| Message ID | 1386160133-24026-14-git-send-email-tomi.valkeinen@ti.com (mailing list archive) |
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* Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 04:31]: Description missing.. But other than that can you please check that the latest patch I posted in thread "[PATCH] ARM: OMAP2+: Fix populating the hwmod data from device" works with this? The test to do is to remove the related reg, interrupt and dma entries from omap_hwmod_*_data.c, and make sure the related hwmod data is initialized from DT properly. I don't know if it makes sense to have them as children of dss_core, they really all seem to be completely independent devices? BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods property and do the lookup based on the compatible property instead ;) So from that point of view we need to get the device mapping right in the .dtsi files, and don't want to start mixing up separate devices into single .dtsi entry. Regards, Tony > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> > --- > arch/arm/boot/dts/omap3.dtsi | 43 +++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 43 insertions(+) > > diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi > index f3a0c26ed0c2..6fc163201cbd 100644 > --- a/arch/arm/boot/dts/omap3.dtsi > +++ b/arch/arm/boot/dts/omap3.dtsi > @@ -588,5 +588,48 @@ > num-eps = <16>; > ram-bits = <12>; > }; > + > + dss@48050000 { > + compatible = "ti,omap3-dss", "simple-bus"; > + reg = <0x48050000 0x200>; > + ti,hwmods = "dss_core"; > + #address-cells = <1>; > + #size-cells = <1>; > + ranges; > + > + dispc@48050400 { > + compatible = "ti,omap3-dispc"; > + reg = <0x48050400 0x400>; > + interrupts = <25>; > + ti,hwmods = "dss_dispc"; > + }; > + > + dpi: encoder@0 { > + compatible = "ti,omap3-dpi"; > + }; > + > + sdi: encoder@1 { > + compatible = "ti,omap3-sdi"; > + }; > + > + dsi: encoder@4804fc00 { > + compatible = "ti,omap3-dsi"; > + reg = <0x4804fc00 0x400>; > + interrupts = <25>; > + ti,hwmods = "dss_dsi1"; > + }; > + > + rfbi: encoder@48050800 { > + compatible = "ti,omap3-rfbi"; > + reg = <0x48050800 0x100>; > + ti,hwmods = "dss_rfbi"; > + }; > + > + venc: encoder@48050c00 { > + compatible = "ti,omap3-venc"; > + reg = <0x48050c00 0x100>; > + ti,hwmods = "dss_venc"; > + }; > + }; > }; > }; > -- > 1.8.3.2 > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013-12-05 19:05, Tony Lindgren wrote: > * Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 04:31]: > > Description missing.. But other than that can you please check that > the latest patch I posted in thread "[PATCH] ARM: OMAP2+: Fix populating > the hwmod data from device" works with this? > > The test to do is to remove the related reg, interrupt and dma entries > from omap_hwmod_*_data.c, and make sure the related hwmod data is initialized > from DT properly. I made a quick test with panda, by applying your patch and reverting b38911f3472be89551bfca740adf0009562b9873. That only effectively tests the DISPC IRQ, but that worked fine. > I don't know if it makes sense to have them as children of dss_core, they > really all seem to be completely independent devices? The DSS subdevices depend on the dss_core. dss_core has to be powered up for any of the subdevices to work. This is done automatically by the runtime PM when the subdevices are children of the dss_core. > BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods > property and do the lookup based on the compatible property instead ;) > So from that point of view we need to get the device mapping right in > the .dtsi files, and don't want to start mixing up separate devices into > single .dtsi entry. Hmm, was that just a general comment, or something that affects the DSS DT data I have in my patch? As far as I understand, the DSS nodes reflect the current hwmods correctly. With the exception that DPI and SDI do not have a matching hwmod, as they are really part of dss_core/dispc. They are separate nodes as they are "video outputs" the same way as the other subnodes. I could perhaps remove the DPI and SDI nodes, and have them as direct video ports from DISPC, but... That's easier said than done. Tomi
* Tomi Valkeinen <tomi.valkeinen@ti.com> [131209 04:46]: > On 2013-12-05 19:05, Tony Lindgren wrote: > > * Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 04:31]: > > > > Description missing.. But other than that can you please check that > > the latest patch I posted in thread "[PATCH] ARM: OMAP2+: Fix populating > > the hwmod data from device" works with this? > > > > The test to do is to remove the related reg, interrupt and dma entries > > from omap_hwmod_*_data.c, and make sure the related hwmod data is initialized > > from DT properly. > > I made a quick test with panda, by applying your patch and reverting > b38911f3472be89551bfca740adf0009562b9873. That only effectively tests > the DISPC IRQ, but that worked fine. OK I've finally pushed a real branch for the mach-omap2 board-*.c file removal patches at omap-for-v3.14/omap3-board-removal so you can use that as a base for testing. I did not apply the dpi panel pdata-quirks.c patch as we discussed earlier. > > I don't know if it makes sense to have them as children of dss_core, they > > really all seem to be