From: Laurent Pinchart <laurent.pinchart@ideasonboard.com> To: Alex Riesen <alexander.riesen@cetitec.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org>, Kieran Bingham <kieran.bingham@ideasonboard.com>, Mauro Carvalho Chehab <mchehab@kernel.org>, Hans Verkuil <hverkuil-cisco@xs4all.nl>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Driver Development <devel@driverdev.osuosl.org>, Linux Media <linux-media@vger.kernel.org>, Linux Kernel <linux-kernel@vger.kernel.org>, Device Tree <devicetree@vger.kernel.org>, Renesas SoC <linux-renesas-soc@vger.kernel.org> Subject: Re: [PATCH 8/8] arm64: dts: renesas: salvator: add a connection from adv748x codec (HDMI input) to the R-Car SoC Date: Fri, 6 Mar 2020 15:16:32 +0200 [thread overview] Message-ID: <20200306131632.GA4878@pendragon.ideasonboard.com> (raw) In-Reply-To: <20200305143628.GB25741@pflmari> Hi Alex, On Thu, Mar 05, 2020 at 03:36:28PM +0100, Alex Riesen wrote: > Geert Uytterhoeven, Mon, Mar 02, 2020 17:13:30 +0100: > > On Mon, Mar 2, 2020 at 5:09 PM Alex Riesen <alexander.riesen@cetitec.com> wrote: > > > Geert Uytterhoeven, Mon, Mar 02, 2020 16:32:32 +0100: > > > > > > > > The #clock-cells should be in the main video-receiver node. > > > > Probably there is more than one clock output, so #clock-cells may be 1? > > > > > > AFAICS, the device can provide only this one clock line (audio master clock > > > for I2S output)... I shall re-check, just in case. > > And you're right, of course: the audio output formatting module of the ADV748x > devices provides a set of clock lines related to the I2S pins: the already > discussed master clock, left-right channel clock and the serial clock (bit > clock?). I don't think we need to model the last two clocks through CCF though, they're part of the I2S protocol, not clock sources that need to be explicitly controlled (or queried). > > > > There is no need for a fixed-clock compatible, nor for clock-frequency > > > > and clock-output-names. > > > > > > > > But most important: this should be documented in the adv748x DT bindings, > > > > and implemented in the adv748x driver. > > > > > > So if the driver is to export that clock for the kernel (like in this case), > > > it must implement its support? > > > > Exactly. Unless that pin is hardcoded to output a fixed clock, in which case > > you can just override the existing audio_clk_c rate. > > Just to try it out (I'll set #clock-cells to 1), I registered a fixed rate > clock in the driver, added a clock provider: > > adv748x_probe: > > clk = clk_register_fixed_rate(state->dev, > "clk-hdmi-i2s-mclk", > NULL /* parent_name */, > 0 /* flags */, > 12288000 /* rate */); > of_clk_add_provider(state->dev->of_node, of_clk_src_simple_get, clk); > > And removed the audio_clk_c frequency setting. I also replaced the audio_clk_c > in the list of input clocks of the R-Car-side sound card with the phandle of > the adv7482 main node: > > salvator-common.dtsi: > > &i2c4 { > status = "okay"; > > adv7482_hdmi_decoder: video-receiver@70 { > #clock-cells = <0>; // to be replaced with <1> > }; > }; > > &rcar_sound { > clocks = ..., <&adv7482_hdmi_decoder>, ...; > }; > > As everything continues to work as before, I assume that at least the clock > dependencies were resolved. This looks good to me. > Is there a way to verify that the added input clock is actually used? > IOW, if its frequency is actually has been programmed into the ssi4 (R-Car > receiving hardware) registers, and not just a left-over from previuos attempts > or plain default setting? > > As the ADV748x devices seem to provide also the clocks for video outputs, will > it make any sense to place the clock definition into the port node? > Or should all provided clocks be indexed in the main device node? Those clocks are part of the CSI-2 protocol and also don't need to be explicitly controlled. As far as I can tell from a quick check of the ADV7482 documentation, only the I2S MCLK is a general-purpose clock that needs to be exposed. -- Regards, Laurent Pinchart
