330 lines
8.0 KiB
C
330 lines
8.0 KiB
C
/*
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* CM3605 Ambient Light and Proximity Sensor
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*
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* Copyright (C) 2016 Linaro Ltd.
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*
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* This hardware was found in the very first Nexus One handset from Google/HTC
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* and an early endavour into mobile light and proximity sensors.
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*/
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#include <linux/module.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/events.h>
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#include <linux/iio/consumer.h> /* To get our ADC channel */
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#include <linux/iio/types.h> /* To deal with our ADC channel */
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#include <linux/init.h>
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#include <linux/leds.h>
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#include <linux/platform_device.h>
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#include <linux/of.h>
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#include <linux/regulator/consumer.h>
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#include <linux/gpio/consumer.h>
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#include <linux/interrupt.h>
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#include <linux/math64.h>
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#include <linux/pm.h>
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#define CM3605_PROX_CHANNEL 0
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#define CM3605_ALS_CHANNEL 1
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#define CM3605_AOUT_TYP_MAX_MV 1550
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/* It should not go above 1.650V according to the data sheet */
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#define CM3605_AOUT_MAX_MV 1650
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/**
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* struct cm3605 - CM3605 state
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* @dev: pointer to parent device
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* @vdd: regulator controlling VDD
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* @aset: sleep enable GPIO, high = sleep
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* @aout: IIO ADC channel to convert the AOUT signal
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* @als_max: maximum LUX detection (depends on RSET)
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* @dir: proximity direction: start as FALLING
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* @led: trigger for the infrared LED used by the proximity sensor
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*/
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struct cm3605 {
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struct device *dev;
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struct regulator *vdd;
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struct gpio_desc *aset;
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struct iio_channel *aout;
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s32 als_max;
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enum iio_event_direction dir;
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struct led_trigger *led;
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};
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static irqreturn_t cm3605_prox_irq(int irq, void *d)
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{
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struct iio_dev *indio_dev = d;
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struct cm3605 *cm3605 = iio_priv(indio_dev);
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u64 ev;
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ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, CM3605_PROX_CHANNEL,
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IIO_EV_TYPE_THRESH, cm3605->dir);
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iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
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/* Invert the edge for each event */
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if (cm3605->dir == IIO_EV_DIR_RISING)
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cm3605->dir = IIO_EV_DIR_FALLING;
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else
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cm3605->dir = IIO_EV_DIR_RISING;
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return IRQ_HANDLED;
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}
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static int cm3605_get_lux(struct cm3605 *cm3605)
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{
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int ret, res;
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s64 lux;
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ret = iio_read_channel_processed(cm3605->aout, &res);
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if (ret < 0)
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return ret;
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dev_dbg(cm3605->dev, "read %d mV from ADC\n", res);
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/*
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* AOUT has an offset of ~30mV then linear at dark
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* then goes from 2.54 up to 650 LUX yielding 1.55V
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* (1550 mV) so scale the returned value to this interval
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* using simple linear interpolation.
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*/
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if (res < 30)
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return 0;
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if (res > CM3605_AOUT_MAX_MV)
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dev_err(cm3605->dev, "device out of range\n");
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/* Remove bias */
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lux = res - 30;
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/* Linear interpolation between 0 and ALS typ max */
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lux *= cm3605->als_max;
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lux = div64_s64(lux, CM3605_AOUT_TYP_MAX_MV);
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return lux;
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}
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static int cm3605_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct cm3605 *cm3605 = iio_priv(indio_dev);
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int ret;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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switch (chan->type) {
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case IIO_LIGHT:
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ret = cm3605_get_lux(cm3605);
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if (ret < 0)
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return ret;
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*val = ret;
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return IIO_VAL_INT;
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default:
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return -EINVAL;
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}
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info cm3605_info = {
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.read_raw = cm3605_read_raw,
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};
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static const struct iio_event_spec cm3605_events[] = {
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{
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.type = IIO_EV_TYPE_THRESH,
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.dir = IIO_EV_DIR_EITHER,
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.mask_separate = BIT(IIO_EV_INFO_ENABLE),
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},
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};
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static const struct iio_chan_spec cm3605_channels[] = {
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{
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.type = IIO_PROXIMITY,
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.event_spec = cm3605_events,
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.num_event_specs = ARRAY_SIZE(cm3605_events),
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},
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{
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.type = IIO_LIGHT,
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
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.channel = CM3605_ALS_CHANNEL,
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},
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};
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static int cm3605_probe(struct platform_device *pdev)
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{
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struct cm3605 *cm3605;
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struct iio_dev *indio_dev;
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node;
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enum iio_chan_type ch_type;
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u32 rset;
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int ret;
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indio_dev = devm_iio_device_alloc(dev, sizeof(*cm3605));
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if (!indio_dev)
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return -ENOMEM;
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platform_set_drvdata(pdev, indio_dev);
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cm3605 = iio_priv(indio_dev);
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cm3605->dev = dev;
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cm3605->dir = IIO_EV_DIR_FALLING;
