![Gregor Boirie](/assets/img/avatar_default.png)
Introduce driver for Murata ZPA2326 pressure and temperature sensor: http://www.murata.com/en-us/products/productdetail?partno=ZPA2326-0311A-R Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
1736 lines
48 KiB
C
1736 lines
48 KiB
C
/*
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* Murata ZPA2326 pressure and temperature sensor IIO driver
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*
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* Copyright (c) 2016 Parrot S.A.
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*
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* Author: Gregor Boirie <gregor.boirie@parrot.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*/
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/**
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* DOC: ZPA2326 theory of operations
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*
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* This driver supports %INDIO_DIRECT_MODE and %INDIO_BUFFER_TRIGGERED IIO
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* modes.
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* A internal hardware trigger is also implemented to dispatch registered IIO
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* trigger consumers upon "sample ready" interrupts.
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*
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* ZPA2326 hardware supports 2 sampling mode: one shot and continuous.
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*
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* A complete one shot sampling cycle gets device out of low power mode,
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* performs pressure and temperature measurements, then automatically switches
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* back to low power mode. It is meant for on demand sampling with optimal power
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* saving at the cost of lower sampling rate and higher software overhead.
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* This is a natural candidate for IIO read_raw hook implementation
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* (%INDIO_DIRECT_MODE). It is also used for triggered buffering support to
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* ensure explicit synchronization with external trigger events
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* (%INDIO_BUFFER_TRIGGERED).
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*
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* The continuous mode works according to a periodic hardware measurement
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* process continuously pushing samples into an internal hardware FIFO (for
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* pressure samples only). Measurement cycle completion may be signaled by a
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* "sample ready" interrupt.
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* Typical software sequence of operations :
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* - get device out of low power mode,
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* - setup hardware sampling period,
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* - at end of period, upon data ready interrupt: pop pressure samples out of
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* hardware FIFO and fetch temperature sample
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* - when no longer needed, stop sampling process by putting device into
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* low power mode.
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* This mode is used to implement %INDIO_BUFFER_TRIGGERED mode if device tree
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* declares a valid interrupt line. In this case, the internal hardware trigger
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* drives acquisition.
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*
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* Note that hardware sampling frequency is taken into account only when
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* internal hardware trigger is attached as the highest sampling rate seems to
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* be the most energy efficient.
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*
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* TODO:
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* preset pressure threshold crossing / IIO events ;
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* differential pressure sampling ;
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* hardware samples averaging.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/regulator/consumer.h>
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#include <linux/pm_runtime.h>
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#include <linux/regmap.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/trigger.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include "zpa2326.h"
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/* 200 ms should be enough for the longest conversion time in one-shot mode. */
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#define ZPA2326_CONVERSION_JIFFIES (HZ / 5)
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/* There should be a 1 ms delay (Tpup) after getting out of reset. */
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#define ZPA2326_TPUP_USEC_MIN (1000)
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#define ZPA2326_TPUP_USEC_MAX (2000)
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/**
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* struct zpa2326_frequency - Hardware sampling frequency descriptor
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* @hz : Frequency in Hertz.
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* @odr: Output Data Rate word as expected by %ZPA2326_CTRL_REG3_REG.
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*/
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struct zpa2326_frequency {
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int hz;
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u16 odr;
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};
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/*
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* Keep these in strict ascending order: last array entry is expected to
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* correspond to the highest sampling frequency.
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*/
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static const struct zpa2326_frequency zpa2326_sampling_frequencies[] = {
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{ .hz = 1, .odr = 1 << ZPA2326_CTRL_REG3_ODR_SHIFT },
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{ .hz = 5, .odr = 5 << ZPA2326_CTRL_REG3_ODR_SHIFT },
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{ .hz = 11, .odr = 6 << ZPA2326_CTRL_REG3_ODR_SHIFT },
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{ .hz = 23, .odr = 7 << ZPA2326_CTRL_REG3_ODR_SHIFT },
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};
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/* Return the highest hardware sampling frequency available. */
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static const struct zpa2326_frequency *zpa2326_highest_frequency(void)
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{
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return &zpa2326_sampling_frequencies[
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ARRAY_SIZE(zpa2326_sampling_frequencies) - 1];
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}
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/**
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* struct zpa_private - Per-device internal private state
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* @timestamp: Buffered samples ready datum.
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* @regmap: Underlying I2C / SPI bus adapter used to abstract slave register
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* accesses.
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* @result: Allows sampling logic to get completion status of operations
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* that interrupt handlers perform asynchronously.
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* @data_ready: Interrupt handler uses this to wake user context up at sampling
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* operation completion.
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* @trigger: Optional hardware / interrupt driven trigger used to notify
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* external devices a new sample is ready.
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* @waken: Flag indicating whether or not device has just been powered on.
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* @irq: Optional interrupt line: negative or zero if not declared into
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* DT, in which case sampling logic keeps polling status register
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* to detect completion.
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* @frequency: Current hardware sampling frequency.
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* @vref: Power / voltage reference.
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* @vdd: Power supply.
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*/
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struct zpa2326_private {
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s64 timestamp;
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struct regmap *regmap;
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int result;
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struct completion data_ready;
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struct iio_trigger *trigger;
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bool waken;
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int irq;
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const struct zpa2326_frequency *frequency;
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struct regulator *vref;
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struct regulator *vdd;
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};
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#define zpa2326_err(_idev, _format, _arg...) \
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dev_err(_idev->dev.parent, _format, ##_arg)
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#define zpa2326_warn(_idev, _format, _arg...) \
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dev_warn(_idev->dev.parent, _format, ##_arg)
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#ifdef DEBUG
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#define zpa2326_dbg(_idev, _format, _arg...) \
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dev_dbg(_idev->dev.parent, _format, ##_arg)
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#else
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#define zpa2326_dbg(_idev, _format, _arg...)
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#endif
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bool zpa2326_isreg_writeable(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case ZPA2326_REF_P_XL_REG:
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case ZPA2326_REF_P_L_REG:
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case ZPA2326_REF_P_H_REG:
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case ZPA2326_RES_CONF_REG:
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case ZPA2326_CTRL_REG0_REG:
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case ZPA2326_CTRL_REG1_REG:
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case ZPA2326_CTRL_REG2_REG:
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case ZPA2326_CTRL_REG3_REG:
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case ZPA2326_THS_P_LOW_REG:
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case ZPA2326_THS_P_HIGH_REG:
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return true;
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default:
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return false;
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}
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}
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EXPORT_SYMBOL_GPL(zpa2326_isreg_writeable);
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bool zpa2326_isreg_readable(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case ZPA2326_REF_P_XL_REG:
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case ZPA2326_REF_P_L_REG:
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case ZPA2326_REF_P_H_REG:
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case ZPA2326_DEVICE_ID_REG:
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case ZPA2326_RES_CONF_REG:
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case ZPA2326_CTRL_REG0_REG:
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case ZPA2326_CTRL_REG1_REG:
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case ZPA2326_CTRL_REG2_REG:
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case ZPA2326_CTRL_REG3_REG:
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case ZPA2326_INT_SOURCE_REG:
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case ZPA2326_THS_P_LOW_REG:
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case ZPA2326_THS_P_HIGH_REG:
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case ZPA2326_STATUS_REG:
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case ZPA2326_PRESS_OUT_XL_REG:
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case ZPA2326_PRESS_OUT_L_REG:
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case ZPA2326_PRESS_OUT_H_REG:
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case ZPA2326_TEMP_OUT_L_REG:
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case ZPA2326_TEMP_OUT_H_REG:
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return true;
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default:
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return false;
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}
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}
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EXPORT_SYMBOL_GPL(zpa2326_isreg_readable);
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bool zpa2326_isreg_precious(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case ZPA2326_INT_SOURCE_REG:
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case ZPA2326_PRESS_OUT_H_REG:
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return true;
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default:
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return false;
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}
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}
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EXPORT_SYMBOL_GPL(zpa2326_isreg_precious);
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/**
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* zpa2326_enable_device() - Enable device, i.e. get out of low power mode.
