Custom DTBO for SPI LCD (BBGW) #304
Description
Environment
- Elixir version (
elixir -v):
Erlang/OTP 25 [erts-13.2.2.1] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns]
Elixir 1.14.5 (compiled with Erlang/OTP 25)
- Nerves environment: (
mix nerves.env --info)
==> nerves
==> nerves_bbgw
|nerves_bootstrap| Environment Package List
Pkg: bbgw_spi
Vsn: 2.17.2
Type: system
BuildRunner: {Nerves.Artifact.BuildRunners.Local, [make_args: ["source", "all", "legal-info"]]}
Pkg: nerves_system_br
Vsn: 1.22.5
Type: system_platform
BuildRunner: {nil, []}
Pkg: nerves_toolchain_armv7_nerves_linux_gnueabihf
Vsn: 1.8.0
Type: toolchain
BuildRunner: {Nerves.Artifact.BuildRunners.Local, []}
Pkg: nerves_toolchain_ctng
Vsn: 1.9.3
Type: toolchain_platform
BuildRunner: {nil, []}
|nerves_bootstrap| Loadpaths Start
|nerves_bootstrap| Precompile Start
==> nerves_toolchain_armv7_nerves_linux_gnueabihf
|nerves_bootstrap| Compile.NervesPackage start
|nerves_bootstrap| Compile.NervesPackage end
==> bbgw_spi
Generated bbgw_spi app
|nerves_bootstrap| Compile.NervesPackage start
|nerves_bootstrap| Compile.NervesPackage end
==> nerves_bbgw
|nerves_bootstrap| Precompile End
Nerves environment
MIX_TARGET: bbgw_spi
MIX_ENV: dev
|nerves_bootstrap| Environment Variable List
target: bbgw_spi
toolchain: /home/serpent/.nerves/artifacts/nerves_toolchain_armv7_nerves_linux_gnueabihf-linux_x86_64-1.8.0
system: /home/serpent/.nerves/artifacts/bbgw_spi-portable-2.17.2
app: .
|nerves_bootstrap| Loadpaths End
- Boot log with additional overlay:
U-Boot 2021.10 (Apr 04 2023 - 02:26:05 +0000)
CPU : AM335X-GP rev 2.1
Model: TI AM335x BeagleBone Black
DRAM: 512 MiB
Reset Source: Global warm SW reset has occurred.
Reset Source: Power-on reset has occurred.
RTC 32KCLK Source: External.
WDT: Started with servicing (60s timeout)
MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
Loading Environment from MMC... OK
Board: BeagleBone Black
BeagleBone Black:
Model: SeeedStudio BeagleBone Green Wireless:
BeagleBone Cape EEPROM: no EEPROM at address: 0x54
BeagleBone Cape EEPROM: no EEPROM at address: 0x55
BeagleBone Cape EEPROM: no EEPROM at address: 0x56
BeagleBone Cape EEPROM: no EEPROM at address: 0x57
Net: Could not get PHY for ethernet@4a100000: addr 0
eth2: ethernet@4a100000
board_name=[A335BNLT] ...
board_rev=[GW1A] ...
loading /zImage.a ...
2860152 bytes read in 253 ms (10.8 MiB/s)
uboot_overlays: [uboot_base_dtb=am335x-bonegreen-wireless-uboot-univ.dtb] ...
uboot_overlays: Switching too: dtb=am335x-bonegreen-wireless-uboot-univ.dtb ...
loading /boot/am335x-bonegreen-wireless-uboot-univ.dtb ...
207617 bytes read in 35 ms (5.7 MiB/s)
uboot_overlays: [fdt_buffer=0x60000] ...
uboot_overlays: loading /lib/firmware/spi0_ili9341_display.dtbo ...
2417 bytes read in 109 ms (21.5 KiB/s)
uboot_overlays: loading /lib/firmware/BB-BONE-eMMC1-01-00A0.dtbo ...
1614 bytes read in 47 ms (33.2 KiB/s)
uboot_overlays: loading /lib/firmware/BB-BBGW-WL1835-00A0.dtbo ...
4289 bytes read in 38 ms (109.4 KiB/s)
debug: [console=ttyS0,115200n8 coherent_pool=1M bone_capemgr.uboot_capemgr_enabled=1 root=/dev/mmcblk0p2 rootfstype=squashfs rootwait coherent_pool=1M net.ifnames=0 omap_wdt.early_enable=1 omap_wdt.timer_margin=120 quiet] ...
debug: [bootz 0x82000000 - 88000000] ...
Kernel image @ 0x82000000 [ 0x000000 - 0x2ba478 ]
## Flattened Device Tree blob at 88000000
Booting using the fdt blob at 0x88000000
Loading Device Tree to 8ff69000, end 8fffffff ... OK
Starting kernel ...
[ 0.159780] l3-aon-clkctrl:0000:0: failed to disable
[ 6.058566] gpio-of-helper ocp:cape-universal: Failed to get gpio property of 'P8_03'
[ 6.058589] gpio-of-helper ocp:cape-universal: Failed to create gpio entry
[ 6.069856] wkup_m3_ipc 44e11324.wkup_m3_ipc: could not get rproc handle
[ 6.378639] pinctrl-single 44e10800.pinmux: pin PIN30 already requested by 481a6000.serial; cannot claim for leds
[ 6.389311] pinctrl-single 44e10800.pinmux: pin-30 (leds) status -22
[ 6.395742] pinctrl-single 44e10800.pinmux: could not request pin 30 (PIN30) from group pinmux_bt_pins on device pinctrl-single
[ 6.407370] leds-gpio leds: Error applying setting, reverse things back
[ 6.424305] omap_voltage_late_init: Voltage driver support not added
Erlang/OTP 25 [erts-13.2] [source] [32-bit] [smp:1:1] [ds:1:1:10] [async-threads:1]
pinctrl errors are exactly the same without overlay. System config is unchanged except for additional BR packages.
