[linux-2.6-block.git] / drivers / iio / proximity / as3935.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * as3935.c - Support for AS3935 Franklin lightning sensor
 *
 * Copyright (C) 2014, 2017-2018
 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/of_gpio.h>


#define AS3935_AFE_GAIN		0x00
#define AS3935_AFE_MASK		0x3F
#define AS3935_AFE_GAIN_MAX	0x1F
#define AS3935_AFE_PWR_BIT	BIT(0)

#define AS3935_NFLWDTH		0x01
#define AS3935_NFLWDTH_MASK	0x7f

#define AS3935_INT		0x03
#define AS3935_INT_MASK		0x0f
#define AS3935_DISTURB_INT	BIT(2)
#define AS3935_EVENT_INT	BIT(3)
#define AS3935_NOISE_INT	BIT(0)

#define AS3935_DATA		0x07
#define AS3935_DATA_MASK	0x3F

#define AS3935_TUNE_CAP		0x08
#define AS3935_DEFAULTS		0x3C
#define AS3935_CALIBRATE	0x3D

#define AS3935_READ_DATA	BIT(14)
#define AS3935_ADDRESS(x)	((x) << 8)

#define MAX_PF_CAP		120
#define TUNE_CAP_DIV		8

struct as3935_state {
	struct spi_device *spi;
	struct iio_trigger *trig;
	struct mutex lock;
	struct delayed_work work;

	unsigned long noise_tripped;
	u32 tune_cap;
	u32 nflwdth_reg;
	u8 buffer[16]; /* 8-bit data + 56-bit padding + 64-bit timestamp */
	u8 buf[2] ____cacheline_aligned;
};

static const struct iio_chan_spec as3935_channels[] = {
	{
		.type           = IIO_PROXIMITY,
		.info_mask_separate =
			BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_PROCESSED) |
			BIT(IIO_CHAN_INFO_SCALE),
		.scan_index     = 0,
		.scan_type = {
			.sign           = 'u',
			.realbits       = 6,
			.storagebits    = 8,
		},
	},
	IIO_CHAN_SOFT_TIMESTAMP(1),
};

static int as3935_read(struct as3935_state *st, unsigned int reg, int *val)
{
	u8 cmd;
	int ret;

	cmd = (AS3935_READ_DATA | AS3935_ADDRESS(reg)) >> 8;
	ret = spi_w8r8(st->spi, cmd);
	if (ret < 0)
		return ret;
	*val = ret;

	return 0;
}

static int as3935_write(struct as3935_state *st,
				unsigned int reg,
				unsigned int val)
{
	u8 *buf = st->buf;

	buf[0] = AS3935_ADDRESS(reg) >> 8;
	buf[1] = val;

	return spi_write(st->spi, buf, 2);
}

static ssize_t as3935_sensor_sensitivity_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	int val, ret;

	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	if (ret)
		return ret;
	val = (val & AS3935_AFE_MASK) >> 1;

	return sprintf(buf, "%d\n", val);
}

static ssize_t as3935_sensor_sensitivity_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t len)
{
	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	unsigned long val;
	int ret;

	ret = kstrtoul((const char *) buf, 10, &val);
	if (ret)
		return -EINVAL;

	if (val > AS3935_AFE_GAIN_MAX)
		return -EINVAL;

	as3935_write(st, AS3935_AFE_GAIN, val << 1);

	return len;
}

static ssize_t as3935_noise_level_tripped_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	int ret;

	mutex_lock(&st->lock);
	ret = sprintf(buf, "%d\n", !time_after(jiffies, st->noise_tripped + HZ));
	mutex_unlock(&st->lock);

	return ret;
}

static IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO | S_IWUSR,
	as3935_sensor_sensitivity_show, as3935_sensor_sensitivity_store, 0);

static IIO_DEVICE_ATTR(noise_level_tripped, S_IRUGO,
	as3935_noise_level_tripped_show, NULL, 0);

static struct attribute *as3935_attributes[] = {
	&iio_dev_attr_sensor_sensitivity.dev_attr.attr,
	&iio_dev_attr_noise_level_tripped.dev_attr.attr,
	NULL,
};

static const struct attribute_group as3935_attribute_group = {
	.attrs = as3935_attributes,
};

static int as3935_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val,
			   int *val2,
			   long m)
{
	struct as3935_state *st = iio_priv(indio_dev);
	int ret;


	switch (m) {
	case IIO_CHAN_INFO_PROCESSED:
	case IIO_CHAN_INFO_RAW:
		*val2 = 0;
		ret = as3935_read(st, AS3935_DATA, val);
		if (ret)
			return ret;

