static void tsc200x_penup_timer(unsigned long data)
{
struct tsc200x *ts = (struct tsc200x *)data;
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
tsc200x_update_pen_state(ts, 0, 0, 0);
spin_unlock_irqrestore(&ts->lock, flags);
}
static void tsc200x_penup_timer(struct timer_list *t)
{
struct tsc200x *ts = from_timer(ts, t, penup_timer);
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
tsc200x_update_pen_state(ts, 0, 0, 0);
spin_unlock_irqrestore(&ts->lock, flags);
}
static void tsc200x_esd_work(struct work_struct *work)
{
struct tsc200x *ts = container_of(work, struct tsc200x, esd_work.work);
int error;
unsigned int r;
if (!mutex_trylock(&ts->mutex)) {
/*
* If the mutex is taken, it means that disable or enable is in
* progress. In that case just reschedule the work. If the work
* is not needed, it will be canceled by disable.
*/
goto reschedule;
}
if (time_is_after_jiffies(ts->last_valid_interrupt +
msecs_to_jiffies(ts->esd_timeout)))
goto out;
/* We should be able to read register without disabling interrupts. */
error = regmap_read(ts->regmap, TSC200X_REG_CFR0, &r);
if (!error &&
!((r ^ TSC200X_CFR0_INITVALUE) & TSC200X_CFR0_RW_MASK)) {
goto out;
}
/*
* If we could not read our known value from configuration register 0
* then we should reset the controller as if from power-up and start
* scanning again.
*/
dev_info(ts->dev, "TSC200X not responding - resetting\n");
disable_irq(ts->irq);
del_timer_sync(&ts->penup_timer);
tsc200x_update_pen_state(ts, 0, 0, 0);
tsc200x_set_reset(ts, false);
usleep_range(100, 500); /* only 10us required */
tsc200x_set_reset(ts, true);
enable_irq(ts->irq);
tsc200x_start_scan(ts);
out:
mutex_unlock(&ts->mutex);
reschedule:
/* re-arm the watchdog */
schedule_delayed_work(&ts->esd_work,
round_jiffies_relative(
msecs_to_jiffies(ts->esd_timeout)));
}
static irqreturn_t tsc200x_irq_thread(int irq, void *_ts)
{
struct tsc200x *ts = _ts;
unsigned long flags;
unsigned int pressure;
struct tsc200x_data tsdata;
int error;
/* read the coordinates */
error = regmap_bulk_read(ts->regmap, TSC200X_REG_X, &tsdata,
TSC200X_DATA_REGS);
if (unlikely(error))
goto out;
/* validate position */
if (unlikely(tsdata.x > MAX_12BIT || tsdata.y > MAX_12BIT))
goto out;
/* Skip reading if the pressure components are out of range */
if (unlikely(tsdata.z1 == 0 || tsdata.z2 > MAX_12BIT))
goto out;
if (unlikely(tsdata.z1 >= tsdata.z2))
goto out;
/*
* Skip point if this is a pen down with the exact same values as
* the value before pen-up - that implies SPI fed us stale data
*/
if (!ts->pen_down &&
ts->in_x == tsdata.x && ts->in_y == tsdata.y &&
ts->in_z1 == tsdata.z1 && ts->in_z2 == tsdata.z2) {
goto out;
}
/*
* At this point we are happy we have a valid and useful reading.
* Remember it for later comparisons. We may now begin downsampling.
*/
ts->in_x = tsdata.x;
ts->in_y = tsdata.y;
ts->in_z1 = tsdata.z1;
ts->in_z2 = tsdata.z2;
/* Compute touch pressure resistance using equation #1 */
pressure = tsdata.x * (tsdata.z2 - tsdata.z1) / tsdata.z1;
pressure = pressure * ts->x_plate_ohm / 4096;
if (unlikely(pressure > MAX_12BIT))
goto out;
spin_lock_irqsave(&ts->lock, flags);
tsc200x_update_pen_state(ts, tsdata.x, tsdata.y, pressure);
mod_timer(&ts->penup_timer,
jiffies + msecs_to_jiffies(TSC200X_PENUP_TIME_MS));
spin_unlock_irqrestore(&ts->lock, flags);
ts->last_valid_interrupt = jiffies;
out:
return IRQ_HANDLED;
}
