Re: [PATCH v6 7/8] iio: dac: ad3552r: add high-speed platform driver

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 14 Oct 2024 12:08:13 +0200
Angelo Dureghello <adureghello@baylibre.com> wrote:

> From: Angelo Dureghello <adureghello@baylibre.com>
> 
> Add High Speed ad3552r platform driver.
> 
> The ad3552r DAC is controlled by a custom (fpga-based) DAC IP
> through the current AXI backend, or similar alternative IIO backend.
> 
> Compared to the existing driver (ad3552r.c), that is a simple SPI
> driver, this driver is coupled with a DAC IIO backend that finally
> controls the ad3552r by a fpga-based "QSPI+DDR" interface, to reach
> maximum transfer rate of 33MUPS using dma stream capabilities.
> 
> All commands involving QSPI bus read/write are delegated to the backend
> through the provided APIs for bus read/write.
> 
> Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Hi Angelo,

You have lots of review already. Just one trivial addition from me.

Jonathan

> diff --git a/drivers/iio/dac/ad3552r-hs.c b/drivers/iio/dac/ad3552r-hs.c
> new file mode 100644
> index 000000000000..cb29a600e141
> --- /dev/null
> +++ b/drivers/iio/dac/ad3552r-hs.c
> @@ -0,0 +1,526 @@

> +static int ad3552r_hs_buffer_postenable(struct iio_dev *indio_dev)
> +{

> +
> +	switch (*indio_dev->active_scan_mask) {
> +	case AD3552R_CH0_ACTIVE:
> +		st->single_channel = true;
> +		loop_len = 2;
> +		val = AD3552R_REG_ADDR_CH_DAC_16B(0);
> +		break;
> +	case AD3552R_CH1_ACTIVE:
> +		st->single_channel = true;
> +		loop_len = 2;
> +		val = AD3552R_REG_ADDR_CH_DAC_16B(1);
> +		break;
> +	case AD3552R_CH0_CH1_ACTIVE:
	case AD3552R_CH0_ACTIVE | AD3552R_CH1_ACTIVE:


> diff --git a/drivers/iio/dac/ad3552r.h b/drivers/iio/dac/ad3552r.h
> index 088eb8ecfac6..fc00ed4c2565 100644
> --- a/drivers/iio/dac/ad3552r.h
> +++ b/drivers/iio/dac/ad3552r.h

> @@ -129,6 +131,11 @@
>  #define AD3552R_GAIN_SCALE				1000
>  #define AD3552R_LDAC_PULSE_US				100
>  
> +#define AD3552R_CH0_ACTIVE				BIT(0)
> +#define AD3552R_CH1_ACTIVE				BIT(1)
> +#define AD3552R_CH0_CH1_ACTIVE				(AD3552R_CH0_ACTIVE | \
> +							 AD3552R_CH1_ACTIVE)

I'd just put that one inline in the case statement.

> +
>  #define AD3552R_MAX_RANGES	5
>  #define AD3542R_MAX_RANGES	6
>  
>