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Commit 666cbe34 authored by David Brownell's avatar David Brownell Committed by Dmitry Torokhov
Browse files

Input: dm355evm_keys - use threaded IRQs 



Convert the dm355evm keys driver to use IRQ threading instead of
a private workqueue.  IRQ threads were added to Linux after this
driver was written, and in this case fit what the driver needs.
(Although the non-shared thread costs more runtime memory.)

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent eef3e4ca

drivers/input/misc/dm355evm_keys.c

+20 −22
Original line number Diff line number Diff line
@@ -23,30 +23,16 @@ 
 * pressed, or its autorepeat kicks in, an event is sent.  This driver

 * read those events from the small (32 event) queue and reports them.

 *

 * Because we communicate with the MSP430 using I2C, and all I2C calls

 * in Linux sleep, we need to cons up a kind of threaded IRQ handler

 * using a work_struct.  The IRQ is active low, but we use it through

 * the GPIO controller so we can trigger on falling edges.

 *

 * Note that physically there can only be one of these devices.

 *

 * This driver was tested with firmware revision A4.

 */

struct dm355evm_keys {

	struct work_struct	work;

	struct input_dev	*input;

	struct device		*dev;

	int			irq;

};



static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)

{

	struct dm355evm_keys	*keys = _keys;



	schedule_work(&keys->work);

	return IRQ_HANDLED;

}



/* These initial keycodes can be remapped by dm355evm_setkeycode(). */

static struct {

	u16	event;
@@ -110,13 +96,12 @@ static struct { 
	{ 0x3169, KEY_PAUSE, },

};



static void dm355evm_keys_work(struct work_struct *work)

/* runs in an IRQ thread -- can (and will!) sleep */

static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)

{

	struct dm355evm_keys	*keys;

	struct dm355evm_keys	*keys = _keys;

	int			status;



	keys = container_of(work, struct dm355evm_keys, work);



	/* For simplicity we ignore INPUT_COUNT and just read

	 * events until we get the "queue empty" indicator.

	 * Reading INPUT_LOW decrements the count.
@@ -183,6 +168,19 @@ static void dm355evm_keys_work(struct work_struct *work) 
		input_report_key(keys->input, keycode, 0);

		input_sync(keys->input);

	}

	return IRQ_HANDLED;

}



/*

 * Because we communicate with the MSP430 using I2C, and all I2C calls

 * in Linux sleep, we use a threaded IRQ handler.  The IRQ itself is

 * active low, but we go through the GPIO controller so we can trigger

 * on falling edges and not worry about enabling/disabling the IRQ in

 * the keypress handling path.

 */

static irqreturn_t dm355evm_keys_hardirq(int irq, void *_keys)

{

	return IRQ_WAKE_THREAD;

}



static int dm355evm_setkeycode(struct input_dev *dev, int index, int keycode)
@@ -233,7 +231,6 @@ static int __devinit dm355evm_keys_probe(struct platform_device *pdev) 


	keys->dev = &pdev->dev;

	keys->input = input;

	INIT_WORK(&keys->work, dm355evm_keys_work);



	/* set up "threaded IRQ handler" */

	status = platform_get_irq(pdev, 0);
@@ -260,7 +257,8 @@ static int __devinit dm355evm_keys_probe(struct platform_device *pdev) 


	/* REVISIT:  flush the event queue? */



	status = request_irq(keys->irq, dm355evm_keys_irq,

	status = request_threaded_irq(keys->irq,

			dm355evm_keys_hardirq, dm355evm_keys_irq,

			IRQF_TRIGGER_FALLING,

			dev_name(&pdev->dev), keys);

	if (status < 0)