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Commit 7a9243b9 authored by Jason Cooper's avatar Jason Cooper
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Merge branch 'irqchip/aspeed' into irqchip/core

parents e04558cb 59528842
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Aspeed Vectored Interrupt Controller

These bindings are for the Aspeed AST2400 interrupt controller register layout.
The SoC has an legacy register layout, but this driver does not support that
mode of operation.

Required properties:

- compatible : should be "aspeed,ast2400-vic".

- interrupt-controller : Identifies the node as an interrupt controller
- #interrupt-cells : Specifies the number of cells needed to encode an
  interrupt source. The value shall be 1.

Example:

 vic: interrupt-controller@1e6c0080 {
      compatible = "aspeed,ast2400-vic";
      interrupt-controller;
      #interrupt-cells = <1>;
      reg = <0x1e6c0080 0x80>;
 };
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@@ -69,3 +69,4 @@ obj-$(CONFIG_PIC32_EVIC) += irq-pic32-evic.o
obj-$(CONFIG_MVEBU_ODMI)		+= irq-mvebu-odmi.o
obj-$(CONFIG_LS_SCFG_MSI)		+= irq-ls-scfg-msi.o
obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o
obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o
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/*
 *  Copyright (C) 2015 - Ben Herrenschmidt, IBM Corp.
 *
 *  Driver for Aspeed "new" VIC as found in SoC generation 3 and later
 *
 *  Based on irq-vic.c:
 *
 *  Copyright (C) 1999 - 2003 ARM Limited
 *  Copyright (C) 2000 Deep Blue Solutions Ltd
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */

#include <linux/export.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/syscore_ops.h>
#include <linux/device.h>
#include <linux/slab.h>

#include <asm/exception.h>
#include <asm/irq.h>

/* These definitions correspond to the "new mapping" of the
 * register set that interleaves "high" and "low". The offsets
 * below are for the "low" register, add 4 to get to the high one
 */
#define AVIC_IRQ_STATUS		0x00
#define AVIC_FIQ_STATUS		0x08
#define AVIC_RAW_STATUS		0x10
#define AVIC_INT_SELECT		0x18
#define AVIC_INT_ENABLE		0x20
#define AVIC_INT_ENABLE_CLR	0x28
#define AVIC_INT_TRIGGER	0x30
#define AVIC_INT_TRIGGER_CLR	0x38
#define AVIC_INT_SENSE		0x40
#define AVIC_INT_DUAL_EDGE	0x48
#define AVIC_INT_EVENT		0x50
#define AVIC_EDGE_CLR		0x58
#define AVIC_EDGE_STATUS	0x60

#define NUM_IRQS		64

struct aspeed_vic {
	void __iomem		*base;
	u32			edge_sources[2];
	struct irq_domain	*dom;
};
static struct aspeed_vic *system_avic;

static void vic_init_hw(struct aspeed_vic *vic)
{
	u32 sense;

	/* Disable all interrupts */
	writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR);
	writel(0xffffffff, vic->base + AVIC_INT_ENABLE_CLR + 4);

	/* Make sure no soft trigger is on */
	writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR);
	writel(0xffffffff, vic->base + AVIC_INT_TRIGGER_CLR + 4);

	/* Set everything to be IRQ */
	writel(0, vic->base + AVIC_INT_SELECT);
	writel(0, vic->base + AVIC_INT_SELECT + 4);

	/* Some interrupts have a programable high/low level trigger
	 * (4 GPIO direct inputs), for now we assume this was configured
	 * by firmware. We read which ones are edge now.
	 */
	sense = readl(vic->base + AVIC_INT_SENSE);
	vic->edge_sources[0] = ~sense;
	sense = readl(vic->base + AVIC_INT_SENSE + 4);
	vic->edge_sources[1] = ~sense;

