/*
* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
* Copyright (C) 2014 Stefan Kristansson <stefan.kristiansson@saunalahti.fi>
*
* This program 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.
*/
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include "irqchip.h"
/* OR1K PIC implementation */
struct or1k_pic_dev {
struct irq_chip chip;
irq_flow_handler_t handle;
unsigned long flags;
};
/*
* We're a couple of cycles faster than the generic implementations with
* these 'fast' versions.
*/
static void or1k_pic_mask(struct irq_data *data)
{
mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq));
}
static void or1k_pic_unmask(struct irq_data *data)
{
mtspr(SPR_PICMR, mfspr(SPR_PICMR) | (1UL << data->hwirq));
}
static void or1k_pic_ack(struct irq_data *data)
{
mtspr(SPR_PICSR, (1UL << data->hwirq));
}
static void or1k_pic_mask_ack(struct irq_data *data)
{
mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq));
mtspr(SPR_PICSR, (1UL << data->hwirq));
}
/*
* There are two oddities with the OR1200 PIC implementation:
* i) LEVEL-triggered interrupts are latched and need to be cleared
* ii) the interrupt latch is cleared by writing a 0 to the bit,
* as opposed to a 1 as mandated by the spec
*/
static void or1k_pic_or1200_ack(struct irq_data *data)
{
mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->hwirq));
}
static void or1k_pic_or1200_mask_ack(struct irq_data *data)
{
mtspr(SPR_PICMR, mfspr(SPR_PICMR) & ~(1UL << data->hwirq));
mtspr(SPR_PICSR, mfspr(SPR_PICSR) & ~(1UL << data->hwirq));
}
static struct or1k_pic_dev or1k_pic_level = {
.chip = {
.name = "or1k-PIC-level",
.irq_unmask = or1k_pic_unmask,
.irq_mask = or1k_pic_mask,
.irq_mask_ack = or1k_pic_mask,
},
.handle = handle_level_irq,
.flags = IRQ_LEVEL | IRQ_NOPROBE,
};
static struct or1k_pic_dev or1k_pic_edge = {
.chip = {
.name = "or1k-PIC-edge",
.irq_unmask = or1k_pic_unmask,
.irq_mask = or1k_pic_mask,
.irq_ack = or1k_pic_ack,
.irq_mask_ack = or1k_pic_mask_ack,
},
.handle = handle_edge_irq,
.flags = IRQ_LEVEL | IRQ_NOPROBE,
};
static struct or1k_pic_dev or1k_pic_or1200 = {
.chip = {
.name = "or1200-PIC",
.irq_unmask = or1k_pic_unmask,
.irq_mask = or1k_pic_mask,
.irq_ack = or1k_pic_or1200_ack,
.irq_mask_ack = or1k_pic_or1200_mask_ack,
},
.handle = handle_level_irq,
.flags = IRQ_LEVEL | IRQ_NOPROBE,
};
static struct irq_domain *root_domain;
static inline int pic_get_irq(int first)
{
int hwirq;
hwirq = ffs(mfspr(SPR_PICSR) >> first);
if (!hwirq)
return NO_IRQ;
else
hwirq = hwirq + first - 1;
return irq_find_mapping(root_domain, hwirq);
}
static void or1k_pic_handle_irq(struct pt_regs *regs)
{
int irq = -1;
while ((irq = pic_get_irq(irq + 1)) != NO_IRQ)
handle_IRQ(irq, regs);
}
static int or1k_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
{
struct or1k_pic_dev *pic = d->host_data;
irq_set_chip_and_handler(irq, &pic->chip, pic->handle);
irq_set_status_flags(irq, pic->flags);
return 0;
}
static const struct irq_domain_ops or1k_irq_domain_ops = {
.xlate = irq_domain_xlate_onecell,
.map = or1k_map,
};
/*
* This sets up the IRQ domain for the PIC built in to the OpenRISC
* 1000 CPU. This is the "root" domain as these are the interrupts
* that directly trigger an exception in the CPU.
*/
static int __init or1k_pic_init(struct device_node *node,
struct or1k_pic_dev *pic)
{
/* Disable all interrupts until explicitly requested */
mtspr(SPR_PICMR, (0UL));
root_domain = irq_domain_add_linear(node, 32, &or1k_irq_domain_ops,
pic);
set_handle_irq(or1k_pic_handle_irq);
return 0;
}
static int __init or1k_pic_or1200_init(struct device_node *node,
struct device_node *parent)
{
return or1k_pic_init(node, &or1k_pic_or1200);
}
IRQCHIP_DECLARE(or1k_pic_or1200, "opencores,or1200-pic", or1k_pic_or1200_init);
IRQCHIP_DECLARE(or1k_pic, "opencores,or1k-pic", or1k_pic_or1200_init);
static int __init or1k_pic_level_init(struct device_node *node,
struct device_node *parent)
{
return or1k_pic_init(node, &or1k_pic_level);
}
IRQCHIP_DECLARE(or1k_pic_level, "opencores,or1k-pic-level",
or1k_pic_level_init);
static int __init or1k_pic_edge_init(struct device_node *node,
struct device_node *parent)
{
return or1k_pic_init(node, &or1k_pic_edge);
}
IRQCHIP_DECLARE(or1k_pic_edge, "opencores,or1k-pic-edge", or1k_pic_edge_init);
