https://github.com/torvalds/linux
Tip revision: 5e01dc7b26d9f24f39abace5da98ccbd6a5ceb52 authored by Linus Torvalds on 03 November 2013, 23:41:51 UTC
Linux 3.12
Linux 3.12
Tip revision: 5e01dc7
irq-renesas-intc-irqpin.c
/*
* Renesas INTC External IRQ Pin Driver
*
* Copyright (C) 2013 Magnus Damm
*
* 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
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_data/irq-renesas-intc-irqpin.h>
#define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
#define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
#define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
#define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
#define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
#define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
#define INTC_IRQPIN_REG_NR 5
/* INTC external IRQ PIN hardware register access:
*
* SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
* PRIO is read-write 32-bit with 4-bits per IRQ (**)
* SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
* MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
* CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
*
* (*) May be accessed by more than one driver instance - lock needed
* (**) Read-modify-write access by one driver instance - lock needed
* (***) Accessed by one driver instance only - no locking needed
*/
struct intc_irqpin_iomem {
void __iomem *iomem;
unsigned long (*read)(void __iomem *iomem);
void (*write)(void __iomem *iomem, unsigned long data);
int width;
};
struct intc_irqpin_irq {
int hw_irq;
int requested_irq;
int domain_irq;
struct intc_irqpin_priv *p;
};
struct intc_irqpin_priv {
struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
struct renesas_intc_irqpin_config config;
unsigned int number_of_irqs;
struct platform_device *pdev;
struct irq_chip irq_chip;
struct irq_domain *irq_domain;
bool shared_irqs;
u8 shared_irq_mask;
};
static unsigned long intc_irqpin_read32(void __iomem *iomem)
{
return ioread32(iomem);
}
static unsigned long intc_irqpin_read8(void __iomem *iomem)
{
return ioread8(iomem);
}
static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
{
iowrite32(data, iomem);
}
static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
{
iowrite8(data, iomem);
}
static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
int reg)
{
struct intc_irqpin_iomem *i = &p->iomem[reg];
return i->read(i->iomem);
}
static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
int reg, unsigned long data)
{
struct intc_irqpin_iomem *i = &p->iomem[reg];
i->write(i->iomem, data);
}
static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
int reg, int hw_irq)
{
return BIT((p->iomem[reg].width - 1) - hw_irq);
}
static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
int reg, int hw_irq)
{
intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
}
static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
int reg, int shift,
int width, int value)
{
unsigned long flags;
unsigned long tmp;
raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
tmp = intc_irqpin_read(p, reg);
tmp &= ~(((1 << width) - 1) << shift);
tmp |= value << shift;
intc_irqpin_write(p, reg, tmp);
raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
}
static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
int irq, int do_mask)
{
int bitfield_width = 4; /* PRIO assumed to have fixed bitfield width */
int shift = (7 - irq) * bitfield_width; /* PRIO assumed to be 32-bit */
intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
shift, bitfield_width,
do_mask ? 0 : (1 << bitfield_width) - 1);
}
static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
{
int bitfield_width = p->config.sense_bitfield_width;
int shift = (7 - irq) * bitfield_width; /* SENSE assumed to be 32-bit */
dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
if (value >= (1 << bitfield_width))
return -EINVAL;
intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
bitfield_width, value);
return 0;
}
static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
{
dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
str, i->requested_irq, i->hw_irq, i->domain_irq);
}
static void intc_irqpin_irq_enable(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int hw_irq = irqd_to_hwirq(d);
intc_irqpin_dbg(&p->irq[hw_irq], "enable");
intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
}
static void intc_irqpin_irq_disable(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int hw_irq = irqd_to_hwirq(d);
intc_irqpin_dbg(&p->irq[hw_irq], "disable");
intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
}
static void intc_irqpin_shared_irq_enable(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int hw_irq = irqd_to_hwirq(d);
intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
p->shared_irq_mask &= ~BIT(hw_irq);
}
static void intc_irqpin_shared_irq_disable(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int hw_irq = irqd_to_hwirq(d);
intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
p->shared_irq_mask |= BIT(hw_irq);
}
static void intc_irqpin_irq_enable_force(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
intc_irqpin_irq_enable(d);
/* enable interrupt through parent interrupt controller,
* assumes non-shared interrupt with 1:1 mapping
* needed for busted IRQs on some SoCs like sh73a0
*/
irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
}
static void intc_irqpin_irq_disable_force(struct irq_data *d)
{
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
/* disable interrupt through parent interrupt controller,
* assumes non-shared interrupt with 1:1 mapping
* needed for busted IRQs on some SoCs like sh73a0
*/
irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
intc_irqpin_irq_disable(d);
}
#define INTC_IRQ_SENSE_VALID 0x10
#define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
[IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
[IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
[IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
[IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
[IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
};
static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
{
unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
if (!(value & INTC_IRQ_SENSE_VALID))
return -EINVAL;
return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
value ^ INTC_IRQ_SENSE_VALID);
}
static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
{
struct intc_irqpin_irq *i = dev_id;
struct intc_irqpin_priv *p = i->p;
unsigned long bit;
intc_irqpin_dbg(i, "demux1");
bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
intc_irqpin_dbg(i, "demux2");
generic_handle_irq(i->domain_irq);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
{
struct intc_irqpin_priv *p = dev_id;
unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
irqreturn_t status = IRQ_NONE;
int k;
for (k = 0; k < 8; k++) {
if (reg_source & BIT(7 - k)) {
if (BIT(k) & p->shared_irq_mask)
continue;
status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
}
}
return status;
}
static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
struct intc_irqpin_priv *p = h->host_data;
p->irq[hw].domain_irq = virq;
p->irq[hw].hw_irq = hw;
intc_irqpin_dbg(&p->irq[hw], "map");
irq_set_chip_data(virq, h->host_data);
irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
set_irq_flags(virq, IRQF_VALID); /* kill me now */
return 0;
}
static struct irq_domain_ops intc_irqpin_irq_domain_ops = {
.map = intc_irqpin_irq_domain_map,
.xlate = irq_domain_xlate_twocell,
};
static int intc_irqpin_probe(struct platform_device *pdev)
{
struct renesas_intc_irqpin_config *pdata = pdev->dev.platform_data;
struct intc_irqpin_priv *p;
struct intc_irqpin_iomem *i;
struct resource *io[INTC_IRQPIN_REG_NR];
struct resource *irq;
struct irq_chip *irq_chip;
void (*enable_fn)(struct irq_data *d);
void (*disable_fn)(struct irq_data *d);
const char *name = dev_name(&pdev->dev);
int ref_irq;
int ret;
int k;
p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
if (!p) {
dev_err(&pdev->dev, "failed to allocate driver data\n");
ret = -ENOMEM;
goto err0;
}
/* deal with driver instance configuration */
if (pdata) {
memcpy(&p->config, pdata, sizeof(*pdata));
} else {
of_property_read_u32(pdev->dev.of_node, "sense-bitfield-width",
&p->config.sense_bitfield_width);
p->config.control_parent = of_property_read_bool(pdev->dev.of_node,
"control-parent");
}
if (!p->config.sense_bitfield_width)
p->config.sense_bitfield_width = 4; /* default to 4 bits */
p->pdev = pdev;
platform_set_drvdata(pdev, p);
/* get hold of manadatory IOMEM */
for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
