參考資料：
https://github.com/xboot/xboot
https://dl.linux-sunxi.org/touchscreen/GT911%20Datasheet.pdf
https://debugdump.com/topic/3633/mq-t113%E4%BD%BF%E7%94%A8xboot%E9%A9%B1%E5%8A%A8gt911%E6%97%B6%E4%B8%AD%E6%96%AD%E6%97%A0%E6%B3%95%E4%BD%BF%E7%94%A8/6
T113-S3開發板
司徒手上並沒有GT911觸控板，因此，司徒使用Arduino Micro模擬GT911訊號
Arduino腳位：
T113-S3腳位：
司徒將GT911 I2C訊號接到T113-S3 I2C-2，GT911的中斷則是接到T113-S3 PB6(手動觸發)
杜邦線連接
Arduino模擬GT911程式
#include <Wire.h>
unsigned short rx = 0;
void receiveEvent(int howMany) {
if (howMany == 2) {
rx = Wire.read();
rx <<= 8;
rx |= Wire.read();
}
else {
while (Wire.available()) {
Wire.read();
}
}
Serial.print("howMany:");
Serial.print(howMany);
Serial.print("\n");
Serial.print("0x");
Serial.print(rx, HEX);
Serial.print("\n");
}
unsigned short x = 0;
unsigned short y = 0;
void requestEvent() {
switch (rx) {
case 0x8047:
Wire.write(byte(0x01));
break;
case 0x8140:
Wire.write('A');
Wire.write('B');
Wire.write('C');
Wire.write('D');
break;
case 0x8144:
Wire.write(byte(0x12));
Wire.write(byte(0x34));
break;
case 0x814e:
Wire.write(byte(0x80 | 1));
break;
case 0x814f:
Wire.write(byte(0x01));
Wire.write(byte(x));
Wire.write(byte(x >> 8));
Wire.write(byte(y));
Wire.write(byte(y >> 8));
Wire.write(byte(0x00));
Wire.write(byte(0x00));
Wire.write(byte(0x00));
x += 1;
y += 1;
break;
}
rx = 0;
}
void setup() {
Wire.begin(20);
Wire.onReceive(receiveEvent);
Wire.onRequest(requestEvent);
Serial.begin(115200);
}
void loop() {
delay(100);
}
src/arch/arm32/mach-t113s3/romdisk/boot/mangopi.json
524 "i2c-t113:2@0x02502800": {
525 "clock-name": "bus-i2c2",
526 "clock-frequency": 400000,
527 "reset": 466,
528 "sda-gpio": 133,
529 "sda-gpio-config": 4,
530 "scl-gpio": 132,
531 "scl-gpio-config": 4
532 },
662 "ts-gt911": {
663 "i2c-bus": "i2c-t113.2",
664 "slave-address": 20,
665 "interrupt-gpio": 38,
666 "interrupt-gpio-config": 14,
667 "reset-gpio": 34,
668 "reset-gpio-config": 1
669 },
src/arch/arm32/mach-t113s3/driver/ts-gt911.c
75 static bool_t gt911_write(struct i2c_device_t * dev, u16_t reg, u8_t * buf, int len)
76 {
77 struct i2c_msg_t msg;
78 u8_t mbuf[256];
79
80 if(len > sizeof(mbuf) - 1)
81 len = sizeof(mbuf) - 1;
82 mbuf[0] = (reg >> 8) & 0xff;
83 mbuf[1] = (reg >> 0) & 0xff;
84 memcpy(&mbuf[2], buf, len);
85
86 msg.addr = dev->addr;
87 msg.flags = 0;
88 msg.len = 32;//len + 2;
89 msg.buf = &mbuf[0];
90
91 if(i2c_transfer(dev->i2c, &msg, 1) != 1)
92 return FALSE;
93 return TRUE;
94 }
134 static bool_t gt911_initial(struct i2c_device_t * dev)
135 {
136 u8_t cfg;
137 u8_t id[4];
138 u8_t ver[2];
139
140 if(!gt911_read(dev, GT911_CONFIG_DATA, &cfg, 1))
141 return FALSE;
142 if(!gt911_read(dev, GT911_PRODUCT_ID, &id[0], 4))