completely independent devices? > > The DSS subdevices depend on the dss_core. dss_core has to be powered up > for any of the subdevices to work. This is done automatically by the > runtime PM when the subdevices are children of the dss_core. OK thanks. Care to also check that it plays along nicely with the comments starting at line 3222 in omap_hwmod_3xxx_data.c? We should set up things so we can eventually remove those kind of hwmod workarounds. > > BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods > > property and do the lookup based on the compatible property instead ;) > > So from that point of view we need to get the device mapping right in > > the .dtsi files, and don't want to start mixing up separate devices into > > single .dtsi entry. > > Hmm, was that just a general comment, or something that affects the DSS > DT data I have in my patch? As far as I understand, the DSS nodes > reflect the current hwmods correctly. Yes that's what we want if there is a dependency to the dss_core at the hardware level and the children cannot be used independently. However, if the children can be enabled and clocked independently, then they should not be children of the dss_core. > With the exception that DPI and SDI do not have a matching hwmod, as > they are really part of dss_core/dispc. They are separate nodes as they > are "video outputs" the same way as the other subnodes. > > I could perhaps remove the DPI and SDI nodes, and have them as direct > video ports from DISPC, but... That's easier said than done. If you need a dev entry created for those where the phandle of that dev is used to select the output for a board, then it makes sense to have them. I guess you could also set them as a pinctrl mux controller and then the board specific .dts file could request those outputs. But there may be more than just mux involved like regulators. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Tomi, On Monday 09 December 2013 14:45:25 Tomi Valkeinen wrote: > On 2013-12-05 19:05, Tony Lindgren wrote: > > * Tomi Valkeinen <tomi.valkeinen@ti.com> [131204 04:31]: > > > > Description missing.. But other than that can you please check that > > the latest patch I posted in thread "[PATCH] ARM: OMAP2+: Fix populating > > the hwmod data from device" works with this? > > > > The test to do is to remove the related reg, interrupt and dma entries > > from omap_hwmod_*_data.c, and make sure the related hwmod data is > > initialized from DT properly. > > I made a quick test with panda, by applying your patch and reverting > b38911f3472be89551bfca740adf0009562b9873. That only effectively tests > the DISPC IRQ, but that worked fine. > > > I don't know if it makes sense to have them as children of dss_core, they > > really all seem to be completely independent devices? > > The DSS subdevices depend on the dss_core. dss_core has to be powered up > for any of the subdevices to work. This is done automatically by the > runtime PM when the subdevices are children of the dss_core. I'd like to get a clearer picture of the hardware here. The OMAP3 ISP is organized in a seemingly similar way, with the hardware subdivided in high- level more-or-less independent modules. However, from a system point of view, the ISP submodules are not standalone: they're part of the same power domain as the ISP core, with subclocks management and interrupts being handled by the ISP core. For those reasons we've modeled the ISP as a single platform device. Are the DSS submodules really independent, or are they organized similarly ? For instance do they each have a clock handled by the OMAP core clock IP, or are the clocks gated by the DSS core ? Do they have interrupts routed to the GIC, or does the DSS core driver demux the interrupts ? If the submodules are not independent, would it make sense to have a single DT node that would be matched with the DSS core driver ? You could list information about the submodules in subnodes, and possibly create platform devices internally in the DSS core, but a single platform device would be instantiated from DT, and the DSS core wouldn't need a "simple-bus" compatible string. My gut feeling is that this would be a better representation of the hardware, but I might not known enough about the DSS and be completely wrong. > > BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods > > property and do the lookup based on the compatible property instead ;) > > So from that point of view we need to get the device mapping right in > > the .dtsi files, and don't want to start mixing up separate devices into > > single .dtsi entry. > > Hmm, was that just a general comment, or something that affects the DSS > DT data I have in my patch? As far as I understand, the DSS nodes > reflect the current hwmods correctly. > > With the exception that DPI and SDI do not have a matching hwmod, as > they are really part of dss_core/dispc. They are separate nodes as they > are "video outputs" the same way as the other subnodes. > > I could perhaps remove the DPI and SDI nodes, and have them as direct > video ports from DISPC, but... That's easier said than done. DPI and SDI indeed seem like ports to me, node devices. Have you given the implementation a thought ? How difficult would it be ?
On 2013-12-12 01:44, Laurent Pinchart wrote: >> The DSS subdevices depend on the dss_core. dss_core has to be powered up >> for any of the subdevices to work. This is done automatically by the >> runtime PM when the subdevices are children of the dss_core. > > I'd like to get a clearer picture of the hardware here. The OMAP3 ISP is > organized in a seemingly similar way, with the hardware subdivided in high- > level more-or-less independent modules. However, from a system point of view, > the ISP submodules are not standalone: they're part of the same power domain > as the ISP core, with subclocks management and interrupts being handled by the > ISP core. For those reasons we've modeled the ISP as a single platform device. > > Are the DSS submodules really independent, or are they organized similarly ? > For instance do they each have a clock handled by the OMAP core clock IP, or > are the clocks gated by the DSS core ? Do they have interrupts routed to the > GIC, or does the DSS core driver demux the interrupts ? The DSS is "interesting". The TRM for various OMAP versions are the best source of information, there's integration section in the very beginning of the DSS chapter. We have the main dss_core (just DSS in the TRM, but for clarity we use dss_core) module, which is kind of a wrapper/glue for all the submodules. dss_core contains things like controlling muxes for signals between submodules, or clocks coming from outside. And there's the DSS power domain, containing all the DSS modules. Then we have DISPC, which reads the pixel data, manipulates it, and outputs raw RGB data to encoder submodules. Then we have DSI, HDMI, RFBI, VENC encoder submodules. They all have separate address spaces, some have dedicated PLLs, PHYs, and interrupts. Then DPI, which I think is mostly just level shifters. It's really just a port, as you say. SDI is a bit unclear to me. The registers for it are in the dss_core. There's only a few registers, but it does have a PHY and a PLL. But I guess it's also more of a port than a separate module. As for the clocks, I'm not sure what the actual point is that you want to clarify. DSS gets one "main" func clock from PRCM, which is used by DISPC and in some cases other submodules. But then we have dedicated DSI and HDMI PLLs, which, at least in DSI's case, can be used to fully satisfy DSI's clock needs. The PLLs can also be used for DISPC, so the PRCM clock is not needed in all cases. The interrupts, then. In OMAP4, DISPC, DSI1, DSI2 and HDMI each have their own interrupt line. In OMAP3, DISPC and DSI shared the same interrupt line. But in both OMAP4 and OMAP3 DISPC and DSI interrupt status/enable is handled via the respective IP. The DSS submodules also are not really designed together. For example, the HDMI IP is from one vendor, not TI. And the HDMI IP is different in OMAP4 and OMAP5. Most of the DSS IPs are, I believe, from TI. But it's not like all the IPs were designed to work together, that's why we have wrappers/glue blocks (e.g. around HDMI). So, are they independent? I don't know =). I think they lean on the independent side. dss_core is always needed for the submodules to work, but for example DSI could be used without DISPC, using system DMA to transfer data from memory to DSI. Not a very useful thing to do, but still, there are dedicated DMA channels for that. > If the submodules are not independent, would it make sense to have a single DT > node that would be matched with the DSS core driver ? You could list > information about the submodules in subnodes, and possibly create platform > devices internally in the DSS core, but a single platform device would be > instantiated from DT, and the DSS core wouldn't need a "simple-bus" compatible > string. My gut feeling is that this would be a better representation of the > hardware, but I might not known enough about the DSS and be completely wrong. I have been wondering about this for a long time. The DSS modules have dependencies, and splitting them into separate devices/drivers brings the issue of probe order. We side-step that by having the virtual omapdss driver add the drivers for DSS modules in proper order. But then, I feel that they are quite independent and probably should be separate devices. And we've had omap hwmods, which I believe force us to have separate devices (although afaik hwmods are going away). >>> BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods >>> property and do the lookup based on the compatible property instead ;) >>> So from that point of view we need to get the device mapping right in >>> the .dtsi files, and don't want to start mixing up separate devices into >>> single .dtsi entry. >> >> Hmm, was that just a general comment, or something that affects the DSS >> DT data I have in my patch? As