From mboxrd@z Thu Jan 1 00:00:00 1970 From: thierry.reding@gmail.com (Thierry Reding) Date: Mon, 18 Nov 2013 16:29:21 +0100 Subject: ARM topic: Is DT on ARM the solution, or is there something better? In-Reply-To: <20131118135727.GD14306@sirena.org.uk> References: <52644A9E.3060007@wwwdotorg.org> <20131118122644.GA26046@ulmo.nvidia.com> <20131118134022.26EE7C409EC@trevor.secretlab.ca> <20131118135727.GD14306@sirena.org.uk> Message-ID: <20131118152920.GL26046@ulmo.nvidia.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Nov 18, 2013 at 01:57:27PM +0000, Mark Brown wrote: > On Mon, Nov 18, 2013 at 01:40:22PM +0000, Grant Likely wrote: > > > Some hardware does that. That's what OHCI, EHCI, UHCI, XHCI, SDHCI, and > > similar are all about. It always helps when well understood hardware > > follows a register interface. It doesn't work for everything, but I > > agree it would be good to have preferred hw interfaces for SPI & I2C. > > You'd need something class based like USB, there's such massive > variation in what the hardware is trying to do and the tradeoffs. A big > issue is that especially with I2C many of the devices are primarily > analogue devices implemnted in larger processes where the cost of adding > additional digital logic can have a noticeable effect on the area and > hence cost of the silicon. My comments were mostly regarding the interface controllers. Those which generate the same bus transactions but need different drivers on every SoC. I suspect that the same costs don't apply (or at least not to the same extent) to SoCs. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: not available URL: