[PATCH 3/3] iio: light: vl6180: Add support for Continuous Mode

From: Abhash Jha
Date: Fri Oct 04 2024 - 11:03:41 EST


Added support for getting continuous readings from vl6180 using
triggered buffer approach. The continuous mode can be enabled by
enabling the buffer.
Also added a trigger and appropriate checks to see that it is used
with this device.

Signed-off-by: Abhash Jha <abhashkumarjha123@xxxxxxxxx>
---
drivers/iio/light/vl6180.c | 138 +++++++++++++++++++++++++++++++++++--
1 file changed, 134 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/light/vl6180.c b/drivers/iio/light/vl6180.c
index 4c2b486e2..e724e752e 100644
--- a/drivers/iio/light/vl6180.c
+++ b/drivers/iio/light/vl6180.c
@@ -25,6 +25,10 @@

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>

#define VL6180_DRV_NAME "vl6180"

@@ -91,10 +95,16 @@ struct vl6180_data {
struct i2c_client *client;
struct mutex lock;
struct completion completion;
+ struct iio_trigger *trig;
unsigned int als_gain_milli;
unsigned int als_it_ms;
unsigned int als_meas_rate;
unsigned int range_meas_rate;
+
+ struct {
+ u16 chan;
+ aligned_u64 timestamp;
+ } scan;
};

enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };
@@ -275,6 +285,12 @@ static const struct iio_chan_spec vl6180_channels[] = {
{
.type = IIO_LIGHT,
.address = VL6180_ALS,
+ .scan_index = VL6180_ALS,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ },
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_INT_TIME) |
BIT(IIO_CHAN_INFO_SCALE) |
@@ -283,14 +299,27 @@ static const struct iio_chan_spec vl6180_channels[] = {
}, {
.type = IIO_DISTANCE,
.address = VL6180_RANGE,
+ .scan_index = VL6180_RANGE,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 8,
+ .storagebits = 8,
+ },
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_SAMP_FREQ),
}, {
.type = IIO_PROXIMITY,
.address = VL6180_PROX,
+ .scan_index = VL6180_PROX,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 16,
+ .storagebits = 16,
+ },
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
- }
+ },
+ IIO_CHAN_SOFT_TIMESTAMP(3),
};

/*
@@ -497,17 +526,99 @@ static irqreturn_t vl6180_threaded_irq(int irq, void *priv)
struct iio_dev *indio_dev = priv;
struct vl6180_data *data = iio_priv(indio_dev);

- complete(&data->completion);
+ if (iio_buffer_enabled(indio_dev))
+ iio_trigger_poll_nested(indio_dev->trig);
+ else
+ complete(&data->completion);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t vl6180_trigger_handler(int irq, void *priv)
+{
+ struct iio_poll_func *pf = priv;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct vl6180_data *data = iio_priv(indio_dev);
+ int ret;
+
+ for (int i = 0; i < indio_dev->masklength; i++) {
+ if (test_bit(i, indio_dev->active_scan_mask)) {
+
+ ret = vl6180_chan_regs_table[i].word ?
+ vl6180_read_word(data->client, vl6180_chan_regs_table[i].value_reg) :
+ vl6180_read_byte(data->client, vl6180_chan_regs_table[i].value_reg);
+ if (ret < 0)
+ dev_err(&data->client->dev, "failed to read from value regs: %d\n", ret);
+
+ data->scan.chan = ret;
+ iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+ iio_get_time_ns(indio_dev));
+ }
+ }
+
+ iio_trigger_notify_done(indio_dev->trig);
+
+ /* Clear the interrupt flag after data read */
+ ret = vl6180_write_byte(data->client, VL6180_INTR_CLEAR,
+ VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE);
+ if (ret < 0)
+ dev_err(&data->client->dev, "failed to clear irq: %d\n", ret);
+
return IRQ_HANDLED;
}

+static int vl6180_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
+{
+ struct vl6180_data *data = iio_priv(indio_dev);
+
+ return data->trig == trig ? 0 : -EINVAL;
+}
+
static const struct iio_info vl6180_info = {
.read_raw = vl6180_read_raw,
.write_raw = vl6180_write_raw,
.attrs = &vl6180_attribute_group,
+ .validate_trigger = vl6180_validate_trigger,
};

-static int vl6180_init(struct vl6180_data *data)
+static int vl6180_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct vl6180_data *data = iio_priv(indio_dev);
+
+ for (int i = 0; i < indio_dev->masklength; i++) {
+ if (test_bit(i, indio_dev->active_scan_mask))
+ return vl6180_write_byte(data->client,
+ vl6180_chan_regs_table[i].start_reg,
+ VL6180_MODE_CONT | VL6180_STARTSTOP);
+ }
+
+ return -EINVAL;
+}
+
+static int vl6180_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ struct vl6180_data *data = iio_priv(indio_dev);
+
+ for (int i = 0; i < indio_dev->masklength; i++) {
+ if (test_bit(i, indio_dev->active_scan_mask))
+ return vl6180_write_byte(data->client,
+ vl6180_chan_regs_table[i].start_reg,
+ VL6180_STARTSTOP);
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+ .postenable = &vl6180_buffer_postenable,
+ .postdisable = &vl6180_buffer_postdisable,
+};
+
+static const struct iio_trigger_ops vl6180_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static int vl6180_init(struct vl6180_data *data, struct iio_dev *indio_dev)
{
struct i2c_client *client = data->client;
int ret;
@@ -547,6 +658,12 @@ static int vl6180_init(struct vl6180_data *data)
if (ret < 0)
return ret;

+ ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
+ &vl6180_trigger_handler,
+ &iio_triggered_buffer_setup_ops);
+ if (ret)
+ return ret;
+
/* Default Range inter-measurement time: 50ms
* reg_val = (50 / 10 - 1) = 4
*/
@@ -603,7 +720,7 @@ static int vl6180_probe(struct i2c_client *client)
indio_dev->name = VL6180_DRV_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;

- ret = vl6180_init(data);
+ ret = vl6180_init(data, indio_dev);
if (ret < 0)
return ret;

@@ -618,6 +735,19 @@ static int vl6180_probe(struct i2c_client *client)
}

init_completion(&data->completion);
+
+ data->trig = devm_iio_trigger_alloc(&client->dev, "%s-dev%d",
+ indio_dev->name, iio_device_id(indio_dev));
+ if (!data->trig)
+ return -ENOMEM;
+
+ data->trig->ops = &vl6180_trigger_ops;
+ iio_trigger_set_drvdata(data->trig, indio_dev);
+ ret = devm_iio_trigger_register(&client->dev, data->trig);
+ if (ret)
+ return ret;
+
+ indio_dev->trig = iio_trigger_get(data->trig);
}

return devm_iio_device_register(&client->dev, indio_dev);
--
2.43.0