		/* storm out of range */
		if (*val == AS3935_DATA_MASK)
			return -EINVAL;

		if (m == IIO_CHAN_INFO_RAW)
			return IIO_VAL_INT;

		if (m == IIO_CHAN_INFO_PROCESSED)
			*val *= 1000;
		break;
	case IIO_CHAN_INFO_SCALE:
		*val = 1000;
		break;
	default:
		return -EINVAL;
	}

	return IIO_VAL_INT;
}

static const struct iio_info as3935_info = {
	.attrs = &as3935_attribute_group,
	.read_raw = &as3935_read_raw,
};

static irqreturn_t as3935_trigger_handler(int irq, void *private)
{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct as3935_state *st = iio_priv(indio_dev);
	int val, ret;

	ret = as3935_read(st, AS3935_DATA, &val);
	if (ret)
		goto err_read;

	st->buffer[0] = val & AS3935_DATA_MASK;
	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
					   iio_get_time_ns(indio_dev));
err_read:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
};

static void as3935_event_work(struct work_struct *work)
{
	struct as3935_state *st;
	int val;
	int ret;

	st = container_of(work, struct as3935_state, work.work);

	ret = as3935_read(st, AS3935_INT, &val);
	if (ret) {
		dev_warn(&st->spi->dev, "read error\n");
		return;
	}

	val &= AS3935_INT_MASK;

	switch (val) {
	case AS3935_EVENT_INT:
		iio_trigger_poll_chained(st->trig);
		break;
	case AS3935_DISTURB_INT:
	case AS3935_NOISE_INT:
		mutex_lock(&st->lock);
		st->noise_tripped = jiffies;
		mutex_unlock(&st->lock);
		dev_warn(&st->spi->dev, "noise level is too high\n");
		break;
	}
}

static irqreturn_t as3935_interrupt_handler(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct as3935_state *st = iio_priv(indio_dev);

	/*
	 * Delay work for >2 milliseconds after an interrupt to allow
	 * estimated distance to recalculated.
	 */

	schedule_delayed_work(&st->work, msecs_to_jiffies(3));

	return IRQ_HANDLED;
}

static void calibrate_as3935(struct as3935_state *st)
{
	as3935_write(st, AS3935_DEFAULTS, 0x96);
	as3935_write(st, AS3935_CALIBRATE, 0x96);
	as3935_write(st, AS3935_TUNE_CAP,
		BIT(5) | (st->tune_cap / TUNE_CAP_DIV));

	mdelay(2);
	as3935_write(st, AS3935_TUNE_CAP, (st->tune_cap / TUNE_CAP_DIV));
	as3935_write(st, AS3935_NFLWDTH, st->nflwdth_reg);
}

#ifdef CONFIG_PM_SLEEP
static int as3935_suspend(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct as3935_state *st = iio_priv(indio_dev);
	int val, ret;

	mutex_lock(&st->lock);
	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	if (ret)
		goto err_suspend;
	val |= AS3935_AFE_PWR_BIT;

	ret = as3935_write(st, AS3935_AFE_GAIN, val);

err_suspend:
	mutex_unlock(&st->lock);

	return ret;
}

static int as3935_resume(struct device *dev)
{
	struct iio_dev *indio_dev = dev_get_drvdata(dev);
	struct as3935_state *st = iio_priv(indio_dev);
	int val, ret;

	mutex_lock(&st->lock);
	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	if (ret)
		goto err_resume;
	val &= ~AS3935_AFE_PWR_BIT;
	ret = as3935_write(st, AS3935_AFE_GAIN, val);

	calibrate_as3935(st);

err_resume:
	mutex_unlock(&st->lock);

	return ret;
}

static SIMPLE_DEV_PM_OPS(as3935_pm_ops, as3935_suspend, as3935_resume);
#define AS3935_PM_OPS (&as3935_pm_ops)

