BCM2708: Use upstream interrupt driver on all Pi1's (Take 2)

0001-BCM2708-Use-upstream-interrupt-driver-on-all-Pi1-s.patch

From f27eee8d093a553d7249a9d8e4231f1f0f781c6e Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.org>
Date: Wed, 19 Aug 2015 08:49:11 +0100
Subject: [PATCH] BCM2708: Use upstream interrupt driver on all Pi1's

Although the aim is to delete the old armctrl driver, that can't happen
while non-DT configurations are still supported. This commit enables
use of the new FIQ-enabled upstream irqchip driver when DT is enabled
on all BCM2835-based RPi platforms (Models A, B, A+, B+ & CM).

BCM2836-based platforms (Pi 2) will get the same treatment at a later
date, unless non-DT support has already been withdrawn.
---
 arch/arm/Kconfig                             |  1 +
 arch/arm/boot/dts/bcm2708.dtsi               |  4 ++
 arch/arm/boot/dts/bcm2708_common.dtsi        |  2 +-
 arch/arm/mach-bcm2708/armctrl.c              | 68 ++++++++++++++++++++++++++++
 arch/arm/mach-bcm2708/bcm2708.c              |  6 ++-
 drivers/irqchip/Makefile                     |  1 +
 drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c |  5 +-
 7 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 10fede1..8d35327 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -330,6 +330,7 @@ config ARCH_BCM2708
 	select GENERIC_CLOCKEVENTS
 	select ARM_ERRATA_411920
 	select MACH_BCM2708
+	select MULTI_IRQ_HANDLER
 	select VC4
 	select FIQ
 	help
diff --git a/arch/arm/boot/dts/bcm2708.dtsi b/arch/arm/boot/dts/bcm2708.dtsi
index 57d4c56..b5b54ce 100644
--- a/arch/arm/boot/dts/bcm2708.dtsi
+++ b/arch/arm/boot/dts/bcm2708.dtsi
@@ -24,3 +24,7 @@
 		};
 	};
 };
+
+&intc {
+	compatible = "brcm,bcm2835-armctrl-ic";
+};
diff --git a/arch/arm/boot/dts/bcm2708_common.dtsi b/arch/arm/boot/dts/bcm2708_common.dtsi
index f096f45..0420ebcb 100644
--- a/arch/arm/boot/dts/bcm2708_common.dtsi
+++ b/arch/arm/boot/dts/bcm2708_common.dtsi
@@ -65,7 +65,7 @@
 			brcm,dma-channel-mask = <0x0f35>;
 		};
 
-		intc: interrupt-controller {
+		intc: interrupt-controller@7e00b200 {
 			compatible = "brcm,bcm2708-armctrl-ic";
 			reg = <0x7e00b200 0x200>;
 			interrupt-controller;
diff --git a/arch/arm/mach-bcm2708/armctrl.c b/arch/arm/mach-bcm2708/armctrl.c
index 0429225..16c6746 100644
--- a/arch/arm/mach-bcm2708/armctrl.c
+++ b/arch/arm/mach-bcm2708/armctrl.c
@@ -26,10 +26,22 @@
 #include <linux/irqdomain.h>
 #include <linux/of.h>
 
+#include <asm/exception.h>
 #include <asm/mach/irq.h>
 #include <mach/hardware.h>
 #include "armctrl.h"
 
+/* Mask out shortcut interrupts where they also appear in the regular bank */
+#define BANK0_HWIRQ	0x001ffcff
+#define BANK1_HWIRQ	BIT(8)
+#define BANK2_HWIRQ	BIT(9)
+#define BANK0_VALID_MASK \
+	(BANK0_HWIRQ + BANK1_HWIRQ + BANK2_HWIRQ)
+#define BANK1_VALID_MASK \
+	(~(BIT(7) | BIT(9) | BIT(10) | BIT(18) | BIT(19)))
+#define BANK2_VALID_MASK \
+	(~(BIT(21) | BIT(22) | BIT(23) | BIT(24) | BIT(25) | BIT(30)))
+
 /* For support of kernels >= 3.0 assume only one VIC for now*/
 static unsigned int remap_irqs[(INTERRUPT_ARASANSDIO + 1) - INTERRUPT_JPEG] = {
 	INTERRUPT_VC_JPEG,
@@ -285,6 +297,59 @@ static struct irq_chip armctrl_chip = {
 	.irq_set_wake = armctrl_set_wake,
 };
 