	/* Clear edge detection latches */
	writel(0xffffffff, vic->base + AVIC_EDGE_CLR);
	writel(0xffffffff, vic->base + AVIC_EDGE_CLR + 4);
}

static void __exception_irq_entry avic_handle_irq(struct pt_regs *regs)
{
	struct aspeed_vic *vic = system_avic;
	u32 stat, irq;

	for (;;) {
		irq = 0;
		stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS);
		if (!stat) {
			stat = readl_relaxed(vic->base + AVIC_IRQ_STATUS + 4);
			irq = 32;
		}
		if (stat == 0)
			break;
		irq += ffs(stat) - 1;
		handle_domain_irq(vic->dom, irq, regs);
	}
}

static void avic_ack_irq(struct irq_data *d)
{
	struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
	unsigned int sidx = d->hwirq >> 5;
	unsigned int sbit = 1u << (d->hwirq & 0x1f);

	/* Clear edge latch for edge interrupts, nop for level */
	if (vic->edge_sources[sidx] & sbit)
		writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
}

static void avic_mask_irq(struct irq_data *d)
{
	struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
	unsigned int sidx = d->hwirq >> 5;
	unsigned int sbit = 1u << (d->hwirq & 0x1f);

	writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);
}

static void avic_unmask_irq(struct irq_data *d)
{
	struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
	unsigned int sidx = d->hwirq >> 5;
	unsigned int sbit = 1u << (d->hwirq & 0x1f);

	writel(sbit, vic->base + AVIC_INT_ENABLE + sidx * 4);
}

/* For level irq, faster than going through a nop "ack" and mask */
static void avic_mask_ack_irq(struct irq_data *d)
{
	struct aspeed_vic *vic = irq_data_get_irq_chip_data(d);
	unsigned int sidx = d->hwirq >> 5;
	unsigned int sbit = 1u << (d->hwirq & 0x1f);

	/* First mask */
	writel(sbit, vic->base + AVIC_INT_ENABLE_CLR + sidx * 4);

	/* Then clear edge latch for edge interrupts */
	if (vic->edge_sources[sidx] & sbit)
		writel(sbit, vic->base + AVIC_EDGE_CLR + sidx * 4);
}

static struct irq_chip avic_chip = {
	.name		= "AVIC",
	.irq_ack	= avic_ack_irq,
	.irq_mask	= avic_mask_irq,
	.irq_unmask	= avic_unmask_irq,
	.irq_mask_ack	= avic_mask_ack_irq,
};

static int avic_map(struct irq_domain *d, unsigned int irq,
		    irq_hw_number_t hwirq)
{
	struct aspeed_vic *vic = d->host_data;
	unsigned int sidx = hwirq >> 5;
	unsigned int sbit = 1u << (hwirq & 0x1f);

	/* Check if interrupt exists */
	if (sidx > 1)
		return -EPERM;

	if (vic->edge_sources[sidx] & sbit)
		irq_set_chip_and_handler(irq, &avic_chip, handle_edge_irq);
	else
		irq_set_chip_and_handler(irq, &avic_chip, handle_level_irq);
	irq_set_chip_data(irq, vic);
	irq_set_probe(irq);
	return 0;
}

static struct irq_domain_ops avic_dom_ops = {
	.map = avic_map,
	.xlate = irq_domain_xlate_onetwocell,
};

static int __init avic_of_init(struct device_node *node,
			       struct device_node *parent)
{
	void __iomem *regs;
	struct aspeed_vic *vic;

	if (WARN(parent, "non-root Aspeed VIC not supported"))
		return -EINVAL;
	if (WARN(system_avic, "duplicate Aspeed VIC not supported"))
		return -EINVAL;

	regs = of_iomap(node, 0);
	if (WARN_ON(!regs))
		return -EIO;

	vic = kzalloc(sizeof(struct aspeed_vic), GFP_KERNEL);
	if (WARN_ON(!vic)) {
		iounmap(regs);
		return -ENOMEM;
	}
	vic->base = regs;

	/* Initialize soures, all masked */
	vic_init_hw(vic);

	/* Ready to receive interrupts */
	system_avic = vic;
	set_handle_irq(avic_handle_irq);

	/* Register our domain */
	vic->dom = irq_domain_add_simple(node, NUM_IRQS, 0,
					 &avic_dom_ops, vic);

	return 0;
}

IRQCHIP_DECLARE(aspeed_new_vic, "aspeed,ast2400-vic", avic_of_init);