Cómo escribir una superposición de árbol de dispositivo para pantalla táctil de dispositivo analógico ad7879 i2c

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Escribí una superposición de árbol de dispositivo para la pantalla táctil del controlador ad7879-i2c (compilado como módulo usando la fuente Raspberry Pi, archivos: ad7879-i2c.c, ad7879.c). El controlador se carga pero supongo que los parámetros no se pasan al controlador. El dispositivo está en i2c1, dirección 0x2c, GPIO 26 (BCM 12). evtest muestra los parámetros predeterminados del controlador y la pantalla táctil no funciona en absoluto.

En /boot/config.txt:

dtparam=i2c_arm=on
dtoverlay=i2c-ad7879

En / etc / modules:

i2c-bcm2708
i2c-dev

Salida de gpio readall:

 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 |     |     |    3.3v |      |   |  1 || 2  |   |      | 5v      |     |     |
 |   2 |   8 |   SDA.1 | ALT0 | 1 |  3 || 4  |   |      | 5V      |     |     |
 |   3 |   9 |   SCL.1 | ALT0 | 1 |  5 || 6  |   |      | 0v      |     |     |
 |   4 |   7 | GPIO. 7 |   IN | 0 |  7 || 8  | 1 | ALT0 | TxD     | 15  | 14  |
 |     |     |      0v |      |   |  9 || 10 | 1 | ALT0 | RxD     | 16  | 15  |
 |  17 |   0 | GPIO. 0 |   IN | 0 | 11 || 12 | 0 | IN   | GPIO. 1 | 1   | 18  |
 |  27 |   2 | GPIO. 2 |   IN | 0 | 13 || 14 |   |      | 0v      |     |     |
 |  22 |   3 | GPIO. 3 |   IN | 0 | 15 || 16 | 0 | IN   | GPIO. 4 | 4   | 23  |
 |     |     |    3.3v |      |   | 17 || 18 | 0 | IN   | GPIO. 5 | 5   | 24  |
 |  10 |  12 |    MOSI |   IN | 0 | 19 || 20 |   |      | 0v      |     |     |
 |   9 |  13 |    MISO |   IN | 0 | 21 || 22 | 0 | IN   | GPIO. 6 | 6   | 25  |
 |  11 |  14 |    SCLK |   IN | 0 | 23 || 24 | 1 | IN   | CE0     | 10  | 8   |
 |     |     |      0v |      |   | 25 || 26 | 1 | IN   | CE1     | 11  | 7   |
 |   0 |  30 |   SDA.0 |   IN | 0 | 27 || 28 | 1 | IN   | SCL.0   | 31  | 1   |
 |   5 |  21 | GPIO.21 |   IN | 1 | 29 || 30 |   |      | 0v      |     |     |
 |   6 |  22 | GPIO.22 |   IN | 0 | 31 || 32 | 1 | IN   | GPIO.26 | 26  | 12  |
 |  13 |  23 | GPIO.23 |   IN | 0 | 33 || 34 |   |      | 0v      |     |     |
 |  19 |  24 | GPIO.24 |   IN | 0 | 35 || 36 | 0 | IN   | GPIO.27 | 27  | 16  |
 |  26 |  25 | GPIO.25 |   IN | 1 | 37 || 38 | 0 | IN   | GPIO.28 | 28  | 20  |
 |     |     |      0v |      |   | 39 || 40 | 0 | IN   | GPIO.29 | 29  | 21  |
 +-----+-----+---------+------+---+----++----+---+------+---------+-----+-----+
 | BCM | wPi |   Name  | Mode | V | Physical | V | Mode | Name    | wPi | BCM |
 +-----+-----+---------+------+---+---Pi 2---+---+------+---------+-----+-----+

Salida de dmesg:

3.235940] input: AD7879 Touchscreen as /devices/platform/soc/3f804000.i2c/i2c-1/1-002c/input/input0

Salida de vcdbg log msg (en modo de depuración):

