original development tree for Linux kernel GTP module; now long in mainline.
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/*
* linux/arch/arm/common/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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/export.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/io.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/amba/bus.h>
#include <asm/exception.h>
#include <asm/mach/irq.h>
#include <asm/hardware/vic.h>
/**
* struct vic_device - VIC PM device
* @irq: The IRQ number for the base of the VIC.
* @base: The register base for the VIC.
* @valid_sources: A bitmask of valid interrupts
* @resume_sources: A bitmask of interrupts for resume.
* @resume_irqs: The IRQs enabled for resume.
* @int_select: Save for VIC_INT_SELECT.
* @int_enable: Save for VIC_INT_ENABLE.
* @soft_int: Save for VIC_INT_SOFT.
* @protect: Save for VIC_PROTECT.
* @domain: The IRQ domain for the VIC.
*/
struct vic_device {
void __iomem *base;
int irq;
u32 valid_sources;
u32 resume_sources;
u32 resume_irqs;
u32 int_select;
u32 int_enable;
u32 soft_int;
u32 protect;
struct irq_domain *domain;
};
/* we cannot allocate memory when VICs are initially registered */
static struct vic_device vic_devices[CONFIG_ARM_VIC_NR];
static int vic_id;
/**
* vic_init2 - common initialisation code
* @base: Base of the VIC.
*
* Common initialisation code for registration
* and resume.
*/
static void vic_init2(void __iomem *base)
{
int i;
for (i = 0; i < 16; i++) {
void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
writel(VIC_VECT_CNTL_ENABLE | i, reg);
}
writel(32, base + VIC_PL190_DEF_VECT_ADDR);
}
#ifdef CONFIG_PM
static void resume_one_vic(struct vic_device *vic)
{
void __iomem *base = vic->base;
printk(KERN_DEBUG "%s: resuming vic at %p\n", __func__, base);
/* re-initialise static settings */
vic_init2(base);
writel(vic->int_select, base + VIC_INT_SELECT);
writel(vic->protect, base + VIC_PROTECT);
/* set the enabled ints and then clear the non-enabled */
writel(vic->int_enable, base + VIC_INT_ENABLE);
writel(~vic->int_enable, base + VIC_INT_ENABLE_CLEAR);
/* and the same for the soft-int register */
writel(vic->soft_int, base + VIC_INT_SOFT);
writel(~vic->soft_int, base + VIC_INT_SOFT_CLEAR);
}
static void vic_resume(void)
{
int id;
for (id = vic_id - 1; id >= 0; id--)
resume_one_vic(vic_devices + id);
}
static void suspend_one_vic(struct vic_device *vic)
{
void __iomem *base = vic->base;
printk(KERN_DEBUG "%s: suspending vic at %p\n", __func__, base);
vic->int_select = readl(base + VIC_INT_SELECT);
vic->int_enable = readl(base + VIC_INT_ENABLE);
vic->soft_int = readl(base + VIC_INT_SOFT);
vic->protect = readl(base + VIC_PROTECT);
/* set the interrupts (if any) that are used for
* resuming the system */
writel(vic->resume_irqs, base + VIC_INT_ENABLE);
writel(~vic->resume_irqs, base + VIC_INT_ENABLE_CLEAR);
}
static int vic_suspend(void)
{
int id;
for (id = 0; id < vic_id; id++)
suspend_one_vic(vic_devices + id);
return 0;
}
struct syscore_ops vic_syscore_ops = {
.suspend = vic_suspend,
.resume = vic_resume,
};
/**
* vic_pm_init - initicall to register VIC pm
*
* This is called via late_initcall() to register
* the resources for the VICs due to the early
* nature of the VIC's registration.
*/
static int __init vic_pm_init(void)
{
if (vic_id > 0)
register_syscore_ops(&vic_syscore_ops);
return 0;
}
late_initcall(vic_pm_init);
#endif /* CONFIG_PM */
static struct irq_chip vic_chip;
static int vic_irqdomain_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct vic_device *v = d->host_data;
/* Skip invalid IRQs, only register handlers for the real ones */
if (!(v->valid_sources & (1 << hwirq)))
return -ENOTSUPP;
irq_set_chip_and_handler(irq, &vic_chip, handle_level_irq);
irq_set_chip_data(irq, v->base);
set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
return 0;
}
static struct irq_domain_ops vic_irqdomain_ops = {
.map = vic_irqdomain_map,
.xlate = irq_domain_xlate_onetwocell,
};
/**
* vic_register() - Register a VIC.