if (!io[k]) {
dev_err(&pdev->dev, "not enough IOMEM resources\n");
ret = -EINVAL;
goto err0;
}
}
/* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
for (k = 0; k < INTC_IRQPIN_MAX; k++) {
irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
if (!irq)
break;
p->irq[k].p = p;
p->irq[k].requested_irq = irq->start;
}
p->number_of_irqs = k;
if (p->number_of_irqs < 1) {
dev_err(&pdev->dev, "not enough IRQ resources\n");
ret = -EINVAL;
goto err0;
}
/* ioremap IOMEM and setup read/write callbacks */
for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
i = &p->iomem[k];
switch (resource_size(io[k])) {
case 1:
i->width = 8;
i->read = intc_irqpin_read8;
i->write = intc_irqpin_write8;
break;
case 4:
i->width = 32;
i->read = intc_irqpin_read32;
i->write = intc_irqpin_write32;
break;
default:
dev_err(&pdev->dev, "IOMEM size mismatch\n");
ret = -EINVAL;
goto err0;
}
i->iomem = devm_ioremap_nocache(&pdev->dev, io[k]->start,
resource_size(io[k]));
if (!i->iomem) {
dev_err(&pdev->dev, "failed to remap IOMEM\n");
ret = -ENXIO;
goto err0;
}
}
/* mask all interrupts using priority */
for (k = 0; k < p->number_of_irqs; k++)
intc_irqpin_mask_unmask_prio(p, k, 1);
/* clear all pending interrupts */
intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
/* scan for shared interrupt lines */
ref_irq = p->irq[0].requested_irq;
p->shared_irqs = true;
for (k = 1; k < p->number_of_irqs; k++) {
if (ref_irq != p->irq[k].requested_irq) {
p->shared_irqs = false;
break;
}
}
/* use more severe masking method if requested */
if (p->config.control_parent) {
enable_fn = intc_irqpin_irq_enable_force;
disable_fn = intc_irqpin_irq_disable_force;
} else if (!p->shared_irqs) {
enable_fn = intc_irqpin_irq_enable;
disable_fn = intc_irqpin_irq_disable;
} else {
enable_fn = intc_irqpin_shared_irq_enable;
disable_fn = intc_irqpin_shared_irq_disable;
}
irq_chip = &p->irq_chip;
irq_chip->name = name;
irq_chip->irq_mask = disable_fn;
irq_chip->irq_unmask = enable_fn;
irq_chip->irq_enable = enable_fn;
irq_chip->irq_disable = disable_fn;
irq_chip->irq_set_type = intc_irqpin_irq_set_type;
irq_chip->flags = IRQCHIP_SKIP_SET_WAKE;
p->irq_domain = irq_domain_add_simple(pdev->dev.of_node,
p->number_of_irqs,
p->config.irq_base,
&intc_irqpin_irq_domain_ops, p);
if (!p->irq_domain) {
ret = -ENXIO;
dev_err(&pdev->dev, "cannot initialize irq domain\n");
goto err0;
}
if (p->shared_irqs) {
/* request one shared interrupt */
if (devm_request_irq(&pdev->dev, p->irq[0].requested_irq,
intc_irqpin_shared_irq_handler,
IRQF_SHARED, name, p)) {
dev_err(&pdev->dev, "failed to request low IRQ\n");
ret = -ENOENT;
goto err1;
}
} else {
/* request interrupts one by one */
for (k = 0; k < p->number_of_irqs; k++) {
if (devm_request_irq(&pdev->dev,
p->irq[k].requested_irq,
intc_irqpin_irq_handler,
0, name, &p->irq[k])) {
dev_err(&pdev->dev,
"failed to request low IRQ\n");
ret = -ENOENT;
goto err1;
}
}
}
/* unmask all interrupts on prio level */
for (k = 0; k < p->number_of_irqs; k++)
intc_irqpin_mask_unmask_prio(p, k, 0);
dev_info(&pdev->dev, "driving %d irqs\n", p->number_of_irqs);
/* warn in case of mismatch if irq base is specified */
if (p->config.irq_base) {
if (p->config.irq_base != p->irq[0].domain_irq)
dev_warn(&pdev->dev, "irq base mismatch (%d/%d)\n",
p->config.irq_base, p->irq[0].domain_irq);
}
return 0;
err1:
irq_domain_remove(p->irq_domain);
err0:
return ret;
}
static int intc_irqpin_remove(struct platform_device *pdev)
{
struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
irq_domain_remove(p->irq_domain);
return 0;
}
static const struct of_device_id intc_irqpin_dt_ids[] = {
{ .compatible = "renesas,intc-irqpin", },
{},
};
MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
static struct platform_driver intc_irqpin_device_driver = {
.probe = intc_irqpin_probe,
.remove = intc_irqpin_remove,
.driver = {
.name = "renesas_intc_irqpin",
.of_match_table = intc_irqpin_dt_ids,
.owner = THIS_MODULE,
}
};
static int __init intc_irqpin_init(void)
{
return platform_driver_register(&intc_irqpin_device_driver);
}
postcore_initcall(intc_irqpin_init);
static void __exit intc_irqpin_exit(void)
{
platform_driver_unregister(&intc_irqpin_device_driver);
}
module_exit(intc_irqpin_exit);
MODULE_AUTHOR("Magnus Damm");
MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
MODULE_LICENSE("GPL v2");