linux/drivers/irqchip/irq-bcm7120-l2.c
Kevin Cernekee c76acf4dff irqchip: bcm7120-l2: Extend driver to support 64+ bit controllers
Most implementations of the bcm7120-l2 controller only have a single
32-bit enable word + 32-bit status word.  But some instances have added
more enable/status pairs in order to support 64+ IRQs (which are all
ORed into one parent IRQ input).  Make the following changes to allow
the driver to support this:

 - Extend DT bindings so that multiple words can be specified for the
   reg property, various masks, etc.

 - Add loops to the probe/handle functions to deal with each word
   separately

 - Allocate 1 generic-chip for every 32 IRQs, so we can still use the
   clr/set helper functions

 - Update the documentation

This uses one domain per bcm7120-l2 DT node.  If the DT node defines
multiple enable/status pairs (i.e. >=64 IRQs) then the driver will
create a single IRQ domain with 2+ generic chips.  Multiple generic chips
are required because the generic-chip code can only handle one
enable/status register pair per instance.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/1415342669-30640-12-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-09 04:03:13 +00:00

252 lines
6.4 KiB
C

/*
* Broadcom BCM7120 style Level 2 interrupt controller driver
*
* Copyright (C) 2014 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/irqdomain.h>
#include <linux/reboot.h>
#include <linux/bitops.h>
#include <linux/irqchip/chained_irq.h>
#include "irqchip.h"
/* Register offset in the L2 interrupt controller */
#define IRQEN 0x00
#define IRQSTAT 0x04
#define MAX_WORDS 4
#define IRQS_PER_WORD 32
struct bcm7120_l2_intc_data {
unsigned int n_words;
void __iomem *base[MAX_WORDS];
struct irq_domain *domain;
bool can_wake;
u32 irq_fwd_mask[MAX_WORDS];
u32 irq_map_mask[MAX_WORDS];
};
static void bcm7120_l2_intc_irq_handle(unsigned int irq, struct irq_desc *desc)
{
struct bcm7120_l2_intc_data *b = irq_desc_get_handler_data(desc);
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int idx;
chained_irq_enter(chip, desc);
for (idx = 0; idx < b->n_words; idx++) {
int base = idx * IRQS_PER_WORD;
struct irq_chip_generic *gc =
irq_get_domain_generic_chip(b->domain, base);
unsigned long pending;
int hwirq;
irq_gc_lock(gc);
pending = __raw_readl(b->base[idx] + IRQSTAT) &
gc->mask_cache;
irq_gc_unlock(gc);
for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
generic_handle_irq(irq_find_mapping(b->domain,
base + hwirq));
}
}
chained_irq_exit(chip, desc);
}
static void bcm7120_l2_intc_suspend(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct bcm7120_l2_intc_data *b = gc->private;
irq_gc_lock(gc);
if (b->can_wake) {
__raw_writel(gc->mask_cache | gc->wake_active,
gc->reg_base + IRQEN);
}
irq_gc_unlock(gc);
}
static void bcm7120_l2_intc_resume(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
/* Restore the saved mask */
irq_gc_lock(gc);
__raw_writel(gc->mask_cache, gc->reg_base + IRQEN);
irq_gc_unlock(gc);
}
static int bcm7120_l2_intc_init_one(struct device_node *dn,
struct bcm7120_l2_intc_data *data,
int irq, const __be32 *map_mask)
{
int parent_irq;
unsigned int idx;
parent_irq = irq_of_parse_and_map(dn, irq);
if (parent_irq < 0) {
pr_err("failed to map interrupt %d\n", irq);
return parent_irq;
}
/* For multiple parent IRQs with multiple words, this looks like:
* <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...>
*/
