target/linux/bcm27xx/patches-5.15/950-0798-overlays-rpi-display-Add-support-for-DRM-driver.patch

   1 From 33020d03596ae7767f278716ba539589b316299e Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
   3 Date: Sun, 27 Mar 2022 18:54:17 +0200
   4 Subject: [PATCH] overlays/rpi-display: Add support for DRM driver
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Add a "drm" parameter that enables use of the drm/mi0283qt driver instead
  10 of fbtft/fb_ili9341. Also add a "backlight-pwm" parameter that can be used
  11 with the "drm" parameter.
  12
  13 Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
  14 ---
  15  arch/arm/boot/dts/overlays/README             | 26 +++++++-
  16  .../boot/dts/overlays/rpi-display-overlay.dts | 61 ++++++++++++++++++-
  17  2 files changed, 84 insertions(+), 3 deletions(-)
  18
  19 --- a/arch/arm/boot/dts/overlays/README
  20 +++ b/arch/arm/boot/dts/overlays/README
  21 @@ -2913,14 +2913,36 @@ Params: <None>
  22
  23  Name:   rpi-display
  24  Info:   RPi-Display - 2.8" Touch Display by Watterott
  25 +        Linux has 2 drivers that support this display and this overlay supports
  26 +        both.
  27 +
  28 +        Examples:
  29 +          fbtft/fb_ili9341: dtoverlay=rpi-display
  30 +          drm/mi0283qt: dtoverlay=rpi-display,drm,backlight-pwm,rotate=180
  31 +
  32 +        Some notable differences with the DRM driver compared to fbtft:
  33 +        - The display is turned on when it's first used and not on driver load
  34 +          as with fbtft. So if nothing uses the display it stays off.
  35 +        - Can run with a higher SPI clock increasing framerate. This is possible
  36 +          since the driver avoids messing up the controller configuration due to
  37 +          transmission errors by running config commands at 10MHz and only pixel
  38 +          data at full speed (occasional pixel glitch might occur).
  39 +        - PWM backlight is supported.
  40 +
  41  Load:   dtoverlay=rpi-display,<param>=<val>
  42  Params: speed                   Display SPI bus speed
  43          rotate                  Display rotation {0,90,180,270}
  44 -        fps                     Delay between frame updates
  45 -        debug                   Debug output level {0-7}
  46 +        fps                     Delay between frame updates (fbtft only)
  47 +        debug                   Debug output level {0-7} (fbtft only)
  48          xohms                   Touchpanel sensitivity (X-plate resistance)
  49          swapxy                  Swap x and y axis
  50          backlight               Change backlight GPIO pin {e.g. 12, 18}
  51 +                                (fbtft only)
  52 +        drm                     Use DRM/KMS driver mi0283qt instead of fbtft.
  53 +                                Set the SPI clock to 70MHz.
  54 +                                This has to be the first parameter.
  55 +        backlight-pwm           Use pwm for backlight (drm only). NB: Disables
  56 +                                audio headphone output as that also uses PWM.
  57
  58
  59  Name:   rpi-ft5406
  60 --- a/arch/arm/boot/dts/overlays/rpi-display-overlay.dts
  61 +++ b/arch/arm/boot/dts/overlays/rpi-display-overlay.dts
  62 @@ -78,14 +78,73 @@
  63                         };
  64                 };
  65         };
  66 +
  67 +       fragment@10 {
  68 +               target = <&rpidisplay>;
  69 +               __dormant__  {
  70 +                       backlight = <&backlight_gpio>;
  71 +               };
  72 +       };
  73 +
  74 +       fragment@11 {
  75 +               target-path = "/";
  76 +               __dormant__  {
  77 +                       backlight_gpio: backlight_gpio {
  78 +                               compatible = "gpio-backlight";
  79 +                               gpios = <&gpio 18 0>; /* GPIO_ACTIVE_HIGH */
  80 +                       };
  81 +               };
  82 +       };
  83 +
  84 +       fragment@20 {
  85 +               target = <&rpidisplay>;
  86 +               __dormant__  {
  87 +                       backlight = <&backlight_pwm>;
  88 +               };
  89 +       };
  90 +
  91 +       fragment@21 {
  92 +               target-path = "/";
  93 +               __dormant__  {
  94 +                       backlight_pwm: backlight_pwm {
  95 +                               compatible = "pwm-backlight";
  96 +                               brightness-levels = <0 6 8 12 16 24 32 40 48 64 96 128 160 192 224 255>;
  97 +                               default-brightness-level = <16>;
  98 +                               pwms = <&pwm 0 200000>;
  99 +                       };
 100 +               };
 101 +       };
 102 +
 103 +       fragment@22 {
 104 +               target = <&pwm>;
 105 +               __dormant__ {
 106 +                       assigned-clock-rates = <1000000>;
 107 +                       status = "okay";
 108 +               };
 109 +       };
 110 +
 111 +       fragment@23 {
 112 +               target = <&audio>;
 113 +               __dormant__  {
 114 +                   brcm,disable-headphones;
 115 +               };
 116 +       };
 117 +
 118         __overrides__ {
 119                 speed =     <&rpidisplay>,"spi-max-frequency:0";
 120 -               rotate =    <&rpidisplay>,"rotate:0";
 121 +               rotate =    <&rpidisplay>,"rotate:0", /* fbtft */
 122 +                           <&rpidisplay>,"rotation:0"; /* drm */
 123                 fps =       <&rpidisplay>,"fps:0";
 124                 debug =     <&rpidisplay>,"debug:0";
 125                 xohms =     <&rpidisplay_ts>,"ti,x-plate-ohms;0";
 126                 swapxy =    <&rpidisplay_ts>,"ti,swap-xy?";
 127                 backlight = <&rpidisplay>,"led-gpios:4",
 128                             <&rpi_display_pins>,"brcm,pins:0";
 129 +               drm =       <&rpidisplay>, "compatible=multi-inno,mi0283qt",
 130 +                           <&rpidisplay>, "spi-max-frequency:0=70000000",
 131 +                           <&rpidisplay>, "reset-gpios:8=0", /* GPIO_ACTIVE_HIGH */
 132 +                           <0>, "+10+11";
 133 +               backlight-pwm = <0>, "-10-11+20+21+22+23",
 134 +                               <&rpi_display_pins>, "brcm,function:0=2"; /* Alt5 */
 135         };
 136  };