* RE: Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property [not found] ` <20230726170141.GA1568248-robh@kernel.org> @ 2023-08-09 20:43 ` Mirela Rabulea 2023-10-02 9:18 ` Hans Verkuil 0 siblings, 1 reply; 4+ messages in thread From: Mirela Rabulea @ 2023-08-09 20:43 UTC (permalink / raw) To: Rob Herring, Alexander Stein Cc: Conor Dooley, Ming Qian, Shijie Qin, Eagle Zhou, Mauro Carvalho Chehab, Krzysztof Kozlowski, Conor Dooley, Shawn Guo, Sascha Hauer, Fabio Estevam, Mark Brown, Anson Huang, dl-linux-imx, Pengutronix Kernel Team, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org > -----Original Message----- > From: Rob Herring <robh@kernel.org> > Sent: Wednesday, July 26, 2023 8:02 PM > To: Alexander Stein <alexander.stein@ew.tq-group.com> > Cc: Conor Dooley <conor@kernel.org>; Mirela Rabulea > <mirela.rabulea@nxp.com>; Ming Qian <ming.qian@nxp.com>; Shijie Qin > <shijie.qin@nxp.com>; Eagle Zhou <eagle.zhou@nxp.com>; Mauro Carvalho > Chehab <mchehab@kernel.org>; Krzysztof Kozlowski > <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley <conor+dt@kernel.org>; > Shawn Guo <shawnguo@kernel.org>; Sascha Hauer <s.hauer@pengutronix.de>; > Fabio Estevam <festevam@gmail.com>; Mark Brown <broonie@kernel.org>; > Anson Huang <Anson.Huang@nxp.com>; dl-linux-imx <linux-imx@nxp.com>; > Pengutronix Kernel Team <kernel@pengutronix.de>; linux- > media@vger.kernel.org; devicetree@vger.kernel.org; linux-arm- > kernel@lists.infradead.org; linux-spi@vger.kernel.org > Subject: [EXT] Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks > property > > Caution: This is an external email. Please take care when clicking links or > opening attachments. When in doubt, report the message using the 'Report this > email' button > > > On Tue, Jul 25, 2023 at 07:31:55AM +0200, Alexander Stein wrote: > > Am Montag, 24. Juli 2023, 20:26:15 CEST schrieb Conor Dooley: > > > On Mon, Jul 24, 2023 at 02:21:00PM +0200, Alexander Stein wrote: > > > > i.MX8 and i.MX8X both use two clocks for accessing the periphery. > > > > Add clocks and clock-names properties accordingly. > > > > > > > > Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> > > > > --- > > > > Changes in v2: > > > > * None > > > > > > > > .../devicetree/bindings/media/nxp,imx8-jpeg.yaml | 8 ++++++++ > > > > 1 file changed, 8 insertions(+) > > > > > > > > diff --git > > > > a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml > > > > b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml index > > > > 3d9d1db37040..2533e16720f2 100644 > > > > --- a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml > > > > +++ b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml > > > > > > > > @@ -46,6 +46,14 @@ properties: > > > > minItems: 2 # Wrapper and 1 slot > > > > maxItems: 5 # Wrapper and 4 slots > > > > > > > > + clocks: > > > > + maxItems: 2 > > > > + > > > > + clock-names: > > > > + items: > > > > + - const: per > > > > + - const: ipg > > > > > > What do "per" and "ipg" mean? I assume "per" is peripheral? > > > > Actually I don't know what "ipg" stands for. It's a quite common name > > on i.MX platforms though. I opted for the names currently used in the > > DT. The driver doesn't care for the names currently. Hi, Sorry for the late response. Yes, the driver uses now the clk_bulk functions, so it does not care for the names anymore (in the past it used the per/ipg names to get the clocks). > > Those names date back about 25 years to Motorola Mcore GSM SoCs. IPG came > from IPG bus which IIRC stood for IP gasket. Essentially the bus was something > like Arm APB being slave only. The IPG clock is essentially the bus and register > access clock. 