brcm63xx: fix external interrupts on BCM6318

Setting the clear bit for an interrupt seems to cause interrupts to be
deasserted again immediately. So unset the bit for BCM6318 to allow
subsequent interrupts to still work.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

target/linux/brcm63xx/dts/bcm6318.dtsi

@@ -36,7 +36,7 @@
 		compatible = "simple-bus";
 
 		ext_intc: interrupt-controller@10000018 {
-			compatible = "brcm,bcm6345-ext-intc";
+			compatible = "brcm,bcm6318-ext-intc";
 			reg = <0x10000018 0x4>;
 
 			interrupt-controller;

target/linux/brcm63xx/patches-4.4/321-irqchip-add-support-for-bcm6345-style-external-inter.patch

@@ -23,7 +23,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +
 +Required properties:
 +
-+- compatible: Should be "brcm,bcm6345-ext-intc".
++- compatible: Should be "brcm,bcm6345-ext-intc" or "brcm,bcm6318-ext-intc".
 +- reg: Specifies the base physical addresses 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 interrupt
@@ -73,7 +73,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  obj-$(CONFIG_METAG)			+= irq-metag-ext.o
 --- /dev/null
 +++ b/drivers/irqchip/irq-bcm6345-ext.c
-@@ -0,0 +1,288 @@
+@@ -0,0 +1,301 @@
 +/*
 + * This file is subject to the terms and conditions of the GNU General Public
 + * License.  See the file "COPYING" in the main directory of this archive
@@ -119,6 +119,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +	int parent_irq[MAX_IRQS];
 +	void __iomem *reg;
 +	int shift;
++	unsigned int toggle_clear_on_ack:1;
 +};
 +
 +static void bcm6345_ext_intc_irq_handle(struct irq_desc *desc)
@@ -148,8 +149,10 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +
 +	raw_spin_lock(&priv->lock);
 +	reg = __raw_readl(priv->reg);
-+	reg |= 1 << (hwirq + EXTIRQ_CFG_CLEAR * priv->shift);
-+	__raw_writel(reg, priv->reg);
++	__raw_writel(reg | (1 << (hwirq + EXTIRQ_CFG_CLEAR * priv->shift)),
++		     priv->reg);
++	if (priv->toggle_clear_on_ack)
++		__raw_writel(reg, priv->reg);
 +	raw_spin_unlock(&priv->lock);
 +}
 +
@@ -263,7 +266,8 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +
 +static int __init __bcm6345_ext_intc_init(struct device_node *node,
 +					  int num_irqs, int *irqs,
-+					  void __iomem *reg, int shift)
++					  void __iomem *reg, int shift,
++					  bool toggle_clear_on_ack)
 +{
 +	struct intc_data *data;
 +	unsigned int i;
@@ -284,6 +288,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +
 +	data->reg = reg;
 +	data->shift = shift;
++	data->toggle_clear_on_ack = toggle_clear_on_ack;
 +
 +	data->chip.name = "bcm6345-ext-intc";
 +	data->chip.irq_ack = bcm6345_ext_intc_irq_ack;
@@ -314,7 +319,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +void __init bcm6345_ext_intc_init(int num_irqs, int *irqs, void __iomem *reg,
 +				  int shift)
 +{
-+	__bcm6345_ext_intc_init(NULL, num_irqs, irqs, reg, shift);
++	__bcm6345_ext_intc_init(NULL, num_irqs, irqs, reg, shift, false);
 +}
 +
 +#ifdef CONFIG_OF
@@ -326,6 +331,7 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +	void __iomem *base;
 +	int irqs[MAX_IRQS] = { 0 };
 +	u32 shift;
++	bool toggle_clear_on_ack = false;
 +
 +	num_irqs = of_irq_count(node);
 +
@@ -335,6 +341,10 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +	if (of_property_read_u32(node, "brcm,field-width", &shift))
 +		shift = 4;
 +
++	/* on BCM6318 setting CLEAR seems to continuously mask interrupts */
++	if (of_device_is_compatible(node, "brcm,bcm6318-ext-intc"))
++		toggle_clear_on_ack = true;
++
 +	for (i = 0; i < num_irqs; i++) {
 +		irqs[i] = irq_of_parse_and_map(node, i);
 +		if (!irqs[i]) {
@@ -347,7 +357,8 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +	if (!base)
 +		goto out_unmap;
 +
-+	ret = __bcm6345_ext_intc_init(node, num_irqs, irqs, base, shift);
++	ret = __bcm6345_ext_intc_init(node, num_irqs, irqs, base, shift,
++				      toggle_clear_on_ack);
 +	if (!ret)
 +		return 0;
 +out_unmap:
@@ -359,6 +370,8 @@ Signed-off-by: Jonas Gorski <jogo@openwrt.org>
 +	return ret;
 +}
 +
++IRQCHIP_DECLARE(bcm6318_ext_intc, "brcm,bcm6318-ext-intc",
++		bcm6345_ext_intc_of_init);
 +IRQCHIP_DECLARE(bcm6345_ext_intc, "brcm,bcm6345-ext-intc",
 +		bcm6345_ext_intc_of_init);
 +#endif