On Sat, Jul 9, 2011 at 12:23 PM, Mark Brown broonie@opensource.wolfsonmicro.com wrote:
On Mon, Jun 13, 2011 at 01:57:36PM -0600, Grant Likely wrote:
On Mon, Jun 13, 2011 at 10:58 AM, Linus Walleij
I would *strongly* recommend against individual device drivers accessing the pinmux api. This is system level configuration code, and should be handled at the system level.
There can also be advantages to putting the pin into the designed mode without the driver being loaded from the electrical point of view. For example, selecting appropriate pull values for pads can cut down on power consumption.
Since the pin control subsystem is reference counting wrt mux settings, one does not exclude the other. So for example a driver may or may not grab a certain set-up of pins and the core platform may do the same, but when they start to request different conflicting things the subsystem will complain, as is apropriate.
So this is a very pure driver framework, without policy, it just does what it's told, and will prevent undefined and impossible settings. Atleast that's the idea.
Thanks, Linus Walleij