linux/arch/powerpc/sysdev/xilinx_intc.c

89 lines
2.2 KiB
C

/*
* 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 <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/i8259.h>
#include <asm/irq.h>
#include <linux/irqchip.h>
#if defined(CONFIG_PPC_I8259)
/*
* Support code for cascading to 8259 interrupt controllers
*/
static void xilinx_i8259_cascade(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int cascade_irq = i8259_irq();
if (cascade_irq)
generic_handle_irq(cascade_irq);
/* Let xilinx_intc end the interrupt */
chip->irq_unmask(&desc->irq_data);
}
static void __init xilinx_i8259_setup_cascade(void)
{
struct device_node *cascade_node;
int cascade_irq;
/* Initialize i8259 controller */
cascade_node = of_find_compatible_node(NULL, NULL, "chrp,iic");
if (!cascade_node)
return;
cascade_irq = irq_of_parse_and_map(cascade_node, 0);
if (!cascade_irq) {
pr_err("virtex_ml510: Failed to map cascade interrupt\n");
goto out;
}
i8259_init(cascade_node, 0);
irq_set_chained_handler(cascade_irq, xilinx_i8259_cascade);
/* Program irq 7 (usb/audio), 14/15 (ide) to level sensitive */
/* This looks like a dirty hack to me --gcl */
outb(0xc0, 0x4d0);
outb(0xc0, 0x4d1);
out:
of_node_put(cascade_node);
}
#else
static inline void xilinx_i8259_setup_cascade(void) { return; }
#endif /* defined(CONFIG_PPC_I8259) */
/*
* Initialize master Xilinx interrupt controller
*/
void __init xilinx_intc_init_tree(void)
{
irqchip_init();
xilinx_i8259_setup_cascade();
}