143 return FALSE;
144 if(!gt911_read(dev, GT911_FIRMWARE_VERSION, &ver[0], 2))
145 return FALSE;
146
147 LOG("GT911 Version: %c%c%c%c(0x%02x%02x)(0x%02x)\r\n", id[0], id[1], id[2], id[3], ver[1], ver[0], cfg);
148 return gt911_send_cfg(dev, (u8_t *)gt911_config_data, ARRAY_SIZE(gt911_config_data));
149 }
151 static void gt911_interrupt(void * data)
152 {
153 struct input_t * input = (struct input_t *)data;
154 struct ts_gt911_pdata_t * pdat = (struct ts_gt911_pdata_t *)input->priv;
155 u8_t status, buf[40];
156 u8_t * p;
157 int count, i;
158 int id, x, y;
159
160 LOG("%s++\r\n", __func__);
161 disable_irq(pdat->irq);
162 for(i = 0; i < 5; i++)
163 {
164 pdat->node[i].valid = 0;
165 }
166 if(gt911_read(pdat->dev, GT911_STATUS, &status, 1) && (status & (1 << 7)))
167 {
168 count = status & 0x0f;
169 if(count > 0 && count < 5)
170 {
171 if(gt911_read(pdat->dev, GT911_COOR_ADDR, &buf[0], count << 3))
172 {
173 for(i = 0; i < count; i++)
174 {
175 p = &buf[i << 3];
176 id = p[0];
177 x = (p[2] << 8) | (p[1] << 0);
178 y = (p[4] << 8) | (p[3] << 0);
179 LOG("%s, count:%d, x:%d, y:%d\r\n", __func__, count, x, y);
...
209 enable_irq(pdat->irq);
210 LOG("%s--\r\n", __func__);
211 }
編譯、下載
$ make CROSS_COMPILE=arm-linux-gnueabihf- PLATFORM=arm32-t113s3 $ xfel ddr t113-s3 $ xfel write 0x40000000 output/xboot.bin $ xfel exec 0x40000000
Arduino GT911可以正常工作，但是，中斷PB6無法被觸發
[ 0.260214]GT911 Version: ABCD(0x3412)(0x01) [ 0.287074]Probe device 'ts-gt911.0' with ts-gt911
為了方便測試，司徒將PB6加上提昇電阻並且改成Falling中斷觸發
282 LOG("%s, gpio:%d, gpiocfg:%d, irqnum:%d\r\n", __func__, gpio, gpiocfg, irq);
283 if(gpio >= 0)
284 {
285 if(gpiocfg >= 0)
286 gpio_set_cfg(gpio, gpiocfg);
287 gpio_set_pull(gpio, GPIO_PULL_UP);
288 }
289 request_irq(pdat->irq, gt911_interrupt, IRQ_TYPE_EDGE_FALLING, input);
PB6=GPIO38、GPIOCFG=14、IRQ=262，這個IRQ應該是抓錯了？
[ 0.266982]ts_gt911_probe, gpio:38, gpiocfg:14, irqnum:262
src/arch/arm32/mach-t113s3/romdisk/boot/mangopi.json
388 "irq-gic400@0x03020000": { "interrupt-base": 32, "interrupt-count": 224 },
389 "irq-t113-gpio@0x02000220": { "interrupt-base": 224, "interrupt-count": 8, "interrupt-parent": 101 },
390 "irq-t113-gpio@0x02000240": { "interrupt-base": 256, "interrupt-count": 8, "interrupt-parent": 103 },
391 "irq-t113-gpio@0x02000260": { "interrupt-base": 288, "interrupt-count": 23, "interrupt-parent": 105 },
392 "irq-t113-gpio@0x02000280": { "interrupt-base": 320, "interrupt-count": 14, "interrupt-parent": 107 },
393 "irq-t113-gpio@0x020002a0": { "interrupt-base": 352, "interrupt-count": 7, "interrupt-parent": 109 },
394 "irq-t113-gpio@0x020002c0": { "interrupt-base": 384, "interrupt-count": 16, "interrupt-parent": 111 },
