Add support for GIC crossbar that routes interrupts on newer omaps.

Looks like people wanted these merged via the omap tree as it's
 the only user for the GIC crossbar.
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Merge tag 'omap-for-v3.15/crossbar-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/drivers

Merge OMAP crossbar support from Tony Lindgren:

Add support for GIC crossbar that routes interrupts on newer omaps.

Looks like people wanted these merged via the omap tree as it's
the only user for the GIC crossbar.

* tag 'omap-for-v3.15/crossbar-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
  ARM: DRA: Enable Crossbar IP support for DRA7XX
  ARM: OMAP4+: Correct Wakeup-gen code to use physical irq number
  DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP
  DRIVERS: IRQCHIP: IRQ-GIC: Add support for routable irqs

Signed-off-by: Olof Johansson <olof@lixom.net>

Documentation/devicetree/bindings/arm/gic.txt

@@ -50,6 +50,11 @@ Optional
   regions, used when the GIC doesn't have banked registers. The offset is
   cpu-offset * cpu-nr.
 
+- arm,routable-irqs : Total number of gic irq inputs which are not directly
+		  connected from the peripherals, but are routed dynamically
+		  by a crossbar/multiplexer preceding the GIC. The GIC irq
+		  input line is assigned dynamically when the corresponding
+		  peripheral's crossbar line is mapped.
 Example:
 
 	intc: interrupt-controller@fff11000 {
@@ -57,6 +62,7 @@ Example:
 		#interrupt-cells = <3>;
 		#address-cells = <1>;
 		interrupt-controller;
+		arm,routable-irqs = <160>;
 		reg = <0xfff11000 0x1000>,
 		      <0xfff10100 0x100>;
 	};

Documentation/devicetree/bindings/arm/omap/crossbar.txt

@@ -0,0 +1,27 @@
+Some socs have a large number of interrupts requests to service
+the needs of its many peripherals and subsystems. All of the
+interrupt lines from the subsystems are not needed at the same
+time, so they have to be muxed to the irq-controller appropriately.
+In such places a interrupt controllers are preceded by an CROSSBAR
+that provides flexibility in muxing the device requests to the controller
+inputs.
+
+Required properties:
+- compatible : Should be "ti,irq-crossbar"
+- reg: Base address and the size of the crossbar registers.
+- ti,max-irqs: Total number of irqs available at the interrupt controller.
+- ti,reg-size: Size of a individual register in bytes. Every individual
+	    register is assumed to be of same size. Valid sizes are 1, 2, 4.
+- ti,irqs-reserved: List of the reserved irq lines that are not muxed using
+		 crossbar. These interrupt lines are reserved in the soc,
+		 so crossbar bar driver should not consider them as free
+		 lines.
+
+Examples:
+		crossbar_mpu: @4a020000 {
+			compatible = "ti,irq-crossbar";
+			reg = <0x4a002a48 0x130>;
+			ti,max-irqs = <160>;
+			ti,reg-size = <2>;
+			ti,irqs-reserved = <0 1 2 3 5 6 131 132 139 140>;
+		};

arch/arm/mach-omap2/Kconfig

@@ -85,6 +85,7 @@ config SOC_DRA7XX
 	select CPU_V7
 	select HAVE_SMP
 	select HAVE_ARM_ARCH_TIMER
+	select IRQ_CROSSBAR
 
 config ARCH_OMAP2PLUS
 	bool

arch/arm/mach-omap2/omap-wakeupgen.c

@@ -138,7 +138,7 @@ static void wakeupgen_mask(struct irq_data *d)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&wakeupgen_lock, flags);
-	_wakeupgen_clear(d->irq, irq_target_cpu[d->irq]);
+	_wakeupgen_clear(d->hwirq, irq_target_cpu[d->hwirq]);
 	raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
 }
 
