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notro / fbtft

Linux Framebuffer drivers for small TFT LCD display modules. Development has moved to https://git.kernel.org/cgit/linux/kernel/git/gregkh/staging.git/tree/drivers/staging/fbtft?h=staging-testing
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HY28b non standard pendown GPIO #316

Closed cburza closed 8 years ago

cburza commented 9 years ago

I am trying to change the hy28b-overlay.dts so I can use GPIO23 instead of GPIO17 for the pen down. I have modified the source file as follows.

brcm,pins = <17 25 18>; --> brcm,pins = <23 25 18>;
interrupts = <17 2>; --> interrupts = <23 2>;
pendown-gpio = <&gpio 17 0>; --> pendown-gpio = <&gpio 23 0>;

And then update.

sudo dtc -@ -I dts -O dtb -o /boot/overlays/hy28b-overlay.dts hy28b-overlay_modified.dts

then restart, but I can still not get the touch screen to work. I have tested my GPIO on Python and it works fine there when touching the screen, so its not a hardware issue.

What am I doing wrong?

notro commented 9 years ago

It looks correct to me. And it's working with the default gpio17? What does cat /proc/interrupts show?

cburza commented 9 years ago

I have this.

sudo cat /proc/interrupts
           CPU0       
  3:      36862   ARMCTRL   3  BCM2708 Timer Tick
 16:          0   ARMCTRL  16  bcm2708_fb dma
 24:        117   ARMCTRL  24  DMA IRQ
 25:       1500   ARMCTRL  25  DMA IRQ
 32:     411131   ARMCTRL  32  dwc_otg, dwc_otg_pcd, dwc_otg_hcd:usb1
 49:          0   ARMCTRL  49  20200000.gpio:bank0
 50:          0   ARMCTRL  50  20200000.gpio:bank1
 65:         10   ARMCTRL  65  2000b880.mailbox
 66:          2   ARMCTRL  66  VCHIQ doorbell
 75:          1   ARMCTRL  75
 77:      17346   ARMCTRL  77  20204000.spi
 79:        767   ARMCTRL  79  20804000.i2c
 80:      37428   ARMCTRL  80  20204000.spi
 84:       6577   ARMCTRL  84  mmc0
411:          0  pinctrl-bcm2835  17  ads7846
FIQ:              usb_fiq
Err:          0
notro commented 9 years ago

The touch driver is using gpio17 for interrupt:

411:          0  pinctrl-bcm2835  17  ads7846

So your changes haven't taken effect.

cburza commented 9 years ago

Ok, there is a typo.

sudo dtc -@ -I dts -O dtb -o /boot/overlays/hy28b-overlay.dts hy28b-overlay_modified.dts

needs to be

sudo dtc -@ -I dts -O dtb -o /boot/overlays/hy28b-overlay.dtb hy28b-overlay_modified.dts
sudo cat /proc/interrupts | grep ads7846
417:          0  pinctrl-bcm2835  23  ads7846