From: Rob Herring <robh@kernel.org> To: Peter Ujfalusi <peter.ujfalusi@ti.com> Cc: Vinod <vkoul@kernel.org>, Nishanth Menon <nm@ti.com>, Santosh Shilimkar <ssantosh@kernel.org>, Dan Williams <dan.j.williams@intel.com>, "open list:DMA GENERIC OFFLOAD ENGINE SUBSYSTEM" <dmaengine@vger.kernel.org>, "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" <linux-arm-kernel@lists.infradead.org>, devicetree@vger.kernel.org, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Grygorii Strashko <grygorii.strashko@ti.com>, Lokesh Vutla <lokeshvutla@ti.com>, Tero Kristo <t-kristo@ti.com>, Tony Lindgren <tony@atomide.com> Subject: Re: [PATCH 09/16] dt-bindings: dma: ti: Add document for K3 UDMA Date: Fri, 14 Jun 2019 07:20:57 -0600 [thread overview] Message-ID: <CAL_JsqJNMkKL_FubZfjKY6jLebMetmgR24EoendHoPM2ckrUQA@mail.gmail.com> (raw) In-Reply-To: <e0d6a264-96b5-31a6-e70b-3b1c2d863988@ti.com> On Thu, Jun 13, 2019 at 2:33 PM Peter Ujfalusi <peter.ujfalusi@ti.com> wrote: > > Rob, > > On 13/06/2019 21.16, Rob Herring wrote: > >> +Remote PSI-L endpoint > >> + > >> +Required properties: > >> +-------------------- > >> +- ti,psil-base: PSI-L thread ID base of the endpoint > >> + > >> +Within the PSI-L endpoint node thread configuration subnodes must present with: > >> +ti,psil-configX naming convention, where X is the thread ID offset. > > > > Don't use vendor prefixes on node names. > > OK. > > >> + > >> +Configuration node Required properties: > >> +-------------------- > >> +- linux,udma-mode: Channel mode, can be: > >> + - UDMA_PKT_MODE: for Packet mode channels (peripherals) > >> + - UDMA_TR_MODE: for Third-Party mode > > > > This is hardly a common linux thing. What determines the value here. > > Unfortunately it is. No, it's a feature of your h/w and in no way is something linux defined which is the point of 'linux' prefix. > Each channel can be configured to Packet or TR mode. For some > peripherals it is true that they only support packet mode, these are the > newer PSI-L native peripherals. > For these channels a udma-mode property would be correct. > > But we have legacy peripherals as well and they are serviced by PDMA > (which is a native peripheral designed to talk to the given legacy IP). > We can use either packet or TR mode in UDMAP to talk to PDMAs, it is in > most cases clear what to use, but for example for audio (McASP) channels > Linux is using TR channel because we need cyclic DMA while for example > RTOS is using Packet mode as it fits their needs better. > > Here I need to prefix the udma-mode with linux as the mode is used by > Linux, but other OS might opt to use different channel mode. So you'd need <os>,udma-mode? That doesn't work... If the setting is per OS, then it belongs in the OS because the same dtb should work across OS's. > The reason why this needs to be in the DT is that when the channel is > requested we need to configure the mode and it can not be swapped > runtime easily between Packet and TR mode. So when the client makes the channel request, why doesn't it specify the mode? Rob
WARNING: multiple messages have this Message-ID (diff)
From: Rob Herring <robh@kernel.org> To: Peter Ujfalusi <peter.ujfalusi@ti.com> Cc: Nishanth Menon <nm@ti.com>, devicetree@vger.kernel.org, Grygorii Strashko <grygorii.strashko@ti.com>, Lokesh Vutla <lokeshvutla@ti.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Tero Kristo <t-kristo@ti.com>, Tony Lindgren <tony@atomide.com>, Vinod <vkoul@kernel.org>, Santosh Shilimkar <ssantosh@kernel.org>, "open list:DMA GENERIC OFFLOAD ENGINE SUBSYSTEM" <dmaengine@vger.kernel.org>, Dan Williams <dan.j.williams@intel.com>, "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH 09/16] dt-bindings: dma: ti: Add document for K3 UDMA Date: Fri, 14 Jun 2019 07:20:57 -0600 [thread overview] Message-ID: <CAL_JsqJNMkKL_FubZfjKY6jLebMetmgR24EoendHoPM2ckrUQA@mail.gmail.com> (raw) In-Reply-To: <e0d6a264-96b5-31a6-e70b-3b1c2d863988@ti.com> On Thu, Jun 13, 2019 at 2:33 PM Peter Ujfalusi <peter.ujfalusi@ti.com> wrote: > > Rob, > > On 13/06/2019 21.16, Rob Herring wrote: > >> +Remote PSI-L endpoint > >> + > >> +Required properties: > >> +-------------------- > >> +- ti,psil-base: PSI-L thread ID base of the endpoint > >> + > >> +Within the PSI-L endpoint node thread configuration subnodes must present with: > >> +ti,psil-configX naming convention, where X is the thread ID offset. > > > > Don't use vendor prefixes on node names. > > OK. > > >> + > >> +Configuration node Required properties: > >> +-------------------- > >> +- linux,udma-mode: Channel mode, can be: > >> + - UDMA_PKT_MODE: for Packet mode channels (peripherals) > >> + - UDMA_TR_MODE: for Third-Party mode > > > > This is hardly a common linux thing. What determines the value here. > > Unfortunately it is. No, it's a feature of your h/w and in no way is something linux defined which is the point of 'linux' prefix. > Each channel can be configured to Packet