Hi!
On Wed, Sep 24, 2014 at 02:09:14PM -0700, Sören Brinkmann wrote:
> Hi,
>
> I think I have pinctrl driver that is covering the pinmux options of
> Zynq and I also figured out how the DT bindings work.
>
> But there are a couple of things that probably could be done better.
>
> One thing making the DT bindings explode, seems to be all those single
> pin functions that can be muxed to every pin.
> Next to GPIO, this applies to SD card and write protect - which are even
> present twice since Zynq has two SDIO cores. Just these functions
> account for a couple of hundred nodes in the DT and a bunch of lines in
> the driver. Is there a better way to do this?
>
> In particular for GPIO there seemed to be a better solution with
> implementing gpio_request_enable(), but that seemed to allow GPIO in
> parallel to request and mux the pin which does not work on Zynq. IOW: I
> expected the core would reject a call of gpio_request_enable for a pin
> that is already muxed to some other function, but that was not the case
> in my testing. Am I missing something here?
>
> And finally, for SD card detect and write protect, we actually have to
> disable the muxing. The problem with those functions is, that they have
> a dedicated mux for that function which is in parallel to the "normal"
> pinmuxes. So, muxing a "normal" function to a pin would not void the
> muxing of the SD signals. I thought this would be easily resolved by
> implementing the 'disable' op, but after I did that, I noticed that
> there is only a stale documentation comment of this member of struct
> pinmux_ops left, the actual function pointer is gone.
>
> Thanks,
> Sören
>
> ------------8<-----------------8<-------------------8<--------------8<----------
> Date: Mon, 15 Sep 2014 17:24:35 -0700
> Subject: [PATCH RFC] pinctrl: Add driver for Zynq
>
> Signed-off-by: Soren Brinkmann <[email protected]>
> ---
> arch/arm/boot/dts/zynq-7000.dtsi | 3039
> +++++++++++++++++++++++++++++++++++++-
> arch/arm/boot/dts/zynq-zc706.dts | 13 +
> arch/arm/mach-zynq/Kconfig | 1 +
> drivers/pinctrl/Kconfig | 8 +
> drivers/pinctrl/Makefile | 1 +
> drivers/pinctrl/pinctrl-zynq.c | 927 ++++++++++++
> 6 files changed, 3988 insertions(+), 1 deletion(-)
> create mode 100644 drivers/pinctrl/pinctrl-zynq.c
>
> diff --git a/arch/arm/boot/dts/zynq-7000.dtsi
> b/arch/arm/boot/dts/zynq-7000.dtsi
> index 6cc83d4c6c76..814873da0392 100644
> --- a/arch/arm/boot/dts/zynq-7000.dtsi
> +++ b/arch/arm/boot/dts/zynq-7000.dtsi
> @@ -229,7 +229,7 @@
> slcr: slcr@f8000000 {
> #address-cells = <1>;
> #size-cells = <1>;
> - compatible = "xlnx,zynq-slcr", "syscon";
> + compatible = "xlnx,zynq-slcr", "syscon", "simple-bus";
> reg = <0xF8000000 0x1000>;
> ranges;
> clkc: clkc@100 {
> @@ -250,6 +250,3043 @@
> "dbg_trc", "dbg_apb";
> reg = <0x100 0x100>;
> };
> +
> + pinctrl0: pinctrl@700 {
> + compatible = "xlnx,pinctrl-zynq";
> + reg = <0x700 0x200>;
> +
> + pinctrl_i2c0_0: pinctrl-i2c0@0 {
> + i2c0-mux {
> + function = "i2c0";
> + pins = "i2c0_0_grp";
> + };
> + };
> +
(...)
> + pinctrl_sdio1_cd_54: pinctrl-sdio1_cd@54 {
> + sdio1_cd-mux {
> + function = "sdio1_cd";
> + pins = "sdio1_emio_cd_grp";
> + };
> + };
> + };
> };
>
Wouldn't this reaaally bloat the dtb?
I know that imx decided to remove all the pinctrls from the dtsis, because
the dtbs got to big.
Regards,
Steffen
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