Commit c899afed authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: ucb1400_ts - convert to threaded IRQ 



Instead of manually create and handler kernel thread switch to threaded
IRQ and let kernel IRQ core manage thread for us.

Acked-by: default avatarMarek Vasut <marek.vasut@gmail.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 75072323

drivers/input/touchscreen/ucb1400_ts.c

+113 −122
Original line number Diff line number Diff line
@@ -20,24 +20,24 @@ 


#include <linux/module.h>

#include <linux/init.h>

#include <linux/completion.h>

#include <linux/delay.h>

#include <linux/sched.h>

#include <linux/wait.h>

#include <linux/input.h>

#include <linux/device.h>

#include <linux/interrupt.h>

#include <linux/suspend.h>

#include <linux/kthread.h>

#include <linux/freezer.h>

#include <linux/ucb1400.h>



#define UCB1400_TS_POLL_PERIOD	10 /* ms */



static int adcsync;

static int ts_delay = 55; /* us */

static int ts_delay_pressure;	/* us */



/* Switch to interrupt mode. */

static void ucb1400_ts_mode_int(struct snd_ac97 *ac97)

static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)

{

	ucb1400_reg_write(ac97, UCB_TS_CR,

	ucb1400_reg_write(ucb->ac97, UCB_TS_CR,

			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |

			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |

			UCB_TS_CR_MODE_INT);
@@ -53,7 +53,9 @@ static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb) 
			UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |

			UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |

			UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);



	udelay(ts_delay_pressure);



	return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);

}
@@ -127,26 +129,26 @@ static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb) 
	return ucb1400_adc_read(ucb->ac97, 0, adcsync);

}



static int ucb1400_ts_pen_up(struct snd_ac97 *ac97)

static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)

{

	unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR);

	unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);



	return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);

}



static void ucb1400_ts_irq_enable(struct snd_ac97 *ac97)

static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)

{

	ucb1400_reg_write(ac97, UCB_IE_CLEAR, UCB_IE_TSPX);

	ucb1400_reg_write(ac97, UCB_IE_CLEAR, 0);

	ucb1400_reg_write(ac97, UCB_IE_FAL, UCB_IE_TSPX);

	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);

	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);

	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);

}



static void ucb1400_ts_irq_disable(struct snd_ac97 *ac97)

static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)

{

	ucb1400_reg_write(ac97, UCB_IE_FAL, 0);

	ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);

}



static void ucb1400_ts_evt_add(struct input_dev *idev, u16 pressure, u16 x, u16 y)

static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)

{

	input_report_abs(idev, ABS_X, x);

	input_report_abs(idev, ABS_Y, y);
@@ -162,7 +164,7 @@ static void ucb1400_ts_event_release(struct input_dev *idev) 
	input_sync(idev);

}



static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb)

static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)

{

	unsigned int isr;
@@ -171,32 +173,34 @@ static void ucb1400_handle_pending_irq(struct ucb1400_ts *ucb) 
	ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);



	if (isr & UCB_IE_TSPX)

		ucb1400_ts_irq_disable(ucb->ac97);

		ucb1400_ts_irq_disable(ucb);

	else

		dev_dbg(&ucb->ts_idev->dev, "ucb1400: unexpected IE_STATUS = %#x\n", isr);

	enable_irq(ucb->irq);

		dev_dbg(&ucb->ts_idev->dev,

			"ucb1400: unexpected IE_STATUS = %#x\n", isr);

}



static int ucb1400_ts_thread(void *_ucb)

/*

 * A restriction with interrupts exists when using the ucb1400, as

 * the codec read/write routines may sleep while waiting for codec

 * access completion and uses semaphores for access control to the

 * AC97 bus. Therefore the driver is forced to use threaded interrupt

 * handler.

 */

static irqreturn_t ucb1400_irq(int irqnr, void *devid)

{

	struct ucb1400_ts *ucb = _ucb;

	struct task_struct *tsk = current;

	int valid = 0;

	struct sched_param param = { .sched_priority = 1 };

	struct ucb1400_ts *ucb = devid;

	unsigned int x, y, p;

	bool penup;



	sched_setscheduler(tsk, SCHED_FIFO, &param);

	if (unlikely(irqnr != ucb->irq))

		return IRQ_NONE;



	set_freezable();

	while (!kthread_should_stop()) {

		unsigned int x, y, p;

		long timeout;

	ucb1400_clear_pending_irq(ucb);



		ucb->ts_restart = 0;

