From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Date: Mon, 20 Oct 2008 04:30:23 +0000 Subject: Re: [PATCH 00/05] sh: GPIO for SuperH using gpiolib Message-Id: <200810192130.24189.david-b@pacbell.net> List-Id: References: <20080927181008.11246.53495.sendpatchset@rx1.opensource.se> In-Reply-To: <20080927181008.11246.53495.sendpatchset@rx1.opensource.se> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-sh@vger.kernel.org On Saturday 27 September 2008, Magnus Damm wrote: > The pinmux code is written so multiple GPIOs map to one physical pin. > So for example on sh7723, pin PTS5 can be accessed as regular Port S pin 5 > GPIO, but it can also be locked to two different functions - as TX pin of > the SCIF1 serial port or as SDHI0D3 - a D3 pin on the first MMC interface. I've lost track of the status of these patches, but as a terminology point I think it's best to keep in mind that those alternate functions are not what's called a "GPIO". The GPIO framework only expects to handle the first function -- "GPIO". > This specific PTS5 pin is exported as 3 different GPIOs: > GPIO_PTS5 > GPIO_FN_SCIF1_PTS_TXD > GPIO_FN_SDHI0D3_PTS > Only one at a time can be selected using gpio_request(). >