diff options
Diffstat (limited to 'drivers/input/touchscreen')
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 156 |
1 files changed, 118 insertions, 38 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index 54d43347786..8670cd13bd5 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -77,7 +77,13 @@ struct ads7846 { struct ts_event tc; struct spi_transfer xfer[10]; - struct spi_message msg; + struct spi_message msg[5]; + int msg_idx; + int read_cnt; + int last_read; + + u16 debounce_max; + u16 debounce_tol; spinlock_t lock; struct timer_list timer; /* P: lock */ @@ -167,7 +173,7 @@ static int ads7846_read12_ser(struct device *dev, unsigned command) if (!req) return -ENOMEM; - INIT_LIST_HEAD(&req->msg.transfers); + spi_message_init(&req->msg); /* activate reference, so it has time to settle; */ req->ref_on = REF_ON; @@ -344,31 +350,76 @@ static void ads7846_rx(void *ads) spin_unlock_irqrestore(&ts->lock, flags); } +static void ads7846_debounce(void *ads) +{ + struct ads7846 *ts = ads; + struct spi_message *m; + struct spi_transfer *t; + u16 val; + int status; + + m = &ts->msg[ts->msg_idx]; + t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list); + val = (*(u16 *)t->rx_buf) >> 3; + + if (!ts->read_cnt || (abs(ts->last_read - val) > ts->debounce_tol + && ts->read_cnt < ts->debounce_max)) { + /* Repeat it, if this was the first read or the read wasn't + * consistent enough + */ + ts->read_cnt++; + ts->last_read = val; + } else { + /* Go for the next read */ + ts->msg_idx++; + ts->read_cnt = 0; + m++; + } + status = spi_async(ts->spi, m); + if (status) + dev_err(&ts->spi->dev, "spi_async --> %d\n", + status); +} + static void ads7846_timer(unsigned long handle) { struct ads7846 *ts = (void *)handle; int status = 0; - unsigned long flags; + + ts->msg_idx = 0; + status = spi_async(ts->spi, &ts->msg[0]); + if (status) + dev_err(&ts->spi->dev, "spi_async --> %d\n", status); +} + +static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs) +{ + struct ads7846 *ts = handle; + unsigned long flags; + int r = IRQ_HANDLED; spin_lock_irqsave(&ts->lock, flags); - if (!ts->pending) { - ts->pending = 1; + if (ts->irq_disabled) + r = IRQ_HANDLED; + else { if (!ts->irq_disabled) { + /* REVISIT irq logic for many ARM chips has cloned a + * bug wherein disabling an irq in its handler won't + * work;(it's disabled lazily, and too late to work. + * until all their irq logic is fixed, we must shadow + * that state here. + */ ts->irq_disabled = 1; + disable_irq(ts->spi->irq); } - status = spi_async(ts->spi, &ts->msg); - if (status) - dev_err(&ts->spi->dev, "spi_async --> %d\n", - status); + if (!ts->pending) { + ts->pending = 1; + mod_timer(&ts->timer, jiffies); + } } spin_unlock_irqrestore(&ts->lock, flags); -} - -static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs) -{ - ads7846_timer((unsigned long) handle); - return IRQ_HANDLED; + return r; } /*--------------------------------------------------------------------------*/ @@ -426,6 +477,7 @@ static int __devinit ads7846_probe(struct spi_device *spi) struct ads7846 *ts; struct input_dev *input_dev; struct ads7846_platform_data *pdata = spi->dev.platform_data; + struct spi_message *m; struct spi_transfer *x; int err; @@ -472,6 +524,8 @@ static int __devinit ads7846_probe(struct spi_device *spi) ts->model = pdata->model ? : 7846; ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100; ts->x_plate_ohms = pdata->x_plate_ohms ? : 400; + ts->debounce_max = pdata->debounce_max ? : 1; + ts->debounce_tol = pdata->debounce_tol ? : 10; snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id); @@ -495,72 +549,98 @@ static int __devinit ads7846_probe(struct spi_device *spi) /* set up the transfers to read touchscreen state; this assumes we * use formula #2 for pressure, not #3. */ - INIT_LIST_HEAD(&ts->msg.transfers); + m = &ts->msg[0]; x = ts->xfer; + spi_message_init(m); + /* y- still on; turn on only y+ (and ADC) */ ts->read_y = READ_Y; x->tx_buf = &ts->read_y; x->len = 1; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); x++; x->rx_buf = &ts->tc.y; x->len = 2; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); + + m->complete = ads7846_debounce; + m->context = ts; + + m++; + spi_message_init(m); + + /* turn y- off, x+ on, then leave in lowpower */ + x++; + ts->read_x = READ_X; + x->tx_buf = &ts->read_x; + x->len = 1; + spi_message_add_tail(x, m); + + x++; + x->rx_buf = &ts->tc.x; + x->len = 2; + spi_message_add_tail(x, m); + + m->complete = ads7846_debounce; + m->context = ts; /* turn y+ off, x- on; we'll use formula #2 */ if (ts->model == 7846) { + m++; + spi_message_init(m); + x++; ts->read_z1 = READ_Z1; x->tx_buf = &ts->read_z1; x->len = 1; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); x++; x->rx_buf = &ts->tc.z1; x->len = 2; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); + + m->complete = ads7846_debounce; + m->context = ts; + + m++; + spi_message_init(m); x++; ts->read_z2 = READ_Z2; x->tx_buf = &ts->read_z2; x->len = 1; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); x++; x->rx_buf = &ts->tc.z2; x->len = 2; - spi_message_add_tail(x, &ts->msg); - } + spi_message_add_tail(x, m); - /* turn y- off, x+ on, then leave in lowpower */ - x++; - ts->read_x = READ_X; - x->tx_buf = &ts->read_x; - x->len = 1; - spi_message_add_tail(x, &ts->msg); - - x++; - x->rx_buf = &ts->tc.x; - x->len = 2; - spi_message_add_tail(x, &ts->msg); + m->complete = ads7846_debounce; + m->context = ts; + } /* power down */ + m++; + spi_message_init(m); + x++; ts->pwrdown = PWRDOWN; x->tx_buf = &ts->pwrdown; x->len = 1; - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); x++; x->rx_buf = &ts->dummy; x->len = 2; CS_CHANGE(*x); - spi_message_add_tail(x, &ts->msg); + spi_message_add_tail(x, m); - ts->msg.complete = ads7846_rx; - ts->msg.context = ts; + m->complete = ads7846_rx; + m->context = ts; if (request_irq(spi->irq, ads7846_irq, SA_SAMPLE_RANDOM | SA_TRIGGER_FALLING, |