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-rw-r--r--kernel/drivers/irqchip/irq-gic-common.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/kernel/drivers/irqchip/irq-gic-common.c b/kernel/drivers/irqchip/irq-gic-common.c
new file mode 100644
index 000000000..ad96ebb0c
--- /dev/null
+++ b/kernel/drivers/irqchip/irq-gic-common.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2002 ARM Limited, All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/irqchip/arm-gic.h>
+
+#include "irq-gic-common.h"
+
+int gic_configure_irq(unsigned int irq, unsigned int type,
+ void __iomem *base, void (*sync_access)(void))
+{
+ u32 enablemask = 1 << (irq % 32);
+ u32 enableoff = (irq / 32) * 4;
+ u32 confmask = 0x2 << ((irq % 16) * 2);
+ u32 confoff = (irq / 16) * 4;
+ bool enabled = false;
+ u32 val, oldval;
+ int ret = 0;
+
+ /*
+ * Read current configuration register, and insert the config
+ * for "irq", depending on "type".
+ */
+ val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
+ if (type & IRQ_TYPE_LEVEL_MASK)
+ val &= ~confmask;
+ else if (type & IRQ_TYPE_EDGE_BOTH)
+ val |= confmask;
+
+ /*
+ * As recommended by the spec, disable the interrupt before changing
+ * the configuration
+ */
+ if (readl_relaxed(base + GIC_DIST_ENABLE_SET + enableoff) & enablemask) {
+ writel_relaxed(enablemask, base + GIC_DIST_ENABLE_CLEAR + enableoff);
+ if (sync_access)
+ sync_access();
+ enabled = true;
+ }
+
+ /*
+ * Write back the new configuration, and possibly re-enable
+ * 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,
+ void (*sync_access)(void))
+{
+ unsigned int i;
+
+ /*
+ * Set all global interrupts to be level triggered, active low.
+ */
+ for (i = 32; i < gic_irqs; i += 16)
+ writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
+ base + GIC_DIST_CONFIG + i / 4);
+
+ /*
+ * Set priority on all global interrupts.
+ */
+ for (i = 32; i < gic_irqs; i += 4)
+ writel_relaxed(GICD_INT_DEF_PRI_X4, base + GIC_DIST_PRI + i);
+
+ /*
+ * Disable all interrupts. Leave the PPI and SGIs alone
+ * as they are enabled by redistributor registers.
+ */
+ for (i = 32; i < gic_irqs; i += 32)
+ writel_relaxed(GICD_INT_EN_CLR_X32,
+ base + GIC_DIST_ENABLE_CLEAR + i / 8);
+
+ if (sync_access)
+ sync_access();
+}
+
+void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
+{
+ int i;
+
+ /*
+ * Deal with the banked PPI and SGI interrupts - disable all
+ * PPI interrupts, ensure all SGI interrupts are enabled.
+ */
+ writel_relaxed(GICD_INT_EN_CLR_PPI, base + GIC_DIST_ENABLE_CLEAR);
+ writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
+
+ /*
+ * Set priority on PPI and SGI interrupts
+ */
+ for (i = 0; i < 32; i += 4)
+ writel_relaxed(GICD_INT_DEF_PRI_X4,
+ base + GIC_DIST_PRI + i * 4 / 4);
+
+ if (sync_access)
+ sync_access();
+}