irqchip: crossbar: Initialise the crossbar with a safe value

Since crossbar is s/w configurable, the initial settings of the crossbar cannot be assumed to be sane. This implies that: a) On initialization all un-reserved crossbars must be initialized to a known 'safe' value. b) When unmapping the interrupt, the safe value must be written to ensure that the crossbar mapping matches with interrupt controller usage. So provide a safe value in the dt data to map if '0' is not safe for the platform and use it during init and unmap While at this, fix the below checkpatch warning. Fixes checkpatch warning: WARNING: Unnecessary space before function pointer arguments #37: FILE: drivers/irqchip/irq-crossbar.c:37: + void (*write) (int, int); Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Sricharan R <r.sricharan@ti.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>

irqchip: crossbar: Initialise the crossbar with a safe value
Since crossbar is s/w configurable, the initial settings of the crossbar cannot be assumed to be sane. This implies that: a) On initialization all un-reserved crossbars must be initialized to a known 'safe' value. b) When unmapping the interrupt, the safe value must be written to ensure that the crossbar mapping matches with interrupt controller usage. So provide a safe value in the dt data to map if '0' is not safe for the platform and use it during init and unmap While at this, fix the below checkpatch warning. Fixes checkpatch warning: WARNING: Unnecessary space before function pointer arguments #37: FILE: drivers/irqchip/irq-crossbar.c:37: + void (*write) (int, int); Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Sricharan R <r.sricharan@ti.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Nishanth Menon · Jason Cooper
1 parent 64e0f8ba5c
Showing 2 changed files with 20 additions and 2 deletions Side-by-side Diff
Documentation/devicetree/bindings/arm/omap/crossbar.txt
drivers/irqchip/irq-crossbar.c
@@ -22,6 +22,9 @@
   SOC-specific hard-wiring of those irqs which unexpectedly bypasses the
   crossbar. These irqs have a crossbar register, but still cannot be used.
  
+- ti,irqs-safe-map: integer which maps to a safe configuration to use
+  when the interrupt controller irq is unused (when not provided, default is 0)
+
 Examples:
 		crossbar_mpu: @4a020000 {
 			compatible = "ti,irq-crossbar";
@@ -23,16 +23,18 @@
  
 /*
  * @int_max: maximum number of supported interrupts
+ * @safe_map: safe default value to initialize the crossbar
  * @irq_map: array of interrupts to crossbar number mapping
  * @crossbar_base: crossbar base address
  * @register_offsets: offsets for each irq number
  */
 struct crossbar_device {
 	uint int_max;
+	uint safe_map;
 	uint *irq_map;
 	void __iomem *crossbar_base;
 	int *register_offsets;
-	void (*write) (int, int);
+	void (*write)(int, int);
 };
  
 static struct crossbar_device *cb;
  
@@ -88,8 +90,10 @@
 {
 	irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
  
-	if (hw > GIC_IRQ_START)
+	if (hw > GIC_IRQ_START) {
 		cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
+		cb->write(hw - GIC_IRQ_START, cb->safe_map);
+	}
 }
  
 static int crossbar_domain_xlate(struct irq_domain *d,
@@ -212,6 +216,17 @@
  
 		cb->register_offsets[i] = reserved;
 		reserved += size;
+	}
+
+	of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map);
+
+	/* Initialize the crossbar with safe map to start with */
+	for (i = 0; i < max; i++) {
+		if (cb->irq_map[i] == IRQ_RESERVED ||
+		    cb->irq_map[i] == IRQ_SKIP)
+			continue;
+
+		cb->write(i, cb->safe_map);
 	}
  
 	register_routable_domain_ops(&routable_irq_domain_ops);
...	...	@@ -22,6 +22,9 @@
22	22	SOC-specific hard-wiring of those irqs which unexpectedly bypasses the
23	23	crossbar. These irqs have a crossbar register, but still cannot be used.
24	24
	25	+- ti,irqs-safe-map: integer which maps to a safe configuration to use
	26	+ when the interrupt controller irq is unused (when not provided, default is 0)
	27	+
25	28	Examples:
26	29	crossbar_mpu: @4a020000 {
27	30	compatible = "ti,irq-crossbar";
...	...	@@ -23,16 +23,18 @@
23	23
24	24	/*
25	25	* @int_max: maximum number of supported interrupts
	26	+ * @safe_map: safe default value to initialize the crossbar
26	27	* @irq_map: array of interrupts to crossbar number mapping
27	28	* @crossbar_base: crossbar base address
28	29	* @register_offsets: offsets for each irq number
29	30	*/
30	31	struct crossbar_device {
31	32	uint int_max;
	33	+ uint safe_map;
32	34	uint *irq_map;
33	35	void __iomem *crossbar_base;
34	36	int *register_offsets;
35		- void (*write) (int, int);
	37	+ void (*write)(int, int);
36	38	};
37	39
38	40	static struct crossbar_device *cb;
39	41
...	...	@@ -88,8 +90,10 @@
88	90	{
89	91	irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
90	92
91		- if (hw > GIC_IRQ_START)
	93	+ if (hw > GIC_IRQ_START) {
92	94	cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
	95	+ cb->write(hw - GIC_IRQ_START, cb->safe_map);
	96	+ }
93	97	}
94	98
95	99	static int crossbar_domain_xlate(struct irq_domain *d,
...	...	@@ -212,6 +216,17 @@
212	216
213	217	cb->register_offsets[i] = reserved;
214	218	reserved += size;
	219	+ }
	220	+
	221	+ of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map);
	222	+
	223	+ /* Initialize the crossbar with safe map to start with */
	224	+ for (i = 0; i < max; i++) {
	225	+ if (cb->irq_map[i] == IRQ_RESERVED \|\|
	226	+ cb->irq_map[i] == IRQ_SKIP)
	227	+ continue;
	228	+
	229	+ cb->write(i, cb->safe_map);
215	230	}
216	231
217	232	register_routable_domain_ops(&routable_irq_domain_ops);