Re: [PATCH v3 6/9] irqchip: Add the ingenic-tcu-intc driver

From: Paul Cercueil
Date: Thu Jan 11 2018 - 11:25:56 EST



Hi Marc,

+static int __init ingenic_tcu_intc_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct irq_domain *domain;
+ struct irq_chip_generic *gc;
+ struct irq_chip_type *ct;
+ int err, i, num_parent_irqs;
+ unsigned int parent_irqs[3];

3 parent interrupts? Really? How do you pick one? Also, given the useage
model below, "int" is the wrong type. Probably should be u32.

See below.

+ struct regmap *map;
+
+ num_parent_irqs = of_property_count_elems_of_size(
+ node, "interrupts", 4);

Nit: on a single line, as here is nothing that hurts my eyes more than
reading something like(
this). Also, 4 is better expressed as sizeof(u32).

That will make checkpatch.pl unhappy :(

+ if (num_parent_irqs < 0 || num_parent_irqs > ARRAY_SIZE(parent_irqs))
+ return -EINVAL;
+
+ map = syscon_node_to_regmap(node->parent);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ domain = irq_domain_add_linear(node, 32, &irq_generic_chip_ops, NULL);
+ if (!domain)
+ return -ENOMEM;
+
+ err = irq_alloc_domain_generic_chips(domain, 32, 1, "TCU",
+ handle_level_irq, 0, IRQ_NOPROBE | IRQ_LEVEL, 0);
+ if (err)
+ goto out_domain_remove;
+
+ gc = irq_get_domain_generic_chip(domain, 0);
+ ct = gc->chip_types;
+
+ gc->wake_enabled = IRQ_MSK(32);
+ gc->private = map;
+
+ ct->regs.disable = TCU_REG_TMSR;
+ ct->regs.enable = TCU_REG_TMCR;
+ ct->regs.ack = TCU_REG_TFCR;
+ ct->chip.irq_unmask = ingenic_tcu_gc_unmask_enable_reg;
+ ct->chip.irq_mask = ingenic_tcu_gc_mask_disable_reg;
+ ct->chip.irq_mask_ack = ingenic_tcu_gc_mask_disable_reg_and_ack;
+ ct->chip.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
+
+ /* Mask all IRQs by default */
+ regmap_write(map, TCU_REG_TMSR, IRQ_MSK(32));
+
+ for (i = 0; i < num_parent_irqs; i++) {
+ parent_irqs[i] = irq_of_parse_and_map(node, i);
+ if (!parent_irqs[i]) {
+ err = -EINVAL;
+ goto out_unmap_irqs;
+ }
+
+ irq_set_chained_handler_and_data(parent_irqs[i],
+ ingenic_tcu_intc_cascade, domain);
+ }

I don't get the multiple parent irq at all. How are the source interrupt
routed to the various cascades?

On JZ4740, channels 0 and 1 have their own interrupt, and channels 2-7 share
one interrupt line.
On JZ4770 and JZ4780, the OST (OS timer) channel has its own interrupt,
channel 5 has its own interrupt, and channels 0-4 and 6-7 share one
interrupt line.

To keep things simple, we register the same interrupt handler for the three
parent interrupts.

-Paul