[linux-yocto] Enable SPIDEV for SPI1-problem

[Bruce Ashfield]

On 15-02-18 07:56 AM, Johan Sandgren wrote:
> Hi
>
> I’m trying to add SPIDEV (on SPI1) in userspace for my board, which I
> run linux-yocto-3.14 on.
>
> I read somewhere that the HDMI-support is conflicting with using some
> pins for SPI1, so I have disabled all I can find with menuconfig
> (graphics LCD drivers and such).
>
> I also modified the dts-file (am335x-boneblack.dts) and compiled it
> again, and put on my sdcard and it boots successfully.
>
> I also notice that in /proc/device-tree/ …. The hdmi-folder is gone,
> which is a success, great!
>
> Now, how I move further I’m not sure and I have problems with what I
> have tried.
>
> Perhaps some of you experienced users can guide me in the right
> direction to do this right.
>
> Here’s the content of my <am335x-boneblack.dts>
>
> /*
>
>   * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
>
>   *
>
>   * This program is free software; you can redistribute it and/or modify
>
>   * it under the terms of the GNU General Public License version 2 as
>
>   * published by the Free Software Foundation.
>
>   */
>
> /dts-v1/;
>
> #include "am33xx.dtsi"
>
> #include "am335x-bone-common.dtsi"
>
> &ldo3_reg {
>
> regulator-min-microvolt = <1800000>;
>
> regulator-max-microvolt = <1800000>;
>
> regulator-always-on;
>
> };
>
> &mmc1 {
>
> vmmc-supply = <&vmmcsd_fixed>;
>
> };
>
> &mmc2 {
>
> vmmc-supply = <&vmmcsd_fixed>;
>
> pinctrl-names = "default";
>
> pinctrl-0 = <&emmc_pins>;
>
> bus-width = <8>;
>
> status = "okay";
>
> ti,vcc-aux-disable-is-sleep;
>
> };
>
> &am33xx_pinmux {
>
> };
>
> &lcdc {
>
> status = "okay";
>
> };
>
> Now to enable SPIDEV or setup the hardware (I’m still trying to
> understand what I’m doing…), I tried to put in some more stuff in my
> device-tree file, to tell linux about this SPI1, how it connects to the
> hardware. The below clip I found somewhere, so it’s not me who created
> it, but it is for beagle bone black.
>
> /* SPI1 */
>
> /* D1 Output and D0 Input */
>
> / {
>
>      compatible = "ti,beaglebone", "ti,beaglebone-black";
>
>      /* identification */
>
>      part-number = "spi1mux";
>
>      fragment at 0 {
>
>          target = <&am33xx_pinmux>;
>
>          __overlay__ {
>
>              spi1_pins_s0: spi1_pins_s0 {
>
>                          pinctrl-single,pins = <
>
>                                  0x190 0x33      /*
> mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 */
>
>                                  0x194 0x33      /* mcasp0_fsx.spi1_d0,
> INPUT_PULLUP | MODE3 */
>
>                                  0x198 0x13      /* mcasp0_axr0.spi1_d1,
> OUTPUT_PULLUP | MODE3 */
>
>                                  0x19c 0x13      /*
> mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
>
>>;
>
>              };
>
>          };
>
>      };
>
>      fragment at 1 {
>
>          target = <&spi1>;
>
>          __overlay__ {
>
>               #address-cells = <1>;
>
>               #size-cells = <0>;
>
>               status = "okay";
>
>               pinctrl-names = "default";
>
>               pinctrl-0 = <&spi1_pins_s0>;
>
>               spidev at 1 {
>
>                   spi-max-frequency = <24000000>;
>
>                   reg = <0>;
>
>                   compatible = "linux,spidev";
>
>              };
>
>          };
>
>      };
>
> };
>
> When I add this last part, (and do all steps to use it) it just doesn't
> boot after "Starting kernel ..." so something is wrong.
>
>
> I have not been able to find out the error yet, so I'm asking for help.
>
> I have a guess, perhaps I'm not using the correct syntax or adding it
> the correct way, since the addition is an "overlay" and I'm not really
> doing an overlay, just adding more to the original device-tree that gets
> compiled to the binary version.


Hmm. But yet it boots before you use your custom DTS and overlay ?

This is pretty specific to the board in question, so we might be out
of our depth on this list. Did you also try asking on the meta-ti
mailing list ?

Bruce

>
> Any help is appreciated.
>
> /Johan
>
> *_______________*
>
> *Johan Sandgren*  (Software Engineer)
>
> Svep Design Center AB
>
> Box 1233, 221 05 Lund, Sweden
>
> E-mail johan.sandgren at svep.se <mailto:johan.sandgren at svep.se>
>
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