far as I understand, the DSS nodes >> reflect the current hwmods correctly. >> >> With the exception that DPI and SDI do not have a matching hwmod, as >> they are really part of dss_core/dispc. They are separate nodes as they >> are "video outputs" the same way as the other subnodes. >> >> I could perhaps remove the DPI and SDI nodes, and have them as direct >> video ports from DISPC, but... That's easier said than done. > > DPI and SDI indeed seem like ports to me, node devices. Have you given the > implementation a thought ? How difficult would it be ? I have not though too much about the implementation. I'll spend some time on that to see how it goes. There's also the question where do the ports belong to. DISPC outputs the pixels. For DPI, I don't see dss_core really doing anything. For SDI, the dss_core contains the control for the SDI PLL and PHY. But SDI PLL and PHY are not parts of dss_core, just the control is done via dss_core. Tomi
On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote: > On 2013-12-12 01:44, Laurent Pinchart wrote: > > So, are they independent? I don't know =). I think they lean on the > independent side. dss_core is always needed for the submodules to work, > but for example DSI could be used without DISPC, using system DMA to > transfer data from memory to DSI. Not a very useful thing to do, but > still, there are dedicated DMA channels for that. If they have separate hwmod entries, they should be considered separate independent devices for sure. To summarize, here are few reasons why they need to be treated as separate devices: 1. The modules maybe clocked/powered/idled separately and can have their own idle configuration so they can do the hardware based idling separately. 2. Doing a readback after a write to one module will not flush the write to the other modules on the (bus depending on the SoC version AFAIK). That can lead to nasty bugs caused by the ordering. 3. If the devices are described in a different way in the .dts files from the hwmod data, we will not have 1-to-1 mapping and will never be able to replace ti,hwmods with just the compatible string. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Tomi, On Thursday 12 December 2013 10:38:34 Tomi Valkeinen wrote: > On 2013-12-12 01:44, Laurent Pinchart wrote: > >> The DSS subdevices depend on the dss_core. dss_core has to be powered up > >> for any of the subdevices to work. This is done automatically by the > >> runtime PM when the subdevices are children of the dss_core. > > > > I'd like to get a clearer picture of the hardware here. The OMAP3 ISP is > > organized in a seemingly similar way, with the hardware subdivided in > > high-level more-or-less independent modules. However, from a system point > > of view, the ISP submodules are not standalone: they're part of the same > > power domain as the ISP core, with subclocks management and interrupts > > being handled by the ISP core. For those reasons we've modeled the ISP as > > a single platform device. > > > > Are the DSS submodules really independent, or are they organized similarly > > ? For instance do they each have a clock handled by the OMAP core clock > > IP, or are the clocks gated by the DSS core ? Do they have interrupts > > routed to the GIC, or does the DSS core driver demux the interrupts ? > > The DSS is "interesting". The TRM for various OMAP versions are the best > source of information, there's integration section in the very beginning > of the DSS chapter. > > We have the main dss_core (just DSS in the TRM, but for clarity we use > dss_core) module, which is kind of a wrapper/glue for all the > submodules. dss_core contains things like controlling muxes for signals > between submodules, or clocks coming from outside. And there's the DSS > power domain, containing all the DSS modules. > > Then we have DISPC, which reads the pixel data, manipulates it, and > outputs raw RGB data to encoder submodules. > > Then we have DSI, HDMI, RFBI, VENC encoder submodules. They all have > separate address spaces, some have dedicated PLLs, PHYs, and interrupts. The separate address spaces are not by themselves a clear indication that the submodules should be considered as separate devices, as the hardware might just group registers related to submodules together. The dedicated interrupts (for DSI and HDMI) and PRCM clocks (for VENC if I'm not mistaken, and HDMI on the OMAP4) are a clearer sign. > Then DPI, which I think is mostly just level shifters. It's really just > a port, as you say. > > SDI is a bit unclear to me. The registers for it are in the dss_core. > There's only a few registers, but it does have a PHY and a PLL. But I > guess it's also more of a port than a separate module. After a quick look at the documentation I would say so. I would be