diff options
| author | Dan Liang <Dan.Liang@atmel.com> | 2008-08-14 22:36:41 -0400 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2008-09-10 12:12:24 -0400 |
| commit | d8c1f317d1b3bb5c21175550968c86acfab3ff36 (patch) | |
| tree | 739c0e70dc5d760bb48df37627a909f2ebab7958 /drivers/input/touchscreen | |
| parent | 160f1fef7e52e974489b3c70fbd4e094c06965c2 (diff) | |
Input: atmel_tsadcc - improve accuracy
Discard the last sample just before pen is up because it is quite often
errorneous.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Dan Liang <dan.liang@atmel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/touchscreen')
| -rw-r--r-- | drivers/input/touchscreen/atmel_tsadcc.c | 37 |
1 files changed, 24 insertions, 13 deletions
diff --git a/drivers/input/touchscreen/atmel_tsadcc.c b/drivers/input/touchscreen/atmel_tsadcc.c index eee126b19e8..a89a6a8f05e 100644 --- a/drivers/input/touchscreen/atmel_tsadcc.c +++ b/drivers/input/touchscreen/atmel_tsadcc.c @@ -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); - input_report_key(input_dev, BTN_TOUCH, 1); - input_sync(input_dev); + 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); |