#else
#define AS3935_PM_OPS NULL
#endif

static void as3935_stop_work(void *data)
{
	struct iio_dev *indio_dev = data;
	struct as3935_state *st = iio_priv(indio_dev);

	cancel_delayed_work_sync(&st->work);
}

static int as3935_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct iio_trigger *trig;
	struct as3935_state *st;
	struct device_node *np = spi->dev.of_node;
	int ret;

	/* Be sure lightning event interrupt is specified */
	if (!spi->irq) {
		dev_err(&spi->dev, "unable to get event interrupt\n");
		return -EINVAL;
	}

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	st->spi = spi;

	spi_set_drvdata(spi, indio_dev);
	mutex_init(&st->lock);

	ret = of_property_read_u32(np,
			"ams,tuning-capacitor-pf", &st->tune_cap);
	if (ret) {
		st->tune_cap = 0;
		dev_warn(&spi->dev,
			"no tuning-capacitor-pf set, defaulting to %d",
			st->tune_cap);
	}

	if (st->tune_cap > MAX_PF_CAP) {
		dev_err(&spi->dev,
			"wrong tuning-capacitor-pf setting of %d\n",
			st->tune_cap);
		return -EINVAL;
	}

	ret = of_property_read_u32(np,
			"ams,nflwdth", &st->nflwdth_reg);
	if (!ret && st->nflwdth_reg > AS3935_NFLWDTH_MASK) {
		dev_err(&spi->dev,
			"invalid nflwdth setting of %d\n",
			st->nflwdth_reg);
		return -EINVAL;
	}

	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->channels = as3935_channels;
	indio_dev->num_channels = ARRAY_SIZE(as3935_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &as3935_info;

	trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
				      indio_dev->name, indio_dev->id);

	if (!trig)
		return -ENOMEM;

	st->trig = trig;
	st->noise_tripped = jiffies - HZ;
	trig->dev.parent = indio_dev->dev.parent;
	iio_trigger_set_drvdata(trig, indio_dev);
	trig->ops = &iio_interrupt_trigger_ops;

	ret = devm_iio_trigger_register(&spi->dev, trig);
	if (ret) {
		dev_err(&spi->dev, "failed to register trigger\n");
		return ret;
	}

	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
					      iio_pollfunc_store_time,
					      as3935_trigger_handler, NULL);

	if (ret) {
		dev_err(&spi->dev, "cannot setup iio trigger\n");
		return ret;
	}

	calibrate_as3935(st);

	INIT_DELAYED_WORK(&st->work, as3935_event_work);
	ret = devm_add_action(&spi->dev, as3935_stop_work, indio_dev);
	if (ret)
		return ret;

	ret = devm_request_irq(&spi->dev, spi->irq,
				&as3935_interrupt_handler,
				IRQF_TRIGGER_RISING,
				dev_name(&spi->dev),
				indio_dev);

	if (ret) {
		dev_err(&spi->dev, "unable to request irq\n");
		return ret;
	}

	ret = devm_iio_device_register(&spi->dev, indio_dev);
	if (ret < 0) {
		dev_err(&spi->dev, "unable to register device\n");
		return ret;
	}
	return 0;
}

static const struct of_device_id as3935_of_match[] = {
	{ .compatible = "ams,as3935", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, as3935_of_match);

static const struct spi_device_id as3935_id[] = {
	{"as3935", 0},
	{},
};
MODULE_DEVICE_TABLE(spi, as3935_id);

static struct spi_driver as3935_driver = {
	.driver = {
		.name	= "as3935",
		.of_match_table = of_match_ptr(as3935_of_match),
		.pm	= AS3935_PM_OPS,
	},
	.probe		= as3935_probe,
	.id_table	= as3935_id,
};
module_spi_driver(as3935_driver);

MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("AS3935 lightning sensor");
MODULE_LICENSE("GPL");
Commit	Line	Data
d6ad8058	1	// SPDX-License-Identifier: GPL-2.0+
24ddb0e4 MR	2	/*
	3	* as3935.c - Support for AS3935 Franklin lightning sensor
	4	*
d6ad8058 MR	5	* Copyright (C) 2014, 2017-2018
d6ad8058 MR	6	* Author: Matt Ranostay <matt.ranostay@konsulko.com>
24ddb0e4 MR	7	*/
	8
	9	#include <linux/module.h>
	10	#include <linux/init.h>
	11	#include <linux/interrupt.h>
	12	#include <linux/delay.h>
	13	#include <linux/workqueue.h>
	14	#include <linux/mutex.h>
	15	#include <linux/err.h>
	16	#include <linux/irq.h>
	17	#include <linux/gpio.h>
	18	#include <linux/spi/spi.h>
	19	#include <linux/iio/iio.h>
	20	#include <linux/iio/sysfs.h>
	21	#include <linux/iio/trigger.h>
	22	#include <linux/iio/trigger_consumer.h>
	23	#include <linux/iio/buffer.h>
	24	#include <linux/iio/triggered_buffer.h>
	25	#include <linux/of_gpio.h>
	26
	27
	28	#define AS3935_AFE_GAIN 0x00
	29	#define AS3935_AFE_MASK 0x3F
	30	#define AS3935_AFE_GAIN_MAX 0x1F
	31	#define AS3935_AFE_PWR_BIT BIT(0)
	32
eb35279d MR	33	#define AS3935_NFLWDTH 0x01
	34	#define AS3935_NFLWDTH_MASK 0x7f
	35
24ddb0e4	36	#define AS3935_INT 0x03
275292d3	37	#define AS3935_INT_MASK 0x0f
eb35279d	38	#define AS3935_DISTURB_INT BIT(2)
24ddb0e4	39	#define AS3935_EVENT_INT BIT(3)
275292d3	40	#define AS3935_NOISE_INT BIT(0)
24ddb0e4 MR	41
	42	#define AS3935_DATA 0x07
	43	#define AS3935_DATA_MASK 0x3F
	44
	45	#define AS3935_TUNE_CAP 0x08
eb35279d	46	#define AS3935_DEFAULTS 0x3C
24ddb0e4 MR	47	#define AS3935_CALIBRATE 0x3D
24ddb0e4 MR	48
24ddb0e4 MR	49	#define AS3935_READ_DATA BIT(14)
	50	#define AS3935_ADDRESS(x) ((x) << 8)
	51
	52	#define MAX_PF_CAP 120
	53	#define TUNE_CAP_DIV 8
	54
	55	struct as3935_state {
	56	struct spi_device *spi;
	57	struct iio_trigger *trig;
	58	struct mutex lock;
	59	struct delayed_work work;
	60
eb35279d	61	unsigned long noise_tripped;
24ddb0e4	62	u32 tune_cap;
eb35279d	63	u32 nflwdth_reg;
37b1ba2c	64	u8 buffer[16]; /* 8-bit data + 56-bit padding + 64-bit timestamp */
24ddb0e4 MR	65	u8 buf[2] ____cacheline_aligned;
	66	};
	67
	68	static const struct iio_chan_spec as3935_channels[] = {
	69	{
	70	.type = IIO_PROXIMITY,
	71	.info_mask_separate =
	72	BIT(IIO_CHAN_INFO_RAW) \|
5138806f MR	73	BIT(IIO_CHAN_INFO_PROCESSED) \|
5138806f MR	74	BIT(IIO_CHAN_INFO_SCALE),
24ddb0e4 MR	75	.scan_index = 0,
	76	.scan_type = {
	77	.sign = 'u',
	78	.realbits = 6,
	79	.storagebits = 8,
	80	},
	81	},
	82	IIO_CHAN_SOFT_TIMESTAMP(1),
	83	};
	84
	85	static int as3935_read(struct as3935_state st, unsigned int reg, int val)
	86	{
	87	u8 cmd;
	88	int ret;
	89
	90	cmd = (AS3935_READ_DATA \| AS3935_ADDRESS(reg)) >> 8;
	91	ret = spi_w8r8(st->spi, cmd);
	92	if (ret < 0)
	93	return ret;
	94	*val = ret;
	95
	96	return 0;
455f0049	97	}
24ddb0e4 MR	98
