Commit d8c1f317 authored by Dan Liang's avatar Dan Liang Committed by Dmitry Torokhov
Browse files

Input: atmel_tsadcc - improve accuracy 



Discard the last sample just before pen is up because it is quite often
errorneous.

Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarDan Liang <dan.liang@atmel.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 160f1fef

drivers/input/touchscreen/atmel_tsadcc.c

+24 −13
Original line number Diff line number Diff line
@@ -91,6 +91,9 @@ struct atmel_tsadcc { 
	char			phys[32];

	struct clk		*clk;

	int			irq;

	unsigned int		prev_absx;

	unsigned int		prev_absy;

	unsigned char		bufferedmeasure;

};



static void __iomem		*tsc_base;
@@ -100,10 +103,9 @@ static void __iomem *tsc_base; 


static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)

{

	struct input_dev *input_dev = ((struct atmel_tsadcc *)dev)->input;

	struct atmel_tsadcc	*ts_dev = (struct atmel_tsadcc *)dev;

	struct input_dev	*input_dev = ts_dev->input;



	unsigned int absx;

	unsigned int absy;

	unsigned int status;

	unsigned int reg;
@@ -121,6 +123,7 @@ static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev) 
		atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);



		input_report_key(input_dev, BTN_TOUCH, 0);

		ts_dev->bufferedmeasure = 0;

		input_sync(input_dev);



	} else if (status & ATMEL_TSADCC_PENCNT) {
@@ -138,16 +141,23 @@ static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev) 
	} else if (status & ATMEL_TSADCC_EOC(3)) {

		/* Conversion finished */



		absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;

		absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);



		absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;

		absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);



		input_report_abs(input_dev, ABS_X, absx);

		input_report_abs(input_dev, ABS_Y, absy);

		if (ts_dev->bufferedmeasure) {

			/* Last measurement is always discarded, since it can

			 * be erroneous.

			 * Always report previous measurement */

			input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);

			input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);

			input_report_key(input_dev, BTN_TOUCH, 1);

			input_sync(input_dev);

		} else

			ts_dev->bufferedmeasure = 1;



		/* Now make new measurement */

		ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;

		ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);



		ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;

		ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);

	}



	return IRQ_HANDLED;
@@ -223,6 +233,7 @@ static int __devinit atmel_tsadcc_probe(struct platform_device *pdev) 
	}



	ts_dev->input = input_dev;

	ts_dev->bufferedmeasure = 0;



	snprintf(ts_dev->phys, sizeof(ts_dev->phys),

		 "%s/input0", pdev->dev.bus_id);

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