linux/drivers/base/regmap/regmap-irq.c

352 lines
8.8 KiB
C

/*
* regmap based irq_chip
*
* Copyright 2011 Wolfson Microelectronics plc
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/export.h>
#include <linux/device.h>
#include <linux/regmap.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/slab.h>
#include "internal.h"
struct regmap_irq_chip_data {
struct mutex lock;
struct regmap *map;
struct regmap_irq_chip *chip;
int irq_base;
struct irq_domain *domain;
unsigned int *status_buf;
unsigned int *mask_buf;
unsigned int *mask_buf_def;
unsigned int irq_reg_stride;
};
static inline const
struct regmap_irq *irq_to_regmap_irq(struct regmap_irq_chip_data *data,
int irq)
{
return &data->chip->irqs[irq];
}
static void regmap_irq_lock(struct irq_data *data)
{
struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
mutex_lock(&d->lock);
}
static void regmap_irq_sync_unlock(struct irq_data *data)
{
struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
struct regmap *map = d->map;
int i, ret;
/*
* If there's been a change in the mask write it back to the
* hardware. We rely on the use of the regmap core cache to
* suppress pointless writes.
*/
for (i = 0; i < d->chip->num_regs; i++) {
ret = regmap_update_bits(d->map, d->chip->mask_base +
(i * map->reg_stride *
d->irq_reg_stride),
d->mask_buf_def[i], d->mask_buf[i]);
if (ret != 0)
dev_err(d->map->dev, "Failed to sync masks in %x\n",
d->chip->mask_base + (i * map->reg_stride));
}
mutex_unlock(&d->lock);
}
static void regmap_irq_enable(struct irq_data *data)
{
struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
struct regmap *map = d->map;
const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
d->mask_buf[irq_data->reg_offset / map->reg_stride] &= ~irq_data->mask;
}
static void regmap_irq_disable(struct irq_data *data)
{
struct regmap_irq_chip_data *d = irq_data_get_irq_chip_data(data);
struct regmap *map = d->map;
const struct regmap_irq *irq_data = irq_to_regmap_irq(d, data->hwirq);
d->mask_buf[irq_data->reg_offset / map->reg_stride] |= irq_data->mask;
}
static struct irq_chip regmap_irq_chip = {
.name = "regmap",
.irq_bus_lock = regmap_irq_lock,
.irq_bus_sync_unlock = regmap_irq_sync_unlock,
.irq_disable = regmap_irq_disable,
.irq_enable = regmap_irq_enable,
};
static irqreturn_t regmap_irq_thread(int irq, void *d)
{
struct regmap_irq_chip_data *data = d;
struct regmap_irq_chip *chip = data->chip;
struct regmap *map = data->map;
int ret, i;
bool handled = false;
/*
* Ignore masked IRQs and ack if we need to; we ack early so
* there is no race between handling and acknowleding the
* interrupt. We assume that typically few of the interrupts
* will fire simultaneously so don't worry about overhead from
* doing a write per register.
*/
for (i = 0; i < data->chip->num_regs; i++) {
ret = regmap_read(map, chip->status_base + (i * map->reg_stride
* data->irq_reg_stride),
&data->status_buf[i]);
if (ret != 0) {
dev_err(map->dev, "Failed to read IRQ status: %d\n",
ret);
return IRQ_NONE;
}
data->status_buf[i] &= ~data->mask_buf[i];
if (data->status_buf[i] && chip->ack_base) {
ret = regmap_write(map, chip->ack_base +
(i * map->reg_stride *
data->irq_reg_stride),
data->status_buf[i]);
if (ret != 0)
dev_err(map->dev, "Failed to ack 0x%x: %d\n",
chip->ack_base + (i * map->reg_stride),
ret);
}
}
for (i = 0; i < chip->num_irqs; i++) {
if (data->status_buf[chip->irqs[i].reg_offset /
map->reg_stride] & chip->irqs[i].mask) {
handle_nested_irq(irq_find_mapping(data->domain, i));
handled = true;
}
}
if (handled)
return IRQ_HANDLED;
else
return IRQ_NONE;
}
static int regmap_irq_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t hw)
{
struct regmap_irq_chip_data *data = h->host_data;
irq_set_chip_data(virq, data);
irq_set_chip_and_handler(virq, &regmap_irq_chip, handle_edge_irq);
irq_set_nested_thread(virq, 1);
/* ARM needs us to explicitly flag the IRQ as valid
* and will set them noprobe when we do so. */
#ifdef CONFIG_ARM
set_irq_flags(virq, IRQF_VALID);
#else
irq_set_noprobe(virq);
#endif
return 0;
}
static struct irq_domain_ops regmap_domain_ops = {
.map = regmap_irq_map,
.xlate = irq_domain_xlate_twocell,
};
/**
* regmap_add_irq_chip(): Use standard regmap IRQ controller handling
*
* map: The regmap for the device.
