[PATCH] gpio: pcf857x: cleanup irq_demux_work and use threaded irq

From: George Cherian
Date: Tue Aug 27 2013 - 06:31:08 EST


This patch
- removes the irq_demux_work
- Uses devm_request_threaded_irq
- Call the user handler iff gpio_to_irq is done.

Signed-off-by: George Cherian <george.cherian@xxxxxx>
---
drivers/gpio/gpio-pcf857x.c | 52 +++++++++++++++++++++++----------------------
1 file changed, 27 insertions(+), 25 deletions(-)

diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c
index 947cff4..aebbba6 100644
--- a/drivers/gpio/gpio-pcf857x.c
+++ b/drivers/gpio/gpio-pcf857x.c
@@ -30,7 +30,7 @@
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
-#include <linux/workqueue.h>
+#include <linux/of_irq.h>


static const struct i2c_device_id pcf857x_id[] = {
@@ -89,12 +89,12 @@ struct pcf857x {
struct gpio_chip chip;
struct i2c_client *client;
struct mutex lock; /* protect 'out' */
- struct work_struct work; /* irq demux work */
struct irq_domain *irq_domain; /* for irq demux */
spinlock_t slock; /* protect irq demux */
unsigned out; /* software latch */
unsigned status; /* current status */
int irq; /* real irq number */
+ int irq_mapped; /* mapped gpio irqs */

int (*write)(struct i2c_client *client, unsigned data);
int (*read)(struct i2c_client *client);
@@ -187,38 +187,35 @@ static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
static int pcf857x_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
+ int ret;

- return irq_create_mapping(gpio->irq_domain, offset);
+ ret = irq_create_mapping(gpio->irq_domain, offset);
+ if (ret > 0)
+ gpio->irq_mapped |= (1 << offset);
+
+ return ret;
}

-static void pcf857x_irq_demux_work(struct work_struct *work)
+static irqreturn_t pcf857x_irq(int irq, void *data)
{
- struct pcf857x *gpio = container_of(work,
- struct pcf857x,
- work);
+ struct pcf857x *gpio = data;
unsigned long change, i, status, flags;

status = gpio->read(gpio->client);

spin_lock_irqsave(&gpio->slock, flags);
+
+ /*
+ * call the interrupt handler iff gpio is used as
+ * interrupt source, just to avoid bad irqs
+ */

- change = gpio->status ^ status;
+ change = ((gpio->status ^ status) & gpio->irq_mapped);
for_each_set_bit(i, &change, gpio->chip.ngpio)
generic_handle_irq(irq_find_mapping(gpio->irq_domain, i));
gpio->status = status;

spin_unlock_irqrestore(&gpio->slock, flags);
-}
-
-static irqreturn_t pcf857x_irq_demux(int irq, void *data)
-{
- struct pcf857x *gpio = data;
-
- /*
- * pcf857x can't read/write data here,
- * since i2c data access might go to sleep.
- */
- schedule_work(&gpio->work);

return IRQ_HANDLED;
}
@@ -226,9 +223,13 @@ static irqreturn_t pcf857x_irq_demux(int irq, void *data)
static int pcf857x_irq_domain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hw)
{
+ struct pcf857x *gpio = domain->host_data;
irq_set_chip_and_handler(virq,
&dummy_irq_chip,
handle_level_irq);
+ set_irq_flags(virq, IRQF_VALID);
+ gpio->irq_mapped |= (1 << hw);
+
return 0;
}

@@ -241,30 +242,31 @@ static void pcf857x_irq_domain_cleanup(struct pcf857x *gpio)
if (gpio->irq_domain)
irq_domain_remove(gpio->irq_domain);

- if (gpio->irq)
- free_irq(gpio->irq, gpio);
}

static int pcf857x_irq_domain_init(struct pcf857x *gpio,
struct i2c_client *client)
{
int status;
+ struct device_node *node;

+ node = client->dev.of_node;
gpio->irq_domain = irq_domain_add_linear(client->dev.of_node,
gpio->chip.ngpio,
&pcf857x_irq_domain_ops,
- NULL);
+ gpio);
if (!gpio->irq_domain)
goto fail;

/* enable real irq */
- status = request_irq(client->irq, pcf857x_irq_demux, 0,
- dev_name(&client->dev), gpio);
+ status = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, pcf857x_irq, IRQF_ONESHOT |
+ IRQF_TRIGGER_FALLING,
+ dev_name(&client->dev), gpio);
if (status)
goto fail;

/* enable gpio_to_irq() */
- INIT_WORK(&gpio->work, pcf857x_irq_demux_work);
gpio->chip.to_irq = pcf857x_to_irq;
gpio->irq = client->irq;

--
1.8.1.4

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