WARNING: multiple messages have this Message-ID (diff)
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com> To: Alex Riesen <alexander.riesen@cetitec.com> Cc: Mark Rutland <mark.rutland@arm.com>, Driver Development <devel@driverdev.osuosl.org>, Device Tree <devicetree@vger.kernel.org>, Kieran Bingham <kieran.bingham@ideasonboard.com>, Linux Kernel <linux-kernel@vger.kernel.org>, Renesas SoC <linux-renesas-soc@vger.kernel.org>, Rob Herring <robh+dt@kernel.org>, Geert Uytterhoeven <geert@linux-m68k.org>, Hans Verkuil <hverkuil-cisco@xs4all.nl>, Mauro Carvalho Chehab <mchehab@kernel.org>, Linux Media <linux-media@vger.kernel.org> Subject: Re: [PATCH 8/8] arm64: dts: renesas: salvator: add a connection from adv748x codec (HDMI input) to the R-Car SoC Date: Fri, 6 Mar 2020 15:16:32 +0200 [thread overview] Message-ID: <20200306131632.GA4878@pendragon.ideasonboard.com> (raw) In-Reply-To: <20200305143628.GB25741@pflmari> Hi Alex, On Thu, Mar 05, 2020 at 03:36:28PM +0100, Alex Riesen wrote: > Geert Uytterhoeven, Mon, Mar 02, 2020 17:13:30 +0100: > > On Mon, Mar 2, 2020 at 5:09 PM Alex Riesen <alexander.riesen@cetitec.com> wrote: > > > Geert Uytterhoeven, Mon, Mar 02, 2020 16:32:32 +0100: > > > > > > > > The #clock-cells should be in the main video-receiver node. > > > > Probably there is more than one clock output, so #clock-cells may be 1? > > > > > > AFAICS, the device can provide only this one clock line (audio master clock > > > for I2S output)... I shall re-check, just in case. > > And you're right, of course: the audio output formatting module of the ADV748x > devices provides a set of clock lines related to the I2S pins: the already > discussed master clock, left-right channel clock and the serial clock (bit > clock?). I don't think we need to model the last two clocks through CCF though, they're part of the I2S protocol, not clock sources that need to be explicitly controlled (or queried). > > > > There is no need for a fixed-clock compatible, nor for clock-frequency > > > > and clock-output-names. > > > > > > > > But most important: this should be documented in the adv748x DT bindings, > > > > and implemented in the adv748x driver. > > > > > > So if the driver is to export that clock for the kernel (like in this case), > > > it must implement its support? > > > > Exactly. Unless that pin is hardcoded to output a fixed clock, in which case > > you can just override the existing audio_clk_c rate. > > Just to try it out (I'll set #clock-cells to 1), I registered a fixed rate > clock in the driver, added a clock provider: > > adv748x_probe: > > clk = clk_register_fixed_rate(state->dev, > "clk-hdmi-i2s-mclk", > NULL /* parent_name */, > 0 /* flags */, > 12288000 /* rate */); > of_clk_add_provider(state->dev->of_node, of_clk_src_simple_get, clk); > > And removed the audio_clk_c frequency setting. I also replaced the audio_clk_c > in the list of input clocks of the R-Car-side sound card with the phandle of > the adv7482 main node: > > salvator-common.dtsi: > > &i2c4 { > status = "okay"; > > adv7482_hdmi_decoder: video-receiver@70 { > #clock-cells = <0>; // to be replaced with <1> > }; > }; > > &rcar_sound { > clocks = ..., <&adv7482_hdmi_decoder>, ...; > }; > > As everything continues to work as before, I assume that at least the clock > dependencies were resolved. This looks good to me. > Is there a way to verify that the added input clock is actually