linux-kernel - Re: [PATCH 3/3] iio: adc: ad7606: add SPI offload support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <vjxnpbxvvh2vdjsamdznhrmrwwfwt5tjhugqik3ktueopajv6l@wmehdnowjvjq>
Date: Mon, 7 Apr 2025 09:41:32 +0200
From: Angelo Dureghello <adureghello@...libre.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Lars-Peter Clausen <lars@...afoo.de>, 
	Michael Hennerich <Michael.Hennerich@...log.com>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Jonathan Corbet <corbet@....net>, David Lechner <dlechner@...libre.com>, linux-iio@...r.kernel.org, 
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org
Subject: Re: [PATCH 3/3] iio: adc: ad7606: add SPI offload support

Hi Jonathan,

On 05.04.2025 16:40, Jonathan Cameron wrote:
> On Thu, 03 Apr 2025 18:19:06 +0200
> Angelo Dureghello <adureghello@...libre.com> wrote:
> 
> > From: Angelo Dureghello <adureghello@...libre.com>
> > 
> > Add SPI offload support for this family.
> > 
> > Signed-off-by: Angelo Dureghello <adureghello@...libre.com>
> Hi Angelo,
> 
> Code looks fine, but there is a TODO I'd like to know more about
> as it sounds 'ominous'. 
> 
> Otherwise this needs a dt review for patch 1 before I queue it up.
> 
> Jonathan
> > diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
> > index b2b975fb7fea4d1af6caef59e75ca495501bc140..b086122497eb22042171580878160334f56baa23 100644
> > --- a/drivers/iio/adc/ad7606_spi.c
> > +++ b/drivers/iio/adc/ad7606_spi.c
> 
> > +static int ad7606_spi_offload_probe(struct device *dev,
> > +				    struct iio_dev *indio_dev)
> > +{
> > +	struct ad7606_state *st = iio_priv(indio_dev);
> > +	struct spi_device *spi = to_spi_device(dev);
> > +	struct spi_bus_data *bus_data;
> > +	struct dma_chan *rx_dma;
> > +	struct spi_offload_trigger_info trigger_info = {
> > +		.fwnode = dev_fwnode(dev),
> > +		.ops = &ad7606_offload_trigger_ops,
> > +		.priv = st,
> > +	};
> > +	int ret;
> > +
> > +	bus_data = devm_kzalloc(dev, sizeof(*bus_data), GFP_KERNEL);
> > +	if (!bus_data)
> > +		return -ENOMEM;
> > +	st->bus_data = bus_data;
> > +
> > +	bus_data->offload = devm_spi_offload_get(dev, spi,
> > +						 &ad7606_spi_offload_config);
> > +	ret = PTR_ERR_OR_ZERO(bus_data->offload);
> > +	if (ret && ret != -ENODEV)
> > +		return dev_err_probe(dev, ret, "failed to get SPI offload\n");
> > +	/* Allow main ad7606_probe function to continue. */
> > +	if (ret == -ENODEV)
> > +		return 0;
> > +
> > +	ret = devm_spi_offload_trigger_register(dev, &trigger_info);
> > +	if (ret)
> > +		return dev_err_probe(dev, ret,
> > +				     "failed to register offload trigger\n");
> > +
> > +	bus_data->offload_trigger = devm_spi_offload_trigger_get(dev,
> > +		bus_data->offload, SPI_OFFLOAD_TRIGGER_DATA_READY);
> > +	if (IS_ERR(bus_data->offload_trigger))
> > +		return dev_err_probe(dev, PTR_ERR(bus_data->offload_trigger),
> > +				     "failed to get offload trigger\n");
> > +
> > +	/* TODO: PWM setup should be ok, done for the backend. PWM mutex ? */
> 
> I don't understand this todo. Perhaps some more details?
>
it was just an initial comment i did, when i started the things
was not clear.
Let me know if you can remove it, or i can send a v2.

Thanks a lot.

Regards,
angelo
 
> > +	rx_dma = devm_spi_offload_rx_stream_request_dma_chan(dev,
> > +							     bus_data->offload);
> > +	if (IS_ERR(rx_dma))
> > +		return dev_err_probe(dev, PTR_ERR(rx_dma),
> > +				     "failed to get offload RX DMA\n");
> > +
> > +	ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev,
> > +		rx_dma, IIO_BUFFER_DIRECTION_IN);
> > +	if (ret)
> > +		return dev_err_probe(dev, PTR_ERR(rx_dma),
> > +				     "failed to setup offload RX DMA\n");
> > +
> > +	/* Use offload ops. */
> > +	indio_dev->setup_ops = &ad7606_offload_buffer_setup_ops;
> > +
> > +	st->offload_en = true;
> > +
> > +	return 0;
> > +}
> 
>