RE: [Resubmit: PATCH-V2] Introducing ti-media directory
-Original Message- From: Mauro Carvalho Chehab [mailto:mche...@redhat.com] Sent: Wednesday, March 24, 2010 5:32 PM To: Laurent Pinchart Cc: Karicheri, Muralidharan; Hiremath, Vaibhav; davinci-linux-open- sou...@linux.davincidsp.com; linux-media@vger.kernel.org Subject: Re: [Resubmit: PATCH-V2] Introducing ti-media directory Laurent Pinchart wrote: Hi Murali, On Tuesday 23 March 2010 18:52:44 Karicheri, Muralidharan wrote: Laurent, I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? [Hiremath, Vaibhav] Laurent, ti-media directory is top level directory where we are putting all TI devices drivers. So having said that, we should worrying about what goes inside this directory. For me ISP is more generic, if you compare davinci and OMAP. Frankly, there are various naming convention we do have from device to device, even if the IP's are being reused. For example, the internal name for OMAP is ISP but Davinci refers it as a VPSS. Could you explain what name space issue you are referring to in linux-omap-camera since I am not quite familiar with that tree? The linux-omap-camera tree contains a driver for the OMAP3 ISP. Basically, most source files start with the isp prefix and are stored in drivers/media/video/isp/. ISP is quite a generic name, and other vendors will probably develop an ISP at some point (if not already done), so there's already a potential name conflict today. Using a dedicated directory in drivers/media/video for TI-specific cores is definitely a good idea (assuming the same IP cores won't be used by other vendors in the future). My concern is that, if we move the ISP driver in drivers/media/video/ti- media, the directory will soon get quite crowded. If a new TI processor comes up with a totally incompatible ISP, we will get a name conflict in drivers/media/video/ti-media. I was thinking about either replacing the isp prefix with omap3isp (or similar), or moving the driver to drivers/media/video/ti-media/omap3isp, but that will impede code sharing code between the Davinci and OMAP processor families. That's where my uncertainty comes from. There are two separate points here. The first one is re-using a driver or some symbols. Whatever directory structure is used, this won't prevent to share the code. Just create the header files under include/media and be sure that the Kbuild system will properly handle the dependencies, with depends on. Myself and Vaibhav had discussed this in the past and ti-media is the generic name that we could agree on. On DM SoCs (DM6446, DM355, DM365) I expect ti-media to be the home for all vpfe and vpbe driver files. Since we had a case of common IP across OMAP and DMxxx SoCs, we want to place all OMAP and DMxxx video driver files in a common directory so that sharing the drivers across the SoCs will be easy. We could discuss and agree on another name if need be. Any suggestions? It's not the name ti-media that I don't agree on, it's just that this will move the problem one step further in the directory hierarchy without actually solving it :-) Is it guaranteed today that no TI processors with new generation video blocks will reuse the names ISP, VPFE and VPBE ? The OMAP3 datasheet refers to VPFE and VPBE, but luckily those blocks are further divided into subblocks, and the driver doesn't refer to the VPFE and VPBE directly. I agree that a name like ti-media would be too generic. Also, if we take a look on how the drivers are currently organized, the trees aren't vendor-based, but chipset-design based. There are even some cases where there's just one or two C files that are directly stored under drivers/media/video (like tvp5150, for example). IMO, simpler drivers where just one or a couple of files are needed should be stored into drivers/media/video. Bigger drivers should be organized by family, and not by vendor. Otherwise, we would need to re-organize the tree to be coherent. One interesting example of the a per-family directory is cx25840. The same driver is used by several different chipsets. The driver supports a separate IC chip (cx25836, cx2584x), and two designs where the decoder logic is inside an IC chip with the bridge and other functional blocks (cx23885 and cx231xx). [Hiremath, Vaibhav] Mauro and Laurent, What is the conclusion on this directory naming convention issue? Actually the V4L2 display driver patch (submitted by me) is dependent on this patch, and due to this it is blocked. As mentioned by Murali, considering the number of files and reusability we come up the ti-media directory naming structure. And also Laurent has admitted that we
