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Message-ID: <4E81C9B7.9000004@gmail.com>
Date: Tue, 27 Sep 2011 08:03:51 -0500
From: Rob Herring <robherring2@...il.com>
To: Grant Likely <grant.likely@...retlab.ca>
CC: linux-arm-kernel@...ts.infradead.org,
devicetree-discuss@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
marc.zyngier@....com, thomas.abraham@...aro.org,
jamie@...ieiles.com, b-cousson@...com, shawn.guo@...aro.org
Subject: Re: [PATCH v4] of/irq: introduce of_irq_init
Grant,
On 09/26/2011 08:53 PM, Grant Likely wrote:
> On Mon, Sep 26, 2011 at 02:24:43PM -0500, Rob Herring wrote:
>> From: Rob Herring <rob.herring@...xeda.com>
>>
>> of_irq_init will scan the devicetree for matching interrupt controller
>> nodes. Then it calls an initialization function for each found controller
>> in the proper order with parent nodes initialized before child nodes.
>>
>> Based on initial pseudo code from Grant Likely.
>>
>> Changes in v4:
>> - Drop unnecessary empty list check
>> - Be more verbose on errors
>> - Simplify "if (!desc) WARN_ON(1)" to "if (WARN_ON(!desc))"
>>
>> Changes in v3:
>> - add missing kfree's found by Jamie
>> - Implement Grant's comments to simplify the init loop
>> - fix function comments
>>
>> Changes in v2:
>> - Complete re-write of list searching code from Grant Likely
>>
>> Signed-off-by: Rob Herring <rob.herring@...xeda.com>
>> Cc: Grant Likely <grant.likely@...retlab.ca>
>
> Looks good to me. Merged.
>
I'm dependent on this and things in rmk's tree for initial highbank
support, so should this series go in thru arm-soc tree? Several others
are dependent on this as well.
Rob
> g.
>
>> ---
>> drivers/of/irq.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++
>> include/linux/of_irq.h | 3 +
>> 2 files changed, 110 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
>> index 6a5b5e7..6d3dd39 100644
>> --- a/drivers/of/irq.c
>> +++ b/drivers/of/irq.c
>> @@ -19,10 +19,12 @@
>> */
>>
>> #include <linux/errno.h>
>> +#include <linux/list.h>
>> #include <linux/module.h>
>> #include <linux/of.h>
>> #include <linux/of_irq.h>
>> #include <linux/string.h>
>> +#include <linux/slab.h>
>>
>> /* For archs that don't support NO_IRQ (such as x86), provide a dummy value */
>> #ifndef NO_IRQ
>> @@ -386,3 +388,108 @@ int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
>>
>> return i;
>> }
>> +
>> +struct intc_desc {
>> + struct list_head list;
>> + struct device_node *dev;
>> + struct device_node *interrupt_parent;
>> +};
>> +
>> +/**
>> + * of_irq_init - Scan and init matching interrupt controllers in DT
>> + * @matches: 0 terminated array of nodes to match and init function to call
>> + *
>> + * This function scans the device tree for matching interrupt controller nodes,
>> + * and calls their initialization functions in order with parents first.
>> + */
>> +void __init of_irq_init(const struct of_device_id *matches)
>> +{
>> + struct device_node *np, *parent = NULL;
>> + struct intc_desc *desc, *temp_desc;
>> + struct list_head intc_desc_list, intc_parent_list;
>> +
>> + INIT_LIST_HEAD(&intc_desc_list);
>> + INIT_LIST_HEAD(&intc_parent_list);
>> +
>> + for_each_matching_node(np, matches) {
>> + if (!of_find_property(np, "interrupt-controller", NULL))
>> + continue;
>> + /*
>> + * Here, we allocate and populate an intc_desc with the node
>> + * pointer, interrupt-parent device_node etc.
>> + */
>> + desc = kzalloc(sizeof(*desc), GFP_KERNEL);
>> + if (WARN_ON(!desc))
>> + goto err;
>> +
>> + desc->dev = np;
>> + desc->interrupt_parent = of_irq_find_parent(np);
>> + list_add_tail(&desc->list, &intc_desc_list);
>> + }
>> +
>> + /*
>> + * The root irq controller is the one without an interrupt-parent.
>> + * That one goes first, followed by the controllers that reference it,
>> + * followed by the ones that reference the 2nd level controllers, etc.
>> + */
>> + while (!list_empty(&intc_desc_list)) {
>> + /*
>> + * Process all controllers with the current 'parent'.
>> + * First pass will be looking for NULL as the parent.
>> + * The assumption is that NULL parent means a root controller.
>> + */
>> + list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
>> + const struct of_device_id *match;
>> + int ret;
>> + of_irq_init_cb_t irq_init_cb;
>> +
>> + if (desc->interrupt_parent != parent)
>> + continue;
>> +
>> + list_del(&desc->list);
>> + match = of_match_node(matches, desc->dev);
>> + if (WARN(!match->data,
>> + "of_irq_init: no init function for %s\n",
>> + match->compatible)) {
>> + kfree(desc);
>> + continue;
>> + }
>> +
>> + pr_debug("of_irq_init: init %s @ %p, parent %p\n",
>> + match->compatible,
>> + desc->dev, desc->interrupt_parent);
>> + irq_init_cb = match->data;
>> + ret = irq_init_cb(desc->dev, desc->interrupt_parent);
>> + if (ret) {
>> + kfree(desc);
>> + continue;
>> + }
>> +
>> + /*
>> + * This one is now set up; add it to the parent list so
>> + * its children can get processed in a subsequent pass.
>> + */
>> + list_add_tail(&desc->list, &intc_parent_list);
>> + }
>> +
>> + /* Get the next pending parent that might have children */
>> + desc = list_first_entry(&intc_parent_list, typeof(*desc), list);
>> + if (list_empty(&intc_parent_list) || !desc) {
>> + pr_err("of_irq_init: children remain, but no parents\n");
>> + break;
>> + }
>> + list_del(&desc->list);
>> + parent = desc->dev;
>> + kfree(desc);
>> + }
>> +
>> + list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
>> + list_del(&desc->list);
>> + kfree(desc);
>> + }
>> +err:
>> + list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
>> + list_del(&desc->list);
>> + kfree(desc);
>> + }
>> +}
>> diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
>> index cd2e61c..d0307ee 100644
>> --- a/include/linux/of_irq.h
>> +++ b/include/linux/of_irq.h
>> @@ -33,6 +33,8 @@ struct of_irq {
>> u32 specifier[OF_MAX_IRQ_SPEC]; /* Specifier copy */
>> };
>>
>> +typedef int (*of_irq_init_cb_t)(struct device_node *, struct device_node *);
>> +
>> /*
>> * Workarounds only applied to 32bit powermac machines
>> */
>> @@ -73,6 +75,7 @@ extern int of_irq_to_resource_table(struct device_node *dev,
>> struct resource *res, int nr_irqs);
>> extern struct device_node *of_irq_find_parent(struct device_node *child);
>>
>> +extern void of_irq_init(const struct of_device_id *matches);
>>
>> #endif /* CONFIG_OF_IRQ */
>> #endif /* CONFIG_OF */
>> --
>> 1.7.5.4
>>
--
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