[PATCH] input: touchscreen: use polling mode in 88pm860x

[Haojian Zhuang]

Measuring point on touchscreen with IRQ mode can only monitor pen-down
event. If finger is moving on touchscreen, it can't be monitored by
IRQ pen-down event. So switch to polling mode after pen-down event.

Signed-off-by: Haojian Zhuang <haojian.zhuang@xxxxxxxxxxx>
---
 drivers/input/touchscreen/88pm860x-ts.c |   77 +++++++++++++++++++++++-------
 1 files changed, 59 insertions(+), 18 deletions(-)

diff --git a/drivers/input/touchscreen/88pm860x-ts.c b/drivers/input/touchscreen/88pm860x-ts.c
index b3aebc2..7d481cc 100644
--- a/drivers/input/touchscreen/88pm860x-ts.c
+++ b/drivers/input/touchscreen/88pm860x-ts.c
@@ -19,6 +19,18 @@
 #define MEAS_LEN		(8)
 #define ACCURATE_BIT		(12)
 
+/*
+ * While 32KHz hardware timer is used for scheduler, we always assign HZ
+ * to 128. It means that 1 tick costs 7.8msec.
+ */
+#define MEASURE_INTERVAL_MS	(7)
+
+/* debounce register */
+#define DEBOUNCE		(0x0A)
+
+#define PD_DEBOUNCE_0MSEC	(0)
+#define PD_DEBOUNCE_MASK	(3)
+
 /* touch register */
 #define MEAS_EN3		(0x52)
 
@@ -39,22 +51,26 @@
 #define MEAS_TSIZ2_EN		(1 << 7)
 
 struct pm860x_touch {
-	struct input_dev *idev;
-	struct i2c_client *i2c;
-	struct pm860x_chip *chip;
-	int irq;
-	int res_x;		/* resistor of Xplate */
+	struct input_dev	*idev;
+	struct i2c_client	*i2c;
+	struct pm860x_chip	*chip;
+	struct delayed_work	poll_work;
+
+	int			irq;
+	int			res_x;		/* resistor of Xplate */
 };
 
-static irqreturn_t pm860x_touch_handler(int irq, void *data)
+static void pm860x_poll_work(struct work_struct *work)
 {
-	struct pm860x_touch *touch = data;
+	struct pm860x_touch *touch = container_of(work, struct pm860x_touch,
+						  poll_work.work);
 	struct pm860x_chip *chip = touch->chip;
+	int x, y, z1, z2, rt = 0;
+	int ret, pen_down, interval;
 	unsigned char buf[MEAS_LEN];
-	int x, y, pen_down;
-	int z1, z2, rt = 0;
-	int ret;
+	struct timeval start, end;
 
+	do_gettimeofday(&start);
 	ret = pm860x_bulk_read(touch->i2c, MEAS_TSIX_1, MEAS_LEN, buf);
 	if (ret < 0)
 		goto out;
@@ -77,6 +93,15 @@ static irqreturn_t pm860x_touch_handler(int irq, void *data)
 		input_report_abs(touch->idev, ABS_PRESSURE, rt);
 		input_report_key(touch->idev, BTN_TOUCH, 1);
 		dev_dbg(chip->dev, "pen down at [%d, %d].\n", x, y);
+
+		do_gettimeofday(&end);
+		interval = (end.tv_sec - start.tv_sec) * 1000000 +
+			(end.tv_usec - start.tv_usec) / 1000;
+		interval = (interval < MEASURE_INTERVAL_MS)
+			? (MEASURE_INTERVAL_MS - interval) : 0;
+		queue_delayed_work(touch->chip->monitor_wqueue,
+				   &touch->poll_work,
+				   msecs_to_jiffies(interval));
 	} else {
 		input_report_abs(touch->idev, ABS_PRESSURE, 0);
 		input_report_key(touch->idev, BTN_TOUCH, 0);
@@ -85,22 +110,36 @@ static irqreturn_t pm860x_touch_handler(int irq, void *data)
 	input_sync(touch->idev);
 
 out:
+	return;
+}
+
+static irqreturn_t pm860x_touch_handler(int irq, void *data)
+{
+	struct pm860x_touch *touch = data;
+	int ret;
+
+	ret = pm860x_reg_read(touch->i2c, PM8607_STATUS_1);
+	dev_dbg(touch->chip->dev, "pen status:%d\n", (ret & PM8607_STATUS_PEN)
+		? 1 : 0);
+	if ((ret & PM8607_STATUS_PEN) == 0)
+		return IRQ_HANDLED;
+
+	pm860x_poll_work(&touch->poll_work.work);
 	return IRQ_HANDLED;
 }
 
 static int pm860x_touch_open(struct input_dev *dev)
 {
 	struct pm860x_touch *touch = input_get_drvdata(dev);
-	int data, ret;
+	int data;
 
+	/* set debounce time with 0ms */
+	pm860x_set_bits(touch->i2c, DEBOUNCE, PD_DEBOUNCE_MASK,
+			PD_DEBOUNCE_0MSEC);
 	data = MEAS_PD_EN | MEAS_TSIX_EN | MEAS_TSIY_EN
 		| MEAS_TSIZ1_EN | MEAS_TSIZ2_EN;
-	ret = pm860x_set_bits(touch->i2c, MEAS_EN3, data, data);
-	if (ret < 0)
-		goto out;
+	pm860x_set_bits(touch->i2c, MEAS_EN3, data, data);
 	return 0;
-out:
-	return ret;
 }
 
 static void pm860x_touch_close(struct input_dev *dev)
@@ -152,14 +191,14 @@ static int __devinit pm860x_touch_probe(struct platform_device *pdev)
 	}
 
 	touch->idev->name = "88pm860x-touch";
-	touch->idev->phys = "88pm860x/input0";
+	touch->idev->phys = "88pm860x/input1";
 	touch->idev->id.bustype = BUS_I2C;
 	touch->idev->dev.parent = &pdev->dev;
 	touch->idev->open = pm860x_touch_open;
 	touch->idev->close = pm860x_touch_close;
 	touch->chip = chip;
 	touch->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
-	touch->irq = irq + chip->irq_base;
+	touch->irq = irq;
 	touch->res_x = pdata->res_x;
 	input_set_drvdata(touch->idev, touch);
 
@@ -188,6 +227,7 @@ static int __devinit pm860x_touch_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, touch);
+	INIT_DELAYED_WORK(&touch->poll_work, pm860x_poll_work);
 	return 0;
 out_rg:
 	free_irq(touch->irq, touch);
@@ -202,6 +242,7 @@ static int __devexit pm860x_touch_remove(struct platform_device *pdev)
 {
 	struct pm860x_touch *touch = platform_get_drvdata(pdev);
 
+	flush_workqueue(touch->chip->monitor_wqueue);
 	input_unregister_device(touch->idev);
 	free_irq(touch->irq, touch);
 	platform_set_drvdata(pdev, NULL);
-- 
1.5.6.5

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