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charset="iso-8859-1" Content-ID: Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-OriginatorOrg: vaisala.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: AMBPR06MB10365.eurprd06.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6d387ff1-97c5-45a0-6850-08de3d2e73bc X-MS-Exchange-CrossTenant-originalarrivaltime: 17 Dec 2025 05:38:05.2645 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 6d7393e0-41f5-4c2e-9b12-4c2be5da5c57 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: Xl/pJdX/c4pGQ+cNUKD52eW9TGrD9wPtTfSzVDe6ImPe7TBDAhl2mGzaY+ScBB2ynOojO0tltvgu/b0ZeX/zww== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM0PR06MB6387 Hi,=0A= =0A= On 16/12/2025 23:27, David Lechner wrote:=0A= > On 12/16/25 9:39 AM, Tomas Melin wrote:=0A= >> Hi,=0A= >>=0A= >> On 16/12/2025 14:56, Nuno S=E1 wrote:=0A= >>> On Tue, 2025-12-16 at 11:40 +0000, Tomas Melin wrote:=0A= >>>> Not all users can or want to use the device with an iio-backend.=0A= >>>> For these users, let the driver work in standalone mode, not coupled= =0A= >>>> to the backend or the services it provides.=0A= >>>>=0A= >>>> Signed-off-by: Tomas Melin =0A= >>>> ---=0A= >>>=0A= >>> Which users? The only usecases (for all the supported devices) we have = require=0A= >>> the FPGA backend. So do you have a specific usecase for a specific devi= ce? If so, I would=0A= >>> prefer an explicit boolean in the chip_info struture for the device(s) = we know this=0A= >>> can happen (unless you have a usecase for all :)).=0A= >>=0A= >> This is generically for all the devices supported by the ad9467, not=0A= >> only a specific device. So it's about how this is used as part of the=0A= >> design.=0A= >>=0A= >> This is aimed at users that do not use the ADI HDL reference backend=0A= >> with these devices, but instead have custom backends suited for their=0A= >> own needs.=0A= > =0A= > If you have your own backend, why would it not use the IIO backend=0A= > framework?=0A= > =0A= > I can understand if this custom backend sends the data somewhere else=0A= > besides an IIO buffer and we don't want to create the buffer for the IIO= =0A= > device. But I would still think that there needs to be some sort of=0A= > communication between the IIO device and the backend.=0A= =0A= True, there needs to some kind of backend, but they don't all have iio=0A= backends or other kernel drivers. Data will flow when the device starts=0A= sending without much further need to configure. Adding a backend driver=0A= in these cases could have some benefits, but often it would just be an=0A= unneeded complication.=0A= =0A= And even if there were a custom iio-backend available, it would not be=0A= compatible with the current assumptions about ADI backend wrt=0A= calibration, test mode enabling and iio buffering. So having a strict=0A= dependency on an iio-backend does not really work in a generic use case.=0A= =0A= > =0A= > Maybe you could explain more how this custom backend is intended to work?= =0A= =0A= I hope the explanation above helps. There is real use case behind, this=0A= is not some imaginary nice to have feature. Before the introduction of=0A= the iio backend, the driver was even more dependent on the backend. At=0A= that point, needed to carry some out of tree patches to remove the=0A= dependency and make it a standalone iio driver. Thankfully with the=0A= introduction of the iio-backend, this is now more loosely coupled and I=0A= see opportunity for making this standalone mode possible also in mainline.= =0A= =0A= Thanks,=0A= Tomas=0A= =0A= > =0A= >> In that case, we need to be able to skip the backend registration and=0A= >> register device as a standalone iio device.=0A= >>=0A= >> Hopefully this made the use case clearer?=0A= >>=0A= >> Thanks,=0A= >> Tomas=0A= >>=0A= >>=0A= >>>=0A= >>> - Nuno S=E1=0A= >>>=0A= >>=0A= > =0A= =0A=