[PATCH v4 0/2] Continuous mode support for VL53l0x

[PATCH v4 0/2] Continuous mode support for VL53l0x

[Abhash Jha]

Hello,

The first patch adds support for checking the sensor ID by reading
MODEL_IDENTIFICATION register and seeing if it returns the value 0xEE

The second patch adds support for continuous mode in the sensor by using
buffers. We enable the sensor's continuous mode in the buffer_postenable
function.
Replaced the irq handler with a threaded irq handler in order to perform
I2C reads for the data. The continuous mode can be disabled by disabling
the buffer.
Added a trigger to the device for the continuous mode. Also validating that
the device uses the internal trigger provided by us.

Changes in v4:
- Added `validate_trigger` callback to check that this device uses its own trigger
- Refactored the vl53l0x_clear_irq function
- Minor code cleanups

Changes in v3:
- Added "asm/unaligned.h" include to fix `-Wimplicit-function-declaration`.
- The above error was pointed during testing by kernel-test-robot
- Link to v2: https://lore.kernel.org/linux-iio/20240902122557.129013-1-abhashkumarjha123@gmail.com/T/#t

Changes in v2:
- Added a trigger for the device
- Added a poll function for the triggered buffer setup
- Performed the data reading and pushing to buffers in the poll function
- Minor code refactoring

- Link to v1: https://lore.kernel.org/linux-iio/20240830201627.298264-1-abhashkumarjha123@gmail.com/T/#t


Abhash Jha (2):
  iio: proximity: vl53l0x-i2c: Added sensor ID check
  iio: proximity: vl53l0x-i2c: Added continuous mode support

 drivers/iio/proximity/vl53l0x-i2c.c | 174 +++++++++++++++++++++++-----
 1 file changed, 146 insertions(+), 28 deletions(-)

-- 
2.43.0

[PATCH v4 1/2] iio: proximity: vl53l0x-i2c: Added sensor ID check

[Abhash Jha]

The commit adds a check for the sensor's model ID. We read the model
identification register (0xC0) and expect a value of 0xEE.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
 drivers/iio/proximity/vl53l0x-i2c.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
index 8d4f3f849..3f416d3db 100644
--- a/drivers/iio/proximity/vl53l0x-i2c.c
+++ b/drivers/iio/proximity/vl53l0x-i2c.c
@@ -39,8 +39,11 @@
 
 #define VL_REG_RESULT_INT_STATUS			0x13
 #define VL_REG_RESULT_RANGE_STATUS			0x14
+#define VL_REG_IDENTIFICATION_MODEL_ID			0xC0
 #define VL_REG_RESULT_RANGE_STATUS_COMPLETE		BIT(0)
 
+#define VL53L0X_MODEL_ID_VAL				0xEE
+
 struct vl53l0x_data {
 	struct i2c_client *client;
 	struct completion completion;
@@ -223,6 +226,7 @@ static int vl53l0x_probe(struct i2c_client *client)
 	struct vl53l0x_data *data;
 	struct iio_dev *indio_dev;
 	int error;
+	int ret;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
@@ -237,6 +241,13 @@ static int vl53l0x_probe(struct i2c_client *client)
 				     I2C_FUNC_SMBUS_BYTE_DATA))
 		return -EOPNOTSUPP;
 
+	ret = i2c_smbus_read_byte_data(data->client, VL_REG_IDENTIFICATION_MODEL_ID);
+	if (ret < 0)
+		return -EINVAL;
+
+	if (ret != VL53L0X_MODEL_ID_VAL)
+		dev_info(&client->dev, "Unknown model id: 0x%x", ret);
+
 	data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
 	if (IS_ERR(data->vdd_supply))
 		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
@@ -265,8 +276,6 @@ static int vl53l0x_probe(struct i2c_client *client)
 
 	/* usage of interrupt is optional */
 	if (client->irq) {
-		int ret;
-
 		init_completion(&data->completion);
 
 		ret = vl53l0x_configure_irq(client, indio_dev);
-- 
2.43.0

[PATCH v4 2/2] iio: proximity: vl53l0x-i2c: Added continuous mode support

[Abhash Jha]

