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Subject[RFC PATCH v2] irqchip: Add support for tango interrupt router
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128 inputs, 24 outputs (to GIC SPI 0-23)
---
There might be a few things wrong with this driver.
When I cat /proc/interrupts the interrupt count appears
to be bogus (as if level IRQ counts are added to edge
IRQ counts). Did I mess something up with the IRQ domains?
---
.../interrupt-controller/sigma,smp8759-intc.txt | 18 ++
drivers/irqchip/Makefile | 2 +-
drivers/irqchip/irq-smp8759.c | 203 +++++++++++++++++++++
3 files changed, 222 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..9ec922f3c0a4
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt
@@ -0,0 +1,18 @@
+Sigma Designs SMP8759 interrupt router
+
+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@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..ec7fee4574ef
--- /dev/null
+++ b/drivers/irqchip/irq-smp8759.c
@@ -0,0 +1,203 @@
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+
+#define IRQ_MAX 128
+#define SPI_MAX 24 /* 24 output lines routed to SPI 0-23 */
+#define LEVEL_SPI 17
+#define IRQ_ENABLE BIT(31)
+
+/*
+ * 128 inputs mapped to 24 outputs
+ * LEVEL_HIGH IRQs are muxed on output line 'LEVEL_SPI'
+ * EDGE_RISING IRQs get a dedicated output line
+ * gic_spi_to_tango_hwirq array maps GIC SPI hwirq to tango hwirq
+ */
+struct tango_intc {
+ DECLARE_BITMAP(enabled, IRQ_MAX);
+ spinlock_t lock;
+ void __iomem *config;
+ void __iomem *status;
+ struct irq_domain *dom;
+ u8 gic_spi_to_tango_hwirq[SPI_MAX];
+};
+
+static void tango_level_isr(struct irq_desc *desc)
+{
+ unsigned int pos, virq;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct tango_intc *intc = irq_desc_get_handler_data(desc);
+ DECLARE_BITMAP(status, IRQ_MAX);
+
+ chained_irq_enter(chip, desc);
+
+ memcpy_fromio(status, intc->status, IRQ_MAX / BITS_PER_BYTE);
+ spin_lock(&intc->lock);
+ bitmap_and(status, status, intc->enabled, IRQ_MAX);
+ spin_unlock(&intc->lock);
+ for_each_set_bit(pos, status, IRQ_MAX) {
+ virq = irq_find_mapping(intc->dom, pos);
+ generic_handle_irq(virq);
+ }
+
+ chained_irq_exit(chip, desc);
+}
+
+static void tango_edge_isr(struct irq_desc *desc)
+{
+ unsigned int virq;
+ struct irq_data *d = &desc->irq_data;
+ struct irq_chip *chip = irq_desc_get_chip(desc);
+ struct tango_intc *intc = irq_desc_get_handler_data(desc);
+
+ /* I don't know how to get the SPI number, d->hwirq - 32 is a hack */
+ int hwirq = intc->gic_spi_to_tango_hwirq[d->hwirq - 32];
+ //printk("%s: SPI=%lu hwirq=%d\n", __func__, d->hwirq, hwirq);
+
+ chained_irq_enter(chip, desc);
+ virq = irq_find_mapping(intc->dom, hwirq);
+ generic_handle_irq(virq);
+ chained_irq_exit(chip, desc);
+}
+
+static void tango_mask(struct irq_data *data)
+{
+ unsigned long flags;
+ struct tango_intc *intc = data->chip_data;
+
+ spin_lock_irqsave(&intc->lock, flags);
+ __clear_bit(data->hwirq, intc->enabled);
+ writel_relaxed(0, intc->config + data->hwirq * 4);
+ spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static void tango_unmask(struct irq_data *data)
+{
+ unsigned long flags;
+ struct tango_intc *intc = data->chip_data;
+
+#if 0
+ if (!in_irq() && !in_interrupt()) {
+ printk("HWIRQ=%lu mask=%u\n", data->hwirq, data->mask);