tempted to consider RFBI as part of the DSS core, but that's less clear. > As for the clocks, I'm not sure what the actual point is that you want > to clarify. DSS gets one "main" func clock from PRCM, which is used by > DISPC and in some cases other submodules. But then we have dedicated DSI > and HDMI PLLs, which, at least in DSI's case, can be used to fully > satisfy DSI's clock needs. The PLLs can also be used for DISPC, so the > PRCM clock is not needed in all cases. > > The interrupts, then. In OMAP4, DISPC, DSI1, DSI2 and HDMI each have > their own interrupt line. In OMAP3, DISPC and DSI shared the same > interrupt line. But in both OMAP4 and OMAP3 DISPC and DSI interrupt > status/enable is handled via the respective IP. > > The DSS submodules also are not really designed together. For example, > the HDMI IP is from one vendor, not TI. And the HDMI IP is different in > OMAP4 and OMAP5. Most of the DSS IPs are, I believe, from TI. But it's > not like all the IPs were designed to work together, that's why we have > wrappers/glue blocks (e.g. around HDMI). > > So, are they independent? I don't know =). I think they lean on the > independent side. I agree with that, except for DPI, SDI and possibly RFBI. > dss_core is always needed for the submodules to work, but for example DSI > could be used without DISPC, using system DMA to transfer data from memory > to DSI. Not a very useful thing to do, but still, there are dedicated DMA > channels for that. Right. The real question is whether the DSI or HDMI IPs can be used in a system without the DSS core. If not, it might make sense to just merge the drivers into a single module (of course with a clear interface between the different parts to avoid spaghetti code). > > If the submodules are not independent, would it make sense to have a > > single DT node that would be matched with the DSS core driver ? You could > > list information about the submodules in subnodes, and possibly create > > platform devices internally in the DSS core, but a single platform device > > would be instantiated from DT, and the DSS core wouldn't need a > > "simple-bus" compatible string. My gut feeling is that this would be a > > better representation of the hardware, but I might not known enough about > > the DSS and be completely wrong. > > I have been wondering about this for a long time. The DSS modules have > dependencies, and splitting them into separate devices/drivers brings > the issue of probe order. We side-step that by having the virtual > omapdss driver Given that the DSS core has a set of registers not dedicated to any of the submodules I believe it should be represented by a device. The omapdss driver thus doesn't look virtual to me, it supports a real piece of hardware. > add the drivers for DSS modules in proper order. > > But then, I feel that they are quite independent and probably should be > separate devices. Even if they're separate devices they could be instantiated by DSS core based on DT nodes. I'm not sure whether that's the best idea, but it might be worth thinking about it. > And we've had omap hwmods, which I believe force us to have separate devices > (although afaik hwmods are going away). > > >>> BTW, for v3.15, I'm hoping to do patches where we deprecate ti,hwmods > >>> property and do the lookup based on the compatible property instead ;) > >>> So from that point of view we need to get the device mapping right in > >>> the .dtsi files, and don't want to start mixing up separate devices into > >>> single .dtsi entry. > >> > >> Hmm, was that just a general comment, or something that affects the DSS > >> DT data I have in my patch? As far as I understand, the DSS nodes > >> reflect the current hwmods correctly. > >> > >> With the exception that DPI and SDI do not have a matching hwmod, as > >> they are really part of dss_core/dispc. They are separate nodes as they > >> are "video outputs" the same way as the other subnodes. > >> > >> I could perhaps remove the DPI and SDI nodes, and have them as direct > >> video ports from DISPC, but... That's easier said than done. > > > > DPI and SDI indeed seem like ports to me, node devices. Have you given the > > implementation a thought ? How difficult would it be ? > > I have not though too much about the implementation. I'll spend some time on > that to see how it goes. > > There's also the question where do the ports belong to. DISPC outputs the > pixels. > > For DPI, I don't see dss_core really doing anything. > > For SDI, the dss_core contains the control for the SDI PLL and PHY. But > SDI PLL and PHY are not parts of dss_core, just the control is done via > dss_core. If the PLL and PHY are solely controlled through registers part of the DSS core register space, they would seem like part of the DSS core to me.
