DTS for Adafruit PiTFT 2.8 capacitive touchscreen ? #1050

ondrej1024 · 2015-07-09T10:24:07Z

Hi,
Is anyone working on a DT overlay for the Adafruit PiTFT 2.8 capacitive touchscreen?
https://www.adafruit.com/products/1983

Adafruit provide their own kernel with an overlay which can be found here:
https://github.com/adafruit/Adafruit-Pi-Kernel-o-Matic/blob/pitft/boot/overlays/pitft28c-overlay.dtb

But if would be much better of course, if the stock RPi firmware would support this display, so we wouldn't have to mess with third party kernels.

There is already an overlay pitft28-resistive-overlay.dtb for the resistive version of the display.

Thanks, Ondrej

pelwell · 2015-07-09T10:30:50Z

We'd be happy to accept it if somebody creates a pull request (or just points me at the source). Perhaps @ladyada or @notro can help?

ondrej1024 · 2015-07-09T11:47:05Z

I wasn't able to find the original source dts file from Adafriut but from the dtb referenced above you can generate it with the device tree compiler:
dtc -I dtb -O dts pitft28c-overlay.dtb > pitft28c-overlay.dts

However I'm afraid that some modifications will be necessary to integrate it nicely into the RPI kernel.

For the resistive display, the pitft28-resistive-overlay.dtb from the RPi kernel and pitft28r-overlay.dtb from Adafruit look substantially different.

ladyada · 2015-07-09T12:24:52Z

there's a lot more than just the dts file - we have to also send over the capacitive device driver and our tweaks to the resistive device driver, both of which we know aren't going to be accepted without quite a bit of effort on my part :(

ondrej1024 · 2015-07-09T12:39:01Z

What about pitft28-resistive-overlay.dtb from the stock RPi kernel? Where did that come from and do we still need the Adafruit custom kernel for this resistive display?

ladyada · 2015-07-09T12:46:30Z

no idea, i didnt submit it :)
i recommend it! you also get the power switch driver. we recently recompiled the kernel a few weeks ago to track this repository

pelwell · 2015-07-09T12:55:41Z

That overlay is by @notro, who is also at least partly responsible for upstreaming the drivers used and who has contributed many similar overlays, as well as work in many other areas.

ondrej1024 · 2015-07-09T13:30:38Z

OK, I get the picture. Eventually I also found the original Adafruit dts files:
pitft28c-overlay.dts
pitft28r-overlay.dts

I was looking at the wrong files before and now I see that the dts file for the resistive display is actually the same for both Adafruit and RPi native kernel. So I expect this to work.

Looks like the main problem ATM is the touch driver for the capacitive display (Focaltech ft6x06) which is not included in the RPi native kernel. Too bad. Hope this can be sorted out sooner or later. Having to use the Adafruit kernel is not an ideal solution.

pssc · 2015-07-09T15:10:59Z

I have the adafruit display working with the stock kernel and pitft28-resistive-overlay.dtb touch screen and all.

pelwell · 2015-07-09T15:19:57Z

But is it the capacitive model? It uses a completely different touchscreen controller.

pssc · 2015-07-09T15:38:49Z

My bad I will now go sit in the corner its the restive 2.8 and 3.5in versions, I do have an additional dt overplay for mapping the buttons on the 28" to cursor keys by default (over-ridable) using the gpio_keys module.

ondrej1024 · 2015-07-14T13:06:57Z

Now I have received both the resistive and the capacitive touch screen and tested them with the stock RPi kernel (4.0.8). As expected, the resistive display works fine OOTB with the provided overlay and the kernel drivers. The capacitive display works also fine but the touch interface is not functional due to the missing ft6x06_ts input driver.
@ladyada @notro: Is there a chance to see this driver in the mainline or at least the RPi kernel any time soon?
Thanks.

ladyada · 2015-07-14T13:21:20Z

@ondrej1024 no change since #1050 (comment)

ondrej1024 · 2015-07-14T20:52:18Z

I take that for a "no" 😏
Thanks anyway.

NickWaterton · 2015-08-06T13:05:44Z

I know this is a few weeks old now, but I have successfully included the touch screen drivers (capacitive) in the latest kernel (V 4.0.9-v7+) for the RPi 2B. You just need a couple of files (and some instructions). I can't attach files here, but let me know if you need the tarball.

ladyada · 2015-08-06T17:57:48Z

@NickWaterton can you email them to support@adafruit.com please and include a link to this thread (so i remember what it is)? i would greatly appreciate it!

