170 int err;
171
172 /* humidity data */
173 ch = &iio_dev->channels[HTS221_SENSOR_H];
174 err = regmap_bulk_read(hw->regmap, ch->address,
175 &hw->scan.channels[0],
176 sizeof(hw->scan.channels[0]));
177 if (err < 0)
178 goto out;
179
180 /* temperature data */
181 ch = &iio_dev->channels[HTS221_SENSOR_T];
182 err = regmap_bulk_read(hw->regmap, ch->address,
183 &hw->scan.channels[1],
184 sizeof(hw->scan.channels[1]));
185 if (err < 0)
186 goto out;
187
188 iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
189 iio_get_time_ns(iio_dev));
190
191 out:
192 iio_trigger_notify_done(hw->trig);
193
194 return IRQ_HANDLED;
195 }
196
hts221_allocate_buffers(struct hts221_hw * hw)197 int hts221_allocate_buffers(struct hts221_hw *hw)
198 {
199 return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
200 NULL, hts221_buffer_handler_thread,
201 &hts221_buffer_ops);
202 }
203
204 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
205 MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
206 MODULE_LICENSE("GPL v2");
207