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ret = of_property_read_u32(np, "capella,aset-resistance-ohms", &rset);
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if (ret) {
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dev_info(dev, "no RSET specified, assuming 100K\n");
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rset = 100000;
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}
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switch (rset) {
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case 50000:
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cm3605->als_max = 650;
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break;
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case 100000:
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cm3605->als_max = 300;
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break;
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case 300000:
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cm3605->als_max = 100;
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break;
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case 600000:
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cm3605->als_max = 50;
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break;
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default:
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dev_info(dev, "non-standard resistance\n");
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return -EINVAL;
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}
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cm3605->aout = devm_iio_channel_get(dev, "aout");
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if (IS_ERR(cm3605->aout)) {
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if (PTR_ERR(cm3605->aout) == -ENODEV) {
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dev_err(dev, "no ADC, deferring...\n");
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return -EPROBE_DEFER;
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}
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dev_err(dev, "failed to get AOUT ADC channel\n");
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return PTR_ERR(cm3605->aout);
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}
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ret = iio_get_channel_type(cm3605->aout, &ch_type);
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if (ret < 0)
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return ret;
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if (ch_type != IIO_VOLTAGE) {
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dev_err(dev, "wrong type of IIO channel specified for AOUT\n");
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return -EINVAL;
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}
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cm3605->vdd = devm_regulator_get(dev, "vdd");
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if (IS_ERR(cm3605->vdd)) {
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dev_err(dev, "failed to get VDD regulator\n");
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return PTR_ERR(cm3605->vdd);
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}
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ret = regulator_enable(cm3605->vdd);
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if (ret) {
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dev_err(dev, "failed to enable VDD regulator\n");
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return ret;
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}
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cm3605->aset = devm_gpiod_get(dev, "aset", GPIOD_OUT_HIGH);
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if (IS_ERR(cm3605->aset)) {
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dev_err(dev, "no ASET GPIO\n");
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ret = PTR_ERR(cm3605->aset);
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goto out_disable_vdd;
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}
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ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
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cm3605_prox_irq, NULL, 0, "cm3605", indio_dev);
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if (ret) {
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dev_err(dev, "unable to request IRQ\n");
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goto out_disable_aset;
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}
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/* Just name the trigger the same as the driver */
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led_trigger_register_simple("cm3605", &cm3605->led);
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led_trigger_event(cm3605->led, LED_FULL);
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indio_dev->dev.parent = dev;
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indio_dev->info = &cm3605_info;
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indio_dev->name = "cm3605";
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indio_dev->channels = cm3605_channels;
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indio_dev->num_channels = ARRAY_SIZE(cm3605_channels);
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indio_dev->modes = INDIO_DIRECT_MODE;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto out_remove_trigger;
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dev_info(dev, "Capella Microsystems CM3605 enabled range 0..%d LUX\n",
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cm3605->als_max);
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return 0;
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out_remove_trigger:
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led_trigger_event(cm3605->led, LED_OFF);
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led_trigger_unregister_simple(cm3605->led);
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out_disable_aset:
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gpiod_set_value_cansleep(cm3605->aset, 0);
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out_disable_vdd:
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regulator_disable(cm3605->vdd);
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return ret;
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}
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static int cm3605_remove(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev = platform_get_drvdata(pdev);
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struct cm3605 *cm3605 = iio_priv(indio_dev);
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led_trigger_event(cm3605->led, LED_OFF);
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led_trigger_unregister_simple(cm3605->led);
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gpiod_set_value_cansleep(cm3605->aset, 0);
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iio_device_unregister(indio_dev);
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regulator_disable(cm3605->vdd);
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return 0;
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}
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static int __maybe_unused cm3605_pm_suspend(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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struct cm3605 *cm3605 = iio_priv(indio_dev);
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led_trigger_event(cm3605->led, LED_OFF);
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regulator_disable(cm3605->vdd);
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return 0;
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}
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static int __maybe_unused cm3605_pm_resume(struct device *dev)
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{
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struct iio_dev *indio_dev = dev_get_drvdata(dev);
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struct cm3605 *cm3605 = iio_priv(indio_dev);
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int ret;
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ret = regulator_enable(cm3605->vdd);
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if (ret)
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dev_err(dev, "failed to enable regulator in resume path\n");
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led_trigger_event(cm3605->led, LED_FULL);
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return 0;
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}
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static const struct dev_pm_ops cm3605_dev_pm_ops = {
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SET_SYSTEM_SLEEP_PM_OPS(cm3605_pm_suspend,
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cm3605_pm_resume)
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};
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static const struct of_device_id cm3605_of_match[] = {
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{.compatible = "capella,cm3605"},
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{ },
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};
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MODULE_DEVICE_TABLE(of, cm3605_of_match);
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static struct platform_driver cm3605_driver = {
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.driver = {
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.name = "cm3605",
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.of_match_table = cm3605_of_match,
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.pm = &cm3605_dev_pm_ops,
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},
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.probe = cm3605_probe,
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.remove = cm3605_remove,
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};
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module_platform_driver(cm3605_driver);
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MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
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MODULE_DESCRIPTION("CM3605 ambient light and proximity sensor driver");
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MODULE_LICENSE("GPL");
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