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charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250127_003134_917905_1A6F88D5 X-CRM114-Status: GOOD ( 22.87 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 27/01/2025 08:59, Dario Binacchi wrote: > On Mon, Jan 27, 2025 at 8:42 AM Krzysztof Kozlowski wrote: >> >> On 25/01/2025 13:58, Dario Binacchi wrote: >>> On Fri, Jan 24, 2025 at 2:19 PM Peng Fan (OSS) wrote: >>>> >>>> - Introduce clk_set_spread_spectrum to set the parameters for enabling >>>> spread spectrum of a clock. >>>> - Parse 'assigned-clock-sscs' and configure it by default before using the >>>> clock. The pull request for this property is at [1] >>>> This property is parsed before parsing clock rate. >>>> >>>> - Enable this feature for clk-scmi on i.MX95. >>>> This may not the best, since checking machine compatibles. >>>> I am thinking to provide an API scmi_get_vendor_info, then driver >>>> could use it for OEM stuff, such as >>>> if (scmi_get_vendor_info returns NXP_IMX) >>>> ops->set_spread_spectrum = scmi_clk_set_spread_spectrum_imx; >>>> >>> >>> I wonder if your solution is truly generic or merely a generalization >>> of your use case, which seems significantly simpler compared to what >> >> Please come with specific arguments why this is not generic enough, not >> just FUD. Does it fit your case? If not, what would had to be changed? >> These are the comments needed to actually work on generic solution. >> >>> happens on the i.MX8M platform, as discussed in thread >>> https://lore.kernel.org/lkml/PAXPR04MB8459537D7D2A49221D0E890D88E32@PAXPR04MB8459.eurprd04.prod.outlook.com/, >>> or on the STM32F platform, where parameters are not written directly >>> to registers but are instead used in calculations involving the >>> parent_rate and the PLL divider, for example. >>> >>> I am the author of the patches that introduced spread spectrum >>> management for the AM33x and STM32Fx platforms, as well as the >>> series, still pending acceptance, for the i.MX8M. >>> From my perspective, this functionality varies significantly >>> from platform to platform, with key differences that must be >>> considered. >> >> So what exactly varies? Come with specifics. > > In all the cases I implemented, I enabled spread spectrum within > the set_rate of the clock/PLL in question, as information such as > the parent rate or the divisor used was necessary to perform the > calculations needed to extract the data for setting the SSCG > register bitfields. > > If I'm not mistaken, I think this is not the case implemented by this > series. It feels like you speak about driver, so I misunderstood the concerns. I did not check the drivers at all, so here I do not claim patchsets are compatible. But the binding takes the same values - the main PLL/clock rate. Best regards, Krzysztof