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+
+static void __exception_irq_entry armctrl_handle_irq(
+	struct pt_regs *regs)
+{
+	u32 stat;
+
+	while ((stat = readl_relaxed(__io_address(ARM_IRQ_PEND0)) &
+		BANK0_VALID_MASK)) {
+		u32 stat2;
+		u32 irq;
+
+		if (stat & BANK0_HWIRQ) {
+			irq = ARM_IRQ0_BASE + ffs(stat & BANK0_HWIRQ) - 1;
+		} else if (stat & BANK1_HWIRQ) {
+			stat2 = readl_relaxed(__io_address(ARM_IRQ_PEND1)) &
+				BANK1_VALID_MASK;
+			if (stat2)
+				irq = ARM_IRQ1_BASE +
+					ffs(stat2 & BANK1_VALID_MASK) - 1;
+			else
+				continue;
+		} else if (stat & BANK2_HWIRQ) {
+			stat2 = readl_relaxed(__io_address(ARM_IRQ_PEND2)) &
+				BANK2_VALID_MASK;
+			if (stat2)
+				irq = ARM_IRQ2_BASE +
+					ffs(stat2 & BANK2_VALID_MASK) - 1;
+			else
+				continue;
+		} else {
+			BUG();
+		}
+
+		handle_IRQ(irq, regs);
+	}
+}
+
+/* This function forces the interrupt numbers to be allocated sequentially,
+ * instead of with gaps due to the sparse BANK0, to make the offset from
+ * IRQs and FIQs constant (and equal to FIQ_START).
+ */
+unsigned int arch_dynirq_lower_bound(unsigned int from)
+{
+	if (from < 24)
+		return from + 24;
+	else if (from >= 104)
+		return from - 24;
+	return from;
+}
+
+#endif
+
 /**
  * armctrl_init - initialise a vectored interrupt controller
  * @base: iomem base address
@@ -308,6 +373,9 @@ int __init armctrl_init(void __iomem * base, unsigned int irq_start,
 		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 	}
 
+#ifdef CONFIG_MULTI_IRQ_HANDLER
+	set_handle_irq(armctrl_handle_irq);
+#endif
 	armctrl_pm_register(base, irq_start, resume_sources);
 	init_FIQ(FIQ_START);
 	armctrl_dt_init();
diff --git a/arch/arm/mach-bcm2708/bcm2708.c b/arch/arm/mach-bcm2708/bcm2708.c
index 39cb7bc..5ad4826 100644
--- a/arch/arm/mach-bcm2708/bcm2708.c
+++ b/arch/arm/mach-bcm2708/bcm2708.c
@@ -25,6 +25,7 @@
 #include <linux/platform_device.h>
 #include <linux/syscore_ops.h>
 #include <linux/interrupt.h>
+#include <linux/irqchip.h>
 #include <linux/amba/bus.h>
 #include <linux/amba/clcd.h>
 #include <linux/clk-provider.h>
@@ -101,7 +102,10 @@ static void __init bcm2708_init_led(void);
 
 void __init bcm2708_init_irq(void)
 {
-	armctrl_init(__io_address(ARMCTRL_IC_BASE), 0, 0, 0);
+	if (of_have_populated_dt())
+		irqchip_init();
+	else
+		armctrl_init(__io_address(ARMCTRL_IC_BASE), 0, 0, 0);
 }
 
 static struct map_desc bcm2708_io_desc[] __initdata = {
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b8d4e96..e5e2447 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_IRQCHIP)			+= irqchip.o
 
 obj-$(CONFIG_ARCH_BCM2835)		+= irq-bcm2835.o
+obj-$(CONFIG_ARCH_BCM2708)		+= irq-bcm2835.o
 obj-$(CONFIG_ARCH_EXYNOS)		+= exynos-combiner.o
 obj-$(CONFIG_ARCH_HIP04)		+= irq-hip04.o
 obj-$(CONFIG_ARCH_MMP)			+= irq-mmp.o
diff --git a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c
index 5c83309..7d9e82d 100644
--- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c
+++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c
@@ -448,7 +448,10 @@ static void hcd_init_fiq(void *cookie)
 #ifdef CONFIG_ARCH_BCM2835
 	enable_fiq(platform_get_irq(otg_dev->os_dep.platformdev, 1));
 #else
-	enable_fiq(INTERRUPT_VC_USB);
+	if (otg_dev->os_dep.platformdev->dev.of_node)
+		enable_fiq(platform_get_irq(otg_dev->os_dep.platformdev, 1));
+	else
+		enable_fiq(INTERRUPT_VC_USB);
 #endif
 	local_fiq_enable();
 }
-- 
1.9.1