NickWaterton · 2015-08-06T18:22:09Z

E-Mail sent, let me know if security strips the tar file.

ladyada · 2015-08-06T18:26:33Z

👍

notro · 2015-10-02T22:56:47Z

The ft6236 driver has just been accepted for mainline: https://git.kernel.org/cgit/linux/kernel/git/dtor/input.git/commit/?id=92deea1350f9fa97a841d45cd1f8228d5e8aa667
I will make a PR backporting it to rpi-4.1.y after the driver shows up in linux-next.

ondrej1024 · 2015-10-03T14:38:25Z

@notro that sounds very good. Glad to see that things got moving eventually. Looking forward to test the driver and the Adafruit PiTFT with the rpi-4.1.y kernel when it will be available.

notro · 2015-10-30T11:31:03Z

The driver is in the latest rpi-update kernel #1176

ondrej1024 · 2015-10-30T11:53:31Z

Thanks @notro, will try it ASAP.

ondrej1024 · 2015-11-04T13:17:30Z

I tried the latest RPi stock kernel 4.1.12 with the ft6236 driver. Now the touch input of the Adafruit PiTFT capacitive touchscreen works fine.

Here is the specific DT overlay I wrote for the display.

/*
 * Device Tree overlay for Adafruit PiTFT 2.8" capavitive touch screen
 *
 */
/dts-v1/;
/plugin/;
/ {
        compatible = "brcm,bcm2835", "brcm,bcm2708", "brcm,bcm2709";
        fragment@0 {
                target = <&spi0>;
                __overlay__ {
                        status = "okay";
                        spidev@0{
                                status = "disabled";
                        };
                        spidev@1{
                                status = "disabled";
                        };
                };
        };
        fragment@1 {
                target = <&gpio>;
                __overlay__ {
                        pitft_pins: pitft_pins {
                                brcm,pins = <24 25>;
                                brcm,function = <0 1>; /* in out */
                                brcm,pull = <2 0>; /* pullup none */
                        };
                };
        };
        fragment@2 {
                target = <&spi0>;
                __overlay__ {
                        /* needed to avoid dtc warning */
                        #address-cells = <1>;
                        #size-cells = <0>;
                        pitft: pitft@0{
                                compatible = "ilitek,ili9340";
                                reg = <0>;
                                pinctrl-names = "default";
                                pinctrl-0 = <&pitft_pins>;
                                spi-max-frequency = <32000000>;
                                rotate = <90>;
                                fps = <25>;
                                bgr;
                                buswidth = <8>;
                                dc-gpios = <&gpio 25 0>;
                                debug = <0>;
                        };
                };
        };
        fragment@3 {
                target = <&i2c1>;
                __overlay__ {
                        /* needed to avoid dtc warning */
                        #address-cells = <1>;
                        #size-cells = <0>;
                        /*pitft_ctp {*/
                        ft6236: ft6236@38 {
                                compatible = "focaltech,ft6236";
                                reg = <0x38>;
                                /*irq-gpio = <&gpio 24 2>;*/
                                interrupt-parent = <&gpio>;
                                interrupts = <24 2>;
                                touchscreen-size-x = <320>;
                                touchscreen-size-y = <480>;
                        };
                };
        };
        __overrides__ {
                speed =   <&pitft>,"spi-max-frequency:0";
                rotate =  <&pitft>,"rotate:0";
                fps =     <&pitft>,"fps:0";
                debug =   <&pitft>,"debug:0";
                invx =    <&ft6236>,"touchscreen-inverted-x?";
                invy =    <&ft6236>,"touchscreen-inverted-y?";
                swapxy =  <&ft6236>,"touchscreen-swapped-x-y?";
        };
};

pelwell · 2015-11-05T12:26:48Z

That looks good. Although there's technically no need to disable spidev@1 since only CE0 is used, having something plugged into the whole 40-way header probably makes it a moot point.

Can you create a pull request for this?

pelwell · 2015-11-05T12:28:25Z

Ah, I see that the header pins are still accessible, so it would be better to remove the:

                        spidev@1{
                                status = "disabled";
                        };

ondrej1024 · 2015-11-06T14:14:23Z

I removed the spidev@1 section as proposed and made some minor changes.
Created pull request #1192.

notro · 2016-08-25T22:21:22Z

Just a heads up, the ft6236 driver will be gone in 4.9. It turned out that edt-ft5x06 also supports ft6236.
The kconfig symbol for this driver is: TOUCHSCREEN_EDT_FT5X06

Input: remove duplicate ft6236 driver:
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/drivers/input/touchscreen?id=d18716542d137beafef2859bdf90d4e0c9a25523

DT binding doc patch:
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/Documentation/devicetree/bindings/input/touchscreen/edt-ft5x06.txt?id=d18716542d137beafef2859bdf90d4e0c9a25523

pelwell · 2016-08-26T07:45:47Z

Thanks for the warning.

