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Commit 377dc553 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: tsc2007 - convert to threaded IRQ 



Instead of using hard IRQ and workqueue solution switch to using threaded
interrupt handler to simplify the code and locking rules.

Tested-by: default avatarThierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 6a20baa9

drivers/input/touchscreen/tsc2007.c

+66 −84
Original line number Diff line number Diff line
@@ -66,7 +66,6 @@ struct ts_event { 
struct tsc2007 {

	struct input_dev	*input;

	char			phys[32];

	struct delayed_work	work;



	struct i2c_client	*client;
@@ -76,9 +75,11 @@ struct tsc2007 { 
	unsigned long		poll_delay;

	unsigned long		poll_period;



	bool			pendown;

	int			irq;



	wait_queue_head_t	wait;

	bool			stopped;



	int			(*get_pendown_state)(void);

	void			(*clear_penirq)(void);

};
@@ -141,25 +142,8 @@ static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc) 
	return rt;

}



static void tsc2007_send_up_event(struct tsc2007 *tsc)

{

	struct input_dev *input = tsc->input;



	dev_dbg(&tsc->client->dev, "UP\n");



	input_report_key(input, BTN_TOUCH, 0);

	input_report_abs(input, ABS_PRESSURE, 0);

	input_sync(input);

}



static void tsc2007_work(struct work_struct *work)

static bool tsc2007_is_pen_down(struct tsc2007 *ts)

{

	struct tsc2007 *ts =

		container_of(to_delayed_work(work), struct tsc2007, work);

	bool debounced = false;

	struct ts_event tc;

	u32 rt;



	/*

	 * NOTE: We can't rely on the pressure to determine the pen down

	 * state, even though this controller has a pressure sensor.
@@ -170,79 +154,82 @@ static void tsc2007_work(struct work_struct *work) 
	 * The only safe way to check for the pen up condition is in the

	 * work function by reading the pen signal state (it's a GPIO

	 * and IRQ). Unfortunately such callback is not always available,

	 * in that case we have rely on the pressure anyway.

	 * in that case we assume that the pen is down and expect caller

	 * to fall back on the pressure reading.

	 */

	if (ts->get_pendown_state) {

		if (unlikely(!ts->get_pendown_state())) {

			tsc2007_send_up_event(ts);

			ts->pendown = false;

			goto out;

		}



		dev_dbg(&ts->client->dev, "pen is still down\n");

	if (!ts->get_pendown_state)

		return true;



	return ts->get_pendown_state();

}



static irqreturn_t tsc2007_soft_irq(int irq, void *handle)

{

	struct tsc2007 *ts = handle;

	struct input_dev *input = ts->input;

	struct ts_event tc;

	u32 rt;



	while (!ts->stopped && tsc2007_is_pen_down(ts)) {



		/* pen is down, continue with the measurement */

		tsc2007_read_values(ts, &tc);



		rt = tsc2007_calculate_pressure(ts, &tc);

	if (rt > ts->max_rt) {



		if (rt == 0 && !ts->get_pendown_state) {

			/*

		 * Sample found inconsistent by debouncing or pressure is

		 * beyond the maximum. Don't report it to user space,

		 * repeat at least once more the measurement.

			 * If pressure reported is 0 and we don't have

			 * callback to check pendown state, we have to

			 * assume that pen was lifted up.

			 */

		dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);

		debounced = true;

		goto out;



			break;

		}



	if (rt) {

		struct input_dev *input = ts->input;



		if (!ts->pendown) {

			dev_dbg(&ts->client->dev, "DOWN\n");

		if (rt <= ts->max_rt) {

			dev_dbg(&ts->client->dev,

				"DOWN point(%4d,%4d), pressure (%4u)\n",

				tc.x, tc.y, rt);



			input_report_key(input, BTN_TOUCH, 1);

			ts->pendown = true;

		}



			input_report_abs(input, ABS_X, tc.x);

			input_report_abs(input, ABS_Y, tc.y);

			input_report_abs(input, ABS_PRESSURE, rt);



			input_sync(input);



		dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",

			tc.x, tc.y, rt);



	} else if (!ts->get_pendown_state && ts->pendown) {

		} else {

			/*

		 * We don't have callback to check pendown state, so we

		 * have to assume that since pressure reported is 0 the

		 * pen was lifted up.

			 * Sample found inconsistent by debouncing or pressure is

			 * beyond the maximum. Don't report it to user space,

			 * repeat at least once more the measurement.

			 */

		tsc2007_send_up_event(ts);

		ts->pendown = false;

			dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);

		}



 out:

	if (ts->pendown || debounced)

		schedule_delayed_work(&ts->work,

		wait_event_timeout(ts->wait, ts->stopped,

				   msecs_to_jiffies(ts->poll_period));

	else

		enable_irq(ts->irq);

	}



static irqreturn_t tsc2007_irq(int irq, void *handle)

	dev_dbg(&ts->client->dev, "UP\n");



	input_report_key(input, BTN_TOUCH, 0);

	input_report_abs(input, ABS_PRESSURE, 0);

	input_sync(input);



	if (ts->clear_penirq)

		ts->clear_penirq();



	return IRQ_HANDLED;

}



static irqreturn_t tsc2007_hard_irq(int irq, void *handle)

{

	struct tsc2007 *ts = handle;



	if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {

		disable_irq_nosync(ts->irq);

		schedule_delayed_work(&ts->work,

				      msecs_to_jiffies(ts->poll_delay));

	}

	if (!ts->get_pendown_state || likely(ts->get_pendown_state()))

		return IRQ_WAKE_THREAD;



	if (ts->clear_penirq)

		ts->clear_penirq();
@@ -252,15 +239,10 @@ static irqreturn_t tsc2007_irq(int irq, void *handle) 


static void tsc2007_free_irq(struct tsc2007 *ts)

{

	ts->stopped = true;

	mb();

	wake_up(&ts->wait);

	free_irq(ts->irq, ts);

	if (cancel_delayed_work_sync(&ts->work)) {

		/*

		 * Work was pending, therefore we need to enable

		 * IRQ here to balance the disable_irq() done in the

		 * interrupt handler.

		 */

		enable_irq(ts->irq);

	}

}



static int __devinit tsc2007_probe(struct i2c_client *client,
@@ -290,7 +272,7 @@ static int __devinit tsc2007_probe(struct i2c_client *client, 
	ts->client = client;

	ts->irq = client->irq;

	ts->input = input_dev;

	INIT_DELAYED_WORK(&ts->work, tsc2007_work);

	init_waitqueue_head(&ts->wait);



	ts->model             = pdata->model;

	ts->x_plate_ohms      = pdata->x_plate_ohms;
@@ -318,8 +300,8 @@ static int __devinit tsc2007_probe(struct i2c_client *client, 
	if (pdata->init_platform_hw)

		pdata->init_platform_hw();



	err = request_irq(ts->irq, tsc2007_irq, 0,

			client->dev.driver->name, ts);

	err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq,

				   IRQF_ONESHOT, client->dev.driver->name, ts);

	if (err < 0) {

		dev_err(&client->dev, "irq %d busy?\n", ts->irq);

		goto err_free_mem;