diff mbox

[RFC,v2] irqchip: Add support for Tango interrupt controller

Message ID 569CE0F2.1060507@sigmadesigns.com (mailing list archive)
State New, archived
Headers show

Commit Message

Marc Gonzalez Jan. 18, 2016, 12:56 p.m. UTC
From: Mans Rullgard <mans@mansr.com>

Add support for the interrupt controller used in Sigma Designs
SMP86xx (Tango3) and SMP87xx (Tango4) chips.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
---
For the arch/arm/mach-tango port, I'm using this driver written
by Mans. Version 1 of the patch was submitted two months ago:
http://thread.gmane.org/gmane.linux.kernel/2089471

I've tried to address Marc's remarks.

I kept Mans as the commit author, but I removed his Signed-off-by
(because I might have introduced errors that he didn't sign off on).
Is that the right thing to do?

I didn't rename tangox to tango inside irq-tango.c because I didn't
want to change the code too much, but I'm OK either way.

The matching DT description currently is

intc: interrupt-controller@6e000 {
	compatible = "sigma,smp8642-intc";
	reg = <0x6e000 0x400>;
	ranges = <0 0x6e000 0x400>;
	interrupt-parent = <&gic>;
	interrupt-controller;
	#address-cells = <1>;
	#size-cells = <1>;

	irq0: irq0@000 {
		reg = <0x000 0x100>;
		interrupt-controller;
		#interrupt-cells = <2>;
		interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
	};

	irq1: irq1@100 {
		reg = <0x100 0x100>;
		interrupt-controller;
		#interrupt-cells = <2>;
		interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
	};

	irq2: irq2@300 {
		reg = <0x300 0x100>;
		interrupt-controller;
		#interrupt-cells = <2>;
		interrupts = <GIC_SPI 4 IRQ_TYPE_LEVEL_HIGH>;
	};
};

---
 drivers/irqchip/Kconfig     |   5 +
 drivers/irqchip/Makefile    |   1 +
 drivers/irqchip/irq-tango.c | 227 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 233 insertions(+)
 create mode 100644 drivers/irqchip/irq-tango.c

Comments

Måns Rullgård Jan. 18, 2016, 1:04 p.m. UTC | #1
Marc Gonzalez <marc_gonzalez@sigmadesigns.com> writes:

> +	if (of_property_read_u32(node, "reg", &ctl))
> +		panic("%s: failed to get reg base", node->name);
> +
> +	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
> +	chip->ctl = ctl;
> +	chip->base = base;

I think it might be better to let the OF core convert the "reg" property
to a struct resource, then get the offset by subtracting from the base
(physical) address.  Otherwise it will break badly if someone thinks
it's safe to drop "ranges" from the outer node and use absolute
addresses in the child nodes (that's how the "reg" property typically
behaves).

Anyway, thanks for revisiting this.  I never got a straight answer (or
any answer for that matter) when I asked which approach would be
preferred, and then I had better things to do than keep trying patches
until people got happy.
Marc Gonzalez Jan. 18, 2016, 3:57 p.m. UTC | #2
On 18/01/2016 13:56, Marc Gonzalez wrote:

> For the arch/arm/mach-tango port, I'm using this driver written
> by Mans. Version 1 of the patch was submitted two months ago:
> http://thread.gmane.org/gmane.linux.kernel/2089471
> 
> I've tried to address Marc Zyngier's remarks.

And my patch is incomplete, v3 coming right up.

drivers/irqchip/irq-tango.c: In function 'tangox_irq_init':
drivers/irqchip/irq-tango.c:183:6: warning: unused variable 'i' [-Wunused-variable]
  int i;
      ^
drivers/irqchip/irq-tango.c: In function 'tangox_of_irq_init':
drivers/irqchip/irq-tango.c:200:6: warning: 'name' may be used uninitialized in this function [-Wmaybe-uninitialized]
  err = irq_alloc_domain_generic_chips(dom, 32, 2, name, handle_level_irq,
      ^
drivers/irqchip/irq-tango.c:179:14: note: 'name' was declared here
  const char *name;
              ^

Regards.
diff mbox

Patch

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 4d7294e5d982..399eda54b860 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -133,6 +133,11 @@  config ST_IRQCHIP
 	help
 	  Enables SysCfg Controlled IRQs on STi based platforms.
 
