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@xxxxxxxxxxxxxxx
Signed-off-by: Matt Ranostay <matt.ranostay@xxxxxxxxxxxx>
---
.../devicetree/bindings/iio/proximity/as3935.txt | 6 +++
drivers/iio/proximity/as3935.c | 43 ++++++++++++++++++++--
2 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/iio/proximity/as3935.txt b/Documentation/devicetree/bindings/iio/proximity/as3935.txt
index ae23dd8da736..50d370fca533 100644
--- a/Documentation/devicetree/bindings/iio/proximity/as3935.txt
+++ b/Documentation/devicetree/bindings/iio/proximity/as3935.txt
@@ -15,14 +15,20 @@ 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:
as3935@0 {
compatible = "ams,as3935";
reg = <0>;
+ spi-max-frequency = <400000>;
spi-cpha;
interrupt-parent = <&gpio1>;
interrupts = <16 1>;
ams,tuning-capacitor-pf = <80>;
+ ams,nflwdth = <0x44>;
};
diff --git a/drivers/iio/proximity/as3935.c b/drivers/iio/proximity/as3935.c
index aa4df0dcc8c9..ec2f40e0791c 100644
--- a/drivers/iio/proximity/as3935.c
+++ b/drivers/iio/proximity/as3935.c
@@ -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;
--
2.11.0
--
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