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* @indio_dev: The IIO device associated with the hardware to enable.
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*
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* Required to access complete register space and to perform any sampling
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* or control operations.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_enable_device(const struct iio_dev *indio_dev)
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{
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int err;
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err = regmap_write(((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap,
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ZPA2326_CTRL_REG0_REG, ZPA2326_CTRL_REG0_ENABLE);
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if (err) {
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zpa2326_err(indio_dev, "failed to enable device (%d)", err);
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return err;
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}
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zpa2326_dbg(indio_dev, "enabled");
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return 0;
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}
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/**
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* zpa2326_sleep() - Disable device, i.e. switch to low power mode.
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* @indio_dev: The IIO device associated with the hardware to disable.
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*
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* Only %ZPA2326_DEVICE_ID_REG and %ZPA2326_CTRL_REG0_REG registers may be
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* accessed once device is in the disabled state.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_sleep(const struct iio_dev *indio_dev)
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{
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int err;
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err = regmap_write(((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap,
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ZPA2326_CTRL_REG0_REG, 0);
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if (err) {
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zpa2326_err(indio_dev, "failed to sleep (%d)", err);
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return err;
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}
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zpa2326_dbg(indio_dev, "sleeping");
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return 0;
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}
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/**
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* zpa2326_reset_device() - Reset device to default hardware state.
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* @indio_dev: The IIO device associated with the hardware to reset.
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*
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* Disable sampling and empty hardware FIFO.
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* Device must be enabled before reset, i.e. not in low power mode.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_reset_device(const struct iio_dev *indio_dev)
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{
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int err;
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err = regmap_write(((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap,
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ZPA2326_CTRL_REG2_REG, ZPA2326_CTRL_REG2_SWRESET);
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if (err) {
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zpa2326_err(indio_dev, "failed to reset device (%d)", err);
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return err;
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}
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usleep_range(ZPA2326_TPUP_USEC_MIN, ZPA2326_TPUP_USEC_MAX);
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zpa2326_dbg(indio_dev, "reset");
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return 0;
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}
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/**
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* zpa2326_start_oneshot() - Start a single sampling cycle, i.e. in one shot
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* mode.
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* @indio_dev: The IIO device associated with the sampling hardware.
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*
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* Device must have been previously enabled and configured for one shot mode.
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* Device will be switched back to low power mode at end of cycle.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_start_oneshot(const struct iio_dev *indio_dev)
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{
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int err;
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err = regmap_write(((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap,
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ZPA2326_CTRL_REG0_REG,
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ZPA2326_CTRL_REG0_ENABLE |
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ZPA2326_CTRL_REG0_ONE_SHOT);
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if (err) {
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zpa2326_err(indio_dev, "failed to start one shot cycle (%d)",
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err);
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return err;
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}
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zpa2326_dbg(indio_dev, "one shot cycle started");
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return 0;
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}
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/**
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* zpa2326_power_on() - Power on device to allow subsequent configuration.
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* @indio_dev: The IIO device associated with the sampling hardware.
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* @private: Internal private state related to @indio_dev.
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*
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* Sampling will be disabled, preventing strange things from happening in our
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* back. Hardware FIFO content will be cleared.
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* When successful, device will be left in the enabled state to allow further
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* configuration.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_power_on(const struct iio_dev *indio_dev,
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const struct zpa2326_private *private)
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{
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int err;
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err = regulator_enable(private->vref);
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if (err)
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return err;
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err = regulator_enable(private->vdd);
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if (err)
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goto vref;
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zpa2326_dbg(indio_dev, "powered on");
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err = zpa2326_enable_device(indio_dev);
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if (err)
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goto vdd;
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err = zpa2326_reset_device(indio_dev);
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if (err)
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goto sleep;
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return 0;
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sleep:
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zpa2326_sleep(indio_dev);
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vdd:
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regulator_disable(private->vdd);
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vref:
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regulator_disable(private->vref);
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zpa2326_dbg(indio_dev, "powered off");
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return err;
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}
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/**
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* zpa2326_power_off() - Power off device, i.e. disable attached power
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* regulators.
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* @indio_dev: The IIO device associated with the sampling hardware.
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* @private: Internal private state related to @indio_dev.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static void zpa2326_power_off(const struct iio_dev *indio_dev,
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const struct zpa2326_private *private)
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{
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regulator_disable(private->vdd);
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regulator_disable(private->vref);
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zpa2326_dbg(indio_dev, "powered off");
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}
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/**
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* zpa2326_config_oneshot() - Setup device for one shot / on demand mode.
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* @indio_dev: The IIO device associated with the sampling hardware.
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* @irq: Optional interrupt line the hardware uses to notify new data
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* samples are ready. Negative or zero values indicate no interrupts
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* are available, meaning polling is required.
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*
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* Output Data Rate is configured for the highest possible rate so that
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* conversion time and power consumption are reduced to a minimum.
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* Note that hardware internal averaging machinery (not implemented in this
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* driver) is not applicable in this mode.
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*
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* Device must have been previously enabled before calling
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* zpa2326_config_oneshot().
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_config_oneshot(const struct iio_dev *indio_dev,
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int irq)
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{
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struct regmap *regs = ((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap;
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const struct zpa2326_frequency *freq = zpa2326_highest_frequency();
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int err;
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/* Setup highest available Output Data Rate for one shot mode. */
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err = regmap_write(regs, ZPA2326_CTRL_REG3_REG, freq->odr);
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if (err)
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return err;
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if (irq > 0) {
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/* Request interrupt when new sample is available. */
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err = regmap_write(regs, ZPA2326_CTRL_REG1_REG,
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(u8)~ZPA2326_CTRL_REG1_MASK_DATA_READY);
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if (err) {
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dev_err(indio_dev->dev.parent,
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"failed to setup one shot mode (%d)", err);
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return err;
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}
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}
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zpa2326_dbg(indio_dev, "one shot mode setup @%dHz", freq->hz);
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return 0;
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}
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|
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/**
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* zpa2326_clear_fifo() - Clear remaining entries in hardware FIFO.
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* @indio_dev: The IIO device associated with the sampling hardware.
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* @min_count: Number of samples present within hardware FIFO.
