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
 38static 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
 48static const struct iio_trigger_ops hts221_trigger_ops = {
 49	.set_trigger_state = hts221_trig_set_state,
 50};
 51
 52static 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
 75int 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	hw->trig->dev.parent = hw->dev;
139	iio_dev->trig = iio_trigger_get(hw->trig);
140
141	return devm_iio_trigger_register(hw->dev, hw->trig);
142}
143
144static int hts221_buffer_preenable(struct iio_dev *iio_dev)
145{
146	return hts221_set_enable(iio_priv(iio_dev), true);
147}
148
149static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
150{
151	return hts221_set_enable(iio_priv(iio_dev), false);
152}
153
154static const struct iio_buffer_setup_ops hts221_buffer_ops = {
155	.preenable = hts221_buffer_preenable,
156	.postdisable = hts221_buffer_postdisable,
157};
158
159static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
160{
161	struct iio_poll_func *pf = p;
162	struct iio_dev *iio_dev = pf->indio_dev;
163	struct hts221_hw *hw = iio_priv(iio_dev);
164	struct iio_chan_spec const *ch;
165	int err;
166
167	/* humidity data */
168	ch = &iio_dev->channels[HTS221_SENSOR_H];
169	err = regmap_bulk_read(hw->regmap, ch->address,
170			       &hw->scan.channels[0],
171			       sizeof(hw->scan.channels[0]));
172	if (err < 0)
173		goto out;
174
175	/* temperature data */
176	ch = &iio_dev->channels[HTS221_SENSOR_T];
177	err = regmap_bulk_read(hw->regmap, ch->address,
178			       &hw->scan.channels[1],
179			       sizeof(hw->scan.channels[1]));
180	if (err < 0)
181		goto out;
182
183	iio_push_to_buffers_with_timestamp(iio_dev, &hw->scan,
184					   iio_get_time_ns(iio_dev));
185
186out:
187	iio_trigger_notify_done(hw->trig);
188
189	return IRQ_HANDLED;
190}
191
192int hts221_allocate_buffers(struct iio_dev *iio_dev)
193{
194	struct hts221_hw *hw = iio_priv(iio_dev);
195	return devm_iio_triggered_buffer_setup(hw->dev, iio_dev,
196					NULL, hts221_buffer_handler_thread,
197					&hts221_buffer_ops);
198}
199
200MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
201MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
202MODULE_LICENSE("GPL v2");