[PATCH v7] irqchip: Add support for tango interrupt mapper
Mason
slash.tmp at free.fr
Mon Aug 28 06:58:35 PDT 2017
This controller maps 128 input lines to 24 output lines.
The 24 output lines are routed to GIC SPI 0 to 23.
This driver only allocates exclusive output lines (hierarchy).
Let the legacy controller mux latency-insensitive interrupts.
---
Changes from v6 to v7
* Muxing level interrupts leaves performance on the table => Give "important"
interrupts a dedicated output line (hierarchical setup). And let the legacy
interrupt controller mux "less important" interrupts.
* Use a bitmap to manage output line allocation
* Don't panic on error; clean up and return error code
---
.../interrupt-controller/sigma,smp8759-intc.txt | 18 +++
drivers/irqchip/Makefile | 2 +-
drivers/irqchip/irq-smp8759.c | 158 +++++++++++++++++++++
3 files changed, 177 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt
create mode 100644 drivers/irqchip/irq-smp8759.c
diff --git a/Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt
new file mode 100644
index 000000000000..f4864979ab44
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt
@@ -0,0 +1,18 @@
+Sigma Designs SMP8759 interrupt mapper
+
+Required properties:
+- compatible: "sigma,smp8759-intc"
+- reg: address/size of register area
+- interrupt-controller
+- #interrupt-cells: <2> (hwirq and trigger_type)
+- interrupt-parent: parent phandle
+
+Example:
+
+ interrupt-controller at 6f800 {
+ compatible = "sigma,smp8759-intc";
+ reg = <0x6f800 0x430>;
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ interrupt-parent = <&gic>;
+ };
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e4dbfc85abdb..013104923b71 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -47,7 +47,7 @@ obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o
obj-$(CONFIG_ARCH_NSPIRE) += irq-zevio.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
obj-$(CONFIG_ST_IRQCHIP) += irq-st.o
-obj-$(CONFIG_TANGO_IRQ) += irq-tango.o
+obj-$(CONFIG_TANGO_IRQ) += irq-tango.o irq-smp8759.o
obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o
obj-$(CONFIG_TS4800_IRQ) += irq-ts4800.o
obj-$(CONFIG_XTENSA) += irq-xtensa-pic.o
diff --git a/drivers/irqchip/irq-smp8759.c b/drivers/irqchip/irq-smp8759.c
new file mode 100644
index 000000000000..359ab706f504
--- /dev/null
+++ b/drivers/irqchip/irq-smp8759.c
@@ -0,0 +1,158 @@
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/syscore_ops.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+
+/*
+ * This controller maps IRQ_MAX input lines to SPI_MAX output lines.
+ * The output lines are routed to GIC SPI 0 to 23.
+ * This driver only allocates exclusive output lines (hierarchy).
+ * Let the legacy controller mux latency-insensitive interrupts.
+ */
+#define IRQ_MAX 128
+#define SPI_MAX 24
+#define IRQ_ENABLE BIT(31)
+#define STATUS 0x420
+
+struct tango_intc {
+ void __iomem *base;
+ DECLARE_BITMAP(used_spi, SPI_MAX);
+ DECLARE_BITMAP(enabled_irq, IRQ_MAX);
+ u8 tango_irq_to_spi[IRQ_MAX];
+ spinlock_t lock;
+};
+
+static struct tango_intc *tango_intc;
+
+static void tango_mask(struct irq_data *data)
+{
+ unsigned long flags;
+ struct tango_intc *intc = data->chip_data;
+
+ spin_lock_irqsave(&intc->lock, flags);
+ writel_relaxed(0, intc->base + data->hwirq * 4);
+ __clear_bit(data->hwirq, intc->enabled_irq);
+ spin_unlock_irqrestore(&intc->lock, flags);
+
+ irq_chip_mask_parent(data);
+}
+
+static void tango_unmask(struct irq_data *data)
+{
+ unsigned long flags;
+ struct tango_intc *intc = data->chip_data;
+ u32 val = IRQ_ENABLE | intc->tango_irq_to_spi[data->hwirq];
+
+ spin_lock_irqsave(&intc->lock, flags);
+ writel_relaxed(val, intc->base + data->hwirq * 4);
+ __set_bit(data->hwirq, intc->enabled_irq);
+ spin_unlock_irqrestore(&intc->lock, flags);
+
+ irq_chip_unmask_parent(data);
+}
+
+static struct irq_chip tango_chip = {
+ .name = "mapper",
+ .irq_mask = tango_mask,
+ .irq_unmask = tango_unmask,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+};
+
+static int alloc_gic_irq(struct irq_domain *dom, uint virq, u32 spi, u32 type)
+{
+ struct fwnode_handle *gic = dom->parent->fwnode;
+ struct irq_fwspec gic_fwspec = { gic, 3, { 0, spi, type }};
+ return irq_domain_alloc_irqs_parent(dom, virq, 1, &gic_fwspec);
+}
+
+static int tango_alloc(struct irq_domain *dom, uint virq, uint nirq, void *arg)
+{
+ int err, spi;
+ unsigned long flags;
+ struct irq_fwspec *fwspec = arg;
+ struct tango_intc *intc = dom->host_data;
+ u32 hwirq = fwspec->param[0], type = fwspec->param[1];
+
+ if (type & IRQ_TYPE_EDGE_FALLING || type & IRQ_TYPE_LEVEL_LOW)
+ return -EINVAL;
+
+ spin_lock_irqsave(&intc->lock, flags);
+ spi = find_first_zero_bit(intc->used_spi, SPI_MAX);
+ if (spi >= SPI_MAX) {
+ spin_unlock_irqrestore(&intc->lock, flags);
+ return -ENOSPC;
+ }
+ __set_bit(spi, intc->used_spi);
+ spin_unlock_irqrestore(&intc->lock, flags);
+
+ err = alloc_gic_irq(dom, virq, spi, type);
+ if (err) {
+ spin_lock_irqsave(&intc->lock, flags);
+ __clear_bit(spi, intc->used_spi);
+ spin_unlock_irqrestore(&intc->lock, flags);
+ return err;
+ }
+
+ intc->tango_irq_to_spi[hwirq] = spi;
+ irq_domain_set_hwirq_and_chip(dom, virq, hwirq, &tango_chip, intc);
+
+ return 0;
+}
+
+static struct irq_domain_ops dom_ops = {
+ .xlate = irq_domain_xlate_twocell,
+ .alloc = tango_alloc,
+};
+
+static void tango_resume(void)
+{
+ int hwirq;
+ struct tango_intc *intc = tango_intc;
+
+ for (hwirq = 0; hwirq < IRQ_MAX; ++hwirq) {
+ u32 val = intc->tango_irq_to_spi[hwirq];
+ if (test_bit(hwirq, intc->enabled_irq))
+ val |= IRQ_ENABLE;
+ writel_relaxed(val, intc->base + hwirq * 4);
+ }
+}
+
+static struct syscore_ops tango_syscore_ops = {
+ .resume = tango_resume,
+};
+
+static int __init tango_irq_init(struct device_node *node, struct device_node *parent)
+{
+ struct tango_intc *intc;
+ struct irq_domain *dom, *gic_dom;
+
+ gic_dom = irq_find_host(parent);
+ if (!gic_dom)
+ return -ENODEV;
+
+ intc = kzalloc(sizeof(*intc), GFP_KERNEL);
+ if (!intc)
+ return -ENOMEM;
+
+ intc->base = of_iomap(node, 0);
+ if (!intc->base) {
+ kfree(intc);
+ return -ENXIO;
+ }
+
+ dom = irq_domain_add_hierarchy(gic_dom, 0, IRQ_MAX, node, &dom_ops, intc);
+ if (!dom) {
+ iounmap(intc->base);
+ kfree(intc);
+ return -ENOMEM;
+ }
+
+ tango_intc = intc;
+ register_syscore_ops(&tango_syscore_ops);
+ spin_lock_init(&intc->lock);
+
+ return 0;
+}
+IRQCHIP_DECLARE(tango_intc, "sigma,smp8759-intc", tango_irq_init);
--
2.11.0
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