Re: [Resubmit: PATCH-V2] Introducing ti-media directory
Hi Murali, On Tuesday 23 March 2010 18:52:44 Karicheri, Muralidharan wrote: Laurent, I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? [Hiremath, Vaibhav] Laurent, ti-media directory is top level directory where we are putting all TI devices drivers. So having said that, we should worrying about what goes inside this directory. For me ISP is more generic, if you compare davinci and OMAP. Frankly, there are various naming convention we do have from device to device, even if the IP's are being reused. For example, the internal name for OMAP is ISP but Davinci refers it as a VPSS. Could you explain what name space issue you are referring to in linux-omap-camera since I am not quite familiar with that tree? The linux-omap-camera tree contains a driver for the OMAP3 ISP. Basically, most source files start with the isp prefix and are stored in drivers/media/video/isp/. ISP is quite a generic name, and other vendors will probably develop an ISP at some point (if not already done), so there's already a potential name conflict today. Using a dedicated directory in drivers/media/video for TI-specific cores is definitely a good idea (assuming the same IP cores won't be used by other vendors in the future). My concern is that, if we move the ISP driver in drivers/media/video/ti-media, the directory will soon get quite crowded. If a new TI processor comes up with a totally incompatible ISP, we will get a name conflict in drivers/media/video/ti-media. I was thinking about either replacing the isp prefix with omap3isp (or similar), or moving the driver to drivers/media/video/ti-media/omap3isp, but that will impede code sharing code between the Davinci and OMAP processor families. That's where my uncertainty comes from. Myself and Vaibhav had discussed this in the past and ti-media is the generic name that we could agree on. On DM SoCs (DM6446, DM355, DM365) I expect ti-media to be the home for all vpfe and vpbe driver files. Since we had a case of common IP across OMAP and DMxxx SoCs, we want to place all OMAP and DMxxx video driver files in a common directory so that sharing the drivers across the SoCs will be easy. We could discuss and agree on another name if need be. Any suggestions? It's not the name ti-media that I don't agree on, it's just that this will move the problem one step further in the directory hierarchy without actually solving it :-) Is it guaranteed today that no TI processors with new generation video blocks will reuse the names ISP, VPFE and VPBE ? The OMAP3 datasheet refers to VPFE and VPBE, but luckily those blocks are further divided into subblocks, and the driver doesn't refer to the VPFE and VPBE directly. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Resubmit: PATCH-V2] Introducing ti-media directory
Laurent Pinchart wrote: Hi Murali, On Tuesday 23 March 2010 18:52:44 Karicheri, Muralidharan wrote: Laurent, I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? [Hiremath, Vaibhav] Laurent, ti-media directory is top level directory where we are putting all TI devices drivers. So having said that, we should worrying about what goes inside this directory. For me ISP is more generic, if you compare davinci and OMAP. Frankly, there are various naming convention we do have from device to device, even if the IP's are being reused. For example, the internal name for OMAP is ISP but Davinci refers it as a VPSS. Could you explain what name space issue you are referring to in linux-omap-camera since I am not quite familiar with that tree? The linux-omap-camera tree contains a driver for the OMAP3 ISP. Basically, most source files start with the isp prefix and are stored in drivers/media/video/isp/. ISP is quite a generic name, and other vendors will probably develop an ISP at some point (if not already done), so there's already a potential name conflict today. Using a dedicated directory in drivers/media/video for TI-specific cores is definitely a good idea (assuming the same IP cores won't be used by other vendors in the future). My concern is that, if we move the ISP driver in drivers/media/video/ti-media, the directory will soon get quite crowded. If a new TI processor comes up with a totally incompatible ISP, we will get a name conflict in drivers/media/video/ti-media. I was thinking about either replacing the isp prefix with omap3isp (or similar), or moving the driver to drivers/media/video/ti-media/omap3isp, but that will impede code sharing code between the Davinci and OMAP processor families. That's where my uncertainty comes from. There are two separate points here. The first one is re-using a driver or some