/*
* Interrupt controller driver for Xilinx Virtex FPGAs
*
* Copyright (C) 2007 Secret Lab Technologies 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.
*
*/
/*
* This is a driver for the interrupt controller typically found in
* Xilinx Virtex FPGA designs.
*
* The interrupt sense levels are hard coded into the FPGA design with
* typically a 1:1 relationship between irq lines and devices (no shared
* irq lines). Therefore, this driver does not attempt to handle edge
* and level interrupts differently.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/irq.h>
/*
* INTC Registers
*/
#define XINTC_ISR 0 /* Interrupt Status */
#define XINTC_IPR 4 /* Interrupt Pending */
#define XINTC_IER 8 /* Interrupt Enable */
#define XINTC_IAR 12 /* Interrupt Acknowledge */
#define XINTC_SIE 16 /* Set Interrupt Enable bits */
#define XINTC_CIE 20 /* Clear Interrupt Enable bits */
#define XINTC_IVR 24 /* Interrupt Vector */
#define XINTC_MER 28 /* Master Enable */
static struct irq_host *master_irqhost;
/*
* IRQ Chip operations
*/
static void xilinx_intc_mask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void * regs = get_irq_chip_data(virq);
pr_debug("mask: %d\n", irq);
out_be32(regs + XINTC_CIE, 1 << irq);
}
static void xilinx_intc_unmask(unsigned int virq)
{
int irq = virq_to_hw(virq);
void * regs = get_irq_chip_data(virq);
pr_debug("unmask: %d\n", irq);
out_be32(regs + XINTC_SIE, 1 << irq);
}
static void xilinx_intc_ack(unsigned int virq)
{
int irq = virq_to_hw(virq);
void * regs = get_irq_chip_data(virq);
pr_debug("ack: %d\n", irq);
out_be32(regs + XINTC_IAR, 1 << irq);
}
static struct irq_chip xilinx_intc_irqchip = {
.typename = "Xilinx INTC",
.mask = xilinx_intc_mask,
.unmask = xilinx_intc_unmask,
.ack = xilinx_intc_ack,
};
/*
* IRQ Host operations
*/
static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
irq_hw_number_t irq)
{
set_irq_chip_data(virq, h->host_data);
set_irq_chip_and_handler(virq, &xilinx_intc_irqchip, handle_level_irq);
set_irq_type(virq, IRQ_TYPE_NONE);
return 0;
}
static struct irq_host_ops xilinx_intc_ops = {
.map = xilinx_intc_map,
};
struct irq_host * __init
xilinx_intc_init(struct device_node *np)
{
struct irq_host * irq;
struct resource res;
void * regs;
int rc;
/* Find and map the intc registers */
rc = of_address_to_resource(np, 0, &res);
if (rc) {
printk(KERN_ERR __FILE__ ": of_address_to_resource() failed\n");
return NULL;
}
regs = ioremap(res.start, 32);
printk(KERN_INFO "Xilinx intc at 0x%08X mapped to 0x%p\n",
res.start, regs);
/* Setup interrupt controller */
out_be32(regs + XINTC_IER, 0); /* disable all irqs */
out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
/* Allocate and initialize an irq_host structure. */
irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 32, &xilinx_intc_ops, -1);
if (!irq)
panic(__FILE__ ": Cannot allocate IRQ host\n");
irq->host_data = regs;
return irq;
}
int xilinx_intc_get_irq(void)
{
void * regs = master_irqhost->host_data;
pr_debug("get_irq:\n");
return irq_linear_revmap(master_irqhost, in_be32(regs + XINTC_IVR));
}
void __init xilinx_intc_init_tree(void)
{
struct device_node *np;
/* find top level interrupt controller */
for_each_compatible_node(np, NULL, "xlnx,opb-intc-1.00.c") {
if (!of_get_property(np, "interrupts", NULL))
break;
}
if (!np) {
for_each_compatible_node(np, NULL, "xlnx,xps-intc-1.00.a") {
if (!of_get_property(np, "interrupts", NULL))
break;
}
}
/* xilinx interrupt controller needs to be top level */
BUG_ON(!np);
master_irqhost = xilinx_intc_init(np);
BUG_ON(!master_irqhost);
irq_set_default_host(master_irqhost);
of_node_put(np);
}
