/*
* Synopsys DW APB ICTL irqchip driver.
*
* Sebastian Hesselbarth <[email protected]>
*
* based on GPL'ed 2.6 kernel sources
* (c) Marvell International Ltd.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/interrupt.h>
#define APB_INT_ENABLE_L 0x00
#define APB_INT_ENABLE_H 0x04
#define APB_INT_MASK_L 0x08
#define APB_INT_MASK_H 0x0c
#define APB_INT_FINALSTATUS_L 0x30
#define APB_INT_FINALSTATUS_H 0x34
#define APB_INT_BASE_OFFSET 0x04
/* irq domain of the primary interrupt controller. */
static struct irq_domain *dw_apb_ictl_irq_domain;
static void __irq_entry dw_apb_ictl_handle_irq(struct pt_regs *regs)
{
struct irq_domain *d = dw_apb_ictl_irq_domain;
int n;
for (n = 0; n < d->revmap_size; n += 32) {
struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n);
u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
while (stat) {
u32 hwirq = ffs(stat) - 1;
generic_handle_domain_irq(d, hwirq);
stat &= ~BIT(hwirq);
}
}
}
static void dw_apb_ictl_handle_irq_cascaded(struct irq_desc *desc)
{
struct irq_domain *d = irq_desc_get_handler_data(desc);
struct irq_chip *chip = irq_desc_get_chip(desc);
int n;
chained_irq_enter(chip, desc);
for (n = 0; n < d->revmap_size; n += 32) {
struct irq_chip_generic *gc = irq_get_domain_generic_chip(d, n);
u32 stat = readl_relaxed(gc->reg_base + APB_INT_FINALSTATUS_L);
while (stat) {
u32 hwirq = ffs(stat) - 1;
generic_handle_domain_irq(d, gc->irq_base + hwirq);
stat &= ~BIT(hwirq);
}
}
chained_irq_exit(chip, desc);
}
static int dw_apb_ictl_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
int i, ret;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
struct irq_fwspec *fwspec = arg;
ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type);
if (ret)
return ret;
for (i = 0; i < nr_irqs; i++)
irq_map_generic_chip(domain, virq + i, hwirq + i);
return 0;
}
static const struct irq_domain_ops dw_apb_ictl_irq_domain_ops = {
.translate = irq_domain_translate_onecell,
.alloc = dw_apb_ictl_irq_domain_alloc,
.free = irq_domain_free_irqs_top,
};
#ifdef CONFIG_PM
static void dw_apb_ictl_resume(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
irq_gc_lock(gc);
writel_relaxed(~0, gc->reg_base + ct->regs.enable);
writel_relaxed(*ct->mask_cache, gc->reg_base + ct->regs.mask);
irq_gc_unlock(gc);
}
#else
#define dw_apb_ictl_resume NULL
#endif /* CONFIG_PM */
static int __init dw_apb_ictl_init(struct device_node *np,
struct device_node *parent)
{
const struct irq_domain_ops *domain_ops;
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
struct resource r;
struct irq_domain *domain;
struct irq_chip_generic *gc;
void __iomem *iobase;
int ret, nrirqs, parent_irq, i;
u32 reg;
if (!parent) {
/* Used as the primary interrupt controller */
parent_irq = 0;
domain_ops = &dw_apb_ictl_irq_domain_ops;
} else {
/* Map the parent interrupt for the chained handler */
parent_irq = irq_of_parse_and_map(np, 0);
if (parent_irq <= 0) {
pr_err("%pOF: unable to parse irq\n", np);
return -EINVAL;
}
domain_ops = &irq_generic_chip_ops;
}
ret = of_address_to_resource(np, 0, &r);
if (ret) {
pr_err("%pOF: unable to get resource\n", np);
return ret;
}
if (!request_mem_region(r.start, resource_size(&r), np->full_name)) {
pr_err("%pOF: unable to request mem region\n", np);
return -ENOMEM;
}
iobase = ioremap(r.start, resource_size(&r));
if (!iobase) {
pr_err("%pOF: unable to map resource\n", np);
ret = -ENOMEM;
goto err_release;
}
/*
* DW IP can be configured to allow 2-64 irqs. We can determine
* the number of irqs supported by writing into enable register
* and look for bits not set, as corresponding flip-flops will
* have been removed by synthesis tool.
*/
/* mask and enable all interrupts */
writel_relaxed(~0, iobase + APB_INT_MASK_L);
writel_relaxed(~0, iobase + APB_INT_MASK_H);
writel_relaxed(~0, iobase + APB_INT_ENABLE_L);
writel_relaxed(~0, iobase + APB_INT_ENABLE_H);
reg = readl_relaxed(iobase + APB_INT_ENABLE_H);
if (reg)
nrirqs = 32 + fls(reg);
else
nrirqs = fls(readl_relaxed(iobase + APB_INT_ENABLE_L));
domain = irq_domain_add_linear(np, nrirqs, domain_ops, NULL);
if (!domain) {
pr_err("%pOF: unable to add irq domain\n", np);
ret = -ENOMEM;
goto err_unmap;
}
ret = irq_alloc_domain_generic_chips(domain, 32, 1, np->name,
handle_level_irq, clr, 0,
IRQ_GC_INIT_MASK_CACHE);
if (ret) {
pr_err("%pOF: unable to alloc irq domain gc\n", np);
goto err_unmap;
}
for (i = 0; i < DIV_ROUND_UP(nrirqs, 32); i++) {
gc = irq_get_domain_generic_chip(domain, i * 32);
gc->reg_base = iobase + i * APB_INT_BASE_OFFSET;
gc->chip_types[0].regs.mask = APB_INT_MASK_L;
gc->chip_types[0].regs.enable = APB_INT_ENABLE_L;
gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
gc->chip_types[0].chip.irq_resume = dw_apb_ictl_resume;
}
if (parent_irq) {
irq_set_chained_handler_and_data(parent_irq,
dw_apb_ictl_handle_irq_cascaded, domain);
} else {
dw_apb_ictl_irq_domain = domain;
set_handle_irq(dw_apb_ictl_handle_irq);
}
return 0;
err_unmap:
iounmap(iobase);
err_release:
release_mem_region(r.start, resource_size(&r));
return ret;
}
IRQCHIP_DECLARE(dw_apb_ictl,
"snps,dw-apb-ictl", dw_apb_ictl_init);
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