From 2eac59a2028e29d5e7b85525d5fbd8989d8f2f39 Mon Sep 17 00:00:00 2001 From: "imre.deak@solidboot.com" Date: Wed, 5 Jul 2006 19:18:32 +0300 Subject: [PATCH] Input: ads7846: detect pen up from IRQ state We can't depend on the pressure value to determine when the pen was lifted, so use the IRQ line state instead. Signed-off-by: Imre Deak Signed-off-by: Juha Yrjola --- drivers/input/touchscreen/ads7846.c | 98 +++++++++++++++++------------ 1 file changed, 57 insertions(+), 41 deletions(-) diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 4ec78757052..94c36b1a7f2 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -370,6 +370,39 @@ static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); /*--------------------------------------------------------------------------*/ +static void ads7846_report_pen_state(struct ads7846 *ts, int down) +{ + struct input_dev *input_dev = ts->input; + + input_report_key(input_dev, BTN_TOUCH, down); + if (!down) + input_report_abs(input_dev, ABS_PRESSURE, 0); +#ifdef VERBOSE + pr_debug("%s: %s\n", ts->spi->dev.bus_id, down ? "DOWN" : "UP"); +#endif +} + +static void ads7846_report_pen_position(struct ads7846 *ts, int x, int y, + int pressure) +{ + struct input_dev *input_dev = ts->input; + + input_report_abs(input_dev, ABS_X, x); + input_report_abs(input_dev, ABS_Y, y); + input_report_abs(input_dev, ABS_PRESSURE, pressure); + +#ifdef VERBOSE + pr_debug("%s: %d/%d/%d\n", ts->spi->dev.bus_id, x, y, pressure); +#endif +} + +static void ads7846_sync_events(struct ads7846 *ts) +{ + struct input_dev *input_dev = ts->input; + + input_sync(input_dev); +} + /* * PENIRQ only kicks the timer. The timer only reissues the SPI transfer, * to retrieve touchscreen status. @@ -381,11 +414,8 @@ static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store); static void ads7846_rx(void *ads) { struct ads7846 *ts = ads; - struct input_dev *input_dev = ts->input; unsigned Rt; - unsigned sync = 0; u16 x, y, z1, z2; - unsigned long flags; /* adjust: on-wire is a must-ignore bit, a BE12 value, then padding; * built from two 8 bit values written msb-first. @@ -399,7 +429,7 @@ static void ads7846_rx(void *ads) if (x == MAX_12BIT) x = 0; - if (likely(x && z1 && !device_suspended(&ts->spi->dev))) { + if (likely(x && z1)) { /* compute touch pressure resistance using equation #2 */ Rt = z2; Rt -= z1; @@ -414,51 +444,31 @@ static void ads7846_rx(void *ads) * the maximum. Don't report it to user space, repeat at least * once more the measurement */ if (ts->tc.ignore || Rt > ts->pressure_max) { +#ifdef VERBOSE + pr_debug("%s: ignored %d pressure %d\n", + ts->spi->dev.bus_id, ts->tc.ignore, Rt); +#endif mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); return; } - /* NOTE: "pendown" is inferred from pressure; we don't rely on - * being able to check nPENIRQ status, or "friendly" trigger modes - * (both-edges is much better than just-falling or low-level). - * - * REVISIT: some boards may require reading nPENIRQ; it's - * needed on 7843. and 7845 reads pressure differently... - * - * REVISIT: the touchscreen might not be connected; this code - * won't notice that, even if nPENIRQ never fires ... + /* NOTE: We can't rely on the pressure to determine the pen down + * state. The pressure value can fluctuate for quite a while + * after lifting the pen and in some cases may not even settle at + * the expected value. The only safe way to check for the pen up + * condition is in the timer by reading the pen IRQ state. */ - if (!ts->pendown && Rt != 0) { - input_report_key(input_dev, BTN_TOUCH, 1); - sync = 1; - } else if (ts->pendown && Rt == 0) { - input_report_key(input_dev, BTN_TOUCH, 0); - sync = 1; - } - if (Rt) { - input_report_abs(input_dev, ABS_X, x); - input_report_abs(input_dev, ABS_Y, y); - sync = 1; - } - - if (sync) { - input_report_abs(input_dev, ABS_PRESSURE, Rt); - input_sync(input_dev); + if (!ts->pendown) { + ads7846_report_pen_state(ts, 1); + ts->pendown = 1; + } + ads7846_report_pen_position(ts, x, y, Rt); + ads7846_sync_events(ts); } -#ifdef VERBOSE - if (Rt || ts->pendown) - pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id, - x, y, Rt, Rt ? "" : " UP"); -#endif - - spin_lock_irqsave(&ts->lock, flags); - ts->pendown = (Rt != 0); mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD); - - spin_unlock_irqrestore(&ts->lock, flags); } static void ads7846_debounce(void *ads) @@ -520,14 +530,20 @@ static void ads7846_timer(unsigned long handle) spin_lock_irq(&ts->lock); - if (unlikely(ts->msg_idx && !ts->pendown)) { + if (unlikely(!ts->get_pendown_state() || + device_suspended(&ts->spi->dev))) { + if (ts->pendown) { + ads7846_report_pen_state(ts, 0); + ads7846_sync_events(ts); + ts->pendown = 0; + } + /* measurment cycle ended */ if (!device_suspended(&ts->spi->dev)) { ts->irq_disabled = 0; enable_irq(ts->spi->irq); } ts->pending = 0; - ts->msg_idx = 0; } else { /* pen is still down, continue with the measurement */ ts->msg_idx = 0; -- 2.41.1