Subject: [RFC PATCH v3] irqchip: Add support for Tango interrupt controller

From: [email-masked] (Marc Zyngier)
Date: Wed, 20 Jan 2016 16:04:05 +0000

On 18/01/16 16:44, Marc Gonzalez wrote:
> From: Mans Rullgard <[email-masked]>
> 
> Add support for the interrupt controller used in Sigma Designs
> SMP86xx (Tango3) and SMP87xx (Tango4) chips.
> 
> Signed-off-by: Marc Gonzalez <[email-masked]>
> ---
> 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.
> 
> 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 at 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 at 000 {
> 		reg = <0x000 0x100>;
> 		interrupt-controller;
> 		#interrupt-cells = <2>;
> 		interrupts = <GIC_SPI 2 IRQ_TYPE_LEVEL_HIGH>;
> 	};
> 
> 	irq1: irq1 at 100 {
> 		reg = <0x100 0x100>;
> 		interrupt-controller;
> 		#interrupt-cells = <2>;
> 		interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
> 	};
> 
> 	irq2: irq2 at 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 | 225 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 231 insertions(+)
>  create mode 100644 drivers/irqchip/irq-tango.c
> 
> 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..ace9bd50be6b
> --- /dev/null
> +++ b/drivers/irqchip/irq-tango.c
> @@ -0,0 +1,225 @@
> +/*
> + * Copyright (C) 2014 Mans Rullgard <[email-masked]>
> + *
> + * 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;
> +	u32 ctl;
> +	int irq;
> +	int err;
> +
> +	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, node->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);
> 

So the whole thing seems sound. For this patch:

Acked-by: Marc Zyngier <[email-masked]>

But you definitely need another patch documenting the DT bindings.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...