	99	static int as3935_write(struct as3935_state *st,
	100	unsigned int reg,
	101	unsigned int val)
	102	{
	103	u8 *buf = st->buf;
	104
84ca8e36	105	buf[0] = AS3935_ADDRESS(reg) >> 8;
24ddb0e4 MR	106	buf[1] = val;
	107
	108	return spi_write(st->spi, buf, 2);
455f0049	109	}
24ddb0e4 MR	110
	111	static ssize_t as3935_sensor_sensitivity_show(struct device *dev,
	112	struct device_attribute *attr,
	113	char *buf)
	114	{
	115	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	116	int val, ret;
	117
	118	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	119	if (ret)
	120	return ret;
	121	val = (val & AS3935_AFE_MASK) >> 1;
	122
	123	return sprintf(buf, "%d\n", val);
455f0049	124	}
24ddb0e4 MR	125
	126	static ssize_t as3935_sensor_sensitivity_store(struct device *dev,
	127	struct device_attribute *attr,
	128	const char *buf, size_t len)
	129	{
	130	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	131	unsigned long val;
	132	int ret;
	133
	134	ret = kstrtoul((const char *) buf, 10, &val);
	135	if (ret)
	136	return -EINVAL;
	137
	138	if (val > AS3935_AFE_GAIN_MAX)
	139	return -EINVAL;
	140
	141	as3935_write(st, AS3935_AFE_GAIN, val << 1);
	142
	143	return len;
455f0049	144	}
24ddb0e4	145
eb35279d MR	146	static ssize_t as3935_noise_level_tripped_show(struct device *dev,
	147	struct device_attribute *attr,
	148	char *buf)
	149	{
	150	struct as3935_state *st = iio_priv(dev_to_iio_dev(dev));
	151	int ret;
	152
	153	mutex_lock(&st->lock);
	154	ret = sprintf(buf, "%d\n", !time_after(jiffies, st->noise_tripped + HZ));
	155	mutex_unlock(&st->lock);
	156
	157	return ret;
	158	}
	159
24ddb0e4 MR	160	static IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO \| S_IWUSR,
	161	as3935_sensor_sensitivity_show, as3935_sensor_sensitivity_store, 0);
	162
eb35279d MR	163	static IIO_DEVICE_ATTR(noise_level_tripped, S_IRUGO,
eb35279d MR	164	as3935_noise_level_tripped_show, NULL, 0);
24ddb0e4 MR	165
	166	static struct attribute *as3935_attributes[] = {
	167	&iio_dev_attr_sensor_sensitivity.dev_attr.attr,
eb35279d	168	&iio_dev_attr_noise_level_tripped.dev_attr.attr,
24ddb0e4 MR	169	NULL,
	170	};
	171
7ab89e1e	172	static const struct attribute_group as3935_attribute_group = {
24ddb0e4 MR	173	.attrs = as3935_attributes,
	174	};
	175
	176	static int as3935_read_raw(struct iio_dev *indio_dev,
	177	struct iio_chan_spec const *chan,
	178	int *val,
	179	int *val2,
	180	long m)
	181	{
	182	struct as3935_state *st = iio_priv(indio_dev);
	183	int ret;
	184
	185
	186	switch (m) {
	187	case IIO_CHAN_INFO_PROCESSED:
	188	case IIO_CHAN_INFO_RAW:
	189	*val2 = 0;
	190	ret = as3935_read(st, AS3935_DATA, val);
	191	if (ret)
	192	return ret;
	193
24ddb0e4 MR	194	/* storm out of range */
	195	if (*val == AS3935_DATA_MASK)
	196	return -EINVAL;
5138806f	197
d532e5b2 MR	198	if (m == IIO_CHAN_INFO_RAW)