* @base: The base address of the VIC.
* @irq: The base IRQ for the VIC.
* @valid_sources: bitmask of valid interrupts
* @resume_sources: bitmask of interrupts allowed for resume sources.
* @node: The device tree node associated with the VIC.
*
* Register the VIC with the system device tree so that it can be notified
* of suspend and resume requests and ensure that the correct actions are
* taken to re-instate the settings on resume.
*
* This also configures the IRQ domain for the VIC.
*/
static void __init vic_register(void __iomem *base, unsigned int irq,
u32 valid_sources, u32 resume_sources,
struct device_node *node)
{
struct vic_device *v;
int i;
if (vic_id >= ARRAY_SIZE(vic_devices)) {
printk(KERN_ERR "%s: too few VICs, increase CONFIG_ARM_VIC_NR\n", __func__);
return;
}
v = &vic_devices[vic_id];
v->base = base;
v->valid_sources = valid_sources;
v->resume_sources = resume_sources;
v->irq = irq;
vic_id++;
v->domain = irq_domain_add_simple(node, fls(valid_sources), irq,
&vic_irqdomain_ops, v);
/* create an IRQ mapping for each valid IRQ */
for (i = 0; i < fls(valid_sources); i++)
if (valid_sources & (1 << i))
irq_create_mapping(v->domain, i);
}
static void vic_ack_irq(struct irq_data *d)
{
void __iomem *base = irq_data_get_irq_chip_data(d);
unsigned int irq = d->hwirq;
writel(1 << irq, base + VIC_INT_ENABLE_CLEAR);
/* moreover, clear the soft-triggered, in case it was the reason */
writel(1 << irq, base + VIC_INT_SOFT_CLEAR);
}
static void vic_mask_irq(struct irq_data *d)
{
void __iomem *base = irq_data_get_irq_chip_data(d);
unsigned int irq = d->hwirq;
writel(1 << irq, base + VIC_INT_ENABLE_CLEAR);
}
static void vic_unmask_irq(struct irq_data *d)
{
void __iomem *base = irq_data_get_irq_chip_data(d);
unsigned int irq = d->hwirq;
writel(1 << irq, base + VIC_INT_ENABLE);
}
#if defined(CONFIG_PM)
static struct vic_device *vic_from_irq(unsigned int irq)
{
struct vic_device *v = vic_devices;
unsigned int base_irq = irq & ~31;
int id;
for (id = 0; id < vic_id; id++, v++) {
if (v->irq == base_irq)
return v;
}
return NULL;
}
static int vic_set_wake(struct irq_data *d, unsigned int on)
{
struct vic_device *v = vic_from_irq(d->irq);
unsigned int off = d->hwirq;
u32 bit = 1 << off;
if (!v)
return -EINVAL;
if (!(bit & v->resume_sources))
return -EINVAL;
if (on)
v->resume_irqs |= bit;
else
v->resume_irqs &= ~bit;
return 0;
}
#else
#define vic_set_wake NULL
#endif /* CONFIG_PM */
static struct irq_chip vic_chip = {
.name = "VIC",
.irq_ack = vic_ack_irq,
.irq_mask = vic_mask_irq,
.irq_unmask = vic_unmask_irq,
.irq_set_wake = vic_set_wake,
};
static void __init vic_disable(void __iomem *base)
{
writel(0, base + VIC_INT_SELECT);
writel(0, base + VIC_INT_ENABLE);
writel(~0, base + VIC_INT_ENABLE_CLEAR);
writel(0, base + VIC_ITCR);
writel(~0, base + VIC_INT_SOFT_CLEAR);
}
static void __init vic_clear_interrupts(void __iomem *base)
{
unsigned int i;
writel(0, base + VIC_PL190_VECT_ADDR);
for (i = 0; i < 19; i++) {
unsigned int value;
value = readl(base + VIC_PL190_VECT_ADDR);
writel(value, base + VIC_PL190_VECT_ADDR);
}
}
/*
* The PL190 cell from ARM has been modified by ST to handle 64 interrupts.