+config TANGO_IRQ
+	bool
+	select IRQ_DOMAIN
+	select GENERIC_IRQ_CHIP
+
 config TB10X_IRQC
 	bool
 	select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 177f78f6e6d6..74512452cc8b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -38,6 +38,7 @@  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_TB10X_IRQC)		+= irq-tb10x.o
 obj-$(CONFIG_XTENSA)			+= irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)			+= irq-xtensa-mx.o
diff --git a/drivers/irqchip/irq-tango.c b/drivers/irqchip/irq-tango.c
new file mode 100644
index 000000000000..5e2383699be0
--- /dev/null
+++ b/drivers/irqchip/irq-tango.c
@@ -0,0 +1,227 @@ 
+/*
+ * Copyright (C) 2014 Mans Rullgard <mans@mansr.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+#define IRQ0_CTL_BASE		0x0000
+#define IRQ1_CTL_BASE		0x0100
+#define EDGE_CTL_BASE		0x0200
+#define IRQ2_CTL_BASE		0x0300
+
+#define IRQ_CTL_HI		0x18
+#define EDGE_CTL_HI		0x20
+
+#define IRQ_STATUS		0x00
+#define IRQ_RAWSTAT		0x04
+#define IRQ_EN_SET		0x08
+#define IRQ_EN_CLR		0x0c
+#define IRQ_SOFT_SET		0x10
+#define IRQ_SOFT_CLR		0x14
+
+#define EDGE_STATUS		0x00
+#define EDGE_RAWSTAT		0x04
+#define EDGE_CFG_RISE		0x08
+#define EDGE_CFG_FALL		0x0c
+#define EDGE_CFG_RISE_SET	0x10
+#define EDGE_CFG_RISE_CLR	0x14
+#define EDGE_CFG_FALL_SET	0x18
+#define EDGE_CFG_FALL_CLR	0x1c
+
+struct tangox_irq_chip {
+	void __iomem *base;
+	unsigned long ctl;
+};
+
+static inline u32 intc_readl(struct tangox_irq_chip *chip, int reg)
+{
+	return readl_relaxed(chip->base + reg);
+}
+
+static inline void intc_writel(struct tangox_irq_chip *chip, int reg, u32 val)
+{
+	writel_relaxed(val, chip->base + reg);
+}
+
+static void tangox_dispatch_irqs(struct irq_domain *dom, unsigned int status,
+				 int base)
+{
+	unsigned int hwirq;
+	unsigned int virq;
+
+	while (status) {
+		hwirq = __ffs(status);
+		virq = irq_find_mapping(dom, base + hwirq);
+		if (virq) generic_handle_irq(virq);
+		status &= ~BIT(hwirq);
+	}
+}
+
+static void tangox_irq_handler(struct irq_desc *desc)
+{
+	struct irq_domain *dom = irq_desc_get_handler_data(desc);
+	struct irq_chip *host_chip = irq_desc_get_chip(desc);
+	struct tangox_irq_chip *chip = dom->host_data;
+	unsigned int status_lo, status_hi;
+
+	chained_irq_enter(host_chip, desc);
+
+	status_lo = intc_readl(chip, chip->ctl + IRQ_STATUS);
+	status_hi = intc_readl(chip, chip->ctl + IRQ_CTL_HI + IRQ_STATUS);
+
+	tangox_dispatch_irqs(dom, status_lo, 0);
+	tangox_dispatch_irqs(dom, status_hi, 32);
+
+	chained_irq_exit(host_chip, desc);
+}
+
+static int tangox_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+	struct tangox_irq_chip *chip = gc->domain->host_data;
+	struct irq_chip_regs *regs = &gc->chip_types[0].regs;
+
+	switch (flow_type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+		intc_writel(chip, regs->type + EDGE_CFG_RISE_SET, d->mask);
+		intc_writel(chip, regs->type + EDGE_CFG_FALL_CLR, d->mask);
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+		intc_writel(chip, regs->type + EDGE_CFG_RISE_CLR, d->mask);
+		intc_writel(chip, regs->type + EDGE_CFG_FALL_SET, d->mask);
+		break;
+
+	case IRQ_TYPE_LEVEL_HIGH:
+		intc_writel(chip, regs->type + EDGE_CFG_RISE_CLR, d->mask);
+		intc_writel(chip, regs->type + EDGE_CFG_FALL_CLR, d->mask);
+		break;
+
+	case IRQ_TYPE_LEVEL_LOW:
+		intc_writel(chip, regs->type + EDGE_CFG_RISE_SET, d->mask);
+		intc_writel(chip, regs->type + EDGE_CFG_FALL_SET, d->mask);
+		break;
+
+	default:
+		pr_err("Invalid trigger mode %x for IRQ %d\n",
+		       flow_type, d->irq);
+		return -EINVAL;
+	}
+
+	return irq_setup_alt_chip(d, flow_type);
+}
+
+static void __init tangox_irq_init_chip(struct irq_chip_generic *gc,
+					unsigned long ctl_offs,
+					unsigned long edge_offs)
+{
+	struct tangox_irq_chip *chip = gc->domain->host_data;
+	struct irq_chip_type *ct = gc->chip_types;
+	unsigned long ctl_base = chip->ctl + ctl_offs;
+	unsigned long edge_base = EDGE_CTL_BASE + edge_offs;
+	int i;
+
+	gc->reg_base = chip->base;
+	gc->unused = 0;
+
+	for (i = 0; i < 2; i++) {
+		ct[i].chip.irq_ack = irq_gc_ack_set_bit;
+		ct[i].chip.irq_mask = irq_gc_mask_disable_reg;
+		ct[i].chip.irq_mask_ack = irq_gc_mask_disable_reg_and_ack;
+		ct[i].chip.irq_unmask = irq_gc_unmask_enable_reg;
+		ct[i].chip.irq_set_type = tangox_irq_set_type;
+		ct[i].chip.name = gc->domain->name;
+
+		ct[i].regs.enable = ctl_base + IRQ_EN_SET;
+		ct[i].regs.disable = ctl_base + IRQ_EN_CLR;
+		ct[i].regs.ack = edge_base + EDGE_RAWSTAT;
+		ct[i].regs.type = edge_base;
+	}
+
+	ct[0].type = IRQ_TYPE_LEVEL_MASK;
+	ct[0].handler = handle_level_irq;
+
+	ct[1].type = IRQ_TYPE_EDGE_BOTH;
+	ct[1].handler = handle_edge_irq;
+
+	intc_writel(chip, ct->regs.disable, 0xffffffff);
+	intc_writel(chip, ct->regs.ack, 0xffffffff);
+}
+
+static void __init tangox_irq_domain_init(struct irq_domain *dom)
+{
+	struct irq_chip_generic *gc;
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		gc = irq_get_domain_generic_chip(dom, i * 32);
+		tangox_irq_init_chip(gc, i * IRQ_CTL_HI, i * EDGE_CTL_HI);
+	}
+}
+
+static int __init tangox_irq_init(void __iomem *base, struct device_node *node)
+{
+	struct tangox_irq_chip *chip;
+	struct irq_domain *dom;
+	const char *name;
+	u32 ctl;
+	int irq;
+	int err;
+	int i;
+
+	irq = irq_of_parse_and_map(node, 0);
+	if (!irq)
+		panic("%s: failed to get IRQ", node->name);
+
+	if (of_property_read_u32(node, "reg", &ctl))
+		panic("%s: failed to get reg base", node->name);
+
+	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	chip->ctl = ctl;
+	chip->base = base;
+
+	dom = irq_domain_add_linear(node, 64, &irq_generic_chip_ops, chip);
+	if (!dom)
+		panic("%s: failed to create irqdomain", node->name);
+
+	err = irq_alloc_domain_generic_chips(dom, 32, 2, name, handle_level_irq,
+					     0, 0, 0);
+	if (err)
+		panic("%s: failed to allocate irqchip", node->name);
+
+	tangox_irq_domain_init(dom);
+
+	irq_set_chained_handler(irq, tangox_irq_handler);
+	irq_set_handler_data(irq, dom);
+
+	return 0;
+}
+
+static int __init tangox_of_irq_init(struct device_node *node,
+				     struct device_node *parent)
+{
+	struct device_node *c;
+	void __iomem *base;
+
+	base = of_iomap(node, 0);
+
+	for_each_child_of_node(node, c)
+		tangox_irq_init(base, c);
+
+	return 0;
+}
+
+IRQCHIP_DECLARE(tangox_intc, "sigma,smp8642-intc", tangox_of_irq_init);