	/* Start with a small delay before checking pendown state */

	msleep(UCB1400_TS_POLL_PERIOD);



		if (ucb->irq_pending) {

			ucb->irq_pending = 0;

			ucb1400_handle_pending_irq(ucb);

		}

	while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {



		ucb1400_adc_enable(ucb->ac97);

		x = ucb1400_ts_read_xpos(ucb);
@@ -204,91 +208,62 @@ static int ucb1400_ts_thread(void *_ucb) 
		p = ucb1400_ts_read_pressure(ucb);

		ucb1400_adc_disable(ucb->ac97);



		/* Switch back to interrupt mode. */

		ucb1400_ts_mode_int(ucb->ac97);

		ucb1400_ts_report_event(ucb->ts_idev, p, x, y);



		msleep(10);



		if (ucb1400_ts_pen_up(ucb->ac97)) {

			ucb1400_ts_irq_enable(ucb->ac97);

		wait_event_timeout(ucb->ts_wait, ucb->stopped,

				   msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));

	}



			/*

			 * If we spat out a valid sample set last time,

			 * spit out a "pen off" sample here.

			 */

			if (valid) {

	ucb1400_ts_event_release(ucb->ts_idev);

				valid = 0;

			}



			timeout = MAX_SCHEDULE_TIMEOUT;

		} else {

			valid = 1;

			ucb1400_ts_evt_add(ucb->ts_idev, p, x, y);

			timeout = msecs_to_jiffies(10);

	if (!ucb->stopped) {

		/* Switch back to interrupt mode. */

		ucb1400_ts_mode_int(ucb);

		ucb1400_ts_irq_enable(ucb);

	}



		wait_event_freezable_timeout(ucb->ts_wait,

			ucb->irq_pending || ucb->ts_restart ||

			kthread_should_stop(), timeout);

	return IRQ_HANDLED;

}



	/* Send the "pen off" if we are stopping with the pen still active */

	if (valid)

		ucb1400_ts_event_release(ucb->ts_idev);

static void ucb1400_ts_stop(struct ucb1400_ts *ucb)

{

	/* Signal IRQ thread to stop polling and disable the handler. */

	ucb->stopped = true;

	mb();

	wake_up(&ucb->ts_wait);

	disable_irq(ucb->irq);



	ucb->ts_task = NULL;

	return 0;

	ucb1400_ts_irq_disable(ucb);

	ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);

}



/*

 * A restriction with interrupts exists when using the ucb1400, as

 * the codec read/write routines may sleep while waiting for codec

 * access completion and uses semaphores for access control to the

 * AC97 bus.  A complete codec read cycle could take  anywhere from

 * 60 to 100uSec so we *definitely* don't want to spin inside the

 * interrupt handler waiting for codec access.  So, we handle the

 * interrupt by scheduling a RT kernel thread to run in process

 * context instead of interrupt context.

 */

static irqreturn_t ucb1400_hard_irq(int irqnr, void *devid)

/* Must be called with ts->lock held */

static void ucb1400_ts_start(struct ucb1400_ts *ucb)

{

	struct ucb1400_ts *ucb = devid;

	/* Tell IRQ thread that it may poll the device. */

	ucb->stopped = false;

	mb();



	if (irqnr == ucb->irq) {

		disable_irq_nosync(ucb->irq);

		ucb->irq_pending = 1;

		wake_up(&ucb->ts_wait);

		return IRQ_HANDLED;

	}

	return IRQ_NONE;

	ucb1400_ts_mode_int(ucb);

	ucb1400_ts_irq_enable(ucb);



	enable_irq(ucb->irq);

}



static int ucb1400_ts_open(struct input_dev *idev)

{

	struct ucb1400_ts *ucb = input_get_drvdata(idev);

	int ret = 0;



	BUG_ON(ucb->ts_task);



	ucb->ts_task = kthread_run(ucb1400_ts_thread, ucb, "UCB1400_ts");

	if (IS_ERR(ucb->ts_task)) {

		ret = PTR_ERR(ucb->ts_task);

		ucb->ts_task = NULL;

	}

	ucb1400_ts_start(ucb);



	return ret;

	return 0;

}



static void ucb1400_ts_close(struct input_dev *idev)

{

	struct ucb1400_ts *ucb = input_get_drvdata(idev);



	if (ucb->ts_task)

		kthread_stop(ucb->ts_task);



	ucb1400_ts_irq_disable(ucb->ac97);

	ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);

	ucb1400_ts_stop(ucb);

}



#ifndef NO_IRQ
@@ -342,11 +317,11 @@ static int __devinit ucb1400_ts_detect_irq(struct ucb1400_ts *ucb) 
	return 0;

