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greybus: gpio: fix atomic sleep when using interrupts

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The irq-chip callbacks are made in atomic context where we must not do
any synchronous greybus operations.

Fix the current gpio-interrupt implementation by using the bus-lock
functionality provided by the irq subsystem.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Johan Hovold 2015-05-26 15:29:24 +02:00 committed by Greg Kroah-Hartman
parent 0cb918d72d
commit 25f11ed965
1 changed files with 93 additions and 28 deletions
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121
drivers/staging/greybus/gpio.c
View file

@ -13,6 +13,8 @@
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/mutex.h>
#include "greybus.h"
struct gb_gpio_line {
@ -22,6 +24,11 @@ struct gb_gpio_line {
direction: 1, /* 0 = output, 1 = input */
value: 1; /* 0 = low, 1 = high */
u16 debounce_usec;
u8 irq_type;
bool irq_type_pending;
bool masked;
bool masked_pending;
};
struct gb_gpio_controller {
@ -38,6 +45,7 @@ struct gb_gpio_controller {
unsigned int irq_base;
irq_flow_handler_t irq_handler;
unsigned int irq_default_type;
struct mutex irq_lock;
};
#define gpio_chip_to_gb_gpio_controller(chip) \
container_of(chip, struct gb_gpio_controller, chip)
@ -211,68 +219,121 @@ static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
return ret;
}
static void gb_gpio_irq_mask(struct irq_data *d)
static void _gb_gpio_irq_mask(struct gb_gpio_controller *ggc, u8 hwirq)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_irq_mask_request request;
int ret;
request.which = d->hwirq;
request.which = hwirq;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_MASK,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(chip->dev, "failed to mask irq: %d\n", ret);
dev_err(ggc->chip.dev, "failed to mask irq: %d\n", ret);
}
static void _gb_gpio_irq_unmask(struct gb_gpio_controller *ggc, u8 hwirq)
{
struct gb_gpio_irq_unmask_request request;
int ret;
request.which = hwirq;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_UNMASK,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(ggc->chip.dev, "failed to unmask irq: %d\n", ret);
}
static void _gb_gpio_irq_set_type(struct gb_gpio_controller *ggc,
u8 hwirq, u8 type)
{
struct gb_gpio_irq_type_request request;
int ret;
request.which = hwirq;
request.type = type;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_TYPE,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(ggc->chip.dev, "failed to set irq type: %d\n", ret);
}
static void gb_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
line->masked = true;
line->masked_pending = true;
}
static void gb_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_irq_unmask_request request;
int ret;
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
request.which = d->hwirq;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_UNMASK,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(chip->dev, "failed to unmask irq: %d\n", ret);
line->masked = false;
line->masked_pending = true;
}
static int gb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_irq_type_request request;
int ret = 0;
request.which = d->hwirq;
request.type = type;
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
switch (type) {
case IRQ_TYPE_NONE:
break;
case IRQ_TYPE_EDGE_RISING:
case IRQ_TYPE_EDGE_FALLING:
case IRQ_TYPE_EDGE_BOTH:
case IRQ_TYPE_LEVEL_LOW:
case IRQ_TYPE_LEVEL_HIGH:
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_TYPE,
&request, sizeof(request), NULL, 0);
if (ret) {
dev_err(chip->dev, "failed to set irq type: %d\n",
ret);
}
break;
default:
dev_err(chip->dev, "unsupported irq type: %u\n", type);
ret = -EINVAL;
return -EINVAL;
}
return ret;
line->irq_type = type;
line->irq_type_pending = true;
return 0;
}
static void gb_gpio_irq_bus_lock(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
mutex_lock(&ggc->irq_lock);
}
static void gb_gpio_irq_bus_sync_unlock(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
if (line->irq_type_pending) {
_gb_gpio_irq_set_type(ggc, d->hwirq, line->irq_type);
line->irq_type_pending = false;
}
if (line->masked_pending) {
if (line->masked)
_gb_gpio_irq_mask(ggc, d->hwirq);
else
_gb_gpio_irq_unmask(ggc, d->hwirq);
line->masked_pending = false;
}
mutex_unlock(&ggc->irq_lock);
}
static int gb_gpio_request_recv(u8 type, struct gb_operation *op)
@ -578,8 +639,12 @@ static int gb_gpio_connection_init(struct gb_connection *connection)
irqc->irq_mask = gb_gpio_irq_mask;
irqc->irq_unmask = gb_gpio_irq_unmask;
irqc->irq_set_type = gb_gpio_irq_set_type;
irqc->irq_bus_lock = gb_gpio_irq_bus_lock;
irqc->irq_bus_sync_unlock = gb_gpio_irq_bus_sync_unlock;
irqc->name = "greybus_gpio";
mutex_init(&ggc->irq_lock);
gpio = &ggc->chip;
gpio->label = "greybus_gpio";