473 lines
10 KiB
C
473 lines
10 KiB
C
/*
|
|
* as3935.c - Support for AS3935 Franklin lightning sensor
|
|
*
|
|
* Copyright (C) 2014 Matt Ranostay <mranostay@gmail.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
*/
|
|
|
|
#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_INT 0x03
|
|
#define AS3935_INT_MASK 0x0f
|
|
#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_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;
|
|
|
|
u32 tune_cap;
|
|
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 IIO_DEVICE_ATTR(sensor_sensitivity, S_IRUGO | S_IWUSR,
|
|
as3935_sensor_sensitivity_show, as3935_sensor_sensitivity_store, 0);
|
|
|
|
|
|
static struct attribute *as3935_attributes[] = {
|
|
&iio_dev_attr_sensor_sensitivity.dev_attr.attr,
|
|
NULL,
|
|
};
|
|
|
|
static 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;
|
|
|
|
if (m == IIO_CHAN_INFO_RAW)
|
|
return IIO_VAL_INT;
|
|
|
|
/* storm out of range */
|
|
if (*val == AS3935_DATA_MASK)
|
|
return -EINVAL;
|
|
|
|
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 = {
|
|
.driver_module = THIS_MODULE,
|
|
.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 = {
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
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_NOISE_INT:
|
|
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)
|
|
{
|
|
/* mask disturber interrupt bit */
|
|
as3935_write(st, AS3935_INT, BIT(5));
|
|
|
|
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));
|
|
}
|
|
|
|
#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 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);
|
|
INIT_DELAYED_WORK(&st->work, as3935_event_work);
|
|
|
|
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;
|
|
}
|
|
|
|
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;
|
|
trig->dev.parent = indio_dev->dev.parent;
|
|
iio_trigger_set_drvdata(trig, indio_dev);
|
|
trig->ops = &iio_interrupt_trigger_ops;
|
|
|
|
ret = iio_trigger_register(trig);
|
|
if (ret) {
|
|
dev_err(&spi->dev, "failed to register trigger\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
|
|
&as3935_trigger_handler, NULL);
|
|
|
|
if (ret) {
|
|
dev_err(&spi->dev, "cannot setup iio trigger\n");
|
|
goto unregister_trigger;
|
|
}
|
|
|
|
calibrate_as3935(st);
|
|
|
|
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");
|
|
goto unregister_buffer;
|
|
}
|
|
|
|
ret = iio_device_register(indio_dev);
|
|
if (ret < 0) {
|
|
dev_err(&spi->dev, "unable to register device\n");
|
|
goto unregister_buffer;
|
|
}
|
|
return 0;
|
|
|
|
unregister_buffer:
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
|
|
unregister_trigger:
|
|
iio_trigger_unregister(st->trig);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int as3935_remove(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
|
struct as3935_state *st = iio_priv(indio_dev);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
iio_trigger_unregister(st->trig);
|
|
|
|
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,
|
|
.remove = as3935_remove,
|
|
.id_table = as3935_id,
|
|
};
|
|
module_spi_driver(as3935_driver);
|
|
|
|
MODULE_AUTHOR("Matt Ranostay <mranostay@gmail.com>");
|
|
MODULE_DESCRIPTION("AS3935 lightning sensor");
|
|
MODULE_LICENSE("GPL");
|