Hi Mark: 在 2015/7/21 0:38, Mark Rutland 写道: >>>> +The mbigen and devices connect to mbigen have the following properties: >> The mbigen chip structrue likes below: >> >> mbigen_chip(domain) >> |------------|------------------| >> mbigen_node0 mbigen_node1 mbigen_node2 >> | | | | | | >> dev1 dev2 dev3 dev4 dev5 dev6 >> >> For each mbigen chip, it contains several mbigen nodes. >> For each mbigen node, it can collect interrupts from different devices. >> >> For example, dev1 and dev2 both connect to mbigen node0.Because dev1 and >> dev2 are >> differnt device, they have different device id. >> >> The device id is encoded in mbigen chip and can not be changed. > > Thanks for the diagram, that clears up some of my confusion regarding > nodes. > > Ok, so each device has it's own device ID. That's good. If a device has > multiple interrupt lines to the mbigen, do these always share the same > device ID? > yes, for the interrupt lines within a device, they always share the same device ID. >>>> + The 2nd cell is the totall interrupt number of this device? >>> >>> I don't follow. What is a "total interrupt number"? >>> >> It's the wired interrupt number connected to a device. >> For the devices connected to mbigen node, the interrupt number varied from >> 1 to 100+ .So I have to specifies this value in dts. >> >>>> + The 3rd cell is the hardware pin number of the interrupt. >>>> + This value depends on the Soc design. >>> >>> This property seems sane. >>> >>>> + The 4th cell is the mbigen node number. This value should refer to the >>>> + vendor soc specification. >>> >>> What is this, and why do you think you need it? >>> >>> Surely the address of the mbigen node is a sufficient unique identifier? >>> >> mbigen_chip(domain) >> |------------|------------------| >> mbigen_node0 mbigen_node1 mbigen_node2 >> | | | | | | >> dev1 dev2 dev3 dev4 dev5 dev6 >> >> To avoid the duplicat hardware irq number problem, the Mbigen node number is >> defined here. >> For example: >> dev1 has 3 interrupts with pin number from 0 to 2 >> dev3 has 5 interrupts with pin number from 0 to 4 >> For dev3 the interrupt from 0 to 2 would be has same hardware irq number >> as dev1 if we only use pin number. >> >> Because these two devices located in same irq domain(mbigen chip),using same >> hwirq number is a mistake. >> >> In mbigen driver, I will use this value and the 3rd cell(pin number) to >> compose >> a new hardware irq( (nid<<8) | pin number) for mbigen using. > > Ok. I now see why you need node and pin. > > However, I don't see why you also need the 'total' interrupt number. Why > isn't node and pin sufficient to uniquely identify an interrupt? > The ITS driver alloc a ITT table for each device. The table size depends on interrupt number of the device. So I need to specify the total interrupt number .
> Thanks, > Mark. > > . > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