src/driver/interrupt/interrupt.c
191 bool_t request_irq(int irq, void (*func)(void *), enum irq_type_t type, void * data)
192 {
193 struct irqchip_t * chip;
194 int offset;
195
196 if(!func)
197 return FALSE;
198
199 chip = search_irqchip(irq);
200 if(!chip)
201 return FALSE;
202
203 offset = irq - chip->base;
204 if(chip->handler[offset].func != null_interrupt_function) {
205 return FALSE;
206 }
207
208 LOG("%s, irq:%d, chip->base:%d, offset:%d\r\n", __func__, irq, chip->base, offset);
XBoot修改到的中斷地址是屬於PC6，但是司徒的中斷是設定成PB6
[ 0.272634]request_irq, irq:262, chip->base:256, offset:6
src/arch/arm32/mach-t113s3/driver/irq-t113-gpio.c
92 addr = pdat->virt + GPIO_INT_CFG0 + ((offset >> 3) << 2);
93 val = read32(addr);
94 val &= ~(0xf << ((offset & 0x7) << 2));
95 val |= ((cfg & 0x7) << ((offset & 0x7) << 2));
96 write32(addr, val);
97
98 LOG("%s, addr:%p, type:%d, offset:%d\r\n", __func__, addr, type, offset);
果然修改到PC6 0x02000240
[ 0.268151]ts_gt911_probe, gpio:38, gpiocfg:14, irqnum:262 [ 0.273812]request_irq, irq:262, chip->base:256, offset:6 [ 0.279202]irq_t113_gpio_settype, addr:0x02000240, type:3, offset:6 [ 0.285373]Probe device 'ts-gt911.0' with ts-gt911
PB6是位於0x02000230
Workaround (src/driver/interrupt/interrupt.c)
62 static struct irqchip_t * search_irqchip(int irq)
63 {
64 struct device_t * pos, * n;
65 struct irqchip_t * chip;
66
67 list_for_each_entry_safe(pos, n, &__device_head[DEVICE_TYPE_IRQCHIP], head)
68 {
69 chip = (struct irqchip_t *)(pos->priv);
70 if(irq == 230){
71 if(chip->base == 224){
72 return chip;
73 }
74 continue;
75 }
76 if((irq >= chip->base) && (irq < (chip->base + chip->nirq)))
77 return chip;
78 }
79 return NULL;
80 }
191 bool_t request_irq(int irq, void (*func)(void *), enum irq_type_t type, void * data)
192 {
193 struct irqchip_t * chip;
194 int offset;
195
196 if(!func)
197 return FALSE;
198
199 if(irq == 262){
200 irq-= 32;
201 }
修改後，就可以正常中斷觸發並且回報觸控點
[ 0.260653]GT911 Version: ABCD(0x3412)(0x01) [ 0.266935]ts_gt911_probe, gpio:38, gpiocfg:14, irqnum:262 [ 0.272326]request_irq, irq:230, chip->base:224, offset:6 [ 0.277959]irq_t113_gpio_settype, addr:0x02000220, type:3, offset:6 [ 0.299301]Probe device 'ts-gt911.0' with ts-gt911 [ 0.304091]Probe device 'g2d-t113.0' with g2d-t113 [ 0.310178]Probe device 'fb-t113-rgb.0' with fb-t113-rgb [ 0.315658]Probe device 'console-uart.0' with console-uart [ 0.322001]mount /private with 'ram' filesystem Press any key to stop auto boot: 0.000 xboot: /# [ 5.434256]gt911_interrupt++ [ 5.440101]gt911_interrupt, count:1, x:1, y:1 [ 5.446270]gt911_interrupt-- [ 9.054572]gt911_interrupt++ [ 9.060405]gt911_interrupt, count:1, x:2, y:2 [ 9.066782]gt911_interrupt--