From a493f339a88ddd20693460c1dcf8230aa3732b8b Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 6 Aug 2015 16:00:31 -0700 Subject: [PATCH] irqchip/bcm2835: Add support for being used as a second level controller The BCM2836 (Raspberry Pi 2) uses two levels of interrupt handling with the CPU-local interrupts being the root, so we need to register ours as chained off of the CPU's local interrupt. Signed-off-by: Eric Anholt Acked-by: Stephen Warren Cc: linux-rpi-kernel@lists.infradead.org Cc: Lee Jones Cc: Jason Cooper Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1438902033-31477-3-git-send-email-eric@anholt.net Signed-off-by: Thomas Gleixner --- .../brcm,bcm2835-armctrl-ic.txt | 25 ++++++++++- drivers/irqchip/irq-bcm2835.c | 43 +++++++++++++++++-- 2 files changed, 64 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt index 7da578d72123..2d6c8bb4d827 100644 --- a/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt +++ b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm2835-armctrl-ic.txt @@ -5,9 +5,14 @@ The BCM2835 contains a custom top-level interrupt controller, which supports controller, or the HW block containing it, is referred to occasionally as "armctrl" in the SoC documentation, hence naming of this binding. +The BCM2836 contains the same interrupt controller with the same +interrupts, but the per-CPU interrupt controller is the root, and an +interrupt there indicates that the ARMCTRL has an interrupt to handle. + Required properties: -- compatible : should be "brcm,bcm2835-armctrl-ic" +- compatible : should be "brcm,bcm2835-armctrl-ic" or + "brcm,bcm2836-armctrl-ic" - reg : Specifies 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 @@ -20,6 +25,12 @@ Required properties: The 2nd cell contains the interrupt number within the bank. Valid values are 0..7 for bank 0, and 0..31 for bank 1. +Additional required properties for brcm,bcm2836-armctrl-ic: +- interrupt-parent : Specifies the parent interrupt controller when this + controller is the second level. +- interrupts : Specifies the interrupt on the parent for this interrupt + controller to handle. + The interrupt sources are as follows: Bank 0: @@ -102,9 +113,21 @@ Bank 2: Example: +/* BCM2835, first level */ intc: interrupt-controller { compatible = "brcm,bcm2835-armctrl-ic"; reg = <0x7e00b200 0x200>; interrupt-controller; #interrupt-cells = <2>; }; + +/* BCM2836, second level */ +intc: interrupt-controller { + compatible = "brcm,bcm2836-armctrl-ic"; + reg = <0x7e00b200 0x200>; + interrupt-controller; + #interrupt-cells = <2>; + + interrupt-parent = <&local_intc>; + interrupts = <8>; +}; diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c index a40d97268b8a..ed4ca9deca70 100644 --- a/drivers/irqchip/irq-bcm2835.c +++ b/drivers/irqchip/irq-bcm2835.c @@ -96,6 +96,7 @@ struct armctrl_ic { static struct armctrl_ic intc __read_mostly; static void __exception_irq_entry bcm2835_handle_irq( struct pt_regs *regs); +static void bcm2836_chained_handle_irq(unsigned int irq, struct irq_desc *desc); static void armctrl_mask_irq(struct irq_data *d) { @@ -139,7 +140,8 @@ static const struct irq_domain_ops armctrl_ops = { }; static int __init armctrl_of_init(struct device_node *node, - struct device_node *parent) + struct device_node *parent, + bool is_2836) { void __iomem *base; int irq, b, i; @@ -168,10 +170,34 @@ static int __init armctrl_of_init(struct device_node *node, } } - set_handle_irq(bcm2835_handle_irq); + if (is_2836) { + int parent_irq = irq_of_parse_and_map(node, 0); + + if (!parent_irq) { + panic("%s: unable to get parent interrupt.\n", + node->full_name); + } + irq_set_chained_handler(parent_irq, bcm2836_chained_handle_irq); + } else { + set_handle_irq(bcm2835_handle_irq); + } + return 0; } +static int __init bcm2835_armctrl_of_init(struct device_node *node, + struct device_node *parent) +{ + return armctrl_of_init(node, parent, false); +} + +static int __init bcm2836_armctrl_of_init(struct device_node *node, + struct device_node *parent) +{ + return armctrl_of_init(node, parent, true); +} + + /* * Handle each interrupt across the entire interrupt controller. This reads the * status register before handling each interrupt, which is necessary given that @@ -219,4 +245,15 @@ static void __exception_irq_entry bcm2835_handle_irq( handle_IRQ(irq_linear_revmap(intc.domain, hwirq), regs); } -IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic", armctrl_of_init); +static void bcm2836_chained_handle_irq(unsigned int irq, struct irq_desc *desc) +{ + u32 hwirq; + + while ((hwirq = get_next_armctrl_hwirq()) != ~0) + generic_handle_irq(irq_linear_revmap(intc.domain, hwirq)); +} + +IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic", + bcm2835_armctrl_of_init); +IRQCHIP_DECLARE(bcm2836_armctrl_ic, "brcm,bcm2836-armctrl-ic", + bcm2836_armctrl_of_init); -- 2.20.1