diff mbox

[RFC,v1] irqchip: Add support for tango interrupt router

Message ID 657580dd-0cfe-e377-e425-0deabf6d20c3@free.fr (mailing list archive)
State New, archived
Headers show

Commit Message

Mason June 6, 2017, 1:42 p.m. UTC
The interrupt router supports 128 inputs -> 24 outputs

---
 .../bindings/interrupt-controller/sigma,smp8759-intc.txt  |  48 ++++++
 drivers/irqchip/Makefile                                  |   2 +-
 drivers/irqchip/irq-smp8759.c                             | 204 ++++++++++++++++++++++++
 3 files changed, 253 insertions(+), 1 deletion(-)

Comments

Thomas Petazzoni June 6, 2017, 3:52 p.m. UTC | #1
Hello,

On Tue, 6 Jun 2017 15:42:36 +0200, Mason wrote:

> +	interrupt-controller@6f800 {
> +		compatible = "sigma,smp8759-intc";
> +		reg = <0x6f800 0x430>;
> +		interrupt-controller;
> +		#interrupt-cells = <2>;
> +		interrupt-parent = <&gic>;
> +		/*
> +		 * There probably is a better way than explicitly listing
> +		 * the 24 interrupts?
> +		 */

What we do on Marvell platforms is:

	marvell,spi-base = <128>, <136>, <144>, <152>;

see marvell,odmi-controller.txt.

In another driver I submitted, we're doing:

	marvell,spi-ranges = <64 64>, <288 64>;

Retrospectively, I would have preferred to use marvell,spi-ranges for
the first DT binding as well, since it allows to express both the base
and number of interrupts available in the range.

Best regards,

Thomas
Mason July 11, 2017, 3:56 p.m. UTC | #2
On 06/06/2017 17:52, Thomas Petazzoni wrote:

> On Tue, 6 Jun 2017 15:42:36 +0200, Mason wrote:
> 
>> +	interrupt-controller@6f800 {
>> +		compatible = "sigma,smp8759-intc";
>> +		reg = <0x6f800 0x430>;
>> +		interrupt-controller;
>> +		#interrupt-cells = <2>;
>> +		interrupt-parent = <&gic>;
>> +		/*
>> +		 * There probably is a better way than explicitly listing
>> +		 * the 24 interrupts?
>> +		 */
> 
> What we do on Marvell platforms is:
> 
> 	marvell,spi-base = <128>, <136>, <144>, <152>;
> 
> see marvell,odmi-controller.txt.
> 
> In another driver I submitted, we're doing:
> 
> 	marvell,spi-ranges = <64 64>, <288 64>;
> 
> Retrospectively, I would have preferred to use marvell,spi-ranges for
> the first DT binding as well, since it allows to express both the base
> and number of interrupts available in the range.

Sorry for the delay, I got distracted by other drivers
(PCIe, clkgen, i2c, infrared).

Thanks for the suggestion.

So, if I remove the "interrupts" property from the controller's
DT node, I can no longer use irq_of_parse_and_map() followed by
irqd_set_trigger_type(), right?

I would have to "emulate" irq_of_parse_and_map() with
something along the lines of:

#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 data = { gic, 3, { GIC_SPI, irq, type }};
	return irq_create_of_mapping(&data);
}

Then map all 24 interrupts at init:

	virq = map_irq(gic, 0, IRQ_TYPE_LEVEL_HIGH);
	for (i = 1; i < 24; ++i)
		virq = map_irq(gic, i, IRQ_TYPE_EDGE_RISING);

Is that correct?

Does it make sense to use a separate ISR for the two kinds
of interrupts?

Regards.
diff mbox

Patch

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..c84ca9315768
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/sigma,smp8759-intc.txt
@@ -0,0 +1,48 @@ 
+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
+- interrupts: list of interrupt lines to parent
+
+Example:
+
+	interrupt-controller@6f800 {
+		compatible = "sigma,smp8759-intc";
+		reg = <0x6f800 0x430>;
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		interrupt-parent = <&gic>;
+		/*
+		 * There probably is a better way than explicitly listing
+		 * the 24 interrupts?
+		 */
+		interrupts =
+			<GIC_SPI  0 IRQ_TYPE_NONE>,
+			<GIC_SPI  1 IRQ_TYPE_NONE>,
+			<GIC_SPI  2 IRQ_TYPE_NONE>,
+			<GIC_SPI  3 IRQ_TYPE_NONE>,
+			<GIC_SPI  4 IRQ_TYPE_NONE>,
+			<GIC_SPI  5 IRQ_TYPE_NONE>,
+			<GIC_SPI  6 IRQ_TYPE_NONE>,
+			<GIC_SPI  7 IRQ_TYPE_NONE>,
+			<GIC_SPI  8 IRQ_TYPE_NONE>,
+			<GIC_SPI  9 IRQ_TYPE_NONE>,
+			<GIC_SPI 10 IRQ_TYPE_NONE>,
+			<GIC_SPI 11 IRQ_TYPE_NONE>,
+			<GIC_SPI 12 IRQ_TYPE_NONE>,
+			<GIC_SPI 13 IRQ_TYPE_NONE>,
+			<GIC_SPI 14 IRQ_TYPE_NONE>,
+			<GIC_SPI 15 IRQ_TYPE_NONE>,
+			<GIC_SPI 16 IRQ_TYPE_NONE>,
+			<GIC_SPI 17 IRQ_TYPE_NONE>,
+			<GIC_SPI 18 IRQ_TYPE_NONE>,
+			<GIC_SPI 19 IRQ_TYPE_NONE>,
+			<GIC_SPI 20 IRQ_TYPE_NONE>,
+			<GIC_SPI 21 IRQ_TYPE_NONE>,
+			<GIC_SPI 22 IRQ_TYPE_NONE>,
+			<GIC_SPI 23 IRQ_TYPE_NONE>;
+	};
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..b8338e14d399
--- /dev/null
+++ b/drivers/irqchip/irq-smp8759.c
@@ -0,0 +1,204 @@ 
+#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 OUTPUT_MAX		24
+#define IRQ_ENABLE		BIT(31)
+#define LEVEL_OUTPUT_LINE	0
+
+/*
+ * 128 inputs -> 24 outputs
+ * Group LEVEL_HIGH IRQs on output line 0
+ * Edge interrupts 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[OUTPUT_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);
+	bitmap_and(status, status, intc->enabled, IRQ_MAX);
+	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 i;
+
+	/* Start at 1, because 0 is reserved for level interrupts */
+	for (i = 1; i < OUTPUT_MAX; ++i)
+		if (intc->gic_spi_to_tango_hwirq[i] == 0)
+			return i;
+
+	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_OUTPUT_LINE;
+		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,
+};
+
+static int __init tango_irq_init(struct device_node *node, struct device_node *parent)
+{
+	int i, virq;
+	struct irq_domain *irq_dom;
+	struct irq_data *irq_data;
+	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);
+
+	/*
+	 * Use output line 0 for level high IRQs
+	 * Should we check that index 0 points to SPI 0?
+	 */
+	virq = irq_of_parse_and_map(node, 0);
+	if (!virq)
+		panic("%s: Failed to map IRQ 0\n", node->name);
+
+	irq_data = irq_get_irq_data(virq);
+	irqd_set_trigger_type(irq_data, IRQ_TYPE_LEVEL_HIGH);
+	irq_set_chained_handler_and_data(virq, tango_level_isr, intc);
+
+	for (i = 1; i < OUTPUT_MAX; ++i)
+	{
+		virq = irq_of_parse_and_map(node, i);
+		if (!virq)
+			panic("%s: Failed to map IRQ %d\n", node->name, i);
+
+		/*
+		 * I don't think trigger type should appear in DT because
+		 * it is a purely SW/driver decision
+		 */
+		irq_data = irq_get_irq_data(virq);
+		irqd_set_trigger_type(irq_data, IRQ_TYPE_EDGE_RISING);
+		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;
+
+	return 0;
+}
+IRQCHIP_DECLARE(tango_intc, "sigma,smp8759-intc", tango_irq_init);