@@ -150,7 +150,7 @@ static void wakeupgen_unmask(struct irq_data *d)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&wakeupgen_lock, flags);
-	_wakeupgen_set(d->irq, irq_target_cpu[d->irq]);
+	_wakeupgen_set(d->hwirq, irq_target_cpu[d->hwirq]);
 	raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
 }
 

arch/arm/mach-omap2/omap4-common.c

@@ -22,6 +22,7 @@
 #include <linux/of_platform.h>
 #include <linux/export.h>
 #include <linux/irqchip/arm-gic.h>
+#include <linux/irqchip/irq-crossbar.h>
 #include <linux/of_address.h>
 #include <linux/reboot.h>
 
@@ -288,5 +289,8 @@ void __init omap_gic_of_init(void)
 
 skip_errata_init:
 	omap_wakeupgen_init();
+#ifdef CONFIG_IRQ_CROSSBAR
+	irqcrossbar_init();
+#endif
 	irqchip_init();
 }

drivers/irqchip/Kconfig

@@ -69,3 +69,11 @@ config VERSATILE_FPGA_IRQ_NR
 config XTENSA_MX
 	bool
 	select IRQ_DOMAIN
+
+config IRQ_CROSSBAR
+	bool
+	help
+	  Support for a CROSSBAR ip that preceeds the main interrupt controller.
+	  The primary irqchip invokes the crossbar's callback which inturn allocates
+	  a free irq and configures the IP. Thus the peripheral interrupts are
+	  routed to one of the free irqchip interrupt lines.

drivers/irqchip/Makefile

@@ -26,3 +26,4 @@ obj-$(CONFIG_ARCH_VT8500)		+= irq-vt8500.o
 obj-$(CONFIG_TB10X_IRQC)		+= irq-tb10x.o
 obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
+obj-$(CONFIG_IRQ_CROSSBAR)		+= irq-crossbar.o