Hi Tony, On Thursday 12 December 2013 21:59:13 Tony Lindgren wrote: > On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote: > > On 2013-12-12 01:44, Laurent Pinchart wrote: > > > > So, are they independent? I don't know =). I think they lean on the > > independent side. dss_core is always needed for the submodules to work, > > but for example DSI could be used without DISPC, using system DMA to > > transfer data from memory to DSI. Not a very useful thing to do, but > > still, there are dedicated DMA channels for that. > > If they have separate hwmod entries, they should be considered separate > independent devices for sure. > > To summarize, here are few reasons why they need to be treated as > separate devices: Are you talking generally here, or about the DSS modules in particular ? > 1. The modules maybe clocked/powered/idled separately and can have their > own idle configuration so they can do the hardware based idling > separately. I don't think this applies to the DSS modules. > 2. Doing a readback after a write to one module will not flush the write > to the other modules on the (bus depending on the SoC version AFAIK). > That can lead to nasty bugs caused by the ordering. How does separate devices solve this ? > 3. If the devices are described in a different way in the .dts files > from the hwmod data, we will not have 1-to-1 mapping and will never > be able to replace ti,hwmods with just the compatible string.
On 2013-12-13 05:24, Laurent Pinchart wrote: > Right. The real question is whether the DSI or HDMI IPs can be used in a > system without the DSS core. If not, it might make sense to just merge the > drivers into a single module (of course with a clear interface between the > different parts to avoid spaghetti code). The drivers are already in single kernel module, omapdss.ko. The HDMI IP is used on another SoC, without DSS. They have their own display architecture. DSI IP might need some small modifications to work without DSS, but not much. It doesn't have any strict DSS/DISPC dependencies. > Given that the DSS core has a set of registers not dedicated to any of the > submodules I believe it should be represented by a device. The omapdss driver > thus doesn't look virtual to me, it supports a real piece of hardware. As noted in another mail, dss_core and omapdss devices are different things. dss_core is not virtual, omapdss is. >> But then, I feel that they are quite independent and probably should be >> separate devices. > > Even if they're separate devices they could be instantiated by DSS core based > on DT nodes. I'm not sure whether that's the best idea, but it might be worth > thinking about it. What would be the difference to the one in this series? In this series, the submodules are instantiated automatically by the driver framework. The only difference I see is that the submodule devices would appear/disappear dynamically, but... what would be the benefit? Tomi
On 2013-12-13 05:27, Laurent Pinchart wrote: > Hi Tony, > > On Thursday 12 December 2013 21:59:13 Tony Lindgren wrote: >> On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote: >>> On 2013-12-12 01:44, Laurent Pinchart wrote: >>> >>> So, are they independent? I don't know =). I think they lean on the >>> independent side. dss_core is always needed for the submodules to work, >>> but for example DSI could be used without DISPC, using system DMA to >>> transfer data from memory to DSI. Not a very useful thing to do, but >>> still, there are dedicated DMA channels for that. >> >> If they have separate hwmod entries, they should be considered separate >> independent devices for sure. >> >> To summarize, here are few reasons why they need to be treated as >> separate devices: > > Are you talking generally here, or about the DSS modules in particular ? > >> 1. The modules maybe clocked/powered/idled separately and can have their >> own idle configuration so they can do the hardware based idling >> separately. > > I don't think this applies to the DSS modules. The DSS submodules have their own SYSCONFIG register, and idle settings can be set per module. So I think they idle separately, even if they are in a common power domain. Tomi
