diff mbox

[09/17] irqchip/irq-mvebu-icu: support ICU subnodes

Message ID 20180421135537.24716-10-miquel.raynal@bootlin.com
State New, archived
Headers show

Commit Message

Miquel Raynal April 21, 2018, 1:55 p.m. UTC
Introduce new bindings for the ICU.

Each DT subnode of the ICU represents a type of interrupt that should
be handled separately. Add the possibility for the ICU to have subnodes
and probe each of them automatically with devm_platform_populate(). If
the node as no child, the probe function for NSRs will still be called
'manually'.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 drivers/irqchip/irq-mvebu-icu.c | 85 +++++++++++++++++++++++++++++++++--------
 1 file changed, 70 insertions(+), 15 deletions(-)

Comments

Thomas Petazzoni May 2, 2018, 8:13 a.m. UTC | #1
Hello Miquèl,

On Sat, 21 Apr 2018 15:55:29 +0200, Miquel Raynal wrote:
> Introduce new bindings for the ICU.

Perhaps this should explain *why* we need new bindings.

> Each DT subnode of the ICU represents a type of interrupt that should
> be handled separately. Add the possibility for the ICU to have subnodes
> and probe each of them automatically with devm_platform_populate(). If
> the node as no child, the probe function for NSRs will still be called
> 'manually'.

 ... in order to preserve backward compatibility with Device Trees
 using the old binding.

> +static struct mvebu_icu *mvebu_dev_get_drvdata(struct platform_device *pdev)

The function should be prefixed by mvebu_icu_, not just mvebu_.

> +{
> +	struct mvebu_icu *icu;
> +
> +	icu = dev_get_drvdata(&pdev->dev);
> +	if (icu) {
> +		/* Legacy bindings: get the device data */

I find this comment weird, because it doesn't document what the test
just below is doing.

> +		if (!icu->legacy_bindings)
> +			return ERR_PTR(-EINVAL);
> +	} else {
> +		/* New bindings: get the parent device (ICU) data */
> +		icu = dev_get_drvdata(pdev->dev.parent);
> +		if (!icu)
> +			return ERR_PTR(-ENODEV);
> +		if (icu->legacy_bindings)
> +			return ERR_PTR(-EINVAL);
> +	}


> @@ -144,7 +170,10 @@ mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
>  		goto free_irqd;
>  	}
>  
> -	icu_irqd->icu_group = fwspec->param[0];
> +	if (icu->legacy_bindings)
> +		icu_irqd->icu_group = fwspec->param[0];
> +	else
> +		icu_irqd->icu_group = ICU_GRP_NSR;

In practice here fwspec->param[0] is always going to be equal to
ICU_GRP_NSR, but OK, the test makes sense as in a future commit, the
"else" case will be changed to support SEIs.

> +static const struct of_device_id mvebu_icu_nsr_of_match[] = {
> +	{ .compatible = "marvell,cp110-icu-nsr", },
> +	{},
> +};
> +
> +static struct platform_driver mvebu_icu_nsr_driver = {
> +	.probe  = mvebu_icu_nsr_probe,
> +	.driver = {
> +		.name = "mvebu-icu-nsr",
> +		.of_match_table = mvebu_icu_nsr_of_match,
> +	},
> +};
> +builtin_platform_driver(mvebu_icu_nsr_driver);

I'm not sure why you call this icu_nsr here, and change it later to
icu_subset. Wouldn't it make sense to call it right away with the final
name ? Note that this is not a very strong request to change this
aspect, I'm fine with how it's done today, it's just that I would have
done it differently.

Other than that, looks good to me.

Thomas
Miquel Raynal May 4, 2018, 8:32 a.m. UTC | #2
Hi Thomas,

On Wed, 2 May 2018 10:13:00 +0200, Thomas Petazzoni
<thomas.petazzoni@bootlin.com> wrote:

> Hello Miquèl,
> 
> On Sat, 21 Apr 2018 15:55:29 +0200, Miquel Raynal wrote:
> > Introduce new bindings for the ICU.  
> 
> Perhaps this should explain *why* we need new bindings.

Sure, I changed the whole message by:

    The ICU can handle several type of interrupt, each of them being
    handled differently on AP side. On CP side, the ICU should be able
    to make the distinction between each interrupt group by pointing to
    the right parent.
    
    This is done through the introduction of new bindings, presenting
    the ICU node as the parent of multiple ICU sub-nodes, each of them
    being an interrupt type with a different interrupt parent. ICU
    interrupt 'clients' now directly point to the right sub-node,
    avoiding the need for the extra ICU_GRP_* parameter.
    
    ICU subnodes are probed automatically with
    devm_platform_populate(). If the node as no child, the probe
    function for NSRs will still be called 'manually' in order to
    preserve backward compatibility with DT using the old binding.
    