}



static int __devinit ucb1400_ts_probe(struct platform_device *dev)

static int __devinit ucb1400_ts_probe(struct platform_device *pdev)

{

	struct ucb1400_ts *ucb = pdev->dev.platform_data;

	int error, x_res, y_res;

	u16 fcsr;

	struct ucb1400_ts *ucb = dev->dev.platform_data;



	ucb->ts_idev = input_allocate_device();

	if (!ucb->ts_idev) {
@@ -362,21 +337,13 @@ static int __devinit ucb1400_ts_probe(struct platform_device *dev) 
			goto err_free_devs;

		}

	}

	printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);



	init_waitqueue_head(&ucb->ts_wait);



	error = request_irq(ucb->irq, ucb1400_hard_irq, IRQF_TRIGGER_RISING,

				"UCB1400", ucb);

	if (error) {

		printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",

				ucb->irq, error);

		goto err_free_devs;

	}

	printk(KERN_DEBUG "UCB1400: found IRQ %d\n", ucb->irq);



	input_set_drvdata(ucb->ts_idev, ucb);



	ucb->ts_idev->dev.parent	= &dev->dev;

	ucb->ts_idev->dev.parent	= &pdev->dev;

	ucb->ts_idev->name		= "UCB1400 touchscreen interface";

	ucb->ts_idev->id.vendor		= ucb1400_reg_read(ucb->ac97,

						AC97_VENDOR_ID1);
@@ -404,6 +371,17 @@ static int __devinit ucb1400_ts_probe(struct platform_device *dev) 
	input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);

	input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);



	ucb1400_ts_stop(ucb);



	error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,

				     IRQF_TRIGGER_RISING | IRQF_ONESHOT,

				     "UCB1400", ucb);

	if (error) {

		printk(KERN_ERR "ucb1400: unable to grab irq%d: %d\n",

				ucb->irq, error);

		goto err_free_devs;

	}



	error = input_register_device(ucb->ts_idev);

	if (error)

		goto err_free_irq;
@@ -418,9 +396,9 @@ static int __devinit ucb1400_ts_probe(struct platform_device *dev) 
	return error;

}



static int __devexit ucb1400_ts_remove(struct platform_device *dev)

static int __devexit ucb1400_ts_remove(struct platform_device *pdev)

{

	struct ucb1400_ts *ucb = dev->dev.platform_data;

	struct ucb1400_ts *ucb = pdev->dev.platform_data;



	free_irq(ucb->irq, ucb);

	input_unregister_device(ucb->ts_idev);
@@ -429,24 +407,37 @@ static int __devexit ucb1400_ts_remove(struct platform_device *dev) 
}



#ifdef CONFIG_PM_SLEEP

static int ucb1400_ts_resume(struct device *dev)

static int ucb1400_ts_suspend(struct device *dev)

{

	struct ucb1400_ts *ucb = dev->platform_data;

	struct input_dev *idev = ucb->ts_idev;



	if (ucb->ts_task) {

		/*

		 * Restart the TS thread to ensure the

		 * TS interrupt mode is set up again

		 * after sleep.

		 */

		ucb->ts_restart = 1;

		wake_up(&ucb->ts_wait);

	mutex_lock(&idev->mutex);



	if (idev->users)

		ucb1400_ts_start(ucb);



	mutex_unlock(&idev->mutex);

	return 0;

}



static int ucb1400_ts_resume(struct device *dev)

{

	struct ucb1400_ts *ucb = dev->platform_data;

	struct input_dev *idev = ucb->ts_idev;



	mutex_lock(&idev->mutex);



	if (idev->users)

		ucb1400_ts_stop(ucb);



	mutex_unlock(&idev->mutex);

	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops, NULL, ucb1400_ts_resume);

static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,

			 ucb1400_ts_suspend, ucb1400_ts_resume);



static struct platform_driver ucb1400_ts_driver = {

	.probe	= ucb1400_ts_probe,

include/linux/ucb1400.h

+2 −4
Original line number Diff line number Diff line
@@ -96,13 +96,11 @@ struct ucb1400_gpio { 


struct ucb1400_ts {

	struct input_dev	*ts_idev;

	struct task_struct	*ts_task;

	int			id;

	wait_queue_head_t	ts_wait;

	unsigned int		ts_restart:1;

	int			irq;

	unsigned int		irq_pending;	/* not bit field shared */

	struct snd_ac97		*ac97;

	wait_queue_head_t	ts_wait;

	bool			stopped;

};



struct ucb1400 {