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*
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* @min_count argument is a hint corresponding to the known minimum number of
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* samples currently living in the FIFO. This allows to reduce the number of bus
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* accesses by skipping status register read operation as long as we know for
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* sure there are still entries left.
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*
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* Return: Zero when successful, a negative error code otherwise.
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*/
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static int zpa2326_clear_fifo(const struct iio_dev *indio_dev,
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unsigned int min_count)
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{
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struct regmap *regs = ((struct zpa2326_private *)
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iio_priv(indio_dev))->regmap;
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int err;
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unsigned int val;
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if (!min_count) {
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/*
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* No hint: read status register to determine whether FIFO is
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* empty or not.
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*/
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err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
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if (err < 0)
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goto err;
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if (val & ZPA2326_STATUS_FIFO_E)
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/* Fifo is empty: nothing to trash. */
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return 0;
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}
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|
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/* Clear FIFO. */
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do {
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/*
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* A single fetch from pressure MSB register is enough to pop
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* values out of FIFO.
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*/
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err = regmap_read(regs, ZPA2326_PRESS_OUT_H_REG, &val);
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if (err < 0)
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goto err;
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if (min_count) {
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/*
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* We know for sure there are at least min_count entries
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* left in FIFO. Skip status register read.
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*/
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min_count--;
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continue;
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}
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|
|
|
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
|
|
if (err < 0)
|
|
goto err;
|
|
|
|
} while (!(val & ZPA2326_STATUS_FIFO_E));
|
|
|
|
zpa2326_dbg(indio_dev, "FIFO cleared");
|
|
|
|
return 0;
|
|
|
|
err:
|
|
zpa2326_err(indio_dev, "failed to clear FIFO (%d)", err);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_dequeue_pressure() - Retrieve the most recent pressure sample from
|
|
* hardware FIFO.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @pressure: Sampled pressure output.
|
|
*
|
|
* Note that ZPA2326 hardware FIFO stores pressure samples only.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_dequeue_pressure(const struct iio_dev *indio_dev,
|
|
u32 *pressure)
|
|
{
|
|
struct regmap *regs = ((struct zpa2326_private *)
|
|
iio_priv(indio_dev))->regmap;
|
|
unsigned int val;
|
|
int err;
|
|
int cleared = -1;
|
|
|
|
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
*pressure = 0;
|
|
|
|
if (val & ZPA2326_STATUS_P_OR) {
|
|
/*
|
|
* Fifo overrun : first sample dequeued from FIFO is the
|
|
* newest.
|
|
*/
|
|
zpa2326_warn(indio_dev, "FIFO overflow");
|
|
|
|
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
|
|
3);
|
|
if (err)
|
|
return err;
|
|
|
|
#define ZPA2326_FIFO_DEPTH (16U)
|
|
/* Hardware FIFO may hold no more than 16 pressure samples. */
|
|
return zpa2326_clear_fifo(indio_dev, ZPA2326_FIFO_DEPTH - 1);
|
|
}
|
|
|
|
/*
|
|
* Fifo has not overflown : retrieve newest sample. We need to pop
|
|
* values out until FIFO is empty : last fetched pressure is the newest.
|
|
* In nominal cases, we should find a single queued sample only.
|
|
*/
|
|
do {
|
|
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, pressure,
|
|
3);
|
|
if (err)
|
|
return err;
|
|
|
|
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
cleared++;
|
|
} while (!(val & ZPA2326_STATUS_FIFO_E));
|
|
|
|
if (cleared)
|
|
/*
|
|
* Samples were pushed by hardware during previous rounds but we
|
|
* didn't consume them fast enough: inform user.
|
|
*/
|
|
zpa2326_dbg(indio_dev, "cleared %d FIFO entries", cleared);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_fill_sample_buffer() - Enqueue new channel samples to IIO buffer.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @private: Internal private state related to @indio_dev.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_fill_sample_buffer(struct iio_dev *indio_dev,
|
|
const struct zpa2326_private *private)
|
|
{
|
|
struct {
|
|
u32 pressure;
|
|
u16 temperature;
|
|
u64 timestamp;
|
|
} sample;
|
|
int err;
|
|
|
|
if (test_bit(0, indio_dev->active_scan_mask)) {
|
|
/* Get current pressure from hardware FIFO. */
|
|
err = zpa2326_dequeue_pressure(indio_dev, &sample.pressure);
|
|
if (err) {
|
|
zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
|
|
err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (test_bit(1, indio_dev->active_scan_mask)) {
|
|
/* Get current temperature. */
|
|
err = regmap_bulk_read(private->regmap, ZPA2326_TEMP_OUT_L_REG,
|
|
&sample.temperature, 2);
|
|
if (err) {
|
|
zpa2326_warn(indio_dev,
|
|
"failed to fetch temperature (%d)", err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now push samples using timestamp stored either :
|
|
* - by hardware interrupt handler if interrupt is available: see
|
|
* zpa2326_handle_irq(),
|
|
* - or oneshot completion polling machinery : see
|
|
* zpa2326_trigger_handler().
|
|
*/
|
|
zpa2326_dbg(indio_dev, "filling raw samples buffer");
|
|
|
|
iio_push_to_buffers_with_timestamp(indio_dev, &sample,
|
|
private->timestamp);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int zpa2326_runtime_suspend(struct device *parent)
|
|
{
|
|
const struct iio_dev *indio_dev = dev_get_drvdata(parent);
|
|
|
|
if (pm_runtime_autosuspend_expiration(parent))
|
|
/* Userspace changed autosuspend delay. */
|
|
return -EAGAIN;
|
|
|
|
zpa2326_power_off(indio_dev, iio_priv(indio_dev));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int zpa2326_runtime_resume(struct device *parent)
|
|
{
|
|
const struct iio_dev *indio_dev = dev_get_drvdata(parent);
|
|
|
|
return zpa2326_power_on(indio_dev, iio_priv(indio_dev));
|
|
}
|
|
|
|
const struct dev_pm_ops zpa2326_pm_ops = {
|
|
SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
|
|
pm_runtime_force_resume)
|
|
SET_RUNTIME_PM_OPS(zpa2326_runtime_suspend, zpa2326_runtime_resume,
|
|
NULL)
|
|
};
|
|
EXPORT_SYMBOL_GPL(zpa2326_pm_ops);
|
|
|
|
/**
|
|
* zpa2326_resume() - Request the PM layer to power supply the device.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Return:
|
|
* < 0 - a negative error code meaning failure ;
|
|
* 0 - success, device has just been powered up ;
|
|
* 1 - success, device was already powered.
|
|
*/
|
|
static int zpa2326_resume(const struct iio_dev *indio_dev)
|
|
{
|
|
int err;
|
|
|
|
err = pm_runtime_get_sync(indio_dev->dev.parent);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (err > 0) {
|
|
/*
|
|
* Device was already power supplied: get it out of low power
|
|
* mode and inform caller.
|
|
*/
|
|
zpa2326_enable_device(indio_dev);
|
|
return 1;
|
|
}
|
|
|
|
/* Inform caller device has just been brought back to life. */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_suspend() - Schedule a power down using autosuspend feature of PM
|
|
* layer.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Device is switched to low power mode at first to save power even when
|
|
* attached regulator is a "dummy" one.
