2 * STMicroelectronics hts221 sensor driver
4 * Copyright 2016 STMicroelectronics Inc.
6 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
8 * Licensed under the GPL-2.
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>
16 #include <linux/iio/iio.h>
17 #include <linux/iio/trigger.h>
18 #include <linux/iio/events.h>
19 #include <linux/iio/trigger_consumer.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/buffer.h>
23 #include <linux/platform_data/st_sensors_pdata.h>
27 #define HTS221_REG_DRDY_HL_ADDR 0x22
28 #define HTS221_REG_DRDY_HL_MASK BIT(7)
29 #define HTS221_REG_DRDY_PP_OD_ADDR 0x22
30 #define HTS221_REG_DRDY_PP_OD_MASK BIT(6)
31 #define HTS221_REG_DRDY_EN_ADDR 0x22
32 #define HTS221_REG_DRDY_EN_MASK BIT(2)
33 #define HTS221_REG_STATUS_ADDR 0x27
34 #define HTS221_RH_DRDY_MASK BIT(1)
35 #define HTS221_TEMP_DRDY_MASK BIT(0)
37 static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
39 struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
40 struct hts221_hw *hw = iio_priv(iio_dev);
43 err = hts221_write_with_mask(hw, HTS221_REG_DRDY_EN_ADDR,
44 HTS221_REG_DRDY_EN_MASK, state);
46 return err < 0 ? err : 0;
49 static const struct iio_trigger_ops hts221_trigger_ops = {
51 .set_trigger_state = hts221_trig_set_state,
54 static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
56 struct hts221_hw *hw = private;
60 err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
66 * H_DA bit (humidity data available) is routed to DRDY line.
67 * Humidity sample is computed after temperature one.
68 * Here we can assume data channels are both available if H_DA bit
69 * is set in status register
71 if (!(status & HTS221_RH_DRDY_MASK))
74 iio_trigger_poll_chained(hw->trig);
79 int hts221_allocate_trigger(struct hts221_hw *hw)
81 struct iio_dev *iio_dev = iio_priv_to_dev(hw);
82 bool irq_active_low = false, open_drain = false;
83 struct device_node *np = hw->dev->of_node;
84 struct st_sensors_platform_data *pdata;
85 unsigned long irq_type;
88 irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
91 case IRQF_TRIGGER_HIGH:
92 case IRQF_TRIGGER_RISING:
94 case IRQF_TRIGGER_LOW:
95 case IRQF_TRIGGER_FALLING:
96 irq_active_low = true;
100 "mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
102 irq_type = IRQF_TRIGGER_RISING;
106 err = hts221_write_with_mask(hw, HTS221_REG_DRDY_HL_ADDR,
107 HTS221_REG_DRDY_HL_MASK, irq_active_low);
111 pdata = (struct st_sensors_platform_data *)hw->dev->platform_data;
112 if ((np && of_property_read_bool(np, "drive-open-drain")) ||
113 (pdata && pdata->open_drain)) {
114 irq_type |= IRQF_SHARED;
118 err = hts221_write_with_mask(hw, HTS221_REG_DRDY_PP_OD_ADDR,
119 HTS221_REG_DRDY_PP_OD_MASK,
124 err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
125 hts221_trigger_handler_thread,
126 irq_type | IRQF_ONESHOT,
129 dev_err(hw->dev, "failed to request trigger irq %d\n",
134 hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
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);
144 return devm_iio_trigger_register(hw->dev, hw->trig);
147 static int hts221_buffer_preenable(struct iio_dev *iio_dev)
149 return hts221_set_enable(iio_priv(iio_dev), true);
152 static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
154 return hts221_set_enable(iio_priv(iio_dev), false);
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,
164 static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
166 u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)];
167 struct iio_poll_func *pf = p;
168 struct iio_dev *iio_dev = pf->indio_dev;
169 struct hts221_hw *hw = iio_priv(iio_dev);
170 struct iio_chan_spec const *ch;
174 ch = &iio_dev->channels[HTS221_SENSOR_H];
175 err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
180 /* temperature data */
181 ch = &iio_dev->channels[HTS221_SENSOR_T];
182 err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
183 buffer + HTS221_DATA_SIZE);
187 iio_push_to_buffers_with_timestamp(iio_dev, buffer,
188 iio_get_time_ns(iio_dev));
191 iio_trigger_notify_done(hw->trig);
196 int hts221_allocate_buffers(struct hts221_hw *hw)
198 return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
199 NULL, hts221_buffer_handler_thread,
203 MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
204 MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
205 MODULE_LICENSE("GPL v2");