[PATCH] Convert the AB3100 driver to use threaded IRH

Linus Walleij
2010-01-07T23:46:44Z

This converts the AB3100 core MFD driver to use a threaded
interrupt handler instead of the explicit top/bottom-half
construction with a workqueue. This saves some code and make it
more similar to other modern MFD drivers.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
---
drivers/mfd/ab3100-core.c | 43 +++++++++++++------------------------------
include/linux/mfd/ab3100.h | 3 ---
2 files changed, 13 insertions(+), 33 deletions(-)

diff --git a/drivers/mfd/ab3100-core.c b/drivers/mfd/ab3100-core.c
index fd42a80..93b2c14 100644
--- a/drivers/mfd/ab3100-core.c
+++ b/drivers/mfd/ab3100-core.c
@@ -365,10 +365,13 @@ int ab3100_event_registers_startup_state_get(struct ab3100 *ab3100,
}
EXPORT_SYMBOL(ab3100_event_registers_startup_state_get);

-/* Interrupt handling worker */
-static void ab3100_work(struct work_struct *work)
+/*
+ * This is a threaded interrupt handler so we can make some
+ * I2C calls etc.
+ */
+static irqreturn_t ab3100_irq_handler(int irq, void *data)
{
- struct ab3100 *ab3100 = container_of(work, struct ab3100, work);
+ struct ab3100 *ab3100 = data;
u8 event_regs[3];
u32 fatevent;
int err;
@@ -376,7 +379,7 @@ static void ab3100_work(struct work_struct *work)
err = ab3100_get_register_page_interruptible(ab3100, AB3100_EVENTA1,
event_regs, 3);
if (err)
- goto err_event_wq;
+ goto err_event;

fatevent = (event_regs[0] << 16) |
(event_regs[1] << 8) |
@@ -398,29 +401,11 @@ static void ab3100_work(struct work_struct *work)
dev_dbg(ab3100->dev,
"IRQ Event: 0x%08x\n", fatevent);

- /* By now the IRQ should be acked and deasserted so enable it again */
- enable_irq(ab3100->i2c_client->irq);
- return;
+ return IRQ_HANDLED;

- err_event_wq:
+ err_event:
dev_dbg(ab3100->dev,
- "error in event workqueue\n");
- /* Enable the IRQ anyway, what choice do we have? */
- enable_irq(ab3100->i2c_client->irq);
- return;
-}
-
-static irqreturn_t ab3100_irq_handler(int irq, void *data)
-{
- struct ab3100 *ab3100 = data;
- /*
- * Disable the IRQ and dispatch a worker to handle the
- * event. Since the chip resides on I2C this is slow
- * stuff and we will re-enable the interrupts once th
- * worker has finished.
- */
- disable_irq_nosync(irq);
- schedule_work(&ab3100->work);
+ "error reading event status\n");
return IRQ_HANDLED;
}

@@ -904,12 +889,10 @@ static int __init ab3100_probe(struct i2c_client *client,
if (err)
goto exit_no_setup;

- INIT_WORK(&ab3100->work, ab3100_work);
-
/* This real unpredictable IRQ is of course sampled for entropy */
- err = request_irq(client->irq, ab3100_irq_handler,
- IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
- "AB3100 IRQ", ab3100);
+ err = request_threaded_irq(client->irq, NULL, ab3100_irq_handler,
+ IRQF_ONESHOT | IRQF_SAMPLE_RANDOM,
+ "ab3100-core", ab3100);
if (err)
goto exit_no_irq;

diff --git a/include/linux/mfd/ab3100.h b/include/linux/mfd/ab3100.h
index e9aa4c9..9a881c3 100644
--- a/include/linux/mfd/ab3100.h
+++ b/include/linux/mfd/ab3100.h
@@ -6,7 +6,6 @@
*/

#include <linux/device.h>
-#include <linux/workqueue.h>
#include <linux/regulator/machine.h>

#ifndef MFD_AB3100_H
@@ -74,7 +73,6 @@
* @testreg_client: secondary client for test registers
* @chip_name: name of this chip variant
* @chip_id: 8 bit chip ID for this chip variant
- * @work: an event handling worker
* @event_subscribers: event subscribers are listed here
* @startup_events: a copy of the first reading of the event registers
* @startup_events_read: whether the first events have been read
@@ -90,7 +88,6 @@ struct ab3100 {
struct i2c_client *testreg_client;
char chip_name[32];
u8 chip_id;
- struct work_struct work;
struct blocking_notifier_head event_subscribers;
u32 startup_events;
bool startup_events_read;
--
1.6.3.3