topic Re: External IRQ with mpc8xxx in linux in QorIQ

External IRQ with mpc8xxx in linux

rans — Mon, 10 Aug 2015 11:23:59 GMT

Hello,

I have some difficulties and using interrupt handler with powerpc, mpc8349, on linux.

In datasheet is shows that there are 8 external interrupts, named irq0-7. We need to use IRQ4.

I don't see the interrupt listed in /proc/interrupts

# cat /proc/interrupts

CPU0

16: 93 IPIC 9 Level serial

18: 0 IPIC 14 Level i2c-mpc

19: 0 IPIC 15 Level i2c-mpc

21: 0 IPIC 18 Level phy_interrupt

32: 0 IPIC 32 Level eth0_g0_tx

33: 14 IPIC 33 Level eth0_g0_rx

34: 0 IPIC 34 Level eth0_g0_er

35: 0 IPIC 35 Level eth1_g0_tx

36: 0 IPIC 36 Level eth1_g0_rx

37: 0 IPIC 37 Level eth1_g0_er

LOC: 60756 Local timer interrupts for timer event device

LOC: 1 Local timer interrupts for others

SPU: 0 Spurious interrupts

PMI: 0 Performance monitoring interrupts

MCE: 0 Machine check exceptions

I have tried to add it in dts (Is that required?), but I still don't see any change in /proc/interrupts:

intc@0{

compatible = "intc";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <4 0x8>; <- is this the way to define IRQ4 ?

};

I've then added the following in the driver, but I also fails:

	np = of_find_node_by_name(NULL,"hello");
	if (np == NULL)
	{
	printk("Error node not found\n");
	}


	printk("Node np = 0x%0x\n",np); <-- Node np = 0xdfffe2f0
	virq = irq_of_parse_and_map(np,0);
//
	printk(" VIRQ: %d \n" , virq); <-- virq = 0 !!??

	if (0 > (error=request_irq(virq, &hello_IRQHandler, IRQF_SHARED, "hello", &value))) {
	printk(KERN_WARNING"hello_IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);
	return -1; <-- request_irq return -22 ....
	}

Thank you for any idea,

Ran

Re: External IRQ with mpc8xxx in linux

bpe — Thu, 13 Aug 2015 11:07:41 GMT

There are several problems:

1. The node name of_find_node_by_name() searches for ("hello"), does not match the name of the node defined above ("intc"), so

the function finds some another node.

2. There is no 'interrupt-parent' property in the 'intc@0' node, so it is not clear to what interrupt controller it connects.

3. The interrupt number in the 'interrupts' property is invalid. Refer to MPC8349EARM, Table 8-6 for interrupt numbers coding.

Have a great day,
Platon

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Re: External IRQ with mpc8xxx in linux

rans — Thu, 13 Aug 2015 13:16:02 GMT

Hi Platon,

You are correct, I've made the relevant changes.

And the request_irq return success now.

But I only did not understand your comment about the invalid number:

We are using external IRQ #4.

What is the problem with the following:

		intc4@0{
		compatible = "intc4";
		#address-cells = <1>;
		#size-cells = <0>;
		reg = <0 0x1000>;
		interrupts = <4 0x8> ;
		interrupt-parent = <&ipic>;
		};

Regards,

Ran

Re: External IRQ with mpc8xxx in linux

scottwood — Thu, 13 Aug 2015 19:20:58 GMT

Look at table 8-6 as was suggested. External IRQ4 is IPIC interrupt 20. Also check that you have the right level/sense -- is this interrupt level triggered and active low?

Re: External IRQ with mpc8xxx in linux

rans — Thu, 13 Aug 2015 21:09:36 GMT

Hi,

So it make sense now.

I got the following printings in code

...

intc_init

Node np = 0xdfffe078

IRQHandler: ISR Setup VIRQ: 20

....

Which says that virq is 20, which fits the external irq number 4.

Thanks for the assistance,

Ran

Re: External IRQ with mpc8xxx in linux

rans — Sun, 16 Aug 2015 08:26:06 GMT

Hello,

I still have some issue with the IRQ.

