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/*
* Copyright (C) 2008 Freescale Semiconductor, Inc. All rights reserved.
*
* Author: John Rigby, <jrigby@freescale.com>
*
* Description:
* MPC5121ADS CPLD irq handling
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <asm/prom.h>
static struct device_node *cpld_pic_node;
static struct irq_domain *cpld_pic_host;
/*
* Bits to ignore in the misc_status register
* 0x10 touch screen pendown is hard routed to irq1
* 0x02 pci status is read from pci status register
*/
#define MISC_IGNORE 0x12
/*
* Nothing to ignore in pci status register
*/
#define PCI_IGNORE 0x00
struct cpld_pic {
u8 pci_mask;
u8 pci_status;
u8 route;
u8 misc_mask;
u8 misc_status;
u8 misc_control;
};
static struct cpld_pic __iomem *cpld_regs;
static void __iomem *
irq_to_pic_mask(unsigned int irq)
{
return irq <= 7 ? &cpld_regs->pci_mask : &cpld_regs->misc_mask;
}
static unsigned int
irq_to_pic_bit(unsigned int irq)
{
return 1 << (irq & 0x7);
}
static void
cpld_mask_irq(struct irq_data *d)
{
unsigned int cpld_irq = (unsigned int)irqd_to_hwirq(d);
void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
out_8(pic_mask,
in_8(pic_mask) | irq_to_pic_bit(cpld_irq));
}
static void
cpld_unmask_irq(struct irq_data *d)
{
unsigned int cpld_irq = (unsigned int)irqd_to_hwirq(d);
void __iomem *pic_mask = irq_to_pic_mask(cpld_irq);
out_8(pic_mask,
in_8(pic_mask) & ~irq_to_pic_bit(cpld_irq));
}
static struct irq_chip cpld_pic = {
.name = "CPLD PIC",
.irq_mask = cpld_mask_irq,
.irq_ack = cpld_mask_irq,
.irq_unmask = cpld_unmask_irq,
};
static int
cpld_pic_get_irq(int offset, u8 ignore, u8 __iomem *statusp,
u8 __iomem *maskp)
{
int cpld_irq;
u8 status = in_8(statusp);
u8 mask = in_8(maskp);
/* ignore don't cares and masked irqs */
status |= (ignore | mask);
if (status == 0xff)
return NO_IRQ;
cpld_irq = ffz(status) + offset;
return irq_linear_revmap(cpld_pic_host, cpld_irq);
}
static void
cpld_pic_cascade(unsigned int irq, struct irq_desc *desc)
{
irq = cpld_pic_get_irq(0, PCI_IGNORE, &cpld_regs->pci_status,
&cpld_regs->pci_mask);
if (irq != NO_IRQ) {
generic_handle_irq(irq);
return;
}
irq = cpld_pic_get_irq(8, MISC_IGNORE, &cpld_regs->misc_status,
&cpld_regs->misc_mask);
if (irq != NO_IRQ) {
generic_handle_irq(irq);
return;
}
}
static int
cpld_pic_host_match(struct irq_domain *h, struct device_node *node)
{
return cpld_pic_node == node;
}
static int
cpld_pic_host_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_status_flags(virq, IRQ_LEVEL);
irq_set_chip_and_handler(virq, &cpld_pic, handle_level_irq);
return 0;
}
static const struct irq_domain_ops cpld_pic_host_ops = {
.match = cpld_pic_host_match,
.map = cpld_pic_host_map,
};
void __init
mpc5121_ads_cpld_map(void)
{
struct device_node *np = NULL;
np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
if (!np) {
printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
return;
}
cpld_regs = of_iomap(np, 0);
of_node_put(np);
}
void __init
mpc5121_ads_cpld_pic_init(void)
{
unsigned int cascade_irq;
struct device_node *np = NULL;
pr_debug("cpld_ic_init\n");
np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121ads-cpld-pic");
if (!np) {
printk(KERN_ERR "CPLD PIC init: can not find cpld-pic node\n");
return;
}
if (!cpld_regs)
goto end;
cascade_irq = irq_of_parse_and_map(np, 0);
if (cascade_irq == NO_IRQ)
goto end;
/*
* statically route touch screen pendown through 1
* and ignore it here
* route all others through our cascade irq
*/
out_8(&cpld_regs->route, 0xfd);
out_8(&cpld_regs->pci_mask, 0xff);
/* unmask pci ints in misc mask */
out_8(&cpld_regs->misc_mask, ~(MISC_IGNORE));
cpld_pic_node = of_node_get(np);
cpld_pic_host = irq_domain_add_linear(np, 16, &cpld_pic_host_ops, NULL);
if (!cpld_pic_host) {
printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
goto end;
}
irq_set_chained_handler(cascade_irq, cpld_pic_cascade);
end:
of_node_put(np);
}
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