> 
> > Each DT subnode of the ICU represents a type of interrupt that should
> > be handled separately. Add the possibility for the ICU to have subnodes
> > and probe each of them automatically with devm_platform_populate(). If
> > the node as no child, the probe function for NSRs will still be called
> > 'manually'.  
> 
>  ... in order to preserve backward compatibility with Device Trees
>  using the old binding.

Added, see above.

> 
> > +static struct mvebu_icu *mvebu_dev_get_drvdata(struct platform_device *pdev)  
> 
> The function should be prefixed by mvebu_icu_, not just mvebu_.

Changed.

> 
> > +{
> > +	struct mvebu_icu *icu;
> > +
> > +	icu = dev_get_drvdata(&pdev->dev);
> > +	if (icu) {
> > +		/* Legacy bindings: get the device data */  
> 
> I find this comment weird, because it doesn't document what the test
> just below is doing.

Refactored a bit the comments in this section.

> 
> > +		if (!icu->legacy_bindings)
> > +			return ERR_PTR(-EINVAL);
> > +	} else {
> > +		/* New bindings: get the parent device (ICU) data */
> > +		icu = dev_get_drvdata(pdev->dev.parent);
> > +		if (!icu)
> > +			return ERR_PTR(-ENODEV);
> > +		if (icu->legacy_bindings)
> > +			return ERR_PTR(-EINVAL);
> > +	}  
> 
> 
> > @@ -144,7 +170,10 @@ mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> >  		goto free_irqd;
> >  	}
> >  
> > -	icu_irqd->icu_group = fwspec->param[0];
> > +	if (icu->legacy_bindings)
> > +		icu_irqd->icu_group = fwspec->param[0];
> > +	else
> > +		icu_irqd->icu_group = ICU_GRP_NSR;  
> 
> In practice here fwspec->param[0] is always going to be equal to
> ICU_GRP_NSR, but OK, the test makes sense as in a future commit, the
> "else" case will be changed to support SEIs.
> 
> > +static const struct of_device_id mvebu_icu_nsr_of_match[] = {
> > +	{ .compatible = "marvell,cp110-icu-nsr", },
> > +	{},
> > +};
> > +
> > +static struct platform_driver mvebu_icu_nsr_driver = {
> > +	.probe  = mvebu_icu_nsr_probe,
> > +	.driver = {
> > +		.name = "mvebu-icu-nsr",
> > +		.of_match_table = mvebu_icu_nsr_of_match,
> > +	},
> > +};
> > +builtin_platform_driver(mvebu_icu_nsr_driver);  
> 
> I'm not sure why you call this icu_nsr here, and change it later to
> icu_subset. Wouldn't it make sense to call it right away with the final
> name ? Note that this is not a very strong request to change this
> aspect, I'm fine with how it's done today, it's just that I would have
> done it differently.

I thought calling it icu_subset right now would not be very clear as
there are not "ICU subset" other than NSR interrupts, but I changed it,
this is not a big deal.

> 
> Other than that, looks good to me.
> 
> Thomas

Thanks for the review,
Miquèl
diff mbox

Patch

diff --git a/drivers/irqchip/irq-mvebu-icu.c b/drivers/irqchip/irq-mvebu-icu.c
index c919110dcee5..1d3cd112619c 100644
--- a/drivers/irqchip/irq-mvebu-icu.c
+++ b/drivers/irqchip/irq-mvebu-icu.c
@@ -44,6 +44,7 @@  struct mvebu_icu {
 	struct irq_chip irq_chip;
 	struct regmap *regmap;
 	struct device *dev;
+	bool legacy_bindings;
 };
 
 struct mvebu_icu_irq_data {
@@ -52,6 +53,27 @@  struct mvebu_icu_irq_data {
 	unsigned int type;
 };
 
+static struct mvebu_icu *mvebu_dev_get_drvdata(struct platform_device *pdev)
+{
+	struct mvebu_icu *icu;
+
+	icu = dev_get_drvdata(&pdev->dev);
+	if (icu) {
+		/* Legacy bindings: get the device data */
+		if (!icu->legacy_bindings)
+			return ERR_PTR(-EINVAL);
+	} else {
+		/* New bindings: get the parent device (ICU) data */
+		icu = dev_get_drvdata(pdev->dev.parent);
+		if (!icu)
+			return ERR_PTR(-ENODEV);
+		if (icu->legacy_bindings)
+			return ERR_PTR(-EINVAL);
+	}
+
+	return icu;
+}
+
 static void mvebu_icu_write_msg(struct msi_desc *desc, struct msi_msg *msg)
 {
 	struct irq_data *d = irq_get_irq_data(desc->irq);
@@ -94,31 +116,35 @@  mvebu_icu_irq_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
 			       unsigned long *hwirq, unsigned int *type)
 {
 	struct mvebu_icu *icu = platform_msi_get_host_data(d);
-	unsigned int icu_group;
+	unsigned int param_count = icu->legacy_bindings ? 3 : 2;
 
