From fd746d540abf8c686f5f868ae62112692e684088 Mon Sep 17 00:00:00 2001 From: Eric Miao Date: Sat, 11 Apr 2009 16:54:59 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/ads7846.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/input/touchscreen/ads7846.c') diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 7c27c8b9b6d..cf7e69766b2 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"; -- cgit v1.2.3-70-g09d2 From 3f3e7c6e139f704e2f48ea3b45ff7724a8d46456 Mon Sep 17 00:00:00 2001 From: Ben Nizette Date: Wed, 15 Apr 2009 18:57:55 -0700 Subject: Input: ads7846 - fix unsafe disable_irq The use of disable_irq inside the handler for the interrupt being disabled has always been dangerous. disable_irq should wait for that handler to complete before returning -> deadlock. For some reason this wasn't actually the case until 3aa551c9b was merged but since this time, the ads7846 driver has deadlocked the system on first interrupt. Convert the driver to use the handler-safe _nosync variant. Signed-off-by: Ben Nizette Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/ads7846.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/input/touchscreen/ads7846.c') diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index cf7e69766b2..8b6e30ac291 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -754,7 +754,7 @@ static irqreturn_t ads7846_irq(int irq, void *handle) * that here. (The "generic irq" framework may help...) */ ts->irq_disabled = 1; - disable_irq(ts->spi->irq); + disable_irq_nosync(ts->spi->irq); ts->pending = 1; hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY), HRTIMER_MODE_REL); -- cgit v1.2.3-70-g09d2