+ dump_stack();
+ }
+#endif
+
+ spin_lock_irqsave(&intc->lock, flags);
+ __set_bit(data->hwirq, intc->enabled);
+ writel_relaxed(IRQ_ENABLE | data->mask, intc->config + data->hwirq * 4);
+ spin_unlock_irqrestore(&intc->lock, flags);
+}
+
+static int find_free_output_line(struct tango_intc *intc)
+{
+ int spi;
+
+ for (spi = 0; spi < SPI_MAX; ++spi)
+ if (intc->gic_spi_to_tango_hwirq[spi] == 0)
+ return spi;
+
+ return -ENOSPC;
+}
+
+int tango_set_type(struct irq_data *data, unsigned int flow_type)
+{
+ struct tango_intc *intc = data->chip_data;
+ printk("%s: IRQ=%lu type=%x\n", __func__, data->hwirq, flow_type);
+ dump_stack();
+ if (flow_type & IRQ_TYPE_LEVEL_HIGH) {
+ data->mask = LEVEL_SPI;
+ return 0;
+ }
+
+ if (flow_type & IRQ_TYPE_EDGE_RISING) {
+ int res = find_free_output_line(intc);
+ if (res < 0)
+ return res;
+ data->mask = res;
+ intc->gic_spi_to_tango_hwirq[res] = data->hwirq;
+ printk("Map tango hwirq %lu to GIC SPI %d\n", data->hwirq, res);
+ return 0;
+ }
+
+ /* LEVEL_LOW and EDGE_FALLING are not supported */
+ return -ENOSYS;
+}
+
+static struct irq_chip tango_chip = {
+ .name = "tango",
+ .irq_mask = tango_mask,
+ .irq_unmask = tango_unmask,
+ .irq_set_type = tango_set_type,
+};
+
+static int tango_map(struct irq_domain *dom, unsigned int virq, irq_hw_number_t hw)
+{
+ struct tango_intc *intc = dom->host_data;
+ struct irq_desc *desc = irq_to_desc(virq);
+ printk("%s: dom=%p virq=%u hwirq=%lu desc=%p\n", __func__, dom, virq, hw, desc);
+ irq_domain_set_info(dom, virq, hw, &tango_chip, intc, handle_simple_irq, NULL, NULL);
+ return 0;
+}
+
+static void tango_unmap(struct irq_domain *d, unsigned int virq)
+{
+ printk("%s: dom=%p virq=%u\n", __func__, d, virq);
+ dump_stack();
+}
+
+struct irq_domain_ops dom_ops =
+{
+ .map = tango_map,
+ .unmap = tango_unmap,
+ .xlate = irq_domain_xlate_twocell,
+};
+
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+static int __init map_irq(struct device_node *gic, int irq, int type)
+{
+ struct of_phandle_args irq_data = { gic, 3, { GIC_SPI, irq, type }};
+ return irq_create_of_mapping(&irq_data);
+}
+
+static int __init tango_irq_init(struct device_node *node, struct device_node *parent)
+{
+ int spi, virq;
+ struct irq_domain *irq_dom;
+ void __iomem *base;
+ struct tango_intc *intc = kzalloc(sizeof(*intc), GFP_KERNEL);
+
+ base = of_iomap(node, 0);
+ if (!base)
+ panic("%s: of_iomap failed", node->name);
+
+ virq = map_irq(parent, LEVEL_SPI, IRQ_TYPE_LEVEL_HIGH);
+ if (!virq)
+ panic("%s: Failed to map IRQ %d\n", node->name, LEVEL_SPI);
+
+ irq_set_chained_handler_and_data(virq, tango_level_isr, intc);
+
+ for (spi = 0; spi < SPI_MAX; ++spi) {
+ if (spi == LEVEL_SPI)
+ continue;
+
+ virq = map_irq(parent, spi, IRQ_TYPE_EDGE_RISING);
+ if (!virq)
+ panic("%s: Failed to map IRQ %d\n", node->name, spi);
+
+ irq_set_chained_handler_and_data(virq, tango_edge_isr, intc);
+ }
+
+ irq_dom = irq_domain_add_linear(node, IRQ_MAX, &dom_ops, intc);
+
+ spin_lock_init(&intc->lock);
+ intc->config = base;
+ intc->status = base + 0x420;
+ intc->dom = irq_dom;
+ intc->gic_spi_to_tango_hwirq[LEVEL_SPI] = ~0;
+
+ return 0;
+}
+IRQCHIP_DECLARE(tango_intc, "sigma,smp8759-intc", tango_irq_init);
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