diff mbox series

[v3,2/2] iio: proximity: vl53l0x-i2c: Added continuous mode support

Message ID 20240903035636.9559-3-abhashkumarjha123@gmail.com (mailing list archive)
State Changes Requested
Headers show
Series Continuous mode support for VL53l0x | expand

Commit Message

Abhash Jha Sept. 3, 2024, 3:56 a.m. UTC
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 | 164 +++++++++++++++++++++++-----
 1 file changed, 139 insertions(+), 25 deletions(-)

Comments

Jonathan Cameron Sept. 7, 2024, 4:51 p.m. UTC | #1
On Tue,  3 Sep 2024 09:26:36 +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>

Just to check, did you try this with other triggers?
Currently you have a check that the trigger is only used with the device
but not the validate_trigger that says the device may only use this
trigger.

A few minor comments inline. This is looking good in general.

Jonathan

> ---
>  drivers/iio/proximity/vl53l0x-i2c.c | 164 +++++++++++++++++++++++-----
>  1 file changed, 139 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
> index 31d6aeb95..f91a9495a 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
>  
> @@ -49,14 +55,75 @@ struct vl53l0x_data {
>  	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)
> +{
> +	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);
It's unusual to carry on after a failed write. Add a comment on why that
makes sense here.
> +
> +	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);
> +		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);
> +	ret = vl53l0x_clear_irq(data);
> +	if (ret < 0)
> +		return ret;

you can't return normal error values from an interrupt handler.
Print a message and return IRQ_HANDLED is probably the right thing to do.

> +
> +	return IRQ_HANDLED;
> +}



>  static int vl53l0x_read_proximity(struct vl53l0x_data *data,
>  				  const struct iio_chan_spec *chan,
>  				  int *val)
> @@ -128,7 +176,9 @@ 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,
> @@ -163,7 +213,14 @@ 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(32),
32
That's a big channel index to set.  Technically you can do that as they
are monotonic only, but more normal to have it right after the previous channel.

>  };
>  
>  static int vl53l0x_read_raw(struct iio_dev *indio_dev,
> @@ -221,6 +278,41 @@ 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, 0x02);
> +}
> +
> +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, 0x01);

Can we name that 0x01 and the 0x02 above with names that give
us a hint what they are doing?

> +	if (ret < 0)
> +		return ret;
> +
> +	/* Let the ongoing reading finish */
> +	reinit_completion(&data->completion);
> +	wait_for_completion_timeout(&data->completion, HZ/10);

Space around the / to comply with kernel style.

> +	vl53l0x_clear_irq(data);
> +	if (ret < 0)

ret not set by anyone.

If it's form vl53l0x_clear_irq() and that can't do positive returns then
return vl53l0x_clear_irq(data);
should work.

> +		return ret;
> +
> +	return 0;
> +}
> +static const struct iio_trigger_ops vl53l0x_trigger_ops = {
> +	.validate_device = iio_trigger_validate_own_device,
> +};
diff mbox series

Patch

diff --git a/drivers/iio/proximity/vl53l0x-i2c.c b/drivers/iio/proximity/vl53l0x-i2c.c
index 31d6aeb95..f91a9495a 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
 
@@ -49,14 +55,75 @@  struct vl53l0x_data {
 	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)
+{
+	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);
+		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);
+	ret = vl53l0x_clear_irq(data);
+	if (ret < 0)
+		return ret;
+
+	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 +138,9 @@  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 +155,6 @@  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 +176,9 @@  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,
@@ -163,7 +213,14 @@  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(32),
 };
 
 static int vl53l0x_read_raw(struct iio_dev *indio_dev,
@@ -221,6 +278,41 @@  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, 0x02);
+}
+
+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, 0x01);
+	if (ret < 0)
+		return ret;
+
+	/* Let the ongoing reading finish */
+	reinit_completion(&data->completion);
+	wait_for_completion_timeout(&data->completion, HZ/10);
+	vl53l0x_clear_irq(data);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+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 +370,31 @@  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);