	199	return IIO_VAL_INT;
	200
5138806f MR	201	if (m == IIO_CHAN_INFO_PROCESSED)
	202	val = 1000;
	203	break;
	204	case IIO_CHAN_INFO_SCALE:
	205	*val = 1000;
24ddb0e4 MR	206	break;
	207	default:
	208	return -EINVAL;
	209	}
	210
	211	return IIO_VAL_INT;
	212	}
	213
	214	static const struct iio_info as3935_info = {
24ddb0e4 MR	215	.attrs = &as3935_attribute_group,
	216	.read_raw = &as3935_read_raw,
	217	};
	218
	219	static irqreturn_t as3935_trigger_handler(int irq, void *private)
	220	{
	221	struct iio_poll_func *pf = private;
	222	struct iio_dev *indio_dev = pf->indio_dev;
	223	struct as3935_state *st = iio_priv(indio_dev);
	224	int val, ret;
	225
	226	ret = as3935_read(st, AS3935_DATA, &val);
	227	if (ret)
	228	goto err_read;
24ddb0e4	229
37b1ba2c MR	230	st->buffer[0] = val & AS3935_DATA_MASK;
37b1ba2c MR	231	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
9122b54f	232	iio_get_time_ns(indio_dev));
24ddb0e4 MR	233	err_read:
	234	iio_trigger_notify_done(indio_dev->trig);
	235
	236	return IRQ_HANDLED;
455f0049	237	}
24ddb0e4 MR	238
24ddb0e4 MR	239	static const struct iio_trigger_ops iio_interrupt_trigger_ops = {
24ddb0e4 MR	240	};
	241
	242	static void as3935_event_work(struct work_struct *work)
	243	{
	244	struct as3935_state *st;
	245	int val;
22ed1a1c	246	int ret;
24ddb0e4 MR	247
	248	st = container_of(work, struct as3935_state, work.work);
	249
22ed1a1c AB	250	ret = as3935_read(st, AS3935_INT, &val);
	251	if (ret) {
	252	dev_warn(&st->spi->dev, "read error\n");
	253	return;
	254	}
	255
24ddb0e4 MR	256	val &= AS3935_INT_MASK;
	257
	258	switch (val) {
	259	case AS3935_EVENT_INT:
9122b54f	260	iio_trigger_poll_chained(st->trig);
24ddb0e4	261	break;
eb35279d	262	case AS3935_DISTURB_INT:
24ddb0e4	263	case AS3935_NOISE_INT:
eb35279d MR	264	mutex_lock(&st->lock);
	265	st->noise_tripped = jiffies;
	266	mutex_unlock(&st->lock);
22ed1a1c	267	dev_warn(&st->spi->dev, "noise level is too high\n");
24ddb0e4 MR	268	break;
24ddb0e4 MR	269	}
455f0049	270	}
24ddb0e4 MR	271
	272	static irqreturn_t as3935_interrupt_handler(int irq, void *private)
	273	{
	274	struct iio_dev *indio_dev = private;
	275	struct as3935_state *st = iio_priv(indio_dev);
	276
	277	/*
	278	* Delay work for >2 milliseconds after an interrupt to allow
	279	* estimated distance to recalculated.
	280	*/
	281
	282	schedule_delayed_work(&st->work, msecs_to_jiffies(3));
	283
	284	return IRQ_HANDLED;
	285	}
	286
	287	static void calibrate_as3935(struct as3935_state *st)
	288	{
eb35279d	289	as3935_write(st, AS3935_DEFAULTS, 0x96);
24ddb0e4 MR	290	as3935_write(st, AS3935_CALIBRATE, 0x96);
	291	as3935_write(st, AS3935_TUNE_CAP,
	292	BIT(5) \| (st->tune_cap / TUNE_CAP_DIV));
	293
	294	mdelay(2);
	295	as3935_write(st, AS3935_TUNE_CAP, (st->tune_cap / TUNE_CAP_DIV));
eb35279d	296	as3935_write(st, AS3935_NFLWDTH, st->nflwdth_reg);
