of/irq: do irq resolution in platform_get_irq

Currently we get the following kind of errors if we try to use interrupt
phandles to irqchips that have not yet initialized:

irq: no irq domain found for /ocp/pinmux@48002030 !
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at drivers/of/platform.c:171 of_device_alloc+0x144/0x184()
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.12.0-00038-g42a9708 #1012
(show_stack+0x14/0x1c)
(dump_stack+0x6c/0xa0)
(warn_slowpath_common+0x64/0x84)
(warn_slowpath_null+0x1c/0x24)
(of_device_alloc+0x144/0x184)
(of_platform_device_create_pdata+0x44/0x9c)
(of_platform_bus_create+0xd0/0x170)
(of_platform_bus_create+0x12c/0x170)
(of_platform_populate+0x60/0x98)

This is because we're wrongly trying to populate resources that are not
yet available. It's perfectly valid to create irqchips dynamically, so
let's fix up the issue by resolving the interrupt resources when
platform_get_irq is called.

And then we also need to accept the fact that some irqdomains do not
exist that early on, and only get initialized later on. So we can
make the current WARN_ON into just into a pr_debug().

We still attempt to populate irq resources when we create the devices.
This allows current drivers which don't use platform_get_irq to continue
to function. Once all drivers are fixed, this code can be removed.

Suggested-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Cc: stable@vger.kernel.org # v3.10+
Signed-off-by: Grant Likely <grant.likely@linaro.org>

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index e714709704e4578ccc3703ca30108e596461ad28..5b47210889e038d72f7a172062b3c4ddd2daa07d 100644 (file)
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -13,6 +13,7 @@
 #include <linux/string.h>
 #include <linux/platform_device.h>
 #include <linux/of_device.h>
+#include <linux/of_irq.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/dma-mapping.h>
@@ -87,7 +88,11 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
                return -ENXIO;
        return dev->archdata.irqs[num];
 #else
-       struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
+       struct resource *r;
+       if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node)
+               return of_irq_get(dev->dev.of_node, num);
+
+       r = platform_get_resource(dev, IORESOURCE_IRQ, num);
 
        return r ? r->start : -ENXIO;
 #endif

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e2e4c548a42fc30b82996a24df8853e1a83cdaf0..5aeb89411350a4c98a2d769302e16a8d650d075f 100644 (file)
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -379,6 +379,32 @@ int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
 }
 EXPORT_SYMBOL_GPL(of_irq_to_resource);
 
+/**
+ * of_irq_get - Decode a node's IRQ and return it as a Linux irq number
+ * @dev: pointer to device tree node
+ * @index: zero-based index of the irq
+ *
+ * Returns Linux irq number on success, or -EPROBE_DEFER if the irq domain
+ * is not yet created.
+ *
+ */
+int of_irq_get(struct device_node *dev, int index)
+{
+       int rc;
+       struct of_phandle_args oirq;
+       struct irq_domain *domain;
+
+       rc = of_irq_parse_one(dev, index, &oirq);
+       if (rc)
+               return rc;
+
+       domain = irq_find_host(oirq.np);
+       if (!domain)
+               return -EPROBE_DEFER;
+
+       return irq_create_of_mapping(&oirq);
+}
+
 /**
  * of_irq_count - Count the number of IRQs a node uses
  * @dev: pointer to device tree node

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1daebefa7d7a5d02cbfb611e9585077c00b0..bd47fbc53dc96258fba942d073ee320f25e5627f 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -168,7 +168,9 @@ struct platform_device *of_device_alloc(struct device_node *np,
                        rc = of_address_to_resource(np, i, res);
                        WARN_ON(rc);
                }
-               WARN_ON(of_irq_to_resource_table(np, res, num_irq) != num_irq);
+               if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
+                       pr_debug("not all legacy IRQ resources mapped for %s\n",
+                                np->name);
        }
 
        dev->dev.of_node = of_node_get(np);

diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index 3f23b4472c3150990237a566ba2d46acb1d1aa82..6404253d810d7482a64fa9e959e99c8bad05c912 100644 (file)
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -44,11 +44,16 @@ extern void of_irq_init(const struct of_device_id *matches);
 
 #ifdef CONFIG_OF_IRQ
 extern int of_irq_count(struct device_node *dev);
+extern int of_irq_get(struct device_node *dev, int index);
 #else
 static inline int of_irq_count(struct device_node *dev)
 {
        return 0;
 }
+static inline int of_irq_get(struct device_node *dev, int index)
+{
+       return 0;
+}
 #endif
 
 #if defined(CONFIG_OF)