Hi Agustin,

On 29/11/16 22:57, Agustin Vega-Frias wrote:

Do you really need this irq_set_parent? This only makes sense if you're
resending edge interrupts, and you seem to be level only.

+	irq_set_noprobe(irq);
+	return 0;
+}
+
+static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
+{
+	irq_set_chip_and_handler(irq, NULL, NULL);
+	irq_set_chip_data(irq, NULL);
+	irq_set_parent(irq, -1);

All of this should probably be replaced with a call to
irq_domain_reset_irq_data().

+}
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY

Is there any case where this is not valid?

+static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
+				  unsigned long *hwirq, unsigned int *type)
+{
+	if (is_acpi_node(fws->fwnode)) {
+		if (fws->param_count != 2)
+			return -EINVAL;
+
+		*hwirq = fws->param[0];
+		*type = fws->param[1];

Given that you're only handling level interrupts, shouldn't you abort if
detecting an edge interrupt?

+		return 0;
+	}
+
+	return -EINVAL;
+}
+#endif
+
+static const struct irq_domain_ops domain_ops = {
+	.map = combiner_irq_map,
+	.unmap = combiner_irq_unmap,
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+	.translate = combiner_irq_translate
+#endif
+};
+
+/*
+ * Device probing
+ */
+
+#ifdef CONFIG_ACPI
+
+static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
+{
+	int *count = context;
+
+	if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		++(*count);
+	return AE_OK;
+}
+
+static int count_registers(struct platform_device *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	acpi_status status;
+	int count = 0;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     count_registers_cb, &count);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+	return count;
+}
+
+struct get_registers_context {
+	struct device *dev;
+	struct combiner *combiner;
+	int err;
+};
+
+static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
+{
+	struct get_registers_context *ctx = context;
+	struct acpi_resource_generic_register *reg;
+	phys_addr_t paddr;
+	void __iomem *vaddr;
+
+	if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
+		return AE_OK;
+
+	reg = &ares->data.generic_reg;
+	paddr = reg->address;
+	if ((reg->space_id != ACPI_SPACE_MEM) ||
+	    (reg->bit_offset != 0) ||
+	    (reg->bit_width > REG_SIZE)) {
+		dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
+		ctx->err = -EINVAL;
+		return AE_ERROR;
+	}
+
+	vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
+	if (IS_ERR(vaddr)) {
+		dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
+		ctx->err = PTR_ERR(vaddr);
+		return AE_ERROR;
+	}
+
+	ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
+	ctx->combiner->nirqs += reg->bit_width;
+	ctx->combiner->nregs++;
+	return AE_OK;
+}
+
+static int get_registers(struct platform_device *pdev, struct combiner *comb)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	acpi_status status;
+	struct get_registers_context ctx;
+
+	if (!acpi_has_method(adev->handle, METHOD_NAME__CRS))
+		return -EINVAL;
+
+	ctx.dev = &pdev->dev;
+	ctx.combiner = comb;
+	ctx.err = 0;
+
+	status = acpi_walk_resources(adev->handle, METHOD_NAME__CRS,
+				     get_registers_cb, &ctx);
+	if (ACPI_FAILURE(status))
+		return ctx.err;
+	return 0;
+}
+
+#else /* !CONFIG_ACPI */
+
+static int count_registers(struct platform_device *pdev)
+{
+	return -EINVAL;
+}
+
+static int get_registers(struct platform_device *pdev, struct combiner *comb)
+{
+	return -EINVAL;
+}

So this driver is obviously ACPI only. Can't you just get rid of these,
of the #ifdef CONFIG_ACPI, and simply make it depend on ACPI?

+
+#endif
+
+static int __init combiner_probe(struct platform_device *pdev)
+{
+	struct combiner *combiner;
+	size_t alloc_sz;
+	u32 nregs;
+	int err;
+
+	nregs = count_registers(pdev);
+	if (nregs <= 0) {
+		dev_err(&pdev->dev, "Error reading register resources\n");
+		return -EINVAL;
+	}
+
+	alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
+	combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
+	if (!combiner)
+		return -ENOMEM;
+
+	err = get_registers(pdev, combiner);
+	if (err < 0)
+		return err;
+
+	combiner->parent_irq = platform_get_irq(pdev, 0);
+	if (combiner->parent_irq <= 0) {
+		dev_err(&pdev->dev, "Error getting IRQ resource\n");
+		return -EINVAL;

Can you ever get in a situation where it'd be more sensible to return
-EPROBE_DEFER? I'm thinking of a case where you'd have this irq chip
cascaded into another one, which is not present yet?

+	}
+
+	combiner->domain = irq_domain_create_linear(
+		pdev->dev.fwnode, combiner->nirqs, &domain_ops, combiner);

On a single line, please. Do no listen to the checkpatch police that
will tell you otherwise. It really hurt my eyes to see this opening
bracket and *nothing* after that.

+	if (!combiner->domain)
+		/* Errors printed by irq_domain_create_linear */
+		return -ENODEV;
+
+	irq_set_chained_handler_and_data(combiner->parent_irq,
+					 combiner_handle_irq, combiner);
+	combiner->irq_chip.irq_mask = combiner_irq_chip_mask_irq;
+	combiner->irq_chip.irq_unmask = combiner_irq_chip_unmask_irq;
+	combiner->irq_chip.name = pdev->name;

Arghh. Please don't do that. Once you've called irq_set_chained_*, the
interrupt is live, and can be requested. Unlikely, but still. In
general, feeding uninitialized data to a function is pretty bad.

Also, do you really need to show pdev->name in /proc/cpuinfo? Just make
the irq_chip structure static, outside of combiner, and have "QCOM80B1"
(or something of your liking) as the name once and for all.

+
+	dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
+		 combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
+	return 0;
+}
+
+static const struct acpi_device_id qcom_irq_combiner_acpi_match[] = {
+	{ "QCOM80B1", },
+	{ }
+};
+
+static struct platform_driver qcom_irq_combiner_probe = {
+	.driver = {
+		.name = "qcom-irq-combiner",
+		.owner = THIS_MODULE,
+		.acpi_match_table = ACPI_PTR(qcom_irq_combiner_acpi_match),
+	},
+	.probe = combiner_probe,
+};
+
+static int __init register_qcom_irq_combiner(void)
+{
+	return platform_driver_register(&qcom_irq_combiner_probe);
+}
+device_initcall(register_qcom_irq_combiner);

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...