Saya menulis overlay pohon perangkat untuk driver layar sentuh ad7879-i2c (dikompilasi sebagai modul menggunakan sumber Raspberry Pi, file: ad7879-i2c.c, ad7879.c). Driver dimuat tetapi saya kira parameter tidak diteruskan ke driver. Perangkat ada di i2c1, alamat 0x2c, GPIO 26 (BCM 12). evtest menunjukkan parameter default driver dan layar sentuh tidak berfungsi sama sekali.
Di / boot / config.txt:
dtparam=i2c_arm=on
dtoverlay=i2c-ad7879
Di / etc / modules:
i2c-bcm2708
i2c-dev
Output dari 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---+---+------+---------+-----+-----+
Output dari dmesg:
3.235940] input: AD7879 Touchscreen as /devices/platform/soc/3f804000.i2c/i2c-1/1-002c/input/input0
Output dari vcdbg log msg (dalam mode debug):
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)
Output dari 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: -- -- -- -- -- -- -- --
Output dari 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
Sumber bagan perangkat overlay, file 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";
};
};
};
};
Output dari evtest / dev / input / layar sentuh:
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)
Apakah ini berhasil? Jika demikian, dapatkah Anda mengirim saya pohon perangkat? Jika tidak, apakah Anda menginginkan bantuan dari orang yang sama dengan Anda? Saya punya saran, mereka mungkin tidak ada gunanya. Saya tidak ingin mengirim mereka jika Anda sudah membuatnya berfungsi. Bob
—
Bob Kruse