|
|
*/
|
|
static void zpa2326_suspend(struct iio_dev *indio_dev)
|
|
{
|
|
struct device *parent = indio_dev->dev.parent;
|
|
|
|
zpa2326_sleep(indio_dev);
|
|
|
|
pm_runtime_mark_last_busy(parent);
|
|
pm_runtime_put_autosuspend(parent);
|
|
}
|
|
|
|
static void zpa2326_init_runtime(struct device *parent)
|
|
{
|
|
pm_runtime_get_noresume(parent);
|
|
pm_runtime_set_active(parent);
|
|
pm_runtime_enable(parent);
|
|
pm_runtime_set_autosuspend_delay(parent, 1000);
|
|
pm_runtime_use_autosuspend(parent);
|
|
pm_runtime_mark_last_busy(parent);
|
|
pm_runtime_put_autosuspend(parent);
|
|
}
|
|
|
|
static void zpa2326_fini_runtime(struct device *parent)
|
|
{
|
|
pm_runtime_disable(parent);
|
|
pm_runtime_set_suspended(parent);
|
|
}
|
|
#else /* !CONFIG_PM */
|
|
static int zpa2326_resume(const struct iio_dev *indio_dev)
|
|
{
|
|
zpa2326_enable_device(indio_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void zpa2326_suspend(struct iio_dev *indio_dev)
|
|
{
|
|
zpa2326_sleep(indio_dev);
|
|
}
|
|
|
|
#define zpa2326_init_runtime(_parent)
|
|
#define zpa2326_fini_runtime(_parent)
|
|
#endif /* !CONFIG_PM */
|
|
|
|
/**
|
|
* zpa2326_handle_irq() - Process hardware interrupts.
|
|
* @irq: Interrupt line the hardware uses to notify new data has arrived.
|
|
* @data: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Timestamp buffered samples as soon as possible then schedule threaded bottom
|
|
* half.
|
|
*
|
|
* Return: Always successful.
|
|
*/
|
|
static irqreturn_t zpa2326_handle_irq(int irq, void *data)
|
|
{
|
|
struct iio_dev *indio_dev = (struct iio_dev *)data;
|
|
|
|
if (iio_buffer_enabled(indio_dev)) {
|
|
/* Timestamping needed for buffered sampling only. */
|
|
((struct zpa2326_private *)
|
|
iio_priv(indio_dev))->timestamp = iio_get_time_ns(indio_dev);
|
|
}
|
|
|
|
return IRQ_WAKE_THREAD;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_handle_threaded_irq() - Interrupt bottom-half handler.
|
|
* @irq: Interrupt line the hardware uses to notify new data has arrived.
|
|
* @data: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Mainly ensures interrupt is caused by a real "new sample available"
|
|
* condition. This relies upon the ability to perform blocking / sleeping bus
|
|
* accesses to slave's registers. This is why zpa2326_handle_threaded_irq() is
|
|
* called from within a thread, i.e. not called from hard interrupt context.
|
|
*
|
|
* When device is using its own internal hardware trigger in continuous sampling
|
|
* mode, data are available into hardware FIFO once interrupt has occurred. All
|
|
* we have to do is to dispatch the trigger, which in turn will fetch data and
|
|
* fill IIO buffer.
|
|
*
|
|
* When not using its own internal hardware trigger, the device has been
|
|
* configured in one-shot mode either by an external trigger or the IIO read_raw
|
|
* hook. This means one of the latter is currently waiting for sampling
|
|
* completion, in which case we must simply wake it up.
|
|
*
|
|
* See zpa2326_trigger_handler().
|
|
*
|
|
* Return:
|
|
* %IRQ_NONE - no consistent interrupt happened ;
|
|
* %IRQ_HANDLED - there was new samples available.
|
|
*/
|
|
static irqreturn_t zpa2326_handle_threaded_irq(int irq, void *data)
|
|
{
|
|
struct iio_dev *indio_dev = (struct iio_dev *)data;
|
|
struct zpa2326_private *priv = iio_priv(indio_dev);
|
|
unsigned int val;
|
|
bool cont;
|
|
irqreturn_t ret = IRQ_NONE;
|
|
|
|
/*
|
|
* Are we using our own internal trigger in triggered buffer mode, i.e.,
|
|
* currently working in continuous sampling mode ?
|
|
*/
|
|
cont = (iio_buffer_enabled(indio_dev) &&
|
|
iio_trigger_using_own(indio_dev));
|
|
|
|
/*
|
|
* Device works according to a level interrupt scheme: reading interrupt
|
|
* status de-asserts interrupt line.
|
|
*/
|
|
priv->result = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
|
|
if (priv->result < 0) {
|
|
if (cont)
|
|
return IRQ_NONE;
|
|
|
|
goto complete;
|
|
}
|
|
|
|
/* Data ready is the only interrupt source we requested. */
|
|
if (!(val & ZPA2326_INT_SOURCE_DATA_READY)) {
|
|
/*
|
|
* Interrupt happened but no new sample available: likely caused
|
|
* by spurious interrupts, in which case, returning IRQ_NONE
|
|
* allows to benefit from the generic spurious interrupts
|
|
* handling.
|
|
*/
|
|
zpa2326_warn(indio_dev, "unexpected interrupt status %02x",
|
|
val);
|
|
|
|
if (cont)
|
|
return IRQ_NONE;
|
|
|
|
priv->result = -ENODATA;
|
|
goto complete;
|
|
}
|
|
|
|
/* New sample available: dispatch internal trigger consumers. */
|
|
iio_trigger_poll_chained(priv->trigger);
|
|
|
|
if (cont)
|
|
/*
|
|
* Internal hardware trigger has been scheduled above : it will
|
|
* fetch data on its own.
|
|
*/
|
|
return IRQ_HANDLED;
|
|
|
|
ret = IRQ_HANDLED;
|
|
|
|
complete:
|
|
/*
|
|
* Wake up direct or externaly triggered buffer mode waiters: see
|
|
* zpa2326_sample_oneshot() and zpa2326_trigger_handler().
|
|
*/
|
|
complete(&priv->data_ready);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_wait_oneshot_completion() - Wait for oneshot data ready interrupt.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @private: Internal private state related to @indio_dev.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_wait_oneshot_completion(const struct iio_dev *indio_dev,
|
|
struct zpa2326_private *private)
|
|
{
|
|
int ret;
|
|
unsigned int val;
|
|
|
|
zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");
|
|
|
|
ret = wait_for_completion_interruptible_timeout(
|
|
&private->data_ready, ZPA2326_CONVERSION_JIFFIES);
|
|
if (ret > 0)
|
|
/*
|
|
* Interrupt handler completed before timeout: return operation
|
|
* status.
