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authorLiviu Dudau <Liviu.Dudau@arm.com>2015-01-20 19:52:59 +0300
committerThomas Gleixner <tglx@linutronix.de>2015-01-26 13:38:23 +0300
commitfb7e7deb7fc348ae131268d30e391c8184285de6 (patch)
treea036b13c9e0bcaeebbe3ce6691042d9f9840d9b6 /drivers/irqchip/irq-gic-common.c
parentd7eb4f2ecccd71f701bc8873bcf07c2d3b0375f6 (diff)
downloadlinux-fb7e7deb7fc348ae131268d30e391c8184285de6.tar.xz
irqchip: gic: Allow interrupt level to be set for PPIs
During a recent cleanup of the arm64 DTs it has become clear that the handling of PPIs in xxxx_set_type() is incorrect. The ARM TRMs for GICv2 and later allow for "implementation defined" support for setting the edge or level type of the PPI interrupts and don't restrict the activation level of the signal. Current ARM implementations do restrict the PPI level type to IRQ_TYPE_LEVEL_LOW, but licensees of the IP can decide to shoot themselves in the foot at any time. Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Acked-by: Marc Zyngier <Marc.Zyngier@arm.com> Cc: LAKML <linux-arm-kernel@lists.infradead.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Rob Herring <robh+dt@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Haojian Zhuang <haojian.zhuang@linaro.org> Link: http://lkml.kernel.org/r/1421772779-25764-1-git-send-email-Liviu.Dudau@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers/irqchip/irq-gic-common.c')
-rw-r--r--drivers/irqchip/irq-gic-common.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/irqchip/irq-gic-common.c b/drivers/irqchip/irq-gic-common.c
index 61541ff24397..ad96ebb0c7ab 100644
--- a/drivers/irqchip/irq-gic-common.c
+++ b/drivers/irqchip/irq-gic-common.c
@@ -21,7 +21,7 @@
#include "irq-gic-common.h"
-void gic_configure_irq(unsigned int irq, unsigned int type,
+int gic_configure_irq(unsigned int irq, unsigned int type,
void __iomem *base, void (*sync_access)(void))
{
u32 enablemask = 1 << (irq % 32);
@@ -29,16 +29,17 @@ void gic_configure_irq(unsigned int irq, unsigned int type,
u32 confmask = 0x2 << ((irq % 16) * 2);
u32 confoff = (irq / 16) * 4;
bool enabled = false;
- u32 val;
+ u32 val, oldval;
+ int ret = 0;
/*
* Read current configuration register, and insert the config
* for "irq", depending on "type".
*/
- val = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
- if (type == IRQ_TYPE_LEVEL_HIGH)
+ val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
+ if (type & IRQ_TYPE_LEVEL_MASK)
val &= ~confmask;
- else if (type == IRQ_TYPE_EDGE_RISING)
+ else if (type & IRQ_TYPE_EDGE_BOTH)
val |= confmask;
/*
@@ -54,15 +55,20 @@ void gic_configure_irq(unsigned int irq, unsigned int type,
/*
* Write back the new configuration, and possibly re-enable
- * the interrupt.
+ * the interrupt. If we tried to write a new configuration and failed,
+ * return an error.
*/
writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
+ if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val && val != oldval)
+ ret = -EINVAL;
if (enabled)
writel_relaxed(enablemask, base + GIC_DIST_ENABLE_SET + enableoff);
if (sync_access)
sync_access();
+
+ return ret;
}
void __init gic_dist_config(void __iomem *base, int gic_irqs,