'per' is the functional clock in cases that need a defined clock rate > such as UART baud clock. > > There is also a shared (between CPU and DSP) bus called SPBA from the same > time which still lives on even though it isn't shared in i.MX chips. Unfortunately, I cannot provide an explanation for the IPG acronym, I asked around, will come back if I get an answer. > > > But cross-checking the reference manual these clocks seems to be called > "jpeg" > > and "ips", individually for both jpeg encoder and decoder. > > Given this block is probably licensed IP, seems like it would use something > different and be directly connected to AHB or AXI. Yes, the Cast JPEG Decoder/Encoder is a licensed core, and it there is also an NXP JPEG Decoder/Encoder Wrapper, which provides the interface for the Cast JPEG Decoder/Encoder. The wrapper also provides AXI DMA engines for fetching Jpeg bitstream from memory and feed it to the Cast Jpeg or for storing the decoded pixel data into system memory through AXI bus. The wrapper also provides APB interface for wrapper and Cast Jpeg register access. From our hardware team, I got the information that: for jpeg wrapper, it has two clocks(axi and apb), for CAST IP it has one clock(axi, whose clock source is same with wrapper on chip). > > > Mirela (added to recipients): As the original author of the DT nodes, > > could you provide additional information regarding the clock names? I understand that "ipg" usually is IP bus clk for register access, but I am not sure. Experimentally, I was not able to get register access unless both clocks were enabled. I'll get back if I get more details. Regards, Mirela > > > > Best regards, > > Alexander _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property 2023-08-09 20:43 ` Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property Mirela Rabulea @ 2023-10-02 9:18 ` Hans Verkuil 2023-10-02 11:16 ` Conor Dooley 0 siblings, 1 reply; 4+ messages in thread From: Hans Verkuil @ 2023-10-02 9:18 UTC (permalink / raw) To: Mirela Rabulea, Rob Herring, Alexander Stein Cc: Conor Dooley, Ming Qian, Shijie Qin, Eagle Zhou, Mauro Carvalho Chehab, Krzysztof Kozlowski, Conor Dooley, Shawn Guo, Sascha Hauer, Fabio Estevam, Mark Brown, Anson Huang, dl-linux-imx, Pengutronix Kernel Team, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org Rob, Conor, On 09/08/2023 22:43, Mirela Rabulea wrote: >> -----Original Message----- >> From: Rob Herring <robh@kernel.org> >> Sent: Wednesday, July 26, 2023 8:02 PM >> To: Alexander Stein <alexander.stein@ew.tq-group.com> >> Cc: Conor Dooley <conor@kernel.org>; Mirela Rabulea >> <mirela.rabulea@nxp.com>; Ming Qian <ming.qian@nxp.com>; Shijie Qin >> <shijie.qin@nxp.com>; Eagle Zhou <eagle.zhou@nxp.com>; Mauro Carvalho >> Chehab <mchehab@kernel.org>; Krzysztof Kozlowski >> <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley <conor+dt@kernel.org>; >> Shawn Guo <shawnguo@kernel.org>; Sascha Hauer <s.hauer@pengutronix.de>; >> Fabio Estevam <festevam@gmail.com>; Mark Brown <broonie@kernel.org>; >> Anson Huang <Anson.Huang@nxp.com>; dl-linux-imx <linux-imx@nxp.com>; >> Pengutronix Kernel Team <kernel@pengutronix.de>; linux- >> media@vger.kernel.org; devicetree@vger.kernel.org; linux-arm- >> kernel@lists.infradead.org; linux-spi@vger.kernel.org >> Subject: [EXT] Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks >> property >> >> Caution: This is an external email. Please take care when clicking links or >> opening attachments. When in doubt, report the message using the 'Report this >> email' button >> >> >> On Tue, Jul 25, 2023 at 07:31:55AM +0200, Alexander Stein wrote: >>> Am Montag, 24. Juli 2023, 20:26:15 CEST schrieb Conor Dooley: >>>> On Mon, Jul 24, 2023 at 02:21:00PM +0200, Alexander Stein wrote: >>>>> i.MX8 and i.MX8X both use two clocks for accessing the periphery. >>>>> Add clocks and clock-names properties accordingly. >>>>> >>>>> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> Is this patch OK or do you want changes? It's a bit unclear. Regards, Hans >>>>> --- >>>>> Changes in v2: >>>>> * None >>>>> >>>>> .../devicetree/bindings/media/nxp,imx8-jpeg.yaml | 8 ++++++++ >>>>> 1 file changed, 8 insertions(+) >>>>> >>>>> diff --git >>>>> a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml >>>>> b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml index >>>>> 3d9d1db37040..2533e16720f2 100644 >>>>> --- a/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml >>>>> +++ b/Documentation/devicetree/bindings/media/nxp,imx8-jpeg.yaml >>>>> >>>>> @@ -46,6 +46,14 @@ properties: >>>>> minItems: 2 # Wrapper and 1 slot >>>>> maxItems: 5 # Wrapper and 4 slots >>>>> >>>>> + clocks: >>>>> + maxItems: 2 >>>>> + >>>>> + clock-names: >>>>> + items: >>>>> + - const: per >>>>> + - const: ipg >>>> >>>> What do "per" and "ipg" mean? I assume "per" is peripheral? >>> >>> Actually I don't know what "ipg" stands for. It's a quite common name >>> on i.MX platforms though. I opted for the names currently used in the >>> DT. The driver doesn't care for the names currently. > > Hi, > Sorry for the late response. > Yes, the driver uses now the clk_bulk functions, so it does not care for the names anymore (in the past it used the per/ipg names to get the clocks). > >> >> Those names date back about 25 years to Motorola Mcore GSM SoCs. IPG came >> from IPG bus which IIRC stood for IP gasket. Essentially the bus was something >> like Arm APB being slave only. The IPG clock is essentially the bus and register >> access clock. 'per' is the functional clock in cases that need a defined clock rate >> such as UART baud clock. >> >> There is also a shared (between CPU and DSP) bus called SPBA from the same >> time which still lives on even though it isn't shared in i.MX chips. > > Unfortunately, I cannot provide an explanation for the IPG acronym, I asked around, will come back if I get an answer. > >> >>> But cross-checking the reference manual these clocks seems to be called >> "jpeg" >>> and "ips", individually for both jpeg encoder and decoder. >> >> Given this block is probably licensed IP, seems like it would use something >> different and be directly connected to AHB or AXI. > > Yes, the Cast JPEG Decoder/Encoder is a licensed core, and it there is also an NXP JPEG Decoder/Encoder Wrapper, which provides the interface for the Cast JPEG Decoder/Encoder. The wrapper also provides AXI DMA engines for fetching Jpeg bitstream from memory and feed it to the Cast Jpeg or for storing the decoded pixel data into system memory through AXI bus. The wrapper also provides APB interface for wrapper and Cast Jpeg register access. > > From our hardware team, I got the information that: for jpeg wrapper, it has two clocks(axi and apb), for CAST IP it has one clock(axi, whose clock source is same with wrapper on chip). > >> >>> Mirela (added to recipients): As the original author of the DT nodes, >>> could you provide additional information regarding the clock names? > > I understand that "ipg" usually is IP bus clk for register access, but I am not sure. Experimentally, I was not able to get register access unless both clocks were enabled. I'll get back if I get more details. > > Regards, > Mirela > >>> >>> Best regards, >>> Alexander _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property 2023-10-02 9:18 ` Hans Verkuil @ 2023-10-02 11:16 ` Conor Dooley 2023-10-05 8:19 ` Hans Verkuil 0 siblings, 1 reply; 4+ messages in thread From: Conor Dooley @ 2023-10-02 11:16 UTC (permalink / raw) To: Hans Verkuil Cc: Mirela Rabulea, Rob Herring, Alexander Stein, Ming Qian, Shijie Qin, Eagle Zhou, Mauro Carvalho Chehab, Krzysztof Kozlowski, Conor Dooley, Shawn Guo, Sascha Hauer, Fabio Estevam, Mark Brown, Anson Huang, dl-linux-imx, Pengutronix Kernel Team, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org [-- Attachment #1.1: Type: text/plain, Size: 2105 bytes --] On Mon, Oct 02, 2023 at 11:18:56AM +0200, Hans Verkuil wrote: > Rob, Conor, > > On 09/08/2023 22:43, Mirela Rabulea wrote: > >> -----Original Message----- > >> From: Rob Herring <robh@kernel.org> > >> Sent: Wednesday, July 26, 2023 8:02 PM > >> To: Alexander Stein <alexander.stein@ew.tq-group.com> > >> Cc: Conor Dooley <conor@kernel.org>; Mirela Rabulea > >> <mirela.rabulea@nxp.com>; Ming Qian <ming.qian@nxp.com>; Shijie Qin > >> <shijie.qin@nxp.com>; Eagle Zhou <eagle.zhou@nxp.com>; Mauro Carvalho > >> Chehab <mchehab@kernel.org>; Krzysztof Kozlowski > >> <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley <conor+dt@kernel.org>; > >> Shawn Guo <shawnguo@kernel.org>; Sascha Hauer <s.hauer@pengutronix.de>; > >> Fabio Estevam <festevam@gmail.com>; Mark Brown <broonie@kernel.org>; > >> Anson Huang <Anson.Huang@nxp.com>; dl-linux-imx <linux-imx@nxp.com>; > >> Pengutronix Kernel Team <kernel@pengutronix.de>; linux- > >> media@vger.kernel.org; devicetree@vger.kernel.org; linux-arm- > >> kernel@lists.infradead.org; linux-spi@vger.kernel.org > >> Subject: [EXT] Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks > >> property > >> > >> Caution: This is an external email. Please take care when clicking links or > >> opening attachments. When in doubt, report the message using the 'Report this > >> email' button > >> > >> > >> On Tue, Jul 25, 2023 at 07:31:55AM +0200, Alexander Stein wrote: > >>> Am Montag, 24. Juli 2023, 20:26:15 CEST schrieb Conor Dooley: > >>>> On Mon, Jul 24, 2023 at 02:21:00PM +0200, Alexander Stein wrote: > >>>>> i.MX8 and i.MX8X both use two clocks for accessing the periphery. > >>>>> Add clocks and clock-names properties accordingly. > >>>>> > >>>>> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> > > Is this patch OK or do you want changes? > > It's a bit unclear. It's unclear to me too at this point, but I wonder if the names should just be removed and replaced by descriptions in the clocks property? One of the responses here mentioned that the names aren't even needed by hardware. [-- Attachment #1.2: signature.asc --] [-- Type: application/pgp-signature, Size: 228 bytes --] [-- Attachment #2: Type: text/plain, Size: 176 bytes --] _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property 2023-10-02 11:16 ` Conor Dooley @ 2023-10-05 8:19 ` Hans Verkuil 0 siblings, 0 replies; 4+ messages in thread From: Hans Verkuil @ 2023-10-05 8:19 UTC (permalink / raw) To: Conor Dooley Cc: Mirela Rabulea, Rob Herring, Alexander Stein, Ming Qian, Shijie Qin, Eagle Zhou, Mauro Carvalho Chehab, Krzysztof Kozlowski, Conor Dooley, Shawn Guo, Sascha Hauer, Fabio Estevam, Mark Brown, Anson Huang, dl-linux-imx, Pengutronix Kernel Team, linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-spi@vger.kernel.org On 02/10/2023 13:16, Conor Dooley wrote: > On Mon, Oct 02, 2023 at 11:18:56AM +0200, Hans Verkuil wrote: >> Rob, Conor, >> >> On 09/08/2023 22:43, Mirela Rabulea wrote: >>>> -----Original Message----- >>>> From: Rob Herring <robh@kernel.org> >>>> Sent: Wednesday, July 26, 2023 8:02 PM >>>> To: Alexander Stein <alexander.stein@ew.tq-group.com> >>>> Cc: Conor Dooley <conor@kernel.org>; Mirela Rabulea >>>> <mirela.rabulea@nxp.com>; Ming Qian <ming.qian@nxp.com>; Shijie Qin >>>> <shijie.qin@nxp.com>; Eagle Zhou <eagle.zhou@nxp.com>; Mauro Carvalho >>>> Chehab <mchehab@kernel.org>; Krzysztof Kozlowski >>>> <krzysztof.kozlowski+dt@linaro.org>; Conor Dooley <conor+dt@kernel.org>; >>>> Shawn Guo <shawnguo@kernel.org>; Sascha Hauer <s.hauer@pengutronix.de>; >>>> Fabio Estevam <festevam@gmail.com>; Mark Brown <broonie@kernel.org>; >>>> Anson Huang <Anson.Huang@nxp.com>; dl-linux-imx <linux-imx@nxp.com>; >>>> Pengutronix Kernel Team <kernel@pengutronix.de>; linux- >>>> media@vger.kernel.org; devicetree@vger.kernel.org; linux-arm- >>>> kernel@lists.infradead.org; linux-spi@vger.kernel.org >>>> Subject: [EXT] Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks >>>> property >>>> >>>> Caution: This is an external email. Please take care when clicking links or >>>> opening attachments. When in doubt, report the message using the 'Report this >>>> email' button >>>> >>>> >>>> On Tue, Jul 25, 2023 at 07:31:55AM +0200, Alexander Stein wrote: >>>>> Am Montag, 24. Juli 2023, 20:26:15 CEST schrieb Conor Dooley: >>>>>> On Mon, Jul 24, 2023 at 02:21:00PM +0200, Alexander Stein wrote: >>>>>>> i.MX8 and i.MX8X both use two clocks for accessing the periphery. >>>>>>> Add clocks and clock-names properties accordingly. >>>>>>> >>>>>>> Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com> >> >> Is this patch OK or do you want changes? >> >> It's a bit unclear. > > It's unclear to me too at this point, but I wonder if the names should > just be removed and replaced by descriptions in the clocks property? > > One of the responses here mentioned that the names aren't even needed by > hardware. Right, I'm marking this as "Obsoleted" based on Mirela's reply. Alexander, if you believe this is still needed, then please post a v2. Regards, Hans _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-08-09 20:43 ` Re: [PATCH v2 3/3] dt-bindings: media: imx-jpeg: Add clocks property Mirela Rabulea
2023-10-02 9:18 ` Hans Verkuil
2023-10-02 11:16 ` Conor Dooley
2023-10-05 8:19 ` Hans Verkuil
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