From mboxrd@z Thu Jan 1 00:00:00 1970 From: broonie@opensource.wolfsonmicro.com (Mark Brown) Date: Thu, 24 Jan 2013 20:17:30 +0800 Subject: [PATCH 6/6 v14] gpio: Add block gpio to several gpio drivers In-Reply-To: References: <1358856404-8975-1-git-send-email-stigge@antcom.de> <1358856404-8975-7-git-send-email-stigge@antcom.de> Message-ID: <20130124121726.GQ4955@opensource.wolfsonmicro.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jan 24, 2013 at 01:02:38PM +0100, Stijn Devriendt wrote: > As a fictive example, consider the i2c-bitbang driver, which you could optimize > by using block-gpio with sda/scl in a single block. By offering the > block-gpio API > even when you cannot set all bits at once, you could cause timing issues. > You might be toggling the clock line before pushing out data, for example. > The same holds below, for a driver that has separate hi/lo bits. If there's a strict ordering requirement on updates then I would expect a user to explictly code that in hardware otherwise there may be hardware level issues with unpredictable results; besides in general it seems silly to force users to open code both versions if they don't want to rely on this API. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: