From mboxrd@z Thu Jan 1 00:00:00 1970 From: antoine.tenart@free-electrons.com (Antoine =?iso-8859-1?Q?T=E9nart?=) Date: Tue, 22 Apr 2014 17:56:02 +0200 Subject: [PATCH RESEND 2/5] pinctrl: berlin: add a pinctrl driver for Marvell Berlin SoCs In-Reply-To: References: <1397135274-10764-1-git-send-email-antoine.tenart@free-electrons.com> <1397135274-10764-3-git-send-email-antoine.tenart@free-electrons.com> <5347AFF4.3050607@gmail.com> <20140411123737.GA5903@kwain> <5347EF8A.8040600@gmail.com> Message-ID: <20140422155602.GA19762@kwain> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Linus, On Tue, Apr 22, 2014 at 02:52:10PM +0200, Linus Walleij wrote: > On Fri, Apr 11, 2014 at 3:35 PM, Sebastian Hesselbarth > wrote: > > On 04/11/2014 02:37 PM, Antoine T?nart wrote: > >> On Fri, Apr 11, 2014 at 11:03:48AM +0200, Sebastian Hesselbarth wrote: > >>> On 04/10/2014 03:07 PM, Antoine T?nart wrote: > > >>> Having said that, the above assumes that each function is unique > >>> but IIRC the idea of the function table was to group pins/groups > >>> with the same function, e.g. function "gpio", groups 1,7,25,... > >> > >> Most of the functions you can use on the Berlin they will be unique and > >> would > >> only be used in one group, except for the 'gpio' one. > > > > Yeah, I had a similar discussion about it back then for mvebu. IIRC, the > > correct answer is: Have a list of functions with groups assigned to it > > no matter if there is only one group per function (or 40 per function as > > it will be for gpio). > > > > Maybe Linus can give an update on how to deal with it? > > Have you considered implementing pinmux_ops > .gpio_request_enable(), .gpio_set_direction() and > .gpio_disable_free() instead of defining groups for each > and every GPIO? The function 'gpio' can be found on different groups. But the Berlin pin muxing does not allow to configure a pin individually. It is then not possible to mux GPIO pins individually. For example the 'gpio' function of group 'GSM2' on the BG2Q will mux GPIOs 17 *and* 18. Groups does not have more than a single 'gpio' function. Since the gpio_request_enable() comment says 'Implement this only if you can mux every pin individually as GPIO', I did not considered implementing these functions. Antoine -- Antoine T?nart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com