linux/drivers/irqchip/irq-xilinx-intc.c

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/*
* Copyright (C) 2007-2013 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2012-2013 Xilinx, Inc.
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/jump_label.h>
#include <linux/bug.h>
#include <linux/of_irq.h>
/* No one else should require these constants, so define them locally here. */
#define ISR 0x00 /* Interrupt Status Register */
#define IPR 0x04 /* Interrupt Pending Register */
#define IER 0x08 /* Interrupt Enable Register */
#define IAR 0x0c /* Interrupt Acknowledge Register */
#define SIE 0x10 /* Set Interrupt Enable bits */
#define CIE 0x14 /* Clear Interrupt Enable bits */
#define IVR 0x18 /* Interrupt Vector Register */
#define MER 0x1c /* Master Enable Register */
#define MER_ME (1<<0)
#define MER_HIE (1<<1)
static DEFINE_STATIC_KEY_FALSE(xintc_is_be);
struct xintc_irq_chip {
void __iomem *base;
struct irq_domain *root_domain;
u32 intr_mask;
};
static struct xintc_irq_chip *xintc_irqc;
static void xintc_write(int reg, u32 data)
{
if (static_branch_unlikely(&xintc_is_be))
iowrite32be(data, xintc_irqc->base + reg);
else
iowrite32(data, xintc_irqc->base + reg);
}
static unsigned int xintc_read(int reg)
{
if (static_branch_unlikely(&xintc_is_be))
return ioread32be(xintc_irqc->base + reg);
else
return ioread32(xintc_irqc->base + reg);
}
static void intc_enable_or_unmask(struct irq_data *d)
{
unsigned long mask = 1 << d->hwirq;
pr_debug("irq-xilinx: enable_or_unmask: %ld\n", d->hwirq);
/* ack level irqs because they can't be acked during
* ack function since the handle_level_irq function
* acks the irq before calling the interrupt handler
*/
if (irqd_is_level_type(d))
xintc_write(IAR, mask);
xintc_write(SIE, mask);
}
static void intc_disable_or_mask(struct irq_data *d)
{
pr_debug("irq-xilinx: disable: %ld\n", d->hwirq);
xintc_write(CIE, 1 << d->hwirq);
}
static void intc_ack(struct irq_data *d)
{
pr_debug("irq-xilinx: ack: %ld\n", d->hwirq);
xintc_write(IAR, 1 << d->hwirq);
}
static void intc_mask_ack(struct irq_data *d)
{
unsigned long mask = 1 << d->hwirq;
pr_debug("irq-xilinx: disable_and_ack: %ld\n", d->hwirq);
xintc_write(CIE, mask);
xintc_write(IAR, mask);
}
static struct irq_chip intc_dev = {
.name = "Xilinx INTC",
.irq_unmask = intc_enable_or_unmask,
.irq_mask = intc_disable_or_mask,
.irq_ack = intc_ack,
.irq_mask_ack = intc_mask_ack,
};
unsigned int xintc_get_irq(void)
{
unsigned int hwirq, irq = -1;
hwirq = xintc_read(IVR);
if (hwirq != -1U)
irq = irq_find_mapping(xintc_irqc->root_domain, hwirq);
pr_debug("irq-xilinx: hwirq=%d, irq=%d\n", hwirq, irq);
return irq;
}
static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
if (xintc_irqc->intr_mask & (1 << hw)) {
irq_set_chip_and_handler_name(irq, &intc_dev,
handle_edge_irq, "edge");
irq_clear_status_flags(irq, IRQ_LEVEL);
} else {
irq_set_chip_and_handler_name(irq, &intc_dev,
handle_level_irq, "level");
irq_set_status_flags(irq, IRQ_LEVEL);
}
return 0;
}
static const struct irq_domain_ops xintc_irq_domain_ops = {
.xlate = irq_domain_xlate_onetwocell,
.map = xintc_map,
};
static void xil_intc_irq_handler(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
u32 pending;
chained_irq_enter(chip, desc);
do {
pending = xintc_get_irq();
if (pending == -1U)
break;
generic_handle_irq(pending);
} while (true);
chained_irq_exit(chip, desc);
}
static int __init xilinx_intc_of_init(struct device_node *intc,
struct device_node *parent)
{
u32 nr_irq;
int ret, irq;
struct xintc_irq_chip *irqc;
if (xintc_irqc) {
pr_err("irq-xilinx: Multiple instances aren't supported\n");
return -EINVAL;
}
irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
if (!irqc)
return -ENOMEM;
xintc_irqc = irqc;
irqc->base = of_iomap(intc, 0);
BUG_ON(!irqc->base);
ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
if (ret < 0) {
pr_err("irq-xilinx: unable to read xlnx,num-intr-inputs\n");
goto err_alloc;
}
ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
if (ret < 0) {
pr_warn("irq-xilinx: unable to read xlnx,kind-of-intr\n");
irqc->intr_mask = 0;
}
if (irqc->intr_mask >> nr_irq)
pr_warn("irq-xilinx: mismatch in kind-of-intr param\n");
pr_info("irq-xilinx: %s: num_irq=%d, edge=0x%x\n",
intc->full_name, nr_irq, irqc->intr_mask);
/*
* Disable all external interrupts until they are
* explicity requested.
*/
xintc_write(IER, 0);
/* Acknowledge any pending interrupts just in case. */
xintc_write(IAR, 0xffffffff);
/* Turn on the Master Enable. */
xintc_write(MER, MER_HIE | MER_ME);
if (!(xintc_read(MER) & (MER_HIE | MER_ME))) {
static_branch_enable(&xintc_is_be);
xintc_write(MER, MER_HIE | MER_ME);
}
irqc->root_domain = irq_domain_add_linear(intc, nr_irq,
&xintc_irq_domain_ops, irqc);
if (!irqc->root_domain) {
pr_err("irq-xilinx: Unable to create IRQ domain\n");
goto err_alloc;
}
if (parent) {
irq = irq_of_parse_and_map(intc, 0);
if (irq) {
irq_set_chained_handler_and_data(irq,
xil_intc_irq_handler,
irqc);
} else {
pr_err("irq-xilinx: interrupts property not in DT\n");
ret = -EINVAL;
goto err_alloc;
}
} else {
irq_set_default_host(irqc->root_domain);
}
return 0;
err_alloc:
xintc_irqc = NULL;
kfree(irqc);
return ret;
}
IRQCHIP_DECLARE(xilinx_intc_xps, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);
IRQCHIP_DECLARE(xilinx_intc_opb, "xlnx,opb-intc-1.00.c", xilinx_intc_of_init);