used? > IOW, if its frequency is actually has been programmed into the ssi4 (R-Car > receiving hardware) registers, and not just a left-over from previuos attempts > or plain default setting? > > As the ADV748x devices seem to provide also the clocks for video outputs, will > it make any sense to place the clock definition into the port node? > Or should all provided clocks be indexed in the main device node? Those clocks are part of the CSI-2 protocol and also don't need to be explicitly controlled. As far as I can tell from a quick check of the ADV7482 documentation, only the I2S MCLK is a general-purpose clock that needs to be exposed. -- Regards, Laurent Pinchart _______________________________________________ devel mailing list devel@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
next prev parent reply other threads:[~2020-03-06 13:16 UTC|newest] Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-13 14:19 [PATCH 0/8] media: i2c: adv748x: add support for HDMI audio Alex Riesen 2020-01-13 14:19 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 1/8] media: adv748x: add a device-specific wrapper for register block read Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 2/8] media: adv748x: add audio mute control and output selection ioctls Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-03-13 8:16 ` Hans Verkuil 2020-03-13 8:16 ` Hans Verkuil 2020-03-13 10:26 ` Alex Riesen 2020-03-13 10:26 ` Alex Riesen 2020-03-13 10:52 ` Hans Verkuil 2020-03-13 10:52 ` Hans Verkuil 2020-03-13 11:00 ` Alex Riesen 2020-03-13 11:00 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 3/8] media: adv748x: add log_status ioctl Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 4/8] media: adv748x: reserve space for the audio (I2S) port in the driver structures Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 5/8] media: adv748x: add an ASoC DAI definition to the driver Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 6/8] media: adv748x: reduce amount of code for bitwise modification of device registers Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 14:15 ` [PATCH 7/8] dt-bindings: adv748x: add information about serial audio interface (I2S/TDM) Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-01-13 22:32 ` Rob Herring 2020-01-13 22:32 ` Rob Herring 2020-01-13 14:15 ` [PATCH 8/8] arm64: dts: renesas: salvator: add a connection from adv748x codec (HDMI input) to the R-Car SoC Alex Riesen 2020-01-13 14:15 ` Alex Riesen 2020-03-02 12:28 ` Geert Uytterhoeven 2020-03-02 12:28 ` Geert Uytterhoeven 2020-03-02 13:40 ` Alex Riesen 2020-03-02 13:40 ` Alex Riesen 2020-03-02 13:47 ` Geert Uytterhoeven 2020-03-02 13:47 ` Geert Uytterhoeven 2020-03-02 15:07 ` Alex Riesen 2020-03-02 15:07 ` Alex Riesen 2020-03-02 15:32 ` Geert Uytterhoeven 2020-03-02 15:32 ` Geert Uytterhoeven 2020-03-02 16:09 ` Alex Riesen 2020-03-02 16:09 ` Alex Riesen 2020-03-02 16:13 ` Geert Uytterhoeven 2020-03-02 16:13 ` Geert Uytterhoeven 2020-03-05 14:36 ` Alex Riesen 2020-03-05 14:36 ` Alex Riesen 2020-03-06 12:21 ` Geert Uytterhoeven 2020-03-06 12:21 ` Geert Uytterhoeven 2020-03-06 13:16 ` Laurent Pinchart [this message] 2020-03-06 13:16 ` Laurent Pinchart 2020-03-06 13:41 ` Alex Riesen 2020-03-06 13:41 ` Alex Riesen 2020-03-06 13:45 ` Laurent Pinchart 2020-03-06 13:45 ` Laurent Pinchart 2020-03-09 1:31 ` Kuninori Morimoto 2020-03-09 1:31 ` Kuninori Morimoto 2020-03-09 11:09 ` Alex Riesen 2020-03-09 11:09 ` Alex Riesen 2020-03-10 1:07 ` Kuninori Morimoto 2020-03-10 1:07 ` Kuninori Morimoto 2020-03-10 8:17 ` Alex Riesen 2020-03-10 8:17 ` Alex Riesen 2020-03-10 10:39 ` Laurent Pinchart 2020-03-10 10:39 ` Laurent Pinchart
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