for (idx = 0; idx < data->n_words; idx++)
data->irq_map_mask[idx] |=
be32_to_cpup(map_mask + irq * data->n_words + idx);
irq_set_handler_data(parent_irq, data);
irq_set_chained_handler(parent_irq, bcm7120_l2_intc_irq_handle);
return 0;
}
int __init bcm7120_l2_intc_of_init(struct device_node *dn,
struct device_node *parent)
{
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
struct bcm7120_l2_intc_data *data;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
const __be32 *map_mask;
int num_parent_irqs;
int ret = 0, len;
unsigned int idx, irq;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;
for (idx = 0; idx < MAX_WORDS; idx++) {
data->base[idx] = of_iomap(dn, idx);
if (!data->base[idx])
break;
data->n_words = idx + 1;
}
if (!data->n_words) {
pr_err("failed to remap intc L2 registers\n");
ret = -ENOMEM;
goto out_unmap;
}
/* Enable all interrupts specified in the interrupt forward mask;
* disable all others. If the property doesn't exist (-EINVAL),
* assume all zeroes.
*/
ret = of_property_read_u32_array(dn, "brcm,int-fwd-mask",
data->irq_fwd_mask, data->n_words);
if (ret == 0 || ret == -EINVAL) {
for (idx = 0; idx < data->n_words; idx++)
__raw_writel(data->irq_fwd_mask[idx],
data->base[idx] + IRQEN);
} else {
/* property exists but has the wrong number of words */
pr_err("invalid int-fwd-mask property\n");
ret = -EINVAL;
goto out_unmap;
}
num_parent_irqs = of_irq_count(dn);
if (num_parent_irqs <= 0) {
pr_err("invalid number of parent interrupts\n");
ret = -ENOMEM;
goto out_unmap;
}
map_mask = of_get_property(dn, "brcm,int-map-mask", &len);
if (!map_mask ||
(len != (sizeof(*map_mask) * num_parent_irqs * data->n_words))) {
pr_err("invalid brcm,int-map-mask property\n");
ret = -EINVAL;
goto out_unmap;
}
for (irq = 0; irq < num_parent_irqs; irq++) {
ret = bcm7120_l2_intc_init_one(dn, data, irq, map_mask);
if (ret)
goto out_unmap;
}
data->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * data->n_words,
&irq_generic_chip_ops, NULL);
if (!data->domain) {
ret = -ENOMEM;
goto out_unmap;
}
ret = irq_alloc_domain_generic_chips(data->domain, IRQS_PER_WORD, 1,
dn->full_name, handle_level_irq, clr, 0,
IRQ_GC_INIT_MASK_CACHE);
if (ret) {
pr_err("failed to allocate generic irq chip\n");
goto out_free_domain;
}
if (of_property_read_bool(dn, "brcm,irq-can-wake"))
data->can_wake = true;
for (idx = 0; idx < data->n_words; idx++) {
irq = idx * IRQS_PER_WORD;
gc = irq_get_domain_generic_chip(data->domain, irq);
gc->unused = 0xffffffff & ~data->irq_map_mask[idx];
gc->reg_base = data->base[idx];
gc->private = data;
ct = gc->chip_types;
ct->regs.mask = IRQEN;
ct->chip.irq_mask = irq_gc_mask_clr_bit;
ct->chip.irq_unmask = irq_gc_mask_set_bit;
ct->chip.irq_ack = irq_gc_noop;
ct->chip.irq_suspend = bcm7120_l2_intc_suspend;
ct->chip.irq_resume = bcm7120_l2_intc_resume;
if (data->can_wake) {
/* This IRQ chip can wake the system, set all
* relevant child interupts in wake_enabled mask
*/
gc->wake_enabled = 0xffffffff;
gc->wake_enabled &= ~gc->unused;
ct->chip.irq_set_wake = irq_gc_set_wake;
}
}
pr_info("registered BCM7120 L2 intc (mem: 0x%p, parent IRQ(s): %d)\n",
data->base[0], num_parent_irqs);
return 0;
out_free_domain:
irq_domain_remove(data->domain);
out_unmap:
for (idx = 0; idx < MAX_WORDS; idx++) {
if (data->base[idx])
iounmap(data->base[idx]);
}
kfree(data);
return ret;
}
IRQCHIP_DECLARE(brcmstb_l2_intc, "brcm,bcm7120-l2-intc",
bcm7120_l2_intc_of_init);