[PATCH V5 3/4] irqchip: mips-gic: Add device-tree support

From: Andrew Bresticker
Date: Wed Nov 12 2014 - 14:44:50 EST


Add device-tree support for the MIPS GIC. Update the GIC irqdomain's
xlate() callback to handle the three-cell specifier described in the
MIPS GIC binding document.

Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Acked-by: Jason Cooper <jason@xxxxxxxxxxxxxx>
---
No changes from v4.
Changes from v3:
- use reserved-cpu-vectors property
- read GIC base from CM if no reg property present
Changes from v2:
- rebased on GIC irqchip cleanups
- updated for change in bindings
- only parse first CPU vector
- allow platforms to use EIC mode
Changes from v1:
- updated for change in bindings
- set base address and enable bit in GCR_GIC_BASE
---
drivers/irqchip/irq-mips-gic.c | 92 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 87 insertions(+), 5 deletions(-)

diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
index 61ac482..8a9ef74 100644
--- a/drivers/irqchip/irq-mips-gic.c
+++ b/drivers/irqchip/irq-mips-gic.c
@@ -12,12 +12,18 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip/mips-gic.h>
+#include <linux/of_address.h>
#include <linux/sched.h>
#include <linux/smp.h>

+#include <asm/mips-cm.h>
#include <asm/setup.h>
#include <asm/traps.h>

+#include <dt-bindings/interrupt-controller/mips-gic.h>
+
+#include "irqchip.h"
+
unsigned int gic_present;

struct gic_pcpu_mask {
@@ -662,14 +668,34 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int virq,
return gic_shared_irq_domain_map(d, virq, hw);
}

+static int gic_irq_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
+ const u32 *intspec, unsigned int intsize,
+ irq_hw_number_t *out_hwirq,
+ unsigned int *out_type)
+{
+ if (intsize != 3)
+ return -EINVAL;
+
+ if (intspec[0] == GIC_SHARED)
+ *out_hwirq = GIC_SHARED_TO_HWIRQ(intspec[1]);
+ else if (intspec[0] == GIC_LOCAL)
+ *out_hwirq = GIC_LOCAL_TO_HWIRQ(intspec[1]);
+ else
+ return -EINVAL;
+ *out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+
+ return 0;
+}
+
static struct irq_domain_ops gic_irq_domain_ops = {
.map = gic_irq_domain_map,
- .xlate = irq_domain_xlate_twocell,
+ .xlate = gic_irq_domain_xlate,
};

-void __init gic_init(unsigned long gic_base_addr,
- unsigned long gic_addrspace_size, unsigned int cpu_vec,
- unsigned int irqbase)
+static void __init __gic_init(unsigned long gic_base_addr,
+ unsigned long gic_addrspace_size,
+ unsigned int cpu_vec, unsigned int irqbase,
+ struct device_node *node)
{
unsigned int gicconfig;

@@ -695,7 +721,7 @@ void __init gic_init(unsigned long gic_base_addr,
gic_irq_dispatch);
}

- gic_irq_domain = irq_domain_add_simple(NULL, GIC_NUM_LOCAL_INTRS +
+ gic_irq_domain = irq_domain_add_simple(node, GIC_NUM_LOCAL_INTRS +
gic_shared_intrs, irqbase,
&gic_irq_domain_ops, NULL);
if (!gic_irq_domain)
@@ -705,3 +731,59 @@ void __init gic_init(unsigned long gic_base_addr,

gic_ipi_init();
}
+
+void __init gic_init(unsigned long gic_base_addr,
+ unsigned long gic_addrspace_size,
+ unsigned int cpu_vec, unsigned int irqbase)
+{
+ __gic_init(gic_base_addr, gic_addrspace_size, cpu_vec, irqbase, NULL);
+}
+
+static int __init gic_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ struct resource res;
+ unsigned int cpu_vec, i = 0, reserved = 0;
+ phys_addr_t gic_base;
+ size_t gic_len;
+
+ /* Find the first available CPU vector. */
+ while (!of_property_read_u32_index(node, "mti,reserved-cpu-vectors",
+ i++, &cpu_vec))
+ reserved |= BIT(cpu_vec);
+ for (cpu_vec = 2; cpu_vec < 8; cpu_vec++) {
+ if (!(reserved & BIT(cpu_vec)))
+ break;
+ }
+ if (cpu_vec == 8) {
+ pr_err("No CPU vectors available for GIC\n");
+ return -ENODEV;
+ }
+
+ if (of_address_to_resource(node, 0, &res)) {
+ /*
+ * Probe the CM for the GIC base address if not specified
+ * in the device-tree.
+ */
+ if (mips_cm_present()) {
+ gic_base = read_gcr_gic_base() &
+ ~CM_GCR_GIC_BASE_GICEN_MSK;
+ gic_len = 0x20000;
+ } else {
+ pr_err("Failed to get GIC memory range\n");
+ return -ENODEV;
+ }
+ } else {
+ gic_base = res.start;
+ gic_len = resource_size(&res);
+ }
+
+ if (mips_cm_present())
+ write_gcr_gic_base(gic_base | CM_GCR_GIC_BASE_GICEN_MSK);
+ gic_present = true;
+
+ __gic_init(gic_base, gic_len, cpu_vec, 0, node);
+
+ return 0;
+}
+IRQCHIP_DECLARE(mips_gic, "mti,gic", gic_of_init);
--
2.1.0.rc2.206.gedb03e5

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