irqchip/brcmstb-l2: Add support for the BCM7271 L2 controller

Add the initialization of the generic irq chip for the BCM7271 L2
interrupt controller.  This controller only supports level
interrupts and uses the "brcm,bcm7271-l2-intc" compatibility
string.

Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Doug Berger <opendmb@gmail.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Documentation/devicetree/bindings/interrupt-controller/brcm,l2-intc.txt

@@ -2,7 +2,8 @@ Broadcom Generic Level 2 Interrupt Controller
 
 Required properties:
 
-- compatible: should be "brcm,l2-intc"
+- compatible: should be "brcm,l2-intc" for latched interrupt controllers
+              should be "brcm,bcm7271-l2-intc" for level interrupt controllers
 - reg: specifies the base physical address and size of the registers
 - interrupt-controller: identifies the node as an interrupt controller
 - #interrupt-cells: specifies the number of cells needed to encode an

drivers/irqchip/irq-brcmstb-l2.c

@@ -31,13 +31,34 @@
 #include <linux/irqchip.h>
 #include <linux/irqchip/chained_irq.h>
 
-/* Register offsets in the L2 interrupt controller */
-#define CPU_STATUS	0x00
-#define CPU_SET		0x04
-#define CPU_CLEAR	0x08
-#define CPU_MASK_STATUS	0x0c
-#define CPU_MASK_SET	0x10
-#define CPU_MASK_CLEAR	0x14
+struct brcmstb_intc_init_params {
+	irq_flow_handler_t handler;
+	int cpu_status;
+	int cpu_clear;
+	int cpu_mask_status;
+	int cpu_mask_set;
+	int cpu_mask_clear;
+};
+
+/* Register offsets in the L2 latched interrupt controller */
+static const struct brcmstb_intc_init_params l2_edge_intc_init = {
+	.handler		= handle_edge_irq,
+	.cpu_status		= 0x00,
+	.cpu_clear		= 0x08,
+	.cpu_mask_status	= 0x0c,
+	.cpu_mask_set		= 0x10,
+	.cpu_mask_clear		= 0x14
+};
+
+/* Register offsets in the L2 level interrupt controller */
+static const struct brcmstb_intc_init_params l2_lvl_intc_init = {
+	.handler		= handle_level_irq,
+	.cpu_status		= 0x00,
+	.cpu_clear		= -1, /* Register not present */
+	.cpu_mask_status	= 0x04,
+	.cpu_mask_set		= 0x08,
+	.cpu_mask_clear		= 0x0C
+};
 
 /* L2 intc private data structure */
 struct brcmstb_l2_intc_data {
@@ -128,7 +149,7 @@ static void brcmstb_l2_intc_resume(struct irq_data *d)
 	struct brcmstb_l2_intc_data *b = gc->private;
 
 	irq_gc_lock(gc);
-	if (ct->chip.irq_ack != irq_gc_noop) {
+	if (ct->chip.irq_ack) {
 		/* Clear unmasked non-wakeup interrupts */
 		irq_reg_writel(gc, ~b->saved_mask & ~gc->wake_active,
 				ct->regs.ack);
@@ -141,7 +162,9 @@ static void brcmstb_l2_intc_resume(struct irq_data *d)
 }
 
 static int __init brcmstb_l2_intc_of_init(struct device_node *np,
-					  struct device_node *parent)
+					  struct device_node *parent,
+					  const struct brcmstb_intc_init_params
+					  *init_params)
 {
 	unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
 	struct brcmstb_l2_intc_data *data;
@@ -163,12 +186,12 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
 	}
 
 	/* Disable all interrupts by default */
-	writel(0xffffffff, base + CPU_MASK_SET);
+	writel(0xffffffff, base + init_params->cpu_mask_set);
 
 	/* Wakeup interrupts may be retained from S5 (cold boot) */
 	data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
-	if (!data->can_wake)
-		writel(0xffffffff, base + CPU_CLEAR);
+	if (!data->can_wake && (init_params->cpu_clear >= 0))
+		writel(0xffffffff, base + init_params->cpu_clear);
 
 	parent_irq = irq_of_parse_and_map(np, 0);
 	if (!parent_irq) {
@@ -193,7 +216,7 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
 
 	/* Allocate a single Generic IRQ chip for this node */
 	ret = irq_alloc_domain_generic_chips(data->domain, 32, 1,
-				np->full_name, handle_edge_irq, clr, 0, flags);
+			np->full_name, init_params->handler, clr, 0, flags);
 	if (ret) {
 		pr_err("failed to allocate generic irq chip\n");
 		goto out_free_domain;
@@ -206,21 +229,26 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
 	data->gc = irq_get_domain_generic_chip(data->domain, 0);
 	data->gc->reg_base = base;
 	data->gc->private = data;
-	data->status_offset = CPU_STATUS;
-	data->mask_offset = CPU_MASK_STATUS;
+	data->status_offset = init_params->cpu_status;
+	data->mask_offset = init_params->cpu_mask_status;
 
 	ct = data->gc->chip_types;
 
-	ct->chip.irq_ack = irq_gc_ack_set_bit;
-	ct->regs.ack = CPU_CLEAR;
+	if (init_params->cpu_clear >= 0) {
+		ct->regs.ack = init_params->cpu_clear;
+		ct->chip.irq_ack = irq_gc_ack_set_bit;
+		ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
+	} else {
+		/* No Ack - but still slightly more efficient to define this */
+		ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
+	}
 
 	ct->chip.irq_mask = irq_gc_mask_disable_reg;
-	ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
-	ct->regs.disable = CPU_MASK_SET;
-	ct->regs.mask = CPU_MASK_STATUS;
+	ct->regs.disable = init_params->cpu_mask_set;
+	ct->regs.mask = init_params->cpu_mask_status;
 
 	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
-	ct->regs.enable = CPU_MASK_CLEAR;
+	ct->regs.enable = init_params->cpu_mask_clear;
 
 	ct->chip.irq_suspend = brcmstb_l2_intc_suspend;
 	ct->chip.irq_resume = brcmstb_l2_intc_resume;
@@ -247,4 +275,18 @@ out_free:
 	kfree(data);
 	return ret;
 }
-IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_intc_of_init);
+
+int __init brcmstb_l2_edge_intc_of_init(struct device_node *np,
+	struct device_node *parent)
+{
+	return brcmstb_l2_intc_of_init(np, parent, &l2_edge_intc_init);
+}
+IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,l2-intc", brcmstb_l2_edge_intc_of_init);
+
+int __init brcmstb_l2_lvl_intc_of_init(struct device_node *np,
+	struct device_node *parent)
+{
+	return brcmstb_l2_intc_of_init(np, parent, &l2_lvl_intc_init);
+}
+IRQCHIP_DECLARE(bcm7271_l2_intc, "brcm,bcm7271-l2-intc",
+	brcmstb_l2_lvl_intc_of_init);