Re: [PATCH v4 06/11] iio: accel: adxl313: add basic interrupt handling for FIFO watermark

From: Andy Shevchenko
Date: Sun Jun 01 2025 - 15:27:31 EST


On Sun, Jun 1, 2025 at 8:22 PM Lothar Rubusch <l.rubusch@xxxxxxxxx> wrote:
>
> Prepare the interrupt handler. Add register entries to evaluate the
> incoming interrupt. Add functions to clear status registers and reset the
> FIFO.
>
> Add FIFO watermark configuration and evaluation. Let a watermark to be
> configured. Evaluate the interrupt accordingly. Read out the FIFO content
> and push the values to the IIO channel.

...

> +static int adxl313_set_watermark(struct iio_dev *indio_dev, unsigned int value)
> +{
> + struct adxl313_data *data = iio_priv(indio_dev);
> + const unsigned int fifo_mask = 0x1f, interrupt_mask = 0x02;

GENMASK()
BIT()

> + int ret;
> +
> + value = min(value, ADXL313_FIFO_SIZE - 1);
> +
> + ret = regmap_update_bits(data->regmap, ADXL313_REG_FIFO_CTL,
> + fifo_mask, value);
> + if (ret)
> + return ret;
> +
> + data->watermark = value;
> +
> + return regmap_update_bits(data->regmap, ADXL313_REG_INT_ENABLE,
> + interrupt_mask, ADXL313_INT_WATERMARK);
> +}

...

> +static int adxl313_get_samples(struct adxl313_data *data)
> +{
> + unsigned int regval = 0;

Useless assignment.

> + int ret;
> +
> + ret = regmap_read(data->regmap, ADXL313_REG_FIFO_STATUS, &regval);
> + if (ret)
> + return ret;
> +
> + return FIELD_GET(ADXL313_REG_FIFO_STATUS_ENTRIES_MSK, regval);
> +}

...

> + ret = devm_request_threaded_irq(dev, irq, NULL,
> + &adxl313_irq_handler,
> + IRQF_SHARED | IRQF_ONESHOT,
> + indio_dev->name, indio_dev);
> + if (ret)
> + return ret;

Now I see the first user of 'irq'. Logically these two patches may not
be split. Or split should be made differently, let's say IRQ type
holding variable + switch case can go in the first preparatory patch
(however it will make a little sense without real users, as it is/will
be a dead code).

--
With Best Regards,
Andy Shevchenko