The continuous mode of the sensor is enabled in the buffer_postenable.
Replaced the original irq handler with a threaded irq handler to perform
i2c reads during continuous mode.
The continuous mode is disabled by disabling the buffer.
Added a trigger for this device to be used for continuous mode.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
 drivers/iio/proximity/vl53l0x-i2c.c | 161 +++++++++++++++++++++++-----
 1 file changed, 135 insertions(+), 26 deletions(-)

diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
index 3f416d3db..cbf030869 100644
--- a/drivers/iio/proximity/vl53l0x-i2c.c
+++ b/drivers/iio/proximity/vl53l0x-i2c.c
@@ -22,6 +22,12 @@
 #include <linux/module.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include <asm/unaligned.h>
 
 #define VL_REG_SYSRANGE_START				0x00
 
@@ -43,20 +49,70 @@
 #define VL_REG_RESULT_RANGE_STATUS_COMPLETE		BIT(0)
 
 #define VL53L0X_MODEL_ID_VAL				0xEE
+#define VL53L0X_CONTINUOUS_MODE				0x02
+#define VL53L0X_SINGLE_MODE				0x01
 
 struct vl53l0x_data {
 	struct i2c_client *client;
 	struct completion completion;
 	struct regulator *vdd_supply;
 	struct gpio_desc *reset_gpio;
+	struct iio_trigger *trig;
+
+	struct {
+		u16 chan;
+		s64 timestamp __aligned(8);
+	} scan;
 };
 
-static irqreturn_t vl53l0x_handle_irq(int irq, void *priv)
+static int vl53l0x_clear_irq(struct vl53l0x_data *data)
+{	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client,
+					VL_REG_SYSTEM_INTERRUPT_CLEAR, 1);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "failed to clear irq: %d\n", ret);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static irqreturn_t vl53l0x_trigger_handler(int irq, void *priv)
+{
+	struct iio_poll_func *pf = priv;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct vl53l0x_data *data = iio_priv(indio_dev);
+	u8 buffer[12];
+	int ret;
+
+	ret = i2c_smbus_read_i2c_block_data(data->client,
+					VL_REG_RESULT_RANGE_STATUS,
+					sizeof(buffer), buffer);
+	if (ret < 0)
+		return ret;
+	else if (ret != 12)
+		return -EREMOTEIO;
+
+	data->scan.chan = get_unaligned_be16(&buffer[10]);
+	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
+					iio_get_time_ns(indio_dev));
+
+	iio_trigger_notify_done(indio_dev->trig);
+	vl53l0x_clear_irq(data);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t vl53l0x_threaded_irq(int irq, void *priv)
 {
 	struct iio_dev *indio_dev = priv;
 	struct vl53l0x_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;
 }
@@ -71,8 +127,9 @@ static int vl53l0x_configure_irq(struct i2c_client *client,
 	if (!irq_flags)
 		irq_flags = IRQF_TRIGGER_FALLING;
 
-	ret = devm_request_irq(&client->dev, client->irq, vl53l0x_handle_irq,
-			irq_flags, indio_dev->name, indio_dev);
+	ret = devm_request_threaded_irq(&client->dev, client->irq,
+			NULL, vl53l0x_threaded_irq,
+			irq_flags | IRQF_ONESHOT, indio_dev->name, indio_dev);
 	if (ret) {
 		dev_err(&client->dev, "devm_request_irq error: %d\n", ret);
 		return ret;
@@ -87,26 +144,6 @@ static int vl53l0x_configure_irq(struct i2c_client *client,
 	return ret;
 }
 
-static void vl53l0x_clear_irq(struct vl53l0x_data *data)
-{
-	struct device *dev = &data->client->dev;
-	int ret;
-
-	ret = i2c_smbus_write_byte_data(data->client,
-					VL_REG_SYSTEM_INTERRUPT_CLEAR, 1);
-	if (ret < 0)
-		dev_err(dev, "failed to clear error irq: %d\n", ret);
-
-	ret = i2c_smbus_write_byte_data(data->client,
-					VL_REG_SYSTEM_INTERRUPT_CLEAR, 0);
-	if (ret < 0)
-		dev_err(dev, "failed to clear range irq: %d\n", ret);
-
-	ret = i2c_smbus_read_byte_data(data->client, VL_REG_RESULT_INT_STATUS);
-	if (ret < 0 || ret & 0x07)
-		dev_err(dev, "failed to clear irq: %d\n", ret);
-}
-
 static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 				  const struct iio_chan_spec *chan,
 				  int *val)
@@ -128,7 +165,9 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 		if (time_left == 0)
 			return -ETIMEDOUT;
 
