drivers/iio/humidity/hts221_buffer.c

Source file repositories/reference/linux-study-clean/drivers/iio/humidity/hts221_buffer.c

File Facts

System
Linux kernel
Corpus path
drivers/iio/humidity/hts221_buffer.c
Extension
.c
Size
5317 bytes
Lines
205
Domain
Driver Families
Bucket
drivers/iio
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * STMicroelectronics hts221 sensor driver
 *
 * Copyright 2016 STMicroelectronics Inc.
 *
 * Lorenzo Bianconi <lorenzo.bianconi@st.com>
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/bitfield.h>

#include <linux/iio/iio.h>
#include <linux/iio/trigger.h>
#include <linux/iio/events.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/buffer.h>

#include <linux/platform_data/st_sensors_pdata.h>

#include "hts221.h"

#define HTS221_REG_DRDY_HL_ADDR		0x22
#define HTS221_REG_DRDY_HL_MASK		BIT(7)
#define HTS221_REG_DRDY_PP_OD_ADDR	0x22
#define HTS221_REG_DRDY_PP_OD_MASK	BIT(6)
#define HTS221_REG_DRDY_EN_ADDR		0x22
#define HTS221_REG_DRDY_EN_MASK		BIT(2)
#define HTS221_REG_STATUS_ADDR		0x27
#define HTS221_RH_DRDY_MASK		BIT(1)
#define HTS221_TEMP_DRDY_MASK		BIT(0)

static int hts221_trig_set_state(struct iio_trigger *trig, bool state)
{
	struct iio_dev *iio_dev = iio_trigger_get_drvdata(trig);
	struct hts221_hw *hw = iio_priv(iio_dev);

	return regmap_update_bits(hw->regmap, HTS221_REG_DRDY_EN_ADDR,
				  HTS221_REG_DRDY_EN_MASK,
				  FIELD_PREP(HTS221_REG_DRDY_EN_MASK, state));
}

static const struct iio_trigger_ops hts221_trigger_ops = {
	.set_trigger_state = hts221_trig_set_state,
};

static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
{
	struct hts221_hw *hw = private;
	int err, status;

	err = regmap_read(hw->regmap, HTS221_REG_STATUS_ADDR, &status);
	if (err < 0)
		return IRQ_HANDLED;

	/*
	 * H_DA bit (humidity data available) is routed to DRDY line.
	 * Humidity sample is computed after temperature one.
	 * Here we can assume data channels are both available if H_DA bit
	 * is set in status register
	 */
	if (!(status & HTS221_RH_DRDY_MASK))
		return IRQ_NONE;

	iio_trigger_poll_nested(hw->trig);

	return IRQ_HANDLED;
}

int hts221_allocate_trigger(struct iio_dev *iio_dev)
{
	struct hts221_hw *hw = iio_priv(iio_dev);
	struct st_sensors_platform_data *pdata = dev_get_platdata(hw->dev);
	bool irq_active_low = false, open_drain = false;
	unsigned long irq_type;
	int err;

	irq_type = irq_get_trigger_type(hw->irq);
	switch (irq_type) {
	case IRQF_TRIGGER_HIGH:
	case IRQF_TRIGGER_RISING:
		break;
	case IRQF_TRIGGER_LOW:
	case IRQF_TRIGGER_FALLING:

Annotation

Implementation Notes