 	/* Check the count of the parameters in dt */
-	if (WARN_ON(fwspec->param_count < 3)) {
+	if (WARN_ON(fwspec->param_count != param_count)) {
 		dev_err(icu->dev, "wrong ICU parameter count %d\n",
 			fwspec->param_count);
 		return -EINVAL;
 	}
 
-	/* Only ICU group type is handled */
-	icu_group = fwspec->param[0];
-	if (icu_group != ICU_GRP_NSR && icu_group != ICU_GRP_SR &&
-	    icu_group != ICU_GRP_SEI && icu_group != ICU_GRP_REI) {
-		dev_err(icu->dev, "wrong ICU group type %x\n", icu_group);
-		return -EINVAL;
+	if (icu->legacy_bindings) {
+		*hwirq = fwspec->param[1];
+		*type = fwspec->param[2];
+		if (fwspec->param[0] != ICU_GRP_NSR) {
+			dev_err(icu->dev, "wrong ICU group type %x\n",
+				fwspec->param[0]);
+			return -EINVAL;
+		}
+	} else {
+		*hwirq = fwspec->param[0];
+		*type = fwspec->param[1];
 	}
 
-	*hwirq = fwspec->param[1];
 	if (*hwirq >= ICU_MAX_IRQS) {
 		dev_err(icu->dev, "invalid interrupt number %ld\n", *hwirq);
 		return -EINVAL;
 	}
 
 	/* Mask the type to prevent wrong DT configuration */
-	*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
+	*type &= IRQ_TYPE_SENSE_MASK;
 
 	return 0;
 }
@@ -144,7 +170,10 @@  mvebu_icu_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 		goto free_irqd;
 	}
 
-	icu_irqd->icu_group = fwspec->param[0];
+	if (icu->legacy_bindings)
+		icu_irqd->icu_group = fwspec->param[0];
+	else
+		icu_irqd->icu_group = ICU_GRP_NSR;
 	icu_irqd->icu = icu;
 
 	err = platform_msi_domain_alloc(domain, virq, nr_irqs);
@@ -200,9 +229,9 @@  static int mvebu_icu_nsr_probe(struct platform_device *pdev)
 	phys_addr_t set, clr;
 	int ret;
 
-	icu = dev_get_drvdata(&pdev->dev);
-	if (!icu)
-		return -ENODEV;
+	icu = mvebu_dev_get_drvdata(pdev);
+	if (IS_ERR(icu))
+		return PTR_ERR(icu);
 
 	pdev->dev.msi_domain = of_msi_get_domain(&pdev->dev, pdev->dev.of_node,
 						 DOMAIN_BUS_PLATFORM_MSI);
@@ -235,6 +264,20 @@  static int mvebu_icu_nsr_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id mvebu_icu_nsr_of_match[] = {
+	{ .compatible = "marvell,cp110-icu-nsr", },
+	{},
+};
+
+static struct platform_driver mvebu_icu_nsr_driver = {
+	.probe  = mvebu_icu_nsr_probe,
+	.driver = {
+		.name = "mvebu-icu-nsr",
+		.of_match_table = mvebu_icu_nsr_of_match,
+	},
+};
+builtin_platform_driver(mvebu_icu_nsr_driver);
+
 static int mvebu_icu_probe(struct platform_device *pdev)
 {
 	struct mvebu_icu *icu;
@@ -262,6 +305,15 @@  static int mvebu_icu_probe(struct platform_device *pdev)
 	if (!icu->irq_chip.name)
 		return -ENOMEM;
 
+	/*
+	 * Legacy bindings: ICU is one node with one MSI parent: force manually
+	 *                  the probe of the NSR interrupts side.
+	 * New bindings: ICU node has children, one per interrupt controller
+	 *               having its own MSI parent: call platform_populate().
+	 */
+	if (!of_get_child_count(pdev->dev.of_node))
+		icu->legacy_bindings = true;
+
 	icu->irq_chip.irq_mask = irq_chip_mask_parent;
 	icu->irq_chip.irq_unmask = irq_chip_unmask_parent;
 	icu->irq_chip.irq_eoi = irq_chip_eoi_parent;
@@ -286,7 +338,10 @@  static int mvebu_icu_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, icu);
 
-	return mvebu_icu_nsr_probe(pdev);
+	if (icu->legacy_bindings)
+		return mvebu_icu_nsr_probe(pdev);
+	else
+		return devm_of_platform_populate(&pdev->dev);
 }
 
 static const struct of_device_id mvebu_icu_of_match[] = {