-		vl53l0x_clear_irq(data);
+		ret = vl53l0x_clear_irq(data);
+		if (ret < 0)
+			return ret;
 	} else {
 		do {
 			ret = i2c_smbus_read_byte_data(client,
@@ -153,7 +192,7 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
 		return -EREMOTEIO;
 
 	/* Values should be between 30~1200 in millimeters. */
-	*val = (buffer[10] << 8) + buffer[11];
+	*val = get_unaligned_be16(&buffer[10]);
 
 	return 0;
 }
@@ -163,7 +202,14 @@ static const struct iio_chan_spec vl53l0x_channels[] = {
 		.type = IIO_DISTANCE,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 				      BIT(IIO_CHAN_INFO_SCALE),
+		.scan_index = 0,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 12,
+			.storagebits = 16,
+		},
 	},
+	IIO_CHAN_SOFT_TIMESTAMP(1),
 };
 
 static int vl53l0x_read_raw(struct iio_dev *indio_dev,
@@ -193,8 +239,16 @@ static int vl53l0x_read_raw(struct iio_dev *indio_dev,
 	}
 }
 
+static int vl53l0x_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
+{
+	struct vl53l0x_data *data = iio_priv(indio_dev);
+
+	return data->trig == trig ? 0 : -EINVAL;
+}
+
 static const struct iio_info vl53l0x_info = {
 	.read_raw = vl53l0x_read_raw,
+	.validate_trigger = vl53l0x_validate_trigger,
 };
 
 static void vl53l0x_power_off(void *_data)
@@ -221,6 +275,39 @@ static int vl53l0x_power_on(struct vl53l0x_data *data)
 	return 0;
 }
 
+static int vl53l0x_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct vl53l0x_data *data = iio_priv(indio_dev);
+
+	return i2c_smbus_write_byte_data(data->client, VL_REG_SYSRANGE_START,
+						VL53L0X_CONTINUOUS_MODE);
+}
+
+static int vl53l0x_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct vl53l0x_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(data->client, VL_REG_SYSRANGE_START,
+						VL53L0X_SINGLE_MODE);
+	if (ret < 0)
+		return ret;
+
+	/* Let the ongoing reading finish */
+	reinit_completion(&data->completion);
+	wait_for_completion_timeout(&data->completion, HZ / 10);
+	return vl53l0x_clear_irq(data);
+}
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+	.postenable = &vl53l0x_buffer_postenable,
+	.postdisable = &vl53l0x_buffer_postdisable,
+};
+
+static const struct iio_trigger_ops vl53l0x_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
 static int vl53l0x_probe(struct i2c_client *client)
 {
 	struct vl53l0x_data *data;
@@ -278,9 +365,31 @@ static int vl53l0x_probe(struct i2c_client *client)
 	if (client->irq) {
 		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 = &vl53l0x_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);
+
 		ret = vl53l0x_configure_irq(client, indio_dev);
 		if (ret)
 			return ret;
+
+		ret = devm_iio_triggered_buffer_setup(&client->dev,
+					indio_dev,
+					NULL,
+					&vl53l0x_trigger_handler,
+					&iio_triggered_buffer_setup_ops);
+		if (ret)
+			return ret;
 	}
 
 	return devm_iio_device_register(&client->dev, indio_dev);
-- 
2.43.0

Re: [PATCH v4 2/2] iio: proximity: vl53l0x-i2c: Added continuous mode support

[Jonathan Cameron]

On Mon,  9 Sep 2024 15:45:07 +0530
Abhash Jha <abhashkumarjha123@gmail.com> wrote:

> The continuous mode of the sensor is enabled in the buffer_postenable.
> Replaced the original irq handler with a threaded irq handler to perform
> i2c reads during continuous mode.
> The continuous mode is disabled by disabling the buffer.
> Added a trigger for this device to be used for continuous mode.
> 
> Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
Hi Abhash,

Applied this with a couple of minor tweaks (see below) to the
testing branch of iio.git.  I'll be rebasing that tree on rc1 once
available and pushing out as togreg which gets picked up by linux-next.

