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/*
* STMicroelectronics hts221 sensor driver
*
* Copyright 2016 STMicroelectronics Inc.
*
* Lorenzo Bianconi <lorenzo.bianconi@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/irqreturn.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 "hts221.h"
#define HTS221_REG_DRDY_HL_ADDR 0x22
#define HTS221_REG_DRDY_HL_MASK BIT(7)
#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 hts221_config_drdy(hw, state);
}
static const struct iio_trigger_ops hts221_trigger_ops = {
.owner = THIS_MODULE,
.set_trigger_state = hts221_trig_set_state,
};
static irqreturn_t hts221_trigger_handler_thread(int irq, void *private)
{
struct hts221_hw *hw = private;
u8 status;
int err;
err = hw->tf->read(hw->dev, HTS221_REG_STATUS_ADDR, sizeof(status),
&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_chained(hw->trig);
return IRQ_HANDLED;
}
int hts221_allocate_trigger(struct hts221_hw *hw)
{
struct iio_dev *iio_dev = iio_priv_to_dev(hw);
bool irq_active_low = false;
unsigned long irq_type;
int err;
irq_type = irqd_get_trigger_type(irq_get_irq_data(hw->irq));
switch (irq_type) {
case IRQF_TRIGGER_HIGH:
case IRQF_TRIGGER_RISING:
break;
case IRQF_TRIGGER_LOW:
case IRQF_TRIGGER_FALLING:
irq_active_low = true;
break;
default:
dev_info(hw->dev,
"mode %lx unsupported, using IRQF_TRIGGER_RISING\n",
irq_type);
irq_type = IRQF_TRIGGER_RISING;
break;
}
err = hts221_write_with_mask(hw, HTS221_REG_DRDY_HL_ADDR,
HTS221_REG_DRDY_HL_MASK, irq_active_low);
if (err < 0)
return err;
err = devm_request_threaded_irq(hw->dev, hw->irq, NULL,
hts221_trigger_handler_thread,
irq_type | IRQF_ONESHOT,
hw->name, hw);
if (err) {
dev_err(hw->dev, "failed to request trigger irq %d\n",
hw->irq);
return err;
}
hw->trig = devm_iio_trigger_alloc(hw->dev, "%s-trigger",
iio_dev->name);
if (!hw->trig)
return -ENOMEM;
iio_trigger_set_drvdata(hw->trig, iio_dev);
hw->trig->ops = &hts221_trigger_ops;
hw->trig->dev.parent = hw->dev;
iio_dev->trig = iio_trigger_get(hw->trig);
return devm_iio_trigger_register(hw->dev, hw->trig);
}
static int hts221_buffer_preenable(struct iio_dev *iio_dev)
{
return hts221_set_enable(iio_priv(iio_dev), true);
}
static int hts221_buffer_postdisable(struct iio_dev *iio_dev)
{
return hts221_set_enable(iio_priv(iio_dev), false);
}
static const struct iio_buffer_setup_ops hts221_buffer_ops = {
.preenable = hts221_buffer_preenable,
.postenable = iio_triggered_buffer_postenable,
.predisable = iio_triggered_buffer_predisable,
.postdisable = hts221_buffer_postdisable,
};
static irqreturn_t hts221_buffer_handler_thread(int irq, void *p)
{
u8 buffer[ALIGN(2 * HTS221_DATA_SIZE, sizeof(s64)) + sizeof(s64)];
struct iio_poll_func *pf = p;
struct iio_dev *iio_dev = pf->indio_dev;
struct hts221_hw *hw = iio_priv(iio_dev);
struct iio_chan_spec const *ch;
int err;
/* humidity data */
ch = &iio_dev->channels[HTS221_SENSOR_H];
err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
buffer);
if (err < 0)
goto out;
/* temperature data */
ch = &iio_dev->channels[HTS221_SENSOR_T];
err = hw->tf->read(hw->dev, ch->address, HTS221_DATA_SIZE,
buffer + HTS221_DATA_SIZE);
if (err < 0)
goto out;
iio_push_to_buffers_with_timestamp(iio_dev, buffer,
iio_get_time_ns(iio_dev));
out:
iio_trigger_notify_done(hw->trig);
return IRQ_HANDLED;
}
int hts221_allocate_buffers(struct hts221_hw *hw)
{
return devm_iio_triggered_buffer_setup(hw->dev, iio_priv_to_dev(hw),
NULL, hts221_buffer_handler_thread,
&hts221_buffer_ops);
}
MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
MODULE_DESCRIPTION("STMicroelectronics hts221 buffer driver");
MODULE_LICENSE("GPL v2");
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