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iio: proximity: as3935: noise detection + threshold changes 

Most applications are too noisy to allow the default noise and
watchdog settings, and thus need to be configurable via DT
properties.

Also default settings to POR defaults on a reset, and register
distuber interrupts as noise since it prevents proper usage.

Cc: devicetree@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
zero-colors
Matt Ranostay 2017-05-24 22:52:29 -07:00 committed by Jonathan Cameron
parent b2e312061c
commit eb35279dd7
3 changed files with 53 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935
View File

@ -14,3 +14,11 @@ Description:
Show or set the gain boost of the amp, from 0-31 range.
18 = indoors (default)
14 = outdoors
What /sys/bus/iio/devices/iio:deviceX/noise_level_tripped
Date: May 2017
KernelVersion: 4.13
Contact: Matt Ranostay <matt.ranostay@konsulko.com>
Description:
When 1 the noise level is over the trip level and not reporting
valid data

5
Documentation/devicetree/bindings/iio/proximity/as3935.txt
View File

@ -16,6 +16,10 @@ Optional properties:
- ams,tuning-capacitor-pf: Calibration tuning capacitor stepping
value 0 - 120pF. This will require using the calibration data from
the manufacturer.
- ams,nflwdth: Set the noise and watchdog threshold register on
startup. This will need to set according to the noise from the
MCU board, and possibly the local environment. Refer to the
datasheet for the threshold settings.
Example:
@ -27,4 +31,5 @@ as3935@0 {
interrupt-parent = <&gpio1>;
interrupts = <16 1>;
ams,tuning-capacitor-pf = <80>;
ams,nflwdth = <0x44>;
};

43
drivers/iio/proximity/as3935.c
View File

@ -39,8 +39,12 @@
#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)
@ -48,6 +52,7 @@
#define AS3935_DATA_MASK 0x3F
#define AS3935_TUNE_CAP 0x08
#define AS3935_DEFAULTS 0x3C
#define AS3935_CALIBRATE 0x3D
#define AS3935_READ_DATA BIT(14)
@ -62,7 +67,9 @@ struct as3935_state {
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;
};
@ -145,12 +152,29 @@ static ssize_t as3935_sensor_sensitivity_store(struct device *dev,
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,
};
@ -246,7 +270,11 @@ static void as3935_event_work(struct work_struct *work)
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;
}
@ -269,15 +297,14 @@ static irqreturn_t as3935_interrupt_handler(int irq, void *private)
static void calibrate_as3935(struct as3935_state *st)
{
/* mask disturber interrupt bit */
as3935_write(st, AS3935_INT, BIT(5));
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
@ -370,6 +397,15 @@ static int as3935_probe(struct spi_device *spi)
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;
@ -384,6 +420,7 @@ static int as3935_probe(struct spi_device *spi)
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;