or TR mode. For some > peripherals it is true that they only support packet mode, these are the > newer PSI-L native peripherals. > For these channels a udma-mode property would be correct. > > But we have legacy peripherals as well and they are serviced by PDMA > (which is a native peripheral designed to talk to the given legacy IP). > We can use either packet or TR mode in UDMAP to talk to PDMAs, it is in > most cases clear what to use, but for example for audio (McASP) channels > Linux is using TR channel because we need cyclic DMA while for example > RTOS is using Packet mode as it fits their needs better. > > Here I need to prefix the udma-mode with linux as the mode is used by > Linux, but other OS might opt to use different channel mode. So you'd need <os>,udma-mode? That doesn't work... If the setting is per OS, then it belongs in the OS because the same dtb should work across OS's. > The reason why this needs to be in the DT is that when the channel is > requested we need to configure the mode and it can not be swapped > runtime easily between Packet and TR mode. So when the client makes the channel request, why doesn't it specify the mode? Rob _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-06-14 13:21 UTC|newest] Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-06 12:34 [PATCH 00/16] dmaengine/soc/firmware: Add Texas Instruments UDMA support Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 01/16] firmware: ti_sci: Add resource management APIs for ringacc, psi-l and udma Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-06-06 6:00 ` Lokesh Vutla 2019-06-06 6:00 ` Lokesh Vutla 2019-06-06 6:00 ` Lokesh Vutla 2019-06-06 12:04 ` Peter Ujfalusi 2019-06-06 12:04 ` Peter Ujfalusi 2019-06-06 12:04 ` Peter Ujfalusi 2019-06-10 9:18 ` [PATCH v1.1] " Peter Ujfalusi 2019-06-10 9:18 ` Peter Ujfalusi 2019-06-10 9:41 ` Lokesh Vutla 2019-06-10 9:41 ` Lokesh Vutla 2019-06-11 17:36 ` Tero Kristo 2019-06-11 17:36 ` Tero Kristo 2019-05-06 12:34 ` [PATCH 02/16] bindings: soc: ti: add documentation for k3 ringacc Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-06-13 18:09 ` Rob Herring 2019-06-13 18:09 ` Rob Herring 2019-05-06 12:34 ` [PATCH 03/16] soc: ti: k3: add navss ringacc driver Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 04/16] dmaengine: doc: Add sections for per descriptor metadata support Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 05/16] dmaengine: Add metadata_ops for dma_async_tx_descriptor Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 06/16] dmaengine: Add support for reporting DMA cached data amount Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 07/16] dmaengine: Add function to request slave channel from a dma_device Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-07 8:37 ` Peter Ujfalusi 2019-05-07 8:37 ` Peter Ujfalusi 2019-05-07 8:37 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 08/16] dmaengine: ti: Add cppi5 header for UDMA Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 09/16] dt-bindings: dma: ti: Add document for K3 UDMA Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-06-13 18:16 ` Rob Herring 2019-06-13 18:16 ` Rob Herring 2019-06-13 20:33 ` Peter Ujfalusi 2019-06-13 20:33 ` Peter Ujfalusi 2019-06-13 20:33 ` Peter Ujfalusi 2019-06-14 13:20 ` Rob Herring [this message] 2019-06-14 13:20 ` Rob Herring 2019-06-14 13:20 ` Rob Herring 2019-06-14 13:43 ` Peter Ujfalusi 2019-06-14 13:43 ` Peter Ujfalusi 2019-06-14 13:43 ` Peter Ujfalusi 2019-06-19 14:04 ` Rob Herring 2019-06-19 14:04 ` Rob Herring 2019-06-19 14:04 ` Rob Herring 2019-06-20 9:56 ` Peter Ujfalusi 2019-06-20 9:56 ` Peter Ujfalusi 2019-06-20 9:56 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 10/16] dmaengine: ti: New driver for K3 UDMA - split#1: defines, structs, io func Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-06-13 18:43 ` Rob Herring 2019-06-13 18:43 ` Rob Herring 2019-06-13 20:40 ` Peter Ujfalusi 2019-06-13 20:40 ` Peter Ujfalusi 2019-06-13 20:40 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 11/16] dmaengine: ti: New driver for K3 UDMA - split#2: probe/remove, xlate and filter_fn Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 12/16] dmaengine: ti: New driver for K3 UDMA - split#3: alloc/free chan_resources Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 13/16] dmaengine: ti: New driver for K3 UDMA - split#4: dma_device callbacks 1 Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 14/16] dmaengine: ti: New driver for K3 UDMA - split#5: dma_device callbacks 2 Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 15/16] dmaengine: ti: New driver for K3 UDMA - split#6: Kconfig and Makefile Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` [PATCH 16/16] dmaengine: ti: k3-udma: Add glue layer for non DMAengine users Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi 2019-05-06 12:34 ` Peter Ujfalusi
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