[ Upstream commit 3347c8a ] When building with LLVM_IAS=1 means using Clang's Integrated Assembly (IAS) from LLVM/Clang >= v10.0.1-rc1+ instead of GNU/as from GNU/binutils I see the following breakage in Debian/testing AMD64: <instantiation>:15:74: error: too many positional arguments PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, ^ arch/x86/crypto/aesni-intel_asm.S:1598:2: note: while in macro instantiation GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp) ^ <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix GHASH_4_ENCRYPT_4_PARALLEL_dec %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc ^ arch/x86/crypto/aesni-intel_asm.S:1599:2: note: while in macro instantiation GCM_ENC_DEC dec ^ <instantiation>:15:74: error: too many positional arguments PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, ^ arch/x86/crypto/aesni-intel_asm.S:1686:2: note: while in macro instantiation GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp) ^ <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix GHASH_4_ENCRYPT_4_PARALLEL_enc %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc ^ arch/x86/crypto/aesni-intel_asm.S:1687:2: note: while in macro instantiation GCM_ENC_DEC enc Craig Topper suggested me in ClangBuiltLinux issue #1050: > I think the "too many positional arguments" is because the parser isn't able > to handle the trailing commas. > > The "unknown use of instruction mnemonic" is because the macro was named > GHASH_4_ENCRYPT_4_PARALLEL_DEC but its being instantiated with > GHASH_4_ENCRYPT_4_PARALLEL_dec I guess gas ignores case on the > macro instantiation, but llvm doesn't. First, I removed the trailing comma in the PRECOMPUTE line. Second, I substituted: 1. GHASH_4_ENCRYPT_4_PARALLEL_DEC -> GHASH_4_ENCRYPT_4_PARALLEL_dec 2. GHASH_4_ENCRYPT_4_PARALLEL_ENC -> GHASH_4_ENCRYPT_4_PARALLEL_enc With these changes I was able to build with LLVM_IAS=1 and boot on bare metal. I confirmed that this works with Linux-kernel v5.7.5 final. NOTE: This patch is on top of Linux v5.7 final. Thanks to Craig and especially Nick for double-checking and his comments. Suggested-by: Craig Topper <craig.topper@intel.com> Suggested-by: Craig Topper <craig.topper@gmail.com> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: "ClangBuiltLinux" <clang-built-linux@googlegroups.com> Link: ClangBuiltLinux/linux#1050 Link: https://bugs.llvm.org/show_bug.cgi?id=24494 Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 3347c8a ] When building with LLVM_IAS=1 means using Clang's Integrated Assembly (IAS) from LLVM/Clang >= v10.0.1-rc1+ instead of GNU/as from GNU/binutils I see the following breakage in Debian/testing AMD64: <instantiation>:15:74: error: too many positional arguments PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, ^ arch/x86/crypto/aesni-intel_asm.S:1598:2: note: while in macro instantiation GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp) ^ <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix GHASH_4_ENCRYPT_4_PARALLEL_dec %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc ^ arch/x86/crypto/aesni-intel_asm.S:1599:2: note: while in macro instantiation GCM_ENC_DEC dec ^ <instantiation>:15:74: error: too many positional arguments PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, ^ arch/x86/crypto/aesni-intel_asm.S:1686:2: note: while in macro instantiation GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp) ^ <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix GHASH_4_ENCRYPT_4_PARALLEL_enc %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc ^ arch/x86/crypto/aesni-intel_asm.S:1687:2: note: while in macro instantiation GCM_ENC_DEC enc Craig Topper suggested me in ClangBuiltLinux issue raspberrypi#1050: > I think the "too many positional arguments" is because the parser isn't able > to handle the trailing commas. > > The "unknown use of instruction mnemonic" is because the macro was named > GHASH_4_ENCRYPT_4_PARALLEL_DEC but its being instantiated with > GHASH_4_ENCRYPT_4_PARALLEL_dec I guess gas ignores case on the > macro instantiation, but llvm doesn't. First, I removed the trailing comma in the PRECOMPUTE line. Second, I substituted: 1. GHASH_4_ENCRYPT_4_PARALLEL_DEC -> GHASH_4_ENCRYPT_4_PARALLEL_dec 2. GHASH_4_ENCRYPT_4_PARALLEL_ENC -> GHASH_4_ENCRYPT_4_PARALLEL_enc With these changes I was able to build with LLVM_IAS=1 and boot on bare metal. I confirmed that this works with Linux-kernel v5.7.5 final. NOTE: This patch is on top of Linux v5.7 final. Thanks to Craig and especially Nick for double-checking and his comments. Suggested-by: Craig Topper <craig.topper@intel.com> Suggested-by: Craig Topper <craig.topper@gmail.com> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Cc: "ClangBuiltLinux" <clang-built-linux@googlegroups.com> Link: ClangBuiltLinux/linux#1050 Link: https://bugs.llvm.org/show_bug.cgi?id=24494 Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Sasha Levin <sashal@kernel.org>

ondrej1024 mentioned this issue Nov 6, 2015

dts: Added overlay for Adafruit PiTFT 2.8" capacitive touch screen #1192

Closed

ondrej1024 closed this as completed Nov 6, 2015

notro mentioned this issue Aug 22, 2016

Capactive touch support for Adafruit 2.8" breakout (PID 2090)? notro/fbtft#409

Closed

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DTS for Adafruit PiTFT 2.8 capacitive touchscreen ? #1050

DTS for Adafruit PiTFT 2.8 capacitive touchscreen ? #1050

ondrej1024 commented Jul 9, 2015

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DTS for Adafruit PiTFT 2.8 capacitive touchscreen ? #1050

DTS for Adafruit PiTFT 2.8 capacitive touchscreen ? #1050

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ondrej1024 commented Jul 9, 2015

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