24ddb0e4 MR	297	}
	298
	299	#ifdef CONFIG_PM_SLEEP
9d9f7800	300	static int as3935_suspend(struct device *dev)
24ddb0e4	301	{
9d9f7800	302	struct iio_dev *indio_dev = dev_get_drvdata(dev);
24ddb0e4 MR	303	struct as3935_state *st = iio_priv(indio_dev);
	304	int val, ret;
	305
	306	mutex_lock(&st->lock);
	307	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	308	if (ret)
	309	goto err_suspend;
	310	val \|= AS3935_AFE_PWR_BIT;
	311
	312	ret = as3935_write(st, AS3935_AFE_GAIN, val);
	313
	314	err_suspend:
	315	mutex_unlock(&st->lock);
	316
	317	return ret;
	318	}
	319
9d9f7800	320	static int as3935_resume(struct device *dev)
24ddb0e4	321	{
9d9f7800	322	struct iio_dev *indio_dev = dev_get_drvdata(dev);
24ddb0e4 MR	323	struct as3935_state *st = iio_priv(indio_dev);
	324	int val, ret;
	325
	326	mutex_lock(&st->lock);
	327	ret = as3935_read(st, AS3935_AFE_GAIN, &val);
	328	if (ret)
	329	goto err_resume;
	330	val &= ~AS3935_AFE_PWR_BIT;
	331	ret = as3935_write(st, AS3935_AFE_GAIN, val);
	332
6272c0de MR	333	calibrate_as3935(st);
6272c0de MR	334
24ddb0e4 MR	335	err_resume:
	336	mutex_unlock(&st->lock);
	337
	338	return ret;
	339	}
9d9f7800 LPC	340
	341	static SIMPLE_DEV_PM_OPS(as3935_pm_ops, as3935_suspend, as3935_resume);
	342	#define AS3935_PM_OPS (&as3935_pm_ops)
	343
24ddb0e4	344	#else
9d9f7800	345	#define AS3935_PM_OPS NULL
24ddb0e4 MR	346	#endif
24ddb0e4 MR	347
11362b7a SVA	348	static void as3935_stop_work(void *data)
	349	{
	350	struct iio_dev *indio_dev = data;
	351	struct as3935_state *st = iio_priv(indio_dev);
	352
	353	cancel_delayed_work_sync(&st->work);
	354	}
	355
24ddb0e4 MR	356	static int as3935_probe(struct spi_device *spi)
	357	{
	358	struct iio_dev *indio_dev;
	359	struct iio_trigger *trig;
	360	struct as3935_state *st;
	361	struct device_node *np = spi->dev.of_node;
	362	int ret;
	363
	364	/* Be sure lightning event interrupt is specified */
	365	if (!spi->irq) {
	366	dev_err(&spi->dev, "unable to get event interrupt\n");
	367	return -EINVAL;
	368	}
	369
f73cde60	370	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
24ddb0e4 MR	371	if (!indio_dev)
	372	return -ENOMEM;
	373
	374	st = iio_priv(indio_dev);
	375	st->spi = spi;
24ddb0e4 MR	376
	377	spi_set_drvdata(spi, indio_dev);
	378	mutex_init(&st->lock);
24ddb0e4 MR	379
	380	ret = of_property_read_u32(np,
	381	"ams,tuning-capacitor-pf", &st->tune_cap);
	382	if (ret) {
	383	st->tune_cap = 0;
	384	dev_warn(&spi->dev,
	385	"no tuning-capacitor-pf set, defaulting to %d",
	386	st->tune_cap);
	387	}
	388
	389	if (st->tune_cap > MAX_PF_CAP) {
	390	dev_err(&spi->dev,
	391	"wrong tuning-capacitor-pf setting of %d\n",
	392	st->tune_cap);
	393	return -EINVAL;
	394	}
	395
eb35279d MR	396	ret = of_property_read_u32(np,
	397	"ams,nflwdth", &st->nflwdth_reg);
	398	if (!ret && st->nflwdth_reg > AS3935_NFLWDTH_MASK) {
	399	dev_err(&spi->dev,