* The original cell has 32 interrupts, while the modified one has 64,
* replocating two blocks 0x00..0x1f in 0x20..0x3f. In that case
* the probe function is called twice, with base set to offset 000
* and 020 within the page. We call this "second block".
*/
static void __init vic_init_st(void __iomem *base, unsigned int irq_start,
u32 vic_sources, struct device_node *node)
{
unsigned int i;
int vic_2nd_block = ((unsigned long)base & ~PAGE_MASK) != 0;
/* Disable all interrupts initially. */
vic_disable(base);
/*
* Make sure we clear all existing interrupts. The vector registers
* in this cell are after the second block of general registers,
* so we can address them using standard offsets, but only from
* the second base address, which is 0x20 in the page
*/
if (vic_2nd_block) {
vic_clear_interrupts(base);
/* ST has 16 vectors as well, but we don't enable them by now */
for (i = 0; i < 16; i++) {
void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
writel(0, reg);
}
writel(32, base + VIC_PL190_DEF_VECT_ADDR);
}
vic_register(base, irq_start, vic_sources, 0, node);
}
void __init __vic_init(void __iomem *base, int irq_start,
u32 vic_sources, u32 resume_sources,
struct device_node *node)
{
unsigned int i;
u32 cellid = 0;
enum amba_vendor vendor;
/* Identify which VIC cell this one is, by reading the ID */
for (i = 0; i < 4; i++) {
void __iomem *addr;
addr = (void __iomem *)((u32)base & PAGE_MASK) + 0xfe0 + (i * 4);
cellid |= (readl(addr) & 0xff) << (8 * i);
}
vendor = (cellid >> 12) & 0xff;
printk(KERN_INFO "VIC @%p: id 0x%08x, vendor 0x%02x\n",
base, cellid, vendor);
switch(vendor) {
case AMBA_VENDOR_ST:
vic_init_st(base, irq_start, vic_sources, node);
return;
default:
printk(KERN_WARNING "VIC: unknown vendor, continuing anyways\n");
/* fall through */
case AMBA_VENDOR_ARM:
break;
}
/* Disable all interrupts initially. */
vic_disable(base);
/* Make sure we clear all existing interrupts */
vic_clear_interrupts(base);
vic_init2(base);
vic_register(base, irq_start, vic_sources, resume_sources, node);
}
/**
* vic_init() - initialise a vectored interrupt controller
* @base: iomem base address
* @irq_start: starting interrupt number, must be muliple of 32
* @vic_sources: bitmask of interrupt sources to allow
* @resume_sources: bitmask of interrupt sources to allow for resume
*/
void __init vic_init(void __iomem *base, unsigned int irq_start,
u32 vic_sources, u32 resume_sources)
{
__vic_init(base, irq_start, vic_sources, resume_sources, NULL);
}
#ifdef CONFIG_OF
int __init vic_of_init(struct device_node *node, struct device_node *parent)
{
void __iomem *regs;
if (WARN(parent, "non-root VICs are not supported"))
return -EINVAL;
regs = of_iomap(node, 0);
if (WARN_ON(!regs))
return -EIO;
/*
* Passing 0 as first IRQ makes the simple domain allocate descriptors
*/
__vic_init(regs, 0, ~0, ~0, node);
return 0;
}
#endif /* CONFIG OF */
/*
* Handle each interrupt in a single VIC. Returns non-zero if we've
* handled at least one interrupt. This reads the status register
* before handling each interrupt, which is necessary given that
* handle_IRQ may briefly re-enable interrupts for soft IRQ handling.
*/
static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs)
{
u32 stat, irq;
int handled = 0;
while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) {
irq = ffs(stat) - 1;
handle_IRQ(irq_find_mapping(vic->domain, irq), regs);
handled = 1;
}
return handled;
}
/*
* Keep iterating over all registered VIC's until there are no pending
* interrupts.
*/
asmlinkage void __exception_irq_entry vic_handle_irq(struct pt_regs *regs)
{
int i, handled;
do {
for (i = 0, handled = 0; i < vic_id; ++i)
handled |= handle_one_vic(&vic_devices[i], regs);
} while (handled);
}