Though it seemed that the registration is successful, I still don't get any of the external interrupt handler called.

After forcing interrupt and checking SEMSR register I see that I have a pending IRQ #2, but the handler was not called.

This are the steps:

1. in DTS (using all external IRQ #0-7):

intc0@0{

compatible = "intc0";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <0 0x8> ;

interrupt-parent = <&ipic>;

};

intc1@0{

compatible = "intc1";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <1 0x8> ;

interrupt-parent = <&ipic>;

};

intc2@0{

compatible = "intc2";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <2 0x8> ;

interrupt-parent = <&ipic>;

};

intc3@0{

compatible = "intc3";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <3 0x8> ;

interrupt-parent = <&ipic>;

};

intc4@0{

compatible = "intc4";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <4 0x8> ;

interrupt-parent = <&ipic>;

};

intc5@0{

compatible = "intc5";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <5 0x8> ;

interrupt-parent = <&ipic>;

};

intc6@0{

compatible = "intc6";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <6 0x8> ;

interrupt-parent = <&ipic>;

};

intc7@0{

compatible = "intc7";

#address-cells = <1>;

#size-cells = <0>;

reg = <0 0x1000>;

interrupts = <7 0x8> ;

interrupt-parent = <&ipic>;

};

2. registration in kernel for all interrupts:

np = of_find_node_by_name(NULL,"intc0");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc0", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc1");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc1", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc2");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc2", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc3");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc3", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc4");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc4", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc5");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc5", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc6");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc6", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

np = of_find_node_by_name(NULL,"intc7");

if (np == NULL)

{

printk("Error node not found\n");

}

printk("Node np = 0x%0x\n",np);

virq = irq_of_parse_and_map(np,0);

printk(KERN_INFO"IRQHandler: ISR Setup VIRQ: %d \n" , virq);

if (0 > (error=request_irq(virq, &IRQHandler, 0, "intc7", &value))) {

printk(KERN_WARNING"IRQHandler: Init: Unable to allocate IRQ error = %d\n\n", error);

return -1;

}

3. interrupt handler code:

int newval = 0;

static irqreturn_t hello_IRQHandler(int irq, void *dev_id)

{

unsigned int status;

struct timespec curr_tm;

printk("key_irq!!!!!\n");

return IRQ_HANDLED;

}

4. in boot I get print which show success with request_irq():

intc_init

Node np = 0xdfffe078

IRQHandler: ISR Setup VIRQ: 20

Node np = 0xdfffe180

IRQHandler: ISR Setup VIRQ: 21

Node np = 0xdfffe288

IRQHandler: ISR Setup VIRQ: 22

Node np = 0xdfffe390

IRQHandler: ISR Setup VIRQ: 23

Node np = 0xdfffe498

IRQHandler: ISR Setup VIRQ: 24

Node np = 0xdfffe5a0

IRQHandler: ISR Setup VIRQ: 25

Node np = 0xdfffe6a8

IRQHandler: ISR Setup VIRQ: 26

Node np = 0xdfffe7b0

IRQHandler: ISR Setup VIRQ: 27

TCP: cubic registered

NET: Registered protocol family 17

5. forcing interrupt in IRQ #2, or #4 result in SEPNR change, but there is no printing from interrupt handler

6. validation in SEPNR register that interrupt was received:

# devmem2 0xe000072c

/dev/mem opened.

Memory mapped at address 0xb7b80000.

Value at address 0xE000072C (0xb7b8072c): 0x20000000

Thank you for any suggestion,

Ran

Re: External IRQ with mpc8xxx in linux

scottwood — Mon, 17 Aug 2015 16:02:55 GMT

Again, you are using invalid interrupt numbers in the device tree. Look at table 8-6 in the SoC reference manual.

Re: External IRQ with mpc8xxx in linux

rans — Tue, 18 Aug 2015 05:22:30 GMT

Platon, Scott,

Thank you very much!!

Finally the interrupt handler is called. Table 8-6 information was essential.

Regards,

Ran