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)
¿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