|
|
*/
|
|
return private->result;
|
|
|
|
/* Clear all interrupts just to be sure. */
|
|
regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);
|
|
|
|
if (!ret)
|
|
/* Timed out. */
|
|
ret = -ETIME;
|
|
|
|
if (ret != -ERESTARTSYS)
|
|
zpa2326_warn(indio_dev, "no one shot interrupt occurred (%d)",
|
|
ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int zpa2326_init_managed_irq(struct device *parent,
|
|
struct iio_dev *indio_dev,
|
|
struct zpa2326_private *private,
|
|
int irq)
|
|
{
|
|
int err;
|
|
|
|
private->irq = irq;
|
|
|
|
if (irq <= 0) {
|
|
/*
|
|
* Platform declared no interrupt line: device will be polled
|
|
* for data availability.
|
|
*/
|
|
dev_info(parent, "no interrupt found, running in polling mode");
|
|
return 0;
|
|
}
|
|
|
|
init_completion(&private->data_ready);
|
|
|
|
/* Request handler to be scheduled into threaded interrupt context. */
|
|
err = devm_request_threaded_irq(parent, irq, zpa2326_handle_irq,
|
|
zpa2326_handle_threaded_irq,
|
|
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
|
|
dev_name(parent), indio_dev);
|
|
if (err) {
|
|
dev_err(parent, "failed to request interrupt %d (%d)", irq,
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
dev_info(parent, "using interrupt %d", irq);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_poll_oneshot_completion() - Actively poll for one shot data ready.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Loop over registers content to detect end of sampling cycle. Used when DT
|
|
* declared no valid interrupt lines.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_poll_oneshot_completion(const struct iio_dev *indio_dev)
|
|
{
|
|
unsigned long tmout = jiffies + ZPA2326_CONVERSION_JIFFIES;
|
|
struct regmap *regs = ((struct zpa2326_private *)
|
|
iio_priv(indio_dev))->regmap;
|
|
unsigned int val;
|
|
int err;
|
|
|
|
zpa2326_dbg(indio_dev, "polling for one shot completion");
|
|
|
|
/*
|
|
* At least, 100 ms is needed for the device to complete its one-shot
|
|
* cycle.
|
|
*/
|
|
if (msleep_interruptible(100))
|
|
return -ERESTARTSYS;
|
|
|
|
/* Poll for conversion completion in hardware. */
|
|
while (true) {
|
|
err = regmap_read(regs, ZPA2326_CTRL_REG0_REG, &val);
|
|
if (err < 0)
|
|
goto err;
|
|
|
|
if (!(val & ZPA2326_CTRL_REG0_ONE_SHOT))
|
|
/* One-shot bit self clears at conversion end. */
|
|
break;
|
|
|
|
if (time_after(jiffies, tmout)) {
|
|
/* Prevent from waiting forever : let's time out. */
|
|
err = -ETIME;
|
|
goto err;
|
|
}
|
|
|
|
usleep_range(10000, 20000);
|
|
}
|
|
|
|
/*
|
|
* In oneshot mode, pressure sample availability guarantees that
|
|
* temperature conversion has also completed : just check pressure
|
|
* status bit to keep things simple.
|
|
*/
|
|
err = regmap_read(regs, ZPA2326_STATUS_REG, &val);
|
|
if (err < 0)
|
|
goto err;
|
|
|
|
if (!(val & ZPA2326_STATUS_P_DA)) {
|
|
/* No sample available. */
|
|
err = -ENODATA;
|
|
goto err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err:
|
|
zpa2326_warn(indio_dev, "failed to poll one shot completion (%d)", err);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_fetch_raw_sample() - Retrieve a raw sample and convert it to CPU
|
|
* endianness.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @type: Type of measurement / channel to fetch from.
|
|
* @value: Sample output.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_fetch_raw_sample(const struct iio_dev *indio_dev,
|
|
enum iio_chan_type type,
|
|
int *value)
|
|
{
|
|
struct regmap *regs = ((struct zpa2326_private *)
|
|
iio_priv(indio_dev))->regmap;
|
|
int err;
|
|
|
|
switch (type) {
|
|
case IIO_PRESSURE:
|
|
zpa2326_dbg(indio_dev, "fetching raw pressure sample");
|
|
|
|
err = regmap_bulk_read(regs, ZPA2326_PRESS_OUT_XL_REG, value,
|
|
3);
|
|
if (err) {
|
|
zpa2326_warn(indio_dev, "failed to fetch pressure (%d)",
|
|
err);
|
|
return err;
|
|
}
|
|
|
|
/* Pressure is a 24 bits wide little-endian unsigned int. */
|
|
*value = (((u8 *)value)[2] << 16) | (((u8 *)value)[1] << 8) |
|
|
((u8 *)value)[0];
|
|
|
|
return IIO_VAL_INT;
|
|
|
|
case IIO_TEMP:
|
|
zpa2326_dbg(indio_dev, "fetching raw temperature sample");
|
|
|
|
err = regmap_bulk_read(regs, ZPA2326_TEMP_OUT_L_REG, value, 2);
|
|
if (err) {
|
|
zpa2326_warn(indio_dev,
|
|
"failed to fetch temperature (%d)", err);
|
|
return err;
|
|
}
|
|
|
|
/* Temperature is a 16 bits wide little-endian signed int. */
|
|
*value = (int)le16_to_cpup((__le16 *)value);
|
|
|
|
return IIO_VAL_INT;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* zpa2326_sample_oneshot() - Perform a complete one shot sampling cycle.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @type: Type of measurement / channel to fetch from.
|
|
* @value: Sample output.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_sample_oneshot(struct iio_dev *indio_dev,
|
|
enum iio_chan_type type,
|
|
int *value)
|
|
{
|
|
int ret;
|
|
struct zpa2326_private *priv;
|
|
|
|
ret = iio_device_claim_direct_mode(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = zpa2326_resume(indio_dev);
|
|
if (ret < 0)
|
|
goto release;
|
|
|
|
priv = iio_priv(indio_dev);
|
|
|
|
if (ret > 0) {
|
|
/*
|
|
* We were already power supplied. Just clear hardware FIFO to
|
|
* get rid of samples acquired during previous rounds (if any).
|
|
* Sampling operation always generates both temperature and
|
|
* pressure samples. The latter are always enqueued into
|
|
* hardware FIFO. This may lead to situations were pressure
|
|
* samples still sit into FIFO when previous cycle(s) fetched
|
|
* temperature data only.
|
|
* Hence, we need to clear hardware FIFO content to prevent from
|
|
* getting outdated values at the end of current cycle.
|
|
*/
|
|
if (type == IIO_PRESSURE) {
|
|
ret = zpa2326_clear_fifo(indio_dev, 0);
|
|
if (ret)
|
|
goto suspend;
|
|
}
|
|
} else {
|
|
/*
|
|
* We have just been power supplied, i.e. device is in default
|
|
* "out of reset" state, meaning we need to reconfigure it
|
|
* entirely.
|
|
*/
|
|
ret = zpa2326_config_oneshot(indio_dev, priv->irq);
|
|
if (ret)
|
|
goto suspend;
|
|
}
|
|
|
|
/* Start a sampling cycle in oneshot mode. */
|
|
ret = zpa2326_start_oneshot(indio_dev);
|
|
if (ret)
|
|
goto suspend;
|
|
|
|
/* Wait for sampling cycle to complete. */
|
|
if (priv->irq > 0)
|
|
ret = zpa2326_wait_oneshot_completion(indio_dev, priv);
|
|
else
|
|
ret = zpa2326_poll_oneshot_completion(indio_dev);
|
|
|
|
if (ret)
|
|
goto suspend;
|
|
|
|
/* Retrieve raw sample value and convert it to CPU endianness. */
|
|
ret = zpa2326_fetch_raw_sample(indio_dev, type, value);
|
|
|
|
suspend:
|
|
zpa2326_suspend(indio_dev);
|
|
release:
|
|
iio_device_release_direct_mode(indio_dev);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_trigger_handler() - Perform an IIO buffered sampling round in one
|
|
* shot mode.
|
|
* @irq: The software interrupt assigned to @data
|
|
* @data: The IIO poll function dispatched by external trigger our device is
|
|
* attached to.
|
|
*
|
|
* Bottom-half handler called by the IIO trigger to which our device is
|
|
* currently attached. Allows us to synchronize this device buffered sampling
|
|
* either with external events (such as timer expiration, external device sample
|
|
* ready, etc...) or with its own interrupt (internal hardware trigger).
|
|
*
|
|
* When using an external trigger, basically run the same sequence of operations
|
|
* as for zpa2326_sample_oneshot() with the following hereafter. Hardware FIFO
|
|
* is not cleared since already done at buffering enable time and samples
|
|
* dequeueing always retrieves the most recent value.
|
|
*
|
|
* Otherwise, when internal hardware trigger has dispatched us, just fetch data
|
|
* from hardware FIFO.
|
|
*
|
|
* Fetched data will pushed unprocessed to IIO buffer since samples conversion
|
|
* is delegated to userspace in buffered mode (endianness, etc...).
|
|
*
|
|
* Return:
|
|
* %IRQ_NONE - no consistent interrupt happened ;
|
|
* %IRQ_HANDLED - there was new samples available.
|
|
*/
|
|
static irqreturn_t zpa2326_trigger_handler(int irq, void *data)
|
|
{
|
|
struct iio_dev *indio_dev = ((struct iio_poll_func *)
|
|
data)->indio_dev;
|
|
struct zpa2326_private *priv = iio_priv(indio_dev);
|
|
bool cont;
|
|
|
|
/*
|
|
* We have been dispatched, meaning we are in triggered buffer mode.
|
|
* Using our own internal trigger implies we are currently in continuous
|
|
* hardware sampling mode.
|
|
*/
|
|
cont = iio_trigger_using_own(indio_dev);
|
|
|
|
if (!cont) {
|
|
/* On demand sampling : start a one shot cycle. */
|
|
if (zpa2326_start_oneshot(indio_dev))
|
|
goto out;
|
|
|
|
/* Wait for sampling cycle to complete. */
|
|
if (priv->irq <= 0) {
|
|
/* No interrupt available: poll for completion. */
|
|
if (zpa2326_poll_oneshot_completion(indio_dev))
|
|
goto out;
|
|
|
|
/* Only timestamp sample once it is ready. */
|
|
priv->timestamp = iio_get_time_ns(indio_dev);
|
|
} else {
|
|
/* Interrupt handlers will timestamp for us. */
|
|
if (zpa2326_wait_oneshot_completion(indio_dev, priv))
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Enqueue to IIO buffer / userspace. */
|
|
zpa2326_fill_sample_buffer(indio_dev, priv);
|
|
|
|
out:
|
|
if (!cont)
|
|
/* Don't switch to low power if sampling continuously. */
|
|
zpa2326_sleep(indio_dev);
|
|
|
|
/* Inform attached trigger we are done. */
|
|
iio_trigger_notify_done(indio_dev->trig);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_preenable_buffer() - Prepare device for configuring triggered
|
|
* sampling
|
|
* modes.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Basically power up device.
|
|
* Called with IIO device's lock held.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_preenable_buffer(struct iio_dev *indio_dev)
|
|
{
|
|
int ret = zpa2326_resume(indio_dev);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
/* Tell zpa2326_postenable_buffer() if we have just been powered on. */
|
|
((struct zpa2326_private *)
|
|
iio_priv(indio_dev))->waken = iio_priv(indio_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* zpa2326_postenable_buffer() - Configure device for triggered sampling.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
*
|
|
* Basically setup one-shot mode if plugging external trigger.
|
|
* Otherwise, let internal trigger configure continuous sampling :
|
|
* see zpa2326_set_trigger_state().
|
|
*
|
|
* If an error is returned, IIO layer will call our postdisable hook for us,
|
|
* i.e. no need to explicitly power device off here.
|
|
* Called with IIO device's lock held.
|
|
*
|
|
* Called with IIO device's lock held.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_postenable_buffer(struct iio_dev *indio_dev)
|
|
{
|
|
const struct zpa2326_private *priv = iio_priv(indio_dev);
|
|
int err;
|
|
|
|
if (!priv->waken) {
|
|
/*
|
|
* We were already power supplied. Just clear hardware FIFO to
|
|
* get rid of samples acquired during previous rounds (if any).
|
|
*/
|
|
err = zpa2326_clear_fifo(indio_dev, 0);
|
|
if (err)
|
|
goto err;
|
|
}
|
|
|
|
if (!iio_trigger_using_own(indio_dev) && priv->waken) {
|
|
/*
|
|
* We are using an external trigger and we have just been
|
|
* powered up: reconfigure one-shot mode.
|
|
*/
|
|
err = zpa2326_config_oneshot(indio_dev, priv->irq);
|
|
if (err)
|
|
goto err;
|
|
}
|
|
|
|
/* Plug our own trigger event handler. */
|
|
err = iio_triggered_buffer_postenable(indio_dev);
|
|
if (err)
|
|
goto err;
|
|
|
|
return 0;
|
|
|
|
err:
|
|
zpa2326_err(indio_dev, "failed to enable buffering (%d)", err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int zpa2326_postdisable_buffer(struct iio_dev *indio_dev)
|
|
{
|
|
zpa2326_suspend(indio_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct iio_buffer_setup_ops zpa2326_buffer_setup_ops = {
|
|
.preenable = zpa2326_preenable_buffer,
|
|
.postenable = zpa2326_postenable_buffer,
|
|
.predisable = iio_triggered_buffer_predisable,
|
|
.postdisable = zpa2326_postdisable_buffer
|
|
};
|
|
|
|
/**
|
|
* zpa2326_set_trigger_state() - Start / stop continuous sampling.
|
|
* @trig: The trigger being attached to IIO device associated with the sampling
|
|
* hardware.
|
|
* @state: Tell whether to start (true) or stop (false)
|
|
*
|
|
* Basically enable / disable hardware continuous sampling mode.
|
|
*
|
|
* Called with IIO device's lock held at postenable() or predisable() time.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_set_trigger_state(struct iio_trigger *trig, bool state)
|
|
{
|
|
const struct iio_dev *indio_dev = dev_get_drvdata(
|
|
trig->dev.parent);
|
|
const struct zpa2326_private *priv = iio_priv(indio_dev);
|
|
int err;
|
|
|
|
if (!state) {
|
|
/*
|
|
* Switch trigger off : in case of failure, interrupt is left
|
|
* disabled in order to prevent handler from accessing released
|
|
* resources.