drivers/irqchip/irq-crossbar.c

@@ -0,0 +1,208 @@
+/*
+ *  drivers/irqchip/irq-crossbar.c
+ *
+ *  Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ *  Author: Sricharan R <r.sricharan@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/irqchip/arm-gic.h>
+
+#define IRQ_FREE	-1
+#define GIC_IRQ_START	32
+
+/*
+ * @int_max: maximum number of supported interrupts
+ * @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 *irq_map;
+	void __iomem *crossbar_base;
+	int *register_offsets;
+	void (*write) (int, int);
+};
+
+static struct crossbar_device *cb;
+
+static inline void crossbar_writel(int irq_no, int cb_no)
+{
+	writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writew(int irq_no, int cb_no)
+{
+	writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writeb(int irq_no, int cb_no)
+{
+	writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline int allocate_free_irq(int cb_no)
+{
+	int i;
+
+	for (i = 0; i < cb->int_max; i++) {
+		if (cb->irq_map[i] == IRQ_FREE) {
+			cb->irq_map[i] = cb_no;
+			return i;
+		}
+	}
+
+	return -ENODEV;
+}
+
+static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
+			       irq_hw_number_t hw)
+{
+	cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
+	return 0;
+}
+
+static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+	irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
+
+	if (hw > GIC_IRQ_START)
+		cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
+}
+
+static int crossbar_domain_xlate(struct irq_domain *d,
+				 struct device_node *controller,
+				 const u32 *intspec, unsigned int intsize,
+				 unsigned long *out_hwirq,
+				 unsigned int *out_type)
+{
+	unsigned long ret;
+
+	ret = allocate_free_irq(intspec[1]);
+
+	if (IS_ERR_VALUE(ret))
+		return ret;
+
+	*out_hwirq = ret + GIC_IRQ_START;
+	return 0;
+}
+
+const struct irq_domain_ops routable_irq_domain_ops = {
+	.map = crossbar_domain_map,
+	.unmap = crossbar_domain_unmap,
+	.xlate = crossbar_domain_xlate
+};
+
+static int __init crossbar_of_init(struct device_node *node)
+{
+	int i, size, max, reserved = 0, entry;
+	const __be32 *irqsr;
+
+	cb = kzalloc(sizeof(struct cb_device *), GFP_KERNEL);
+
+	if (!cb)
+		return -ENOMEM;
+
+	cb->crossbar_base = of_iomap(node, 0);
+	if (!cb->crossbar_base)
+		goto err1;
+
+	of_property_read_u32(node, "ti,max-irqs", &max);
+	cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL);
+	if (!cb->irq_map)
+		goto err2;
+
+	cb->int_max = max;
+
+	for (i = 0; i < max; i++)
+		cb->irq_map[i] = IRQ_FREE;
+
+	/* Get and mark reserved irqs */
+	irqsr = of_get_property(node, "ti,irqs-reserved", &size);
+	if (irqsr) {
+		size /= sizeof(__be32);
+
+		for (i = 0; i < size; i++) {
+			of_property_read_u32_index(node,
+						   "ti,irqs-reserved",
+						   i, &entry);
+			if (entry > max) {
+				pr_err("Invalid reserved entry\n");
+				goto err3;
+			}
+			cb->irq_map[entry] = 0;
+		}
+	}
+
+	cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL);
+	if (!cb->register_offsets)
+		goto err3;
+
+	of_property_read_u32(node, "ti,reg-size", &size);
+
+	switch (size) {
+	case 1:
+		cb->write = crossbar_writeb;
+		break;
+	case 2:
+		cb->write = crossbar_writew;
+		break;
+	case 4:
+		cb->write = crossbar_writel;
+		break;
+	default:
+		pr_err("Invalid reg-size property\n");
+		goto err4;
+		break;
+	}
+
+	/*
+	 * Register offsets are not linear because of the
+	 * reserved irqs. so find and store the offsets once.
+	 */
+	for (i = 0; i < max; i++) {
+		if (!cb->irq_map[i])
+			continue;
+
+		cb->register_offsets[i] = reserved;
+		reserved += size;
+	}
+
+	register_routable_domain_ops(&routable_irq_domain_ops);
+	return 0;
+
+err4:
+	kfree(cb->register_offsets);
+err3:
+	kfree(cb->irq_map);
+err2:
+	iounmap(cb->crossbar_base);
+err1:
+	kfree(cb);
+	return -ENOMEM;
+}
+
+static const struct of_device_id crossbar_match[] __initconst = {
+	{ .compatible = "ti,irq-crossbar" },
+	{}
+};
+
+int __init irqcrossbar_init(void)
+{
+	struct device_node *np;
+	np = of_find_matching_node(NULL, crossbar_match);
+	if (!np)
+		return -ENODEV;
+
+	crossbar_of_init(np);
+	return 0;
+}

drivers/irqchip/irq-gic.c

@@ -824,16 +824,25 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
 		irq_set_chip_and_handler(irq, &gic_chip,
 					 handle_fasteoi_irq);
 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+
+		gic_routable_irq_domain_ops->map(d, irq, hw);
 	}
 	irq_set_chip_data(irq, d->host_data);
 	return 0;
 }
 
+static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+	gic_routable_irq_domain_ops->unmap(d, irq);
+}
+
 static int gic_irq_domain_xlate(struct irq_domain *d,
 				struct device_node *controller,
 				const u32 *intspec, unsigned int intsize,
 				unsigned long *out_hwirq, unsigned int *out_type)
 {
+	unsigned long ret = 0;
+
 	if (d->of_node != controller)
 		return -EINVAL;
 	if (intsize < 3)
@@ -843,11 +852,20 @@ static int gic_irq_domain_xlate(struct irq_domain *d,
 	*out_hwirq = intspec[1] + 16;
 
 	/* For SPIs, we need to add 16 more to get the GIC irq ID number */
-	if (!intspec[0])
-		*out_hwirq += 16;
+	if (!intspec[0]) {
+		ret = gic_routable_irq_domain_ops->xlate(d, controller,
+							 intspec,
+							 intsize,
+							 out_hwirq,
+							 out_type);
+
+		if (IS_ERR_VALUE(ret))
+			return ret;
+	}
 
