A20GPIO中断类型差别结果迥异的问题思考
最近在使用全志A20做开发时，发现在处理中断的时候，用电平触发模式，报中断比较乱，用边沿触发则很稳定，不会乱报。笔者感到比较困惑，笔者用电平触发写的code如下：
reverseHandle = sw_gpio_irq_request(gReverseCar_gpio_hdle.gpio, TRIG_LEVL_HIGH, \
&sw_reverseCar_irq_Handle, &privateData);
if (!reverseHandle) {
printk("Failed to get gpio irq for reverse car detection\n");
}
privateData.trigtype = TRIG_LEVL_HIGH;
static int sw_reverseCar_irq_Handle(void *para){
printk("IRQ sw_reverseCar_irq: %d ", privateData.trigtype);
printk("IO:%d, value:%d\n",gReverseCar_gpio_hdle.gpio, \
__gpio_get_value(gReverseCar_gpio_hdle.gpio));
sw_gpio_eint_set_enable(gReverseCar_gpio_hdle.gpio, 0);
sw_gpio_eint_clr_irqpd_sta(gReverseCar_gpio_hdle.gpio);
//TRIG_LEVL_LOW TRIG_LEVL_HIGH TRIG_EDGE_POSITIVE TRIG_EDGE_NEGATIVE
if(privateData.trigtype == TRIG_LEVL_HIGH) {
if(0 == sw_gpio_eint_set_trigtype(gReverseCar_gpio_hdle.gpio,TRIG_LEVL_LOW))
privateData.trigtype = TRIG_LEVL_LOW;
} else if(privateData.trigtype == TRIG_LEVL_LOW) {
if(0 == sw_gpio_eint_set_trigtype(gReverseCar_gpio_hdle.gpio,TRIG_LEVL_HIGH))
privateData.trigtype = TRIG_LEVL_HIGH;
}
sw_gpio_eint_set_enable(gReverseCar_gpio_hdle.gpio, 1);
return 0;
}
中断类型设置成DEBO中断打印信息有问题，具体如下：
root@android:/ # [ 519.018955] IRQ sw_reverseCar_irq: 2 IO:188, value:1 [ 519.024773] IRQ sw_reverseCar_irq: 3 IO:188, value:1 [ 519.030576] IRQ sw_reverseCar_irq: 2 IO:188, value:1 [ 519.036378] IRQ sw_reverseCar_irq: 3 IO:188, value:1 [ 519.042169] IRQ sw_reverseCar_irq: 2 IO:188, value:1 [ 520.898643] IRQ sw_reverseCar_irq: 3 IO:188, value:0 [ 520.904456] IRQ sw_reverseCar_irq: 2 IO:188, value:0 [ 520.910363] IRQ sw_reverseCar_irq: 3 IO:188, value:0 [ 520.916215] IRQ sw_reverseCar_irq: 2 IO:188, value:0 [ 520.921995] IRQ sw_reverseCar_irq: 3 IO:188, value:0 [ 520.927832] IRQ sw_reverseCar_irq: 2 IO:188, value:0 [ 520.933612] IRQ sw_reverseCar_irq: 3 IO:188, value:0 [ 520.939432] IRQ sw_reverseCar_irq: 2 IO:188, value:0 [ 520.945317] IRQ sw_reverseCar_irq: 3 IO:188, value:0
用边沿触发写的code如下，
gPrivData.trigtype = TRIG_EDGE_POSITIVE;
gPrivData.irqReqHandle = sw_gpio_irq_request(gPrivData.gpio_hdle.gpio, TRIG_EDGE_POSITIVE, \
(peint_handle)&sw_reverseCar_irq_Handle, (void *)&gPrivData);
static int sw_reverseCar_irq_Handle(void *para){
//printk("IRQ sw_reverseCar_irq: %d ", gPrivData.trigtype);
gPrivData.CarStatus = __gpio_get_value(gPrivData.gpio_hdle.gpio);
//printk("io:%d, value:%d\n",gPrivData.gpio_hdle.gpio, gPrivData.CarStatus);
/*if app has no capacity for handle reverse event, system need reboot*/
if(1 == gPrivData.needRebootFlag) {
printk("Reboot for handle reverse in boot now!\n");
*(volatile __u32 *)(0xf1c20c94) = 0x3;
}
up(&gPrivData.sem_lock);
sw_gpio_eint_set_enable(gPrivData.gpio_hdle.gpio, 0);
sw_gpio_eint_clr_irqpd_sta(gPrivData.gpio_hdle.gpio);
if(gPrivData.trigtype == TRIG_EDGE_POSITIVE) {
if(0 == sw_gpio_eint_set_trigtype(gPrivData.gpio_hdle.gpio,TRIG_EDGE_NEGATIVE))
gPrivData.trigtype = TRIG_EDGE_NEGATIVE;
} else if(gPrivData.trigtype == TRIG_EDGE_NEGATIVE) {
if(0 == sw_gpio_eint_set_trigtype(gPrivData.gpio_hdle.gpio,TRIG_EDGE_POSITIVE))
gPrivData.trigtype = TRIG_EDGE_POSITIVE;
}
sw_gpio_eint_set_enable(gPrivData.gpio_hdle.gpio, 1);
return 0;
}
EDGE时还可以设置中断类型为TRIG_EDGE_DOUBLE，笔者暂时没有采用，中断打印信息正常，如下：
root@android:/ # [ 517.116361] IRQ sw_reverseCar_irq: 0 io:188, value:1 [ 518.103095] IRQ sw_reverseCar_irq: 1 io:188, value:0 root@android:/ # [ 520.918512] IRQ sw_reverseCar_irq: 0 io:188, value:1 [ 521.876038] IRQ sw_reverseCar_irq: 1 io:188, value:0 [ 527.796107] IRQ sw_reverseCar_irq: 0 io:188, value:1 [ 528.843397] IRQ sw_reverseCar_irq: 1 io:188, value:0 [ 531.335858] IRQ sw_reverseCar_irq: 0 io:188, value:1 [ 532.306660] IRQ sw_reverseCar_irq: 1 io:188, value:0 [ 534.552011] IRQ sw_reverseCar_irq: 0 io:188, value:1 [ 535.101586] IRQ sw_reverseCar_irq: 1 io:188, value:0
笔者不清楚原因，怀疑是芯片驱动的问题，但是驱动也就那样写了啊，难道是芯片设计的问题，当然这种也就是在刚有中断时会有乱irq上来，如果用delaywork延时一下处理也是可以绕过去的。望哪位大侠清楚的解释一下。