symbols. Whatever directory structure is used, this won't prevent to share the code. Just create the header files under include/media and be sure that the Kbuild system will properly handle the dependencies, with depends on. Myself and Vaibhav had discussed this in the past and ti-media is the generic name that we could agree on. On DM SoCs (DM6446, DM355, DM365) I expect ti-media to be the home for all vpfe and vpbe driver files. Since we had a case of common IP across OMAP and DMxxx SoCs, we want to place all OMAP and DMxxx video driver files in a common directory so that sharing the drivers across the SoCs will be easy. We could discuss and agree on another name if need be. Any suggestions? It's not the name ti-media that I don't agree on, it's just that this will move the problem one step further in the directory hierarchy without actually solving it :-) Is it guaranteed today that no TI processors with new generation video blocks will reuse the names ISP, VPFE and VPBE ? The OMAP3 datasheet refers to VPFE and VPBE, but luckily those blocks are further divided into subblocks, and the driver doesn't refer to the VPFE and VPBE directly. I agree that a name like ti-media would be too generic. Also, if we take a look on how the drivers are currently organized, the trees aren't vendor-based, but chipset-design based. There are even some cases where there's just one or two C files that are directly stored under drivers/media/video (like tvp5150, for example). IMO, simpler drivers where just one or a couple of files are needed should be stored into drivers/media/video. Bigger drivers should be organized by family, and not by vendor. Otherwise, we would need to re-organize the tree to be coherent. One interesting example of the a per-family directory is cx25840. The same driver is used by several different chipsets. The driver supports a separate IC chip (cx25836, cx2584x), and two designs where the decoder logic is inside an IC chip with the bridge and other functional blocks (cx23885 and cx231xx). -- Cheers, Mauro -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [Resubmit: PATCH-V2] Introducing ti-media directory
Laurent, Using a dedicated directory in drivers/media/video for TI-specific cores is definitely a good idea (assuming the same IP cores won't be used by other vendors in the future). If another vendor uses it in another SOC (assuming for discussion), then the driver should be re-used. So there shouldn't be another version of the driver right? So why is this an issue? My concern is that, if we move the ISP driver in drivers/media/video/ti- media, the directory will soon get quite crowded. If a new TI processor comes up with a totally incompatible ISP, we will get a name conflict in drivers/media/video/ti-media. I was thinking about either replacing the isp prefix with omap3isp (or similar), or moving the driver to drivers/media/video/ti-media/omap3isp, but that will impede code sharing code between the Davinci and OMAP processor families. That's where my uncertainty comes from. I think vpfe is used for DM devices which is equivalent to ISP in OMAP. omap3 CCDC/Previewer/Resizer/H3A is re-used from DM6446 CCDC or vice-versa. The ccdc is also re-used in AM35xxx OMAP device (excuse me if I wrote the name incorrectly) that Vaibhav is working on. So we might want to name it as just ccdc.c/resizer.c/previewer.c. Currently we have dm644x_ccdc.c under davinci for DM644x and dm355_ccdc.c for DM355. We need to sort out the differences in the driver and use a common ccdc.c on OMAP/DM644x/AM35xxx. I am not sure if we have any control on how hardware designers name the IP, and would have to deal with it as it happens. For new IPs that is considerably different, but share the same name might have to be named by adding some prefix/suffix as appropriate (example v1, v2 etc for different versions of the same IP, resizer.c for OMAP/DM644x/AM35xxx, resizer_v1.c for resizer on DM355). Myself and Vaibhav had discussed this in the past and ti-media is the generic name that we could agree on. On DM SoCs (DM6446, DM355, DM365) I expect ti-media to be the home for all vpfe and vpbe driver files. Since we had a case of common IP across OMAP and DMxxx SoCs, we want to place all OMAP and DMxxx video driver files in a common directory so that sharing the drivers across the SoCs will be easy. We could discuss and agree on another name if need be. Any suggestions? It's not the name ti-media that I don't agree on, it's just that this will move the problem one step further in the directory hierarchy without actually solving it :-) Is it guaranteed today that no TI processors with new generation video blocks will reuse the names ISP, VPFE and VPBE ? The OMAP3 datasheet refers to VPFE and VPBE, but luckily those blocks are further divided into subblocks, and the driver doesn't refer to the VPFE and VPBE directly. As discussed above, we will have to expect name conflicts in future and come up with some naming convention to name files(and add it to v4 documentation). I think this shouldn't prevent this patch from merging to the tree since you are okay with the name. I will send a pull request if you are okay with this patch. -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Resubmit: PATCH-V2] Introducing ti-media directory
