Hello Andy,

Thanks for the review:

-----Original Message-----
From: Andy Shevchenko <redacted>
Sent: Friday, July 16, 2021 5:53 PM
To: Miclaus, Antoniu <Antoniu.Miclaus@analog.com>
Cc: linux-iio@vger.kernel.org; linux-kernel@vger.kernel.org;
jic23@kernel.org; devicetree@vger.kernel.org
Subject: Re: [PATCH v6 1/2] iio: frequency: adrf6780: add support for
ADRF6780

[External]

On Fri, Jul 16, 2021 at 2:43 PM Antoniu Miclaus
[off-list ref] wrote:

quoted

The ADRF6780 is a silicon germanium (SiGe) design, wideband,
microwave upconverter optimized for point to point microwave
radio designs operating in the 5.9 GHz to 23.6 GHz frequency
range.

quoted

Datasheet:
https://www.analog.com/media/en/technical-documentation/data-

sheets/ADRF6780.pdf

Is it one line? If not, please put on one line and drop below the
blank line so it will go as a tag.

Yes, it is one line.

quoted

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>

First question is why not to use the regmap API (I have heard it has
gained support of 17 bit)?

Initially that was the plan, but after this patch:
https://github.com/torvalds/linux/commit/4191f19792bf91267835eb090d970e9cd6277a65
the custom write formats for regmap allow the read only via cached registers.

Therefore, I preferred using spi transfers for write/read to/from the device.

...

quoted

+        depends on COMMON_CLK

Is it mandatory for any function inside the device?

Yes. It will serve as LO input to the device.

...

quoted

+static int adrf6780_spi_read(struct adrf6780_dev *dev, unsigned int reg,
+                             unsigned int *val)
+{
+       int ret;
+       struct spi_transfer t = {0};

quoted

+       dev->data[0] = 0x80 | (reg << 1);

This 0x80 I guess is pretty much standard and regmap SPI supports it.

quoted

+       dev->data[1] = 0x0;
+       dev->data[2] = 0x0;
+
+       t.rx_buf = &dev->data[0];
+       t.tx_buf = &dev->data[0];
+       t.len = 3;
+
+       ret = spi_sync_transfer(dev->spi, &t, 1);
+       if (ret)
+               return ret;
+
+       *val = (get_unaligned_be24(&dev->data[0]) >> 1) & GENMASK(15, 0);
+
+       return ret;
+}

...

quoted

+       usleep_range(200, 250);

Needs a comment.

Will add in next patch version.

--
With Best Regards,
Andy Shevchenko

Regards,
Antoniu