002590.952: Loaded overlay 'i2c-ad7879'
002591.011: dtdebug: Found fragment 0 (offset 36)
002596.047: dtdebug: merge_fragment(/soc/i2c@7e804000,/fragment@0/__overlay__)
002596.070: dtdebug:   +prop(#address-cells)
002596.967: dtdebug:   +prop(#size-cells)
002597.869: dtdebug:   +prop(status)
002601.245: dtdebug: merge_fragment(/soc/i2c@7e804000/ad7879@2c,/fragment@0/__overlay__/ad7879@2c)
002601.271: dtdebug:   +prop(compatible)
002602.139: dtdebug:   +prop(reg)
002603.067: dtdebug:   +prop(adi,swap-xy-axis-enable)
002604.278: dtdebug:   +prop(adi,x-plate-ohms)
002605.510: dtdebug:   +prop(adi,x-min)
002606.760: dtdebug:   +prop(adi,x-max)
002608.025: dtdebug:   +prop(adi,y-min)
002609.306: dtdebug:   +prop(adi,y.max)
002610.619: dtdebug:   +prop(adi,pressure-min)
002611.927: dtdebug:   +prop(adi,pressure-max)
002613.257: dtdebug:   +prop(adi,pen-down-acquisition-interval)
002614.601: dtdebug:   +prop(adi,first-conversion-delay)
002615.968: dtdebug:   +prop(adi,acquisition-time)
002617.359: dtdebug:   +prop(adi,averaging)
002618.773: dtdebug:   +prop(adi,median)
002620.213: dtdebug:   +prop(interrupts)
002621.325: dtdebug:   +prop(interrupt-parent)
002622.386: dtdebug:   +prop(status)
002623.509: dtdebug:   +prop(linux,phandle)
002624.646: dtdebug:   +prop(phandle)
002625.820: dtdebug: merge_fragment() end
002625.867: dtdebug: merge_fragment() end
002626.003: dtdebug: delete_node(/hat)

Salida de i2cdetect -y 1:

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- UU -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: 60 -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --                        

Salida de lsmod:

Module                  Size  Used by
cfg80211              420690  0 
rfkill                 16659  1 cfg80211
i2c_dev                 6047  0 
snd_bcm2835            19769  0 
snd_pcm                74825  1 snd_bcm2835
snd_seq                53561  0 
snd_seq_device          3650  1 snd_seq
snd_timer              18157  2 snd_pcm,snd_seq
snd                    52116  5 snd_bcm2835,snd_timer,snd_pcm,snd_seq,snd_seq_device
evdev                  10216  1 
joydev                  9047  0 
ad7879_i2c              1525  0 
ad7879                  5379  1 ad7879_i2c
rtc_abx80x              3247  0 
i2c_bcm2708             5014  0 
bcm2835_gpiomem         3023  0 
uio_pdrv_genirq         2966  0 
uio                     8235  1 uio_pdrv_genirq

Fuente del árbol de dispositivos superpuestos, archivo i2c-ad7879-overlay.dts:

// Definition for I2C based Touch screen ad7879
/dts-v1/;
/plugin/;

/ {
    compatible = "brcm,bcm2708";

    fragment@0 {
            target = <&i2c_arm>;
            __overlay__ {
                    #address-cells = <1>;
                    #size-cells = <0>;
                    status = "okay";

                    ad7879: ad7879@2c {
                            compatible = "adi,ad7879";
                            reg = <0x2c>;

                            adi,swap-xy-axis-enable = <0>;
                            adi,x-plate-ohms = <620>;
                            adi,x-min = <0>;
                            adi,x-max = <4000>;
                            adi,y-min = <0>;
                            adi,y-max = <4000>;
                            adi,pressure-min = <0>;
                            adi,pressure-max = <10000>;

                            interrupts = <26 2>;  /* falling edge */
                            interrupt-parent = <&gpio>;

                            status = "okay";
                    };
            };
      };
};

Salida de evtest / dev / input / touchscreen:

Input driver version is 1.0.1
Input device ID: bus 0x18 vendor 0x0 product 0x79 version 0x3
Input device name: "AD7879 Touchscreen"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 330 (BTN_TOUCH)
  Event type 3 (EV_ABS)
    Event code 0 (ABS_X)
      Value    286
      Min        0
      Max     4095
    Event code 1 (ABS_Y)
      Value   2729
      Min        0
      Max     4095
    Event code 24 (ABS_PRESSURE)
      Value      0
      Min        0
      Max        0
Properties:
Testing ... (interrupt to exit)
usuario2016555
fuente
¿Funcionó esto? Si es así, ¿podría enviarme el árbol de dispositivos? Si no, ¿le gustaría la ayuda de alguien en el mismo barco que usted? Tengo sugerencias, puede que no sean buenas. No quiero enviarlos si ya lo tienes funcionando. Bob
Bob Kruse

Respuestas: