On Tue, 3 Sep 2024 09:26:36 +0530
Abhash Jha <abhashkumarjha123@xxxxxxxxx> 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@xxxxxxxxx>
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,
> +};
