Re: [PATCH v5 12/16] iio: adc: ad7944: add support for SPI offload

From: Jonathan Cameron
Date: Sun Nov 24 2024 - 12:24:52 EST


On Fri, 15 Nov 2024 14:18:51 -0600
David Lechner <dlechner@xxxxxxxxxxxx> wrote:

> This adds support for SPI offload to the ad7944 driver. This allows
> reading data at the max sample rate of 2.5 MSPS.
>
> Signed-off-by: David Lechner <dlechner@xxxxxxxxxxxx>
One request for some documentation on the storagebits value.

Otherwise looks good to me.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Note I'm giving tags because it might not all go through my tree +
it's big and complex so they have the advantage I won't read things
again if I've already tagged them (probably!)

Jonathan


> @@ -129,13 +144,33 @@ static const struct ad7944_chip_info _name##_chip_info = { \
> }, \
> IIO_CHAN_SOFT_TIMESTAMP(1), \
> }, \
> + /* basically the same minus soft timestamp plus sampling freq */\
> + .offload_channels = { \
> + { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .differential = _diff, \
> + .channel = 0, \
> + .channel2 = _diff ? 1 : 0, \
> + .scan_index = 0, \
> + .scan_type.sign = _diff ? 's' : 'u', \
> + .scan_type.realbits = _bits, \
> + .scan_type.storagebits = 32, \

Add a comment somewhere here on why it jumps up to 32 bits.

> + .scan_type.endianness = IIO_CPU, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
> + | BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_SAMP_FREQ), \
> + .info_mask_separate_available = \
> + BIT(IIO_CHAN_INFO_SAMP_FREQ), \
> + }, \
> + }, \
> }