Thanks,

Jonathan

> ---
>  drivers/iio/proximity/vl53l0x-i2c.c | 161 +++++++++++++++++++++++-----
>  1 file changed, 135 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
> index 3f416d3db..cbf030869 100644
> --- a/drivers/iio/proximity/vl53l0x-i2c.c
> +++ b/drivers/iio/proximity/vl53l0x-i2c.c
> @@ -22,6 +22,12 @@
>  #include <linux/module.h>
>  
>  #include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#include <asm/unaligned.h>
>  
>  #define VL_REG_SYSRANGE_START				0x00
>  
> @@ -43,20 +49,70 @@
>  #define VL_REG_RESULT_RANGE_STATUS_COMPLETE		BIT(0)
>  
>  #define VL53L0X_MODEL_ID_VAL				0xEE
> +#define VL53L0X_CONTINUOUS_MODE				0x02
> +#define VL53L0X_SINGLE_MODE				0x01
>  
>  struct vl53l0x_data {
>  	struct i2c_client *client;
>  	struct completion completion;
>  	struct regulator *vdd_supply;
>  	struct gpio_desc *reset_gpio;
> +	struct iio_trigger *trig;
> +
> +	struct {
> +		u16 chan;
> +		s64 timestamp __aligned(8);
I tweak this whilst applying to use the new aligned_s64
(the patch crossed with yours)

> +	} scan;
>  };
>  
>
> @@ -153,7 +192,7 @@ static int vl53l0x_read_proximity(struct vl53l0x_data *data,
>  		return -EREMOTEIO;
>  
>  	/* Values should be between 30~1200 in millimeters. */
> -	*val = (buffer[10] << 8) + buffer[11];
> +	*val = get_unaligned_be16(&buffer[10]);

In theory this should have been a different patch, but meh it's tiny so
I'll just take it in here.

>  
>  	return 0;
>  }
> @@ -163,7 +202,14 @@ static const struct iio_chan_spec vl53l0x_channels[] = {
>  		.type = IIO_DISTANCE,
>  		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
>  				      BIT(IIO_CHAN_INFO_SCALE),
> +		.scan_index = 0,
> +		.scan_type = {
> +			.sign = 'u',
> +			.realbits = 12,
> +			.storagebits = 16,
> +		},
>  	},
> +	IIO_CHAN_SOFT_TIMESTAMP(1),
>  };
>  
>  static int vl53l0x_read_raw(struct iio_dev *indio_dev,
> @@ -193,8 +239,16 @@ static int vl53l0x_read_raw(struct iio_dev *indio_dev,
>  	}
>  }
>  
> +static int vl53l0x_validate_trigger(struct iio_dev *indio_dev, struct iio_trigger *trig)
> +{
> +	struct vl53l0x_data *data = iio_priv(indio_dev);
> +
> +	return data->trig == trig ? 0 : -EINVAL;
> +}
> +
>  static const struct iio_info vl53l0x_info = {
>  	.read_raw = vl53l0x_read_raw,
> +	.validate_trigger = vl53l0x_validate_trigger,
>  };
>  
>  static void vl53l0x_power_off(void *_data)
> @@ -221,6 +275,39 @@ static int vl53l0x_power_on(struct vl53l0x_data *data)
>  	return 0;
>  }
>  
> +static int vl53l0x_buffer_postenable(struct iio_dev *indio_dev)
> +{
> +	struct vl53l0x_data *data = iio_priv(indio_dev);
> +
> +	return i2c_smbus_write_byte_data(data->client, VL_REG_SYSRANGE_START,
> +						VL53L0X_CONTINUOUS_MODE);
> +}
> +
> +static int vl53l0x_buffer_postdisable(struct iio_dev *indio_dev)
> +{
> +	struct vl53l0x_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(data->client, VL_REG_SYSRANGE_START,
> +						VL53L0X_SINGLE_MODE);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Let the ongoing reading finish */
> +	reinit_completion(&data->completion);
> +	wait_for_completion_timeout(&data->completion, HZ / 10);
Trivial but I'll add a blank line here to separate the completion related
bits from the clear irq as they are more or less unrelated.

> +	return vl53l0x_clear_irq(data);
> +}