* irq: The IRQ the device uses to signal interrupts
* irq_flags: The IRQF_ flags to use for the primary interrupt.
* chip: Configuration for the interrupt controller.
* data: Runtime data structure for the controller, allocated on success
*
* Returns 0 on success or an errno on failure.
*
* In order for this to be efficient the chip really should use a
* register cache. The chip driver is responsible for restoring the
* register values used by the IRQ controller over suspend and resume.
*/
int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
int irq_base, struct regmap_irq_chip *chip,
struct regmap_irq_chip_data **data)
{
struct regmap_irq_chip_data *d;
int i;
int ret = -ENOMEM;
for (i = 0; i < chip->num_irqs; i++) {
if (chip->irqs[i].reg_offset % map->reg_stride)
return -EINVAL;
if (chip->irqs[i].reg_offset / map->reg_stride >=
chip->num_regs)
return -EINVAL;
}
if (irq_base) {
irq_base = irq_alloc_descs(irq_base, 0, chip->num_irqs, 0);
if (irq_base < 0) {
dev_warn(map->dev, "Failed to allocate IRQs: %d\n",
irq_base);
return irq_base;
}
}
d = kzalloc(sizeof(*d), GFP_KERNEL);
if (!d)
return -ENOMEM;
*data = d;
d->status_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
GFP_KERNEL);
if (!d->status_buf)
goto err_alloc;
d->mask_buf = kzalloc(sizeof(unsigned int) * chip->num_regs,
GFP_KERNEL);
if (!d->mask_buf)
goto err_alloc;
d->mask_buf_def = kzalloc(sizeof(unsigned int) * chip->num_regs,
GFP_KERNEL);
if (!d->mask_buf_def)
goto err_alloc;
d->map = map;
d->chip = chip;
d->irq_base = irq_base;
if (chip->irq_reg_stride)
d->irq_reg_stride = chip->irq_reg_stride;
else
d->irq_reg_stride = 1;
mutex_init(&d->lock);
for (i = 0; i < chip->num_irqs; i++)
d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
|= chip->irqs[i].mask;
/* Mask all the interrupts by default */
for (i = 0; i < chip->num_regs; i++) {
d->mask_buf[i] = d->mask_buf_def[i];
ret = regmap_write(map, chip->mask_base + (i * map->reg_stride
* d->irq_reg_stride),
d->mask_buf[i]);
if (ret != 0) {
dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
chip->mask_base + (i * map->reg_stride), ret);
goto err_alloc;
}
}
if (irq_base)
d->domain = irq_domain_add_legacy(map->dev->of_node,
chip->num_irqs, irq_base, 0,
&regmap_domain_ops, d);
else
d->domain = irq_domain_add_linear(map->dev->of_node,
chip->num_irqs,
&regmap_domain_ops, d);
if (!d->domain) {
dev_err(map->dev, "Failed to create IRQ domain\n");
ret = -ENOMEM;
goto err_alloc;
}
ret = request_threaded_irq(irq, NULL, regmap_irq_thread, irq_flags,
chip->name, d);
if (ret != 0) {
dev_err(map->dev, "Failed to request IRQ %d: %d\n", irq, ret);
goto err_domain;
}
return 0;
err_domain:
/* Should really dispose of the domain but... */
err_alloc:
kfree(d->mask_buf_def);
kfree(d->mask_buf);
kfree(d->status_buf);
kfree(d);
return ret;
}
EXPORT_SYMBOL_GPL(regmap_add_irq_chip);
/**
* regmap_del_irq_chip(): Stop interrupt handling for a regmap IRQ chip
*
* @irq: Primary IRQ for the device
* @d: regmap_irq_chip_data allocated by regmap_add_irq_chip()
*/
void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
{
if (!d)
return;
free_irq(irq, d);
/* We should unmap the domain but... */
kfree(d->mask_buf_def);
kfree(d->mask_buf);
kfree(d->status_buf);
kfree(d);
}
EXPORT_SYMBOL_GPL(regmap_del_irq_chip);
/**
* regmap_irq_chip_get_base(): Retrieve interrupt base for a regmap IRQ chip
*
* Useful for drivers to request their own IRQs.
*
* @data: regmap_irq controller to operate on.
*/
int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data)
{
WARN_ON(!data->irq_base);
return data->irq_base;
}
EXPORT_SYMBOL_GPL(regmap_irq_chip_get_base);
/**
* regmap_irq_get_virq(): Map an interrupt on a chip to a virtual IRQ
*
* Useful for drivers to request their own IRQs.
*
* @data: regmap_irq controller to operate on.
* @irq: index of the interrupt requested in the chip IRQs
*/
int regmap_irq_get_virq(struct regmap_irq_chip_data *data, int irq)
{
return irq_create_mapping(data->domain, irq);
}
EXPORT_SYMBOL_GPL(regmap_irq_get_virq);