diff options
| author | Eric Miao <eric.miao@marvell.com> | 2009-04-12 03:54:59 +0400 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-04-12 04:09:15 +0400 |
| commit | fd746d540abf8c686f5f868ae62112692e684088 (patch) | |
| tree | 2ed9a62f6566468750aec17944febfbff3e0d04d | |
| parent | b79e83bdd961ec9b862191c0df51aaeb3cb85664 (diff) | |
| download | linux-fd746d540abf8c686f5f868ae62112692e684088.tar.xz | |
Input: ads7846 - introduce platform specific way to synchronize sampling
Noises can be introduced when LCD signals are being driven, some platforms
provide a signal to assist the synchronization of this sampling procedure.
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 10 | ||||
| -rw-r--r-- | include/linux/spi/ads7846.h | 1 |
2 files changed, 11 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 7c27c8b9b6d0..cf7e69766b2b 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -127,6 +127,8 @@ struct ads7846 { void (*filter_cleanup)(void *data); int (*get_pendown_state)(void); int gpio_pendown; + + void (*wait_for_sync)(void); }; /* leave chip selected when we're done, for quicker re-select? */ @@ -511,6 +513,10 @@ static int get_pendown_state(struct ads7846 *ts) return !gpio_get_value(ts->gpio_pendown); } +static void null_wait_for_sync(void) +{ +} + /* * PENIRQ only kicks the timer. The timer only reissues the SPI transfer, * to retrieve touchscreen status. @@ -686,6 +692,7 @@ static void ads7846_rx_val(void *ads) default: BUG(); } + ts->wait_for_sync(); status = spi_async(ts->spi, m); if (status) dev_err(&ts->spi->dev, "spi_async --> %d\n", @@ -723,6 +730,7 @@ static enum hrtimer_restart ads7846_timer(struct hrtimer *handle) } else { /* pen is still down, continue with the measurement */ ts->msg_idx = 0; + ts->wait_for_sync(); status = spi_async(ts->spi, &ts->msg[0]); if (status) dev_err(&ts->spi->dev, "spi_async --> %d\n", status); @@ -947,6 +955,8 @@ static int __devinit ads7846_probe(struct spi_device *spi) ts->penirq_recheck_delay_usecs = pdata->penirq_recheck_delay_usecs; + ts->wait_for_sync = pdata->wait_for_sync ? : null_wait_for_sync; + snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev)); input_dev->name = "ADS784x Touchscreen"; diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h index 05eab2f11e63..2ea20320c093 100644 --- a/include/linux/spi/ads7846.h +++ b/include/linux/spi/ads7846.h @@ -51,5 +51,6 @@ struct ads7846_platform_data { void **filter_data); int (*filter) (void *filter_data, int data_idx, int *val); void (*filter_cleanup)(void *filter_data); + void (*wait_for_sync)(void); }; |