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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/iio/proximity/as3935.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/iio/proximity/as3935.c')
-rw-r--r--drivers/iio/proximity/as3935.c470
1 files changed, 470 insertions, 0 deletions
diff --git a/drivers/iio/proximity/as3935.c b/drivers/iio/proximity/as3935.c
new file mode 100644
index 000000000..ebc95cf8f
--- /dev/null
+++ b/drivers/iio/proximity/as3935.c
@@ -0,0 +1,470 @@
+// 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/mod_devicetable.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/devm-helpers.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/irq.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>
+
+#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;
+ /* Ensure timestamp is naturally aligned */
+ struct {
+ u8 chan;
+ s64 timestamp __aligned(8);
+ } scan;
+ u8 buf[2] __aligned(IIO_DMA_MINALIGN);
+};
+
+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 sysfs_emit(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(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 = sysfs_emit(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->scan.chan = val & AS3935_DATA_MASK;
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
+ iio_get_time_ns(indio_dev));
+err_read:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+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);
+}
+
+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 DEFINE_SIMPLE_DEV_PM_OPS(as3935_pm_ops, as3935_suspend, as3935_resume);
+
+static int as3935_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct iio_trigger *trig;
+ struct as3935_state *st;
+ int ret;
+
+ /* Be sure lightning event interrupt is specified */
+ if (!spi->irq) {
+ dev_err(dev, "unable to get event interrupt\n");
+ return -EINVAL;
+ }
+
+ indio_dev = devm_iio_device_alloc(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 = device_property_read_u32(dev,
+ "ams,tuning-capacitor-pf", &st->tune_cap);
+ if (ret) {
+ st->tune_cap = 0;
+ dev_warn(dev, "no tuning-capacitor-pf set, defaulting to %d",
+ st->tune_cap);
+ }
+
+ if (st->tune_cap > MAX_PF_CAP) {
+ dev_err(dev, "wrong tuning-capacitor-pf setting of %d\n",
+ st->tune_cap);
+ return -EINVAL;
+ }
+
+ ret = device_property_read_u32(dev,
+ "ams,nflwdth", &st->nflwdth_reg);
+ if (!ret && st->nflwdth_reg > AS3935_NFLWDTH_MASK) {
+ dev_err(dev, "invalid nflwdth setting of %d\n",
+ st->nflwdth_reg);
+ return -EINVAL;
+ }
+
+ 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(dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+
+ if (!trig)
+ return -ENOMEM;
+
+ st->trig = trig;
+ st->noise_tripped = jiffies - HZ;
+ iio_trigger_set_drvdata(trig, indio_dev);
+
+ ret = devm_iio_trigger_register(dev, trig);
+ if (ret) {
+ dev_err(dev, "failed to register trigger\n");
+ return ret;
+ }
+
+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ as3935_trigger_handler, NULL);
+
+ if (ret) {
+ dev_err(dev, "cannot setup iio trigger\n");
+ return ret;
+ }
+
+ calibrate_as3935(st);
+
+ ret = devm_delayed_work_autocancel(dev, &st->work, as3935_event_work);
+ if (ret)
+ return ret;
+
+ ret = devm_request_irq(dev, spi->irq,
+ &as3935_interrupt_handler,
+ IRQF_TRIGGER_RISING,
+ dev_name(dev),
+ indio_dev);
+
+ if (ret) {
+ dev_err(dev, "unable to request irq\n");
+ return ret;
+ }
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret < 0) {
+ dev_err(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 = as3935_of_match,
+ .pm = pm_sleep_ptr(&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");