On Friday 19 March 2010 10:35:50 hvaib...@ti.com wrote: From: Vaibhav Hiremath hvaib...@ti.com Looking towards the number of files which are cluttering in media/video/ directory, it is required to introduce seperate working directory for TI devices. You should then move the omap24xxcam driver as well. Again the IP's are being re-used across the devices which makes it very difficuilt to re-use the driver code. For example, DM6446 and AM3517 both uses exactly same VPFE/CCDC IP, but the driver is encapsulated under DAVINCI which makes it impossible to re-use. I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? Signed-off-by: Vaibhav Hiremath hvaib...@ti.com -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [Resubmit: PATCH-V2] Introducing ti-media directory
-Original Message- From: Laurent Pinchart [mailto:laurent.pinch...@ideasonboard.com] Sent: Tuesday, March 23, 2010 5:11 PM To: davinci-linux-open-sou...@linux.davincidsp.com Cc: Hiremath, Vaibhav; linux-media@vger.kernel.org Subject: Re: [Resubmit: PATCH-V2] Introducing ti-media directory On Friday 19 March 2010 10:35:50 hvaib...@ti.com wrote: From: Vaibhav Hiremath hvaib...@ti.com Looking towards the number of files which are cluttering in media/video/ directory, it is required to introduce seperate working directory for TI devices. You should then move the omap24xxcam driver as well. [Hiremath, Vaibhav] I wanted to move this file to ti-media directory, but left it only because it is based on V4L2-Int framework (legacy). Again the IP's are being re-used across the devices which makes it very difficuilt to re-use the driver code. For example, DM6446 and AM3517 both uses exactly same VPFE/CCDC IP, but the driver is encapsulated under DAVINCI which makes it impossible to re-use. I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? [Hiremath, Vaibhav] Laurent, ti-media directory is top level directory where we are putting all TI devices drivers. So having said that, we should worrying about what goes inside this directory. For me ISP is more generic, if you compare davinci and OMAP. Frankly, there are various naming convention we do have from device to device, even if the IP's are being reused. For example, the internal name for OMAP is ISP but Davinci refers it as a VPSS. Thanks, Vaibhav Signed-off-by: Vaibhav Hiremath hvaib...@ti.com -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [Resubmit: PATCH-V2] Introducing ti-media directory
Laurent, I'm not too sure to like the ti-media name. It will soon get quite crowded, and name collisions might occur (look at the linux-omap-camera tree and the ISP driver in there for instance). Isn't there an internal name to refer to both the DM6446 and AM3517 that could be used ? [Hiremath, Vaibhav] Laurent, ti-media directory is top level directory where we are putting all TI devices drivers. So having said that, we should worrying about what goes inside this directory. For me ISP is more generic, if you compare davinci and OMAP. Frankly, there are various naming convention we do have from device to device, even if the IP's are being reused. For example, the internal name for OMAP is ISP but Davinci refers it as a VPSS. Could you explain what name space issue you are referring to in linux-omap-camera since I am not quite familiar with that tree? Myself and Vaibhav had discussed this in the past and ti-media is the generic name that we could agree on. On DM SoCs (DM6446, DM355, DM365) I expect ti-media to be the home for all vpfe and vpbe driver files. Since we had a case of common IP across OMAP and DMxxx SoCs, we want to place all OMAP and DMxxx video driver files in a common directory so that sharing the drivers across the SoCs will be easy. We could discuss and agree on another name if need be. Any suggestions? Thanks, Vaibhav Signed-off-by: Vaibhav Hiremath hvaib...@ti.com -- Regards, Laurent Pinchart ___ Davinci-linux-open-source mailing list davinci-linux-open-sou...@linux.davincidsp.com http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