Changes in provisioning.conf:
uboot_setenv(uboot-env, "uboot_overlay_addr4", "/lib/firmware/spi0_ili9341_display.dtbo")
#uboot_setenv(uboot-env, "enable_uboot_cape_universal", "1")
Actual U-Boot env on target:
iex(1)> ubootenv(~r/^uboot_/)
uboot_base_dtb="am335x-boneblack-uboot.dtb"
uboot_base_dtb_univ="am335x-bonegreen-wireless-uboot-univ.dtb"
uboot_emmc="BB-BONE-eMMC1-01-00A0.dtbo"
uboot_overlay_addr4="/lib/firmware/spi0_ili9341_display.dtbo"
uboot_wireless="BB-BBGW-WL1835-00A0.dtbo"
:ok
iex(2)> ubootenv(~r/^enable_/)
enable_uboot_overlays="1"
:ok
DTS file package/extra-dts/spi0_ili9341_display.dts:
// run `make extra-dts-rebuild` in Nerves shell to rebuild manually, then `make all` to bundle
/dts-v1/;
/plugin/;
#include <dt-bindings/pinctrl/omap.h>
/ {
fragment@1 {
target-path="/";
__overlay__ {
compatible = "ti,am335x-bone-green-wireless", "ti,am335x-bone-green", "ti,am335x-bone", "ti,am33xx";
// /* state the resources this cape uses */
// exclusive-use =
// /* the pin header uses */
// /* "P9.17", /* spi0_cs0 */
// "P9.18", /* spi0_d1 */
// "P9.21", /* spi0_d0 */
// "P9.22", /* spi0_sclk */
// "P9.16", /* backlight LED */
// "P9.24", /* SPI DC (direction) */
// "P9.23", /* reset */
// /* the hardware ip uses */
// "spi0",
// "ehrpwm1B";
};
};
/*
* Free up the pins used by the cape from the pinmux helpers.
*/
fragment@2 {
target = <&ocp>;
__overlay__ {
P9_18_pinmux { status = "disabled"; };
P9_21_pinmux { status = "disabled"; };
P9_22_pinmux { status = "disabled"; };
P9_16_pinmux { status = "disabled"; };
P9_24_pinmux { status = "disabled"; };
P9_23_pinmux { status = "disabled"; };
};
};
fragment@3 {
target = <&am33xx_pinmux>;
__overlay__ {
backlight_pins_default: backlight_pins_default {
// P9.16
pinctrl-single,pins = <
AM33XX_IOPAD(0x84c, PIN_OUTPUT | MUX_MODE6) /* (T14) gpmc_a3.ehrpwm1B */
>;
};
spi_dc_pins_default: spi_dc_pins_default {
// P9.24
pinctrl-single,pins = <
AM33XX_IOPAD(0x984, PIN_OUTPUT | MUX_MODE7) /* (D15) uart1_txd.gpio0[15] */
>;
};
reset_pins_default: reset_pins_default {
// P9.23
pinctrl-single,pins = <
AM33XX_IOPAD(0x844, PIN_OUTPUT | MUX_MODE7) /* (V14) gpmc_a1.gpio1[17] */
>;
};
spi0_pins_default: spi0_pins_default {
// P9.22, P9.21, P9.18
pinctrl-single,pins = <
AM33XX_IOPAD(0x950, PIN_OUTPUT | MUX_MODE0) /* (A17) spi0_sclk.spi0_sclk */
AM33XX_IOPAD(0x954, PIN_INPUT | MUX_MODE0) /* (B17) spi0_d0.spi0_d0 */
AM33XX_IOPAD(0x958, PIN_OUTPUT | MUX_MODE0) /* (B16) spi0_d1.spi0_d1 */
>;
};
};
};
fragment@4 {
target = <&epwmss2>;
__overlay__ {
status = "okay";
};
};
fragment@5 {
target = <&ehrpwm2>;
__overlay__ {
status = "okay";
};
};
fragment@6 {
target = <&ocp>;
__overlay__ {
backlight {
compatible = "pwm-backlight";
pinctrl-names = "default";
pinctrl-0 = <&backlight_pins_default>;
pwms = <&ehrpwm1 1 500000>;
brightness-levels = <0 4 8 16 32 64 128 255>;
default-brightness-level = <6>;
};
};
};
fragment@7 {
target = <&spi0>;
__overlay__ {
// avoid warning
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
pinctrl-names = "default";
pinctrl-0 = <&spi0_pins_default>;
ti,spi-num-cs = <0>;
/*
lcd@0 {
compatible = "ilitek,ili9341";
reg = <0>;
buswidth = <8>;
spi-max-frequency = <24000000>;
dc-gpios = <&gpio0 15 0>; // P9_24
reset-gpios = <&gpio1 17 0>; // P9_23
rotation = <270>;
backlight = <&backlight>;
status = "okay";
};
*/
};
};
};
Current behavior
- Universal cape seems always to be loaded
Even changinguboot_base_dtbanduboot_base_dtb_univtoam335x-bonegreen-wireless.dtbdoes not make any difference. /sys/class/backlightdoes not show up- DTBO becomes unloadable when enabling the
lcdpart
Expected behavior
PWM backlight should be available.
I'm fairly new to the whole device tree business, so probably I made some mistakes in my DTS.
Where can I find information about exclusive-use? Is it BeagleBone specific? Some overlays make use of it, others disable the pinmux nodes (like I did for now).
Is <&ehrpwm1 1 x> the right way to address ehrpwm1B? Where can I find this kind of information?
Any pointers appreciated to get this to work.