|
|
*/
|
|
unsigned int val;
|
|
|
|
/*
|
|
* As device is working in continuous mode, handlers may be
|
|
* accessing resources we are currently freeing...
|
|
* Prevent this by disabling interrupt handlers and ensure
|
|
* the device will generate no more interrupts unless explicitly
|
|
* required to, i.e. by restoring back to default one shot mode.
|
|
*/
|
|
disable_irq(priv->irq);
|
|
|
|
/*
|
|
* Disable continuous sampling mode to restore settings for
|
|
* one shot / direct sampling operations.
|
|
*/
|
|
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
|
|
zpa2326_highest_frequency()->odr);
|
|
if (err)
|
|
return err;
|
|
|
|
/*
|
|
* Now that device won't generate interrupts on its own,
|
|
* acknowledge any currently active interrupts (may happen on
|
|
* rare occasions while stopping continuous mode).
|
|
*/
|
|
err = regmap_read(priv->regmap, ZPA2326_INT_SOURCE_REG, &val);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
/*
|
|
* Re-enable interrupts only if we can guarantee the device will
|
|
* generate no more interrupts to prevent handlers from
|
|
* accessing released resources.
|
|
*/
|
|
enable_irq(priv->irq);
|
|
|
|
zpa2326_dbg(indio_dev, "continuous mode stopped");
|
|
} else {
|
|
/*
|
|
* Switch trigger on : start continuous sampling at required
|
|
* frequency.
|
|
*/
|
|
|
|
if (priv->waken) {
|
|
/* Enable interrupt if getting out of reset. */
|
|
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG1_REG,
|
|
(u8)
|
|
~ZPA2326_CTRL_REG1_MASK_DATA_READY);
|
|
if (err)
|
|
return err;
|
|
}
|
|
|
|
/* Enable continuous sampling at specified frequency. */
|
|
err = regmap_write(priv->regmap, ZPA2326_CTRL_REG3_REG,
|
|
ZPA2326_CTRL_REG3_ENABLE_MEAS |
|
|
priv->frequency->odr);
|
|
if (err)
|
|
return err;
|
|
|
|
zpa2326_dbg(indio_dev, "continuous mode setup @%dHz",
|
|
priv->frequency->hz);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct iio_trigger_ops zpa2326_trigger_ops = {
|
|
.owner = THIS_MODULE,
|
|
.set_trigger_state = zpa2326_set_trigger_state,
|
|
};
|
|
|
|
/**
|
|
* zpa2326_init_trigger() - Create an interrupt driven / hardware trigger
|
|
* allowing to notify external devices a new sample is
|
|
* ready.
|
|
* @parent: Hardware sampling device @indio_dev is a child of.
|
|
* @indio_dev: The IIO device associated with the sampling hardware.
|
|
* @private: Internal private state related to @indio_dev.
|
|
* @irq: Optional interrupt line the hardware uses to notify new data
|
|
* samples are ready. Negative or zero values indicate no interrupts
|
|
* are available, meaning polling is required.
|
|
*
|
|
* Only relevant when DT declares a valid interrupt line.
|
|
*
|
|
* Return: Zero when successful, a negative error code otherwise.
|
|
*/
|
|
static int zpa2326_init_managed_trigger(struct device *parent,
|
|
struct iio_dev *indio_dev,
|
|
struct zpa2326_private *private,
|
|
int irq)
|
|
{
|
|
struct iio_trigger *trigger;
|
|
int ret;
|
|
|
|
if (irq <= 0)
|
|
return 0;
|
|
|
|
trigger = devm_iio_trigger_alloc(parent, "%s-dev%d",
|
|
indio_dev->name, indio_dev->id);
|
|
if (!trigger)
|
|
return -ENOMEM;
|
|
|
|
/* Basic setup. */
|
|
trigger->dev.parent = parent;
|
|
trigger->ops = &zpa2326_trigger_ops;
|
|
|
|
private->trigger = trigger;
|
|
|
|
/* Register to triggers space. */
|
|
ret = devm_iio_trigger_register(parent, trigger);
|
|
if (ret)
|
|
dev_err(parent, "failed to register hardware trigger (%d)",
|
|
ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int zpa2326_get_frequency(const struct iio_dev *indio_dev)
|
|
{
|
|
return ((struct zpa2326_private *)iio_priv(indio_dev))->frequency->hz;
|
|
}
|
|
|
|
static int zpa2326_set_frequency(struct iio_dev *indio_dev, int hz)
|
|
{
|
|
struct zpa2326_private *priv = iio_priv(indio_dev);
|
|
int freq;
|
|
int err;
|
|
|
|
/* Check if requested frequency is supported. */
|
|
for (freq = 0; freq < ARRAY_SIZE(zpa2326_sampling_frequencies); freq++)
|
|
if (zpa2326_sampling_frequencies[freq].hz == hz)
|
|
break;
|
|
if (freq == ARRAY_SIZE(zpa2326_sampling_frequencies))
|
|
return -EINVAL;
|
|
|
|
/* Don't allow changing frequency if buffered sampling is ongoing. */
|
|
err = iio_device_claim_direct_mode(indio_dev);
|
|
if (err)
|
|
return err;
|
|
|
|
priv->frequency = &zpa2326_sampling_frequencies[freq];
|
|
|
|
iio_device_release_direct_mode(indio_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* Expose supported hardware sampling frequencies (Hz) through sysfs. */
|
|
static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("1 5 11 23");
|
|
|
|
static struct attribute *zpa2326_attributes[] = {
|
|
&iio_const_attr_sampling_frequency_available.dev_attr.attr,
|
|
NULL
|
|
};
|
|
|
|
static const struct attribute_group zpa2326_attribute_group = {
|
|
.attrs = zpa2326_attributes,
|
|
};
|
|
|
|
static int zpa2326_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan,
|
|
int *val,
|
|
int *val2,
|
|
long mask)
|
|
{
|
|
switch (mask) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
return zpa2326_sample_oneshot(indio_dev, chan->type, val);
|
|
|
|
case IIO_CHAN_INFO_SCALE:
|
|
switch (chan->type) {
|
|
case IIO_PRESSURE:
|
|
/*
|
|
* Pressure resolution is 1/64 Pascal. Scale to kPascal
|
|
* as required by IIO ABI.
|
|
*/
|
|
*val = 1;
|
|
*val2 = 64000;
|
|
return IIO_VAL_FRACTIONAL;
|
|
|
|
case IIO_TEMP:
|
|
/*
|
|
* Temperature follows the equation:
|
|
* Temp[degC] = Tempcode * 0.00649 - 176.83
|
|
* where:
|
|
* Tempcode is composed the raw sampled 16 bits.
