[PATCH NEXT 2/4] powerpc/pasemi: Add Nemo board IRQ init routine

[Christian Zigotzky]

Hello Michael,

I haven't reached Darren yet but I try to help a little bit.

On 03 May 2018 at 3:06PM, Michael Ellerman wrote:
> Darren Stevens <darren at stevens-zone.net> writes:
>
>> diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
>> index c4a3e93..c583c17 100644
>> --- a/arch/powerpc/platforms/pasemi/setup.c
>> +++ b/arch/powerpc/platforms/pasemi/setup.c
>> @@ -183,6 +184,99 @@ static int __init pas_setup_mce_regs(void)
>>   }
>>   machine_device_initcall(pasemi, pas_setup_mce_regs);
>>   
>> +#ifdef CONFIG_PPC_PASEMI_NEMO
>> +static void sb600_8259_cascade(struct irq_desc *desc)
>> +{
>> +	struct irq_chip *chip = irq_desc_get_chip(desc);
>> +	unsigned int cascade_irq = i8259_irq();
>> +
>> +	if (cascade_irq)
>> +               generic_handle_irq(cascade_irq);
>> +
>> +	chip->irq_eoi(&desc->irq_data);
>> +}
>> +
>> +static __init void nemo_init_IRQ(void)
>> +{
>> +	struct device_node *np;
>> +	struct device_node *root, *mpic_node, *i8259_node;
>> +	unsigned long openpic_addr;
>> +	const unsigned int *opprop;
>> +	int naddr, opplen;
>> +	int mpic_flags;
>> +	const unsigned int *nmiprop;
>> +	struct mpic *mpic;
>> +	int gpio_virq;
>> +
>> +	mpic_node = NULL;
> This is basically a copy of the existing routine.
Yes, at the begin of 'nemo_init_IRQ' it is a copy of the existing 
routine. But the code before is new code. A similar code is in the file 
"arch/powerpc/platforms/pseries/setup.c" but for the pSeries.
>
>> +	for_each_node_by_type(np, "interrupt-controller")
>> +		if (of_device_is_compatible(np, "open-pic")) {
>> +			mpic_node = np;
>> +			break;
>> +		}
>> +	if (!mpic_node)
>> +		for_each_node_by_type(np, "open-pic") {
>> +			mpic_node = np;
>> +			break;
>> +		}
>> +	if (!mpic_node) {
>> +		printk(KERN_ERR
>> +			"Failed to locate the MPIC interrupt controller\n");
>> +		return;
>> +	}
>> +
>> +	/* Find address list in /platform-open-pic */
>> +	root = of_find_node_by_path("/");
>> +	naddr = of_n_addr_cells(root);
>> +	opprop = of_get_property(root, "platform-open-pic", &opplen);
>> +	if (!opprop) {
>> +		printk(KERN_ERR "No platform-open-pic property.\n");
>> +		of_node_put(root);
>> +		return;
>> +	}
>> +	openpic_addr = of_read_number(opprop, naddr);
>> +	printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
>> +
>> +	mpic_flags = MPIC_LARGE_VECTORS | MPIC_NO_BIAS | MPIC_NO_RESET;
>> +
>> +	nmiprop = of_get_property(mpic_node, "nmi-source", NULL);
>> +	if (nmiprop)
>> +		mpic_flags |= MPIC_ENABLE_MCK;
>> +
>> +	mpic = mpic_alloc(mpic_node, openpic_addr,
>> +			  mpic_flags, 0, 0, "PASEMI-OPIC");
>> +	BUG_ON(!mpic);
>> +
>> +	mpic_assign_isu(mpic, 0, mpic->paddr + 0x10000);
>> +	mpic_init(mpic);
>> +	/* The NMI/MCK source needs to be prio 15 */
>> +	if (nmiprop) {
>> +		nmi_virq = irq_create_mapping(NULL, *nmiprop);
>> +		mpic_irq_set_priority(nmi_virq, 15);
>> +		irq_set_irq_type(nmi_virq, IRQ_TYPE_EDGE_RISING);
>> +		mpic_unmask_irq(irq_get_irq_data(nmi_virq));
>> +	}
> Except for this bit:
>
>> +	/* Connect the SB600's legacy i8259 controller */
>> +	i8259_node = of_find_node_by_path("/pxp at 0,e0000000");
>> +	i8259_init(i8259_node, 0);
>> +	of_node_put(i8259_node);
>> +
>> +	gpio_virq = irq_create_mapping(NULL, 3);
>> +	irq_set_irq_type(gpio_virq, IRQ_TYPE_LEVEL_HIGH);
>> +	irq_set_chained_handler(gpio_virq, sb600_8259_cascade);
>> +	mpic_unmask_irq(irq_get_irq_data(gpio_virq));
>> +
>> +	irq_set_default_host(mpic->irqhost);
> So that should just go in a separate routine that is empty when NEMO=n.
>
> cheers
>
What do you think about the following code. This uses 'pas_init_IRQ':

static __init void pas_init_IRQ(void)
  {
      struct device_node *np;
-    struct device_node *root, *mpic_node;
+    struct device_node *root, *mpic_node, *i8259_node;
      unsigned long openpic_addr;
      const unsigned int *opprop;
      int naddr, opplen;
      int mpic_flags;
      const unsigned int *nmiprop;
      struct mpic *mpic;
+    int gpio_virq;

      mpic_node = NULL;

@@ -244,6 +270,22 @@ static __init void pas_init_IRQ(void)
          mpic_unmask_irq(irq_get_irq_data(nmi_virq));
      }

+
+#ifdef CONFIG_PPC_PASEMI_NEMO
+    /* Connect the SB600's legacy i8259 controller */
+    i8259_node = of_find_node_by_path("/pxp at 0,e0000000");
+    i8259_init(i8259_node, 0);
+    of_node_put(i8259_node);
+
+    gpio_virq = irq_create_mapping(NULL, 3);
+    irq_set_irq_type(gpio_virq, IRQ_TYPE_LEVEL_HIGH);
+    irq_set_chained_handler(gpio_virq, sb600_8259_cascade);
+    mpic_unmask_irq(irq_get_irq_data(gpio_virq));
+
+    irq_set_default_host(mpic->irqhost);
+
+#endif
      of_node_put(mpic_node);
      of_node_put(root);
  }

----

Shall I add 'ifdef CONFIG_PPC_PASEMI_NEMO' for 'struct device_node 
*root, *mpic_node, *i8259_node;' and 'int gpio_virq;'?

Note: I am not a programmer. I work for the Linux first level support 
for A-EON but sometimes I try to help. This is only a suggestion.

Thanks,
Christian