* Tomi Valkeinen <tomi.valkeinen@ti.com> [131213 02:19]: > On 2013-12-13 05:27, Laurent Pinchart wrote: > > Hi Tony, > > > > On Thursday 12 December 2013 21:59:13 Tony Lindgren wrote: > >> On Thu, Dec 12, 2013 at 10:38:34AM +0200, Tomi Valkeinen wrote: > >>> On 2013-12-12 01:44, Laurent Pinchart wrote: > >>> > >>> So, are they independent? I don't know =). I think they lean on the > >>> independent side. dss_core is always needed for the submodules to work, > >>> but for example DSI could be used without DISPC, using system DMA to > >>> transfer data from memory to DSI. Not a very useful thing to do, but > >>> still, there are dedicated DMA channels for that. > >> > >> If they have separate hwmod entries, they should be considered separate > >> independent devices for sure. > >> > >> To summarize, here are few reasons why they need to be treated as > >> separate devices: > > > > Are you talking generally here, or about the DSS modules in particular ? > > > >> 1. The modules maybe clocked/powered/idled separately and can have their > >> own idle configuration so they can do the hardware based idling > >> separately. > > > > I don't think this applies to the DSS modules. > > The DSS submodules have their own SYSCONFIG register, and idle settings > can be set per module. So I think they idle separately, even if they are > in a common power domain. Yes. Please see the current omap_hwmod_*_data.c files, if they are separate entries there, that means we need to treat them as separate devices to avoid the issues I listed. We do have some entries still missing from omap_hwmod_*_data.c files, like the SSI entries as they are undocumented. But for the existing ones there please follow the same layout for the .dts entries. Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013-12-13 05:24, Laurent Pinchart wrote: >> Then DPI, which I think is mostly just level shifters. It's really just >> a port, as you say. >> >> SDI is a bit unclear to me. The registers for it are in the dss_core. >> There's only a few registers, but it does have a PHY and a PLL. But I >> guess it's also more of a port than a separate module. > > After a quick look at the documentation I would say so. I would be tempted to > consider RFBI as part of the DSS core, but that's less clear. I had a look at this, mainly the DPI side so far. There's one extra complication, which actually affects all other outputs also (and CDF): pinctrl. In the current series, I just have pinctrl for each device, with "default" name, which ends up being used by default without any code on my part. However, if DPI is no longer a device, it can't have pinctrl entry. But this is a wider issue, as the pinctrl should really be per endpoint, not per device. When an endpoint is selected to be used, a particular pinmuxing should be taken into use. I'm not sure what would be the cleanest solution to this. I currently have this working: &dss { pinctrl-names = "default-0-0"; pinctrl-0 = <&dss_dpi_pins>; port@0 { dpi_out: endpoint { remote-endpoint = <&tfp410_in>; data-lines = <24>; }; }; }; So here I have 'port@0' for DSS, which is the DPI output, and it has a single endpoint. For DSS device, I have pinctrl data. When the DPI endpoint is initialized, the code looks for pinctrl with name "default-<portnum>-<endpointnum>". As the DPI is port 0, and just one endpoint, the code looks for "default-0-0". For omap3 board with both DPI and SDI as options (they can't be used at the same time, though), I imagine it'd be like: &dss { vdds_dsi-supply = <&vpll2>; vdds_sdi-supply = <&vpll2>; pinctrl-names = "default-0-0", "default-1-0"; pinctrl-0 = <&dss_dpi_pins>; pinctrl-1 = <&dss_sdi_pins>; ports { #address-cells = <1>; #size-cells = <0>; port@0 { reg = <0>; dpi_out: endpoint { }; }; port@1 { reg = <1>; sdi_out: endpoint { }; }; }; }; Any thoughts? Every time I work with ports/endpoints, I feel that this is needlessly complex. But I have never come up with any cleaner or simpler way to handle this. I also think this multiple-peripherals-per-single-port is not really display related, although, for some reason, it seems like display is the most abused hardware. Maybe ports/endpoints or similar should be in the common driver framework? Tomi