|
|
*
|
|
* Hence, to produce a temperature in milli-degrees
|
|
* Celsius according to IIO ABI, we need to apply the
|
|
* following equation to raw samples:
|
|
* Temp[milli degC] = (Tempcode + Offset) * Scale
|
|
* where:
|
|
* Offset = -176.83 / 0.00649
|
|
* Scale = 0.00649 * 1000
|
|
*/
|
|
*val = 6;
|
|
*val2 = 490000;
|
|
return IIO_VAL_INT_PLUS_MICRO;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
case IIO_CHAN_INFO_OFFSET:
|
|
switch (chan->type) {
|
|
case IIO_TEMP:
|
|
*val = -17683000;
|
|
*val2 = 649;
|
|
return IIO_VAL_FRACTIONAL;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
case IIO_CHAN_INFO_SAMP_FREQ:
|
|
*val = zpa2326_get_frequency(indio_dev);
|
|
return IIO_VAL_INT;
|
|
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
static int zpa2326_write_raw(struct iio_dev *indio_dev,
|
|
const struct iio_chan_spec *chan,
|
|
int val,
|
|
int val2,
|
|
long mask)
|
|
{
|
|
if ((mask != IIO_CHAN_INFO_SAMP_FREQ) || val2)
|
|
return -EINVAL;
|
|
|
|
return zpa2326_set_frequency(indio_dev, val);
|
|
}
|
|
|
|
static const struct iio_chan_spec zpa2326_channels[] = {
|
|
[0] = {
|
|
.type = IIO_PRESSURE,
|
|
.scan_index = 0,
|
|
.scan_type = {
|
|
.sign = 'u',
|
|
.realbits = 24,
|
|
.storagebits = 32,
|
|
.endianness = IIO_LE,
|
|
},
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
|
BIT(IIO_CHAN_INFO_SCALE),
|
|
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
|
|
},
|
|
[1] = {
|
|
.type = IIO_TEMP,
|
|
.scan_index = 1,
|
|
.scan_type = {
|
|
.sign = 's',
|
|
.realbits = 16,
|
|
.storagebits = 16,
|
|
.endianness = IIO_LE,
|
|
},
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
|
|
BIT(IIO_CHAN_INFO_SCALE) |
|
|
BIT(IIO_CHAN_INFO_OFFSET),
|
|
.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
|
|
},
|
|
[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
|
|
};
|
|
|
|
static const struct iio_info zpa2326_info = {
|
|
.driver_module = THIS_MODULE,
|
|
.attrs = &zpa2326_attribute_group,
|
|
.read_raw = zpa2326_read_raw,
|
|
.write_raw = zpa2326_write_raw,
|
|
};
|
|
|
|
static struct iio_dev *zpa2326_create_managed_iiodev(struct device *device,
|
|
const char *name,
|
|
struct regmap *regmap)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
|
|
/* Allocate space to hold IIO device internal state. */
|
|
indio_dev = devm_iio_device_alloc(device,
|
|
sizeof(struct zpa2326_private));
|
|
if (!indio_dev)
|
|
return NULL;
|
|
|
|
/* Setup for userspace synchronous on demand sampling. */
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->dev.parent = device;
|
|
indio_dev->channels = zpa2326_channels;
|
|
indio_dev->num_channels = ARRAY_SIZE(zpa2326_channels);
|
|
indio_dev->name = name;
|
|
indio_dev->info = &zpa2326_info;
|
|
|
|
return indio_dev;
|
|
}
|
|
|
|
int zpa2326_probe(struct device *parent,
|
|
const char *name,
|
|
int irq,
|
|
unsigned int hwid,
|
|
struct regmap *regmap)
|
|
{
|
|
struct iio_dev *indio_dev;
|
|
struct zpa2326_private *priv;
|
|
int err;
|
|
unsigned int id;
|
|
|
|
indio_dev = zpa2326_create_managed_iiodev(parent, name, regmap);
|
|
if (!indio_dev)
|
|
return -ENOMEM;
|
|
|
|
priv = iio_priv(indio_dev);
|
|
|
|
priv->vref = devm_regulator_get(parent, "vref");
|
|
if (IS_ERR(priv->vref))
|
|
return PTR_ERR(priv->vref);
|
|
|
|
priv->vdd = devm_regulator_get(parent, "vdd");
|
|
if (IS_ERR(priv->vdd))
|
|
return PTR_ERR(priv->vdd);
|
|
|
|
/* Set default hardware sampling frequency to highest rate supported. */
|
|
priv->frequency = zpa2326_highest_frequency();
|
|
|
|
/*
|
|
* Plug device's underlying bus abstraction : this MUST be set before
|
|
* registering interrupt handlers since an interrupt might happen if
|
|
* power up sequence is not properly applied.
|
|
*/
|
|
priv->regmap = regmap;
|
|
|
|
err = devm_iio_triggered_buffer_setup(parent, indio_dev, NULL,
|
|
zpa2326_trigger_handler,
|
|
&zpa2326_buffer_setup_ops);
|
|
if (err)
|
|
return err;
|
|
|
|
err = zpa2326_init_managed_trigger(parent, indio_dev, priv, irq);
|
|
if (err)
|
|
return err;
|
|
|
|
err = zpa2326_init_managed_irq(parent, indio_dev, priv, irq);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Power up to check device ID and perform initial hardware setup. */
|
|
err = zpa2326_power_on(indio_dev, priv);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Read id register to check we are talking to the right slave. */
|
|
err = regmap_read(regmap, ZPA2326_DEVICE_ID_REG, &id);
|
|
if (err)
|
|
goto sleep;
|
|
|
|
if (id != hwid) {
|
|
dev_err(parent, "found device with unexpected id %02x", id);
|
|
err = -ENODEV;
|
|
goto sleep;
|
|
}
|
|
|
|
err = zpa2326_config_oneshot(indio_dev, irq);
|
|
if (err)
|
|
goto sleep;
|
|
|
|
/* Setup done : go sleeping. Device will be awaken upon user request. */
|
|
err = zpa2326_sleep(indio_dev);
|
|
if (err)
|
|
goto poweroff;
|
|
|
|
dev_set_drvdata(parent, indio_dev);
|
|
|
|
zpa2326_init_runtime(parent);
|
|
|
|
err = iio_device_register(indio_dev);
|
|
if (err) {
|
|
zpa2326_fini_runtime(parent);
|
|
goto poweroff;
|
|
}
|
|
|
|
return 0;
|
|
|
|
sleep:
|
|
/* Put to sleep just in case power regulators are "dummy" ones. */
|
|
zpa2326_sleep(indio_dev);
|
|
poweroff:
|
|
zpa2326_power_off(indio_dev, priv);
|
|
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(zpa2326_probe);
|
|
|
|
void zpa2326_remove(const struct device *parent)
|
|
{
|
|
struct iio_dev *indio_dev = dev_get_drvdata(parent);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
zpa2326_fini_runtime(indio_dev->dev.parent);
|
|
zpa2326_sleep(indio_dev);
|
|
zpa2326_power_off(indio_dev, iio_priv(indio_dev));
|
|
}
|
|
EXPORT_SYMBOL_GPL(zpa2326_remove);
|
|
|
|
MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
|
|
MODULE_DESCRIPTION("Core driver for Murata ZPA2326 pressure sensor");
|
|
MODULE_LICENSE("GPL v2");
|