	400	"invalid nflwdth setting of %d\n",
	401	st->nflwdth_reg);
	402	return -EINVAL;
	403	}
	404
24ddb0e4 MR	405	indio_dev->dev.parent = &spi->dev;
	406	indio_dev->name = spi_get_device_id(spi)->name;
	407	indio_dev->channels = as3935_channels;
	408	indio_dev->num_channels = ARRAY_SIZE(as3935_channels);
	409	indio_dev->modes = INDIO_DIRECT_MODE;
	410	indio_dev->info = &as3935_info;
	411
	412	trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
	413	indio_dev->name, indio_dev->id);
	414
	415	if (!trig)
	416	return -ENOMEM;
	417
	418	st->trig = trig;
eb35279d	419	st->noise_tripped = jiffies - HZ;
24ddb0e4 MR	420	trig->dev.parent = indio_dev->dev.parent;
	421	iio_trigger_set_drvdata(trig, indio_dev);
	422	trig->ops = &iio_interrupt_trigger_ops;
	423
11362b7a	424	ret = devm_iio_trigger_register(&spi->dev, trig);
24ddb0e4 MR	425	if (ret) {
	426	dev_err(&spi->dev, "failed to register trigger\n");
	427	return ret;
	428	}
	429
11362b7a SVA	430	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
	431	iio_pollfunc_store_time,
	432	as3935_trigger_handler, NULL);
24ddb0e4 MR	433
	434	if (ret) {
	435	dev_err(&spi->dev, "cannot setup iio trigger\n");
11362b7a	436	return ret;
24ddb0e4 MR	437	}
	438
	439	calibrate_as3935(st);
	440
11362b7a SVA	441	INIT_DELAYED_WORK(&st->work, as3935_event_work);
	442	ret = devm_add_action(&spi->dev, as3935_stop_work, indio_dev);
	443	if (ret)
	444	return ret;
	445
24ddb0e4 MR	446	ret = devm_request_irq(&spi->dev, spi->irq,
	447	&as3935_interrupt_handler,
	448	IRQF_TRIGGER_RISING,
	449	dev_name(&spi->dev),
	450	indio_dev);
	451
	452	if (ret) {
	453	dev_err(&spi->dev, "unable to request irq\n");
11362b7a	454	return ret;
24ddb0e4 MR	455	}
24ddb0e4 MR	456
11362b7a	457	ret = devm_iio_device_register(&spi->dev, indio_dev);
24ddb0e4 MR	458	if (ret < 0) {
24ddb0e4 MR	459	dev_err(&spi->dev, "unable to register device\n");
11362b7a	460	return ret;
24ddb0e4 MR	461	}
24ddb0e4 MR	462	return 0;
455f0049	463	}
24ddb0e4	464
8b7c826d JMC	465	static const struct of_device_id as3935_of_match[] = {
	466	{ .compatible = "ams,as3935", },
	467	{ /* sentinel */ },
	468	};
	469	MODULE_DEVICE_TABLE(of, as3935_of_match);
	470
24ddb0e4 MR	471	static const struct spi_device_id as3935_id[] = {
	472	{"as3935", 0},
	473	{},
	474	};
	475	MODULE_DEVICE_TABLE(spi, as3935_id);
	476
	477	static struct spi_driver as3935_driver = {
	478	.driver = {
	479	.name = "as3935",
8b7c826d	480	.of_match_table = of_match_ptr(as3935_of_match),
9d9f7800	481	.pm = AS3935_PM_OPS,
24ddb0e4 MR	482	},
24ddb0e4 MR	483	.probe = as3935_probe,
24ddb0e4	484	.id_table = as3935_id,
24ddb0e4 MR	485	};
	486	module_spi_driver(as3935_driver);
	487
d6ad8058	488	MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
24ddb0e4 MR	489	MODULE_DESCRIPTION("AS3935 lightning sensor");
24ddb0e4 MR	490	MODULE_LICENSE("GPL");