 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
-	return 0;
+
+	return ret;
 }
 
 #ifdef CONFIG_SMP
@@ -871,9 +889,41 @@ static struct notifier_block gic_cpu_notifier = {
 
 const struct irq_domain_ops gic_irq_domain_ops = {
 	.map = gic_irq_domain_map,
+	.unmap = gic_irq_domain_unmap,
 	.xlate = gic_irq_domain_xlate,
 };
 
+/* Default functions for routable irq domain */
+static int gic_routable_irq_domain_map(struct irq_domain *d, unsigned int irq,
+			      irq_hw_number_t hw)
+{
+	return 0;
+}
+
+static void gic_routable_irq_domain_unmap(struct irq_domain *d,
+					  unsigned int irq)
+{
+}
+
+static int gic_routable_irq_domain_xlate(struct irq_domain *d,
+				struct device_node *controller,
+				const u32 *intspec, unsigned int intsize,
+				unsigned long *out_hwirq,
+				unsigned int *out_type)
+{
+	*out_hwirq += 16;
+	return 0;
+}
+
+const struct irq_domain_ops gic_default_routable_irq_domain_ops = {
+	.map = gic_routable_irq_domain_map,
+	.unmap = gic_routable_irq_domain_unmap,
+	.xlate = gic_routable_irq_domain_xlate,
+};
+
+const struct irq_domain_ops *gic_routable_irq_domain_ops =
+					&gic_default_routable_irq_domain_ops;
+
 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 			   void __iomem *dist_base, void __iomem *cpu_base,
 			   u32 percpu_offset, struct device_node *node)
@@ -881,6 +931,7 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 	irq_hw_number_t hwirq_base;
 	struct gic_chip_data *gic;
 	int gic_irqs, irq_base, i;
+	int nr_routable_irqs;
 
 	BUG_ON(gic_nr >= MAX_GIC_NR);
 
@@ -946,14 +997,25 @@ void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 	gic->gic_irqs = gic_irqs;
 
 	gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
-	irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, numa_node_id());
-	if (IS_ERR_VALUE(irq_base)) {
-		WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
-		     irq_start);
-		irq_base = irq_start;
+
+	if (of_property_read_u32(node, "arm,routable-irqs",
+				 &nr_routable_irqs)) {
+		irq_base = irq_alloc_descs(irq_start, 16, gic_irqs,
+					   numa_node_id());
+		if (IS_ERR_VALUE(irq_base)) {
+			WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
+			     irq_start);
+			irq_base = irq_start;
+		}
+
+		gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
+					hwirq_base, &gic_irq_domain_ops, gic);
+	} else {
+		gic->domain = irq_domain_add_linear(node, nr_routable_irqs,
+						    &gic_irq_domain_ops,
+						    gic);
 	}
-	gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
-				    hwirq_base, &gic_irq_domain_ops, gic);
+
 	if (WARN_ON(!gic->domain))
 		return;
 

include/linux/irqchip/arm-gic.h

@@ -93,6 +93,11 @@ int gic_get_cpu_id(unsigned int cpu);
 void gic_migrate_target(unsigned int new_cpu_id);
 unsigned long gic_get_sgir_physaddr(void);
 
+extern const struct irq_domain_ops *gic_routable_irq_domain_ops;
+static inline void __init register_routable_domain_ops
+					(const struct irq_domain_ops *ops)
+{
+	gic_routable_irq_domain_ops = ops;
+}
 #endif /* __ASSEMBLY */
-
 #endif

include/linux/irqchip/irq-crossbar.h

@@ -0,0 +1,11 @@
+/*
+ *  drivers/irqchip/irq-crossbar.h
+ *
+ *  Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+int irqcrossbar_init(void);