Re: [PATCH v27 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs and transfer-mode properties
Rob Herring <[email protected]>
| Newsgroups | org.ozlabs.lists.openbmc,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-i2c,org.kernel.vger.linux-kernel,org.ozlabs.lists.linux-aspeed |
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| Message-ID | <[email protected]> |
On Wed, Mar 25, 2026 at 08:11:54AM +0000, Ryan Chen wrote: > Hello Jeremy, > Thanks the review. > > > Subject: Re: [PATCH v27 2/4] dt-bindings: i2c: ast2600-i2c.yaml: Add global-regs > > and transfer-mode properties > > > > Hi Ryan, > > > > > The AST2600 I2C controller supports three transfer modes (byte, > > > buffer, DMA). Add "aspeed,transfer-mode" so DT can select the > > > preferred transfer method per controller instance. > > > > This patch does not add an aspeed,transfer-mode property. > Will update use aspeed,enable-dma [...] > > > +Â aspeed,enable-dma: > > > +Â Â Â type: boolean > > > +Â Â Â description: | > > > +Â Â Â Â Â I2C bus enable dma mode transfer. > > > + > > > +Â Â Â Â Â ASPEED ast2600 platform equipped with 16 I2C controllers that > > > +share a > > > +Â Â Â Â Â single DMA engine. DTS files can specify the data transfer mode > > > +to/from > > > +Â Â Â Â Â the device, either DMA or programmed I/O. > > > > As we had discussed: this does not define the transfer mode, only whether > > DMA is available to the peripheral. > > > > Why mention the 16 i2c controllers here? > > > > Please keep this description simple and relevant to the specific purpose of the > > property. > > Will update with following. > description: Enable DMA for transfers on this I2C bus. You still don't understand the distinction. It's not enable, but that the h/w instance *has* DMA capability or not. It is still up to the OS what to do with that information. Rob