Re: [PATCH 01/13] input: touchscreen: use polling mode in 88pm860x

[Wanlong Gao]

On 4/16/11, Haojian Zhuang <haojian.zhuang@xxxxxxxxxxx> wrote:
> 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>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Acked-by: Wanlong Gao <wanlong.gao@xxxxxxxxx>
> ---
>  drivers/input/touchscreen/88pm860x-ts.c |   79
> ++++++++++++++++++++++++------
>  1 files changed, 63 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/input/touchscreen/88pm860x-ts.c
> b/drivers/input/touchscreen/88pm860x-ts.c
> index b3aebc2..dbb3435 100644
> --- a/drivers/input/touchscreen/88pm860x-ts.c
> +++ b/drivers/input/touchscreen/88pm860x-ts.c
> @@ -12,13 +12,25 @@
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/i2c.h>
> +#include <linux/slab.h>
>  #include <linux/input.h>
>  #include <linux/mfd/88pm860x.h>
> -#include <linux/slab.h>
>
>  #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 +51,27 @@
>  #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;
> +	struct mutex		lock;
> +
> +	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;
> @@ -77,14 +94,39 @@ 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;
> +		schedule_delayed_work(&touch->poll_work,
> +				      msecs_to_jiffies(interval));
>  	} else {
>  		input_report_abs(touch->idev, ABS_PRESSURE, 0);
>  		input_report_key(touch->idev, BTN_TOUCH, 0);
>  		dev_dbg(chip->dev, "pen release\n");
> +		mutex_unlock(&touch->lock);
>  	}
>  	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;
> +
> +	mutex_lock(&touch->lock);
> +	pm860x_poll_work(&touch->poll_work.work);
>  	return IRQ_HANDLED;
>  }
>
> @@ -93,12 +135,14 @@ static int pm860x_touch_open(struct input_dev *dev)
>  	struct pm860x_touch *touch = input_get_drvdata(dev);
>  	int data, ret;
>
> +	/* set debounce time with 0ms */
> +	ret = pm860x_set_bits(touch->i2c, DEBOUNCE, PD_DEBOUNCE_MASK,
> +			      PD_DEBOUNCE_0MSEC);
> +	if (ret < 0)
> +		goto out;
>  	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;
> -	return 0;
>  out:
>  	return ret;
>  }
> @@ -152,16 +196,17 @@ 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);
> +	mutex_init(&touch->lock);
>
>  	ret = request_threaded_irq(touch->irq, NULL, pm860x_touch_handler,
>  				   IRQF_ONESHOT, "touch", touch);
> @@ -188,6 +233,7 @@ 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 +248,7 @@ static int __devexit pm860x_touch_remove(struct
> platform_device *pdev)
>  {
>  	struct pm860x_touch *touch = platform_get_drvdata(pdev);
>
> +	flush_scheduled_work();
>  	input_unregister_device(touch->idev);
>  	free_irq(touch->irq, touch);
>  	platform_set_drvdata(pdev, NULL);
> --
> 1.5.6.5
>
It looks all good to me now .
Thanks for your great work .

Best regards .
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