Hi Tomi, On Monday 16 December 2013 12:49:03 Tomi Valkeinen wrote: > On 2013-12-13 05:24, Laurent Pinchart wrote: > >> Then DPI, which I think is mostly just level shifters. It's really just > >> a port, as you say. > >> > >> SDI is a bit unclear to me. The registers for it are in the dss_core. > >> There's only a few registers, but it does have a PHY and a PLL. But I > >> guess it's also more of a port than a separate module. > > > > After a quick look at the documentation I would say so. I would be tempted > > to consider RFBI as part of the DSS core, but that's less clear. > > I had a look at this, mainly the DPI side so far. There's one extra > complication, which actually affects all other outputs also (and CDF): > pinctrl. > > In the current series, I just have pinctrl for each device, with > "default" name, which ends up being used by default without any code on > my part. > > However, if DPI is no longer a device, it can't have pinctrl entry. But > this is a wider issue, as the pinctrl should really be per endpoint, not > per device. When an endpoint is selected to be used, a particular > pinmuxing should be taken into use. > > I'm not sure what would be the cleanest solution to this. I currently > have this working: > > &dss { > pinctrl-names = "default-0-0"; > pinctrl-0 = <&dss_dpi_pins>; > > port@0 { > dpi_out: endpoint { > remote-endpoint = <&tfp410_in>; > data-lines = <24>; > }; > }; > }; > > So here I have 'port@0' for DSS, which is the DPI output, and it has a > single endpoint. For DSS device, I have pinctrl data. > > When the DPI endpoint is initialized, the code looks for pinctrl with > name "default-<portnum>-<endpointnum>". As the DPI is port 0, and just > one endpoint, the code looks for "default-0-0". > > For omap3 board with both DPI and SDI as options (they can't be used at > the same time, though), I imagine it'd be like: > > &dss { > vdds_dsi-supply = <&vpll2>; > vdds_sdi-supply = <&vpll2>; > > pinctrl-names = "default-0-0", "default-1-0"; > pinctrl-0 = <&dss_dpi_pins>; > pinctrl-1 = <&dss_sdi_pins>; > > ports { > #address-cells = <1>; > #size-cells = <0>; > > port@0 { > reg = <0>; > dpi_out: endpoint { > }; > }; > > port@1 { > reg = <1>; > sdi_out: endpoint { > }; > }; > }; > }; > > Any thoughts? Would it be feasible to put the pinctrl properties in the port or endpoint nodes ? That could require changes to the pinctrl core, most probably just exporting a few internal functions (possibly requiring a bit of refactoring), but it might make the result simpler. > Every time I work with ports/endpoints, I feel that this is needlessly > complex. But I have never come up with any cleaner or simpler way to > handle this. > > I also think this multiple-peripherals-per-single-port is not really > display related, although, for some reason, it seems like display is the > most abused hardware. Maybe ports/endpoints or similar should be in the > common driver framework? Ports and endpoints is the way we have come up with to describe a graph in DT. I wouldn't call it needlessly complex, as I believe it's both generic and simple, but I agree it's a bit on the verbose side. Omitting the ports and port nodes as a shortcut might be a good way to reduce the verbosity. Regarding moving this to the device core, I'm not opposed to it, but I'd like to see interest from other users first.
diff --git a/arch/arm/boot/dts/omap3.dtsi b/arch/arm/boot/dts/omap3.dtsi index f3a0c26ed0c2..6fc163201cbd 100644 --- a/arch/arm/boot/dts/omap3.dtsi +++ b/arch/arm/boot/dts/omap3.dtsi @@ -588,5 +588,48 @@ num-eps = <16>; ram-bits = <12>; }; + + dss@48050000 { + compatible = "ti,omap3-dss", "simple-bus"; + reg = <0x48050000 0x200>; + ti,hwmods = "dss_core"; + #address-cells = <1>; + #size-cells = <1>; + ranges; + + dispc@48050400 { + compatible = "ti,omap3-dispc"; + reg = <0x48050400 0x400>; + interrupts = <25>; + ti,hwmods = "dss_dispc"; + }; + + dpi: encoder@0 { + compatible = "ti,omap3-dpi"; + }; + + sdi: encoder@1 { + compatible = "ti,omap3-sdi"; + }; + + dsi: encoder@4804fc00 { + compatible = "ti,omap3-dsi"; + reg = <0x4804fc00 0x400>; + interrupts = <25>; + ti,hwmods = "dss_dsi1"; + }; + + rfbi: encoder@48050800 { + compatible = "ti,omap3-rfbi"; + reg = <0x48050800 0x100>; + ti,hwmods = "dss_rfbi"; + }; + + venc: encoder@48050c00 { + compatible = "ti,omap3-venc"; + reg = <0x48050c00 0x100>; + ti,hwmods = "dss_venc"; + }; + }; }; };
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> --- arch/arm/boot/dts/omap3.dtsi | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+)