On Mon, Nov 26, 2012 at 12:28 PM, Lee Jones <lee.jo...@linaro.org> wrote: > On Fri, 23 Nov 2012, Shiraz Hashim wrote:
[About st-norequest-mask] >> This is a board dependent parameter which just informs gpio driver >> about pins, which must not be requested. It may happen for a stmpe >> variant where such gpio pins are multiplexed with some other >> function. >> >> Hence it must be part of DT itself. > > Doesn't pinctrl normally handle this kind of stuff? So this is a signal that something might be strange about the driver architecture at large. The datasheet for STMPE1601 says: "The STMPE1601 offers great flexibility, as each I/O can be configured as input, output or specific functions." Hm hm. Well this driver existed before the pin control system so we have to live with this. We *could* assume that the above DT property could be set beacause someone connected a GPIO to ground and trying to use it would burn the system or something. But if it's actually dealing with the sideeffects of pinmuxing it's done in the wrong place. Apart from the pinctrl API another way to handle these beasts is what I do in the drivers/mfd/tps6105x.c, where the hardware is such that you basically always nail down the hardware for one specific use case of 3 possible. Then it's done by configuring the root MFD device. The crucial question is: can the STMPE controllers be used for GPIO, PWM, keypad and touchscreen at the *same time* or are they nailed to *one* usecase during electronics design? Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
