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Input: ad7877 - switch to using threaded IRQ

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Instead of using asynchronous SPI API and then spinning waiting for SPI
transfer to complete when disabling the device, let's use threaded IRQ
model and spi_sync().

Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Tested-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2010-10-18 09:24:22 -07:00
parent 2fd18abad1
commit b534422b2d
1 changed files with 25 additions and 40 deletions
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65
drivers/input/touchscreen/ad7877.c
View file

@ -191,13 +191,12 @@ struct ad7877 {
struct spi_message msg;
struct mutex mutex;
unsigned disabled:1; /* P: mutex */
unsigned gpio3:1; /* P: mutex */
unsigned gpio4:1; /* P: mutex */
bool disabled; /* P: mutex */
bool gpio3; /* P: mutex */
bool gpio4; /* P: mutex */
spinlock_t lock;
struct timer_list timer; /* P: lock */
unsigned pending:1; /* P: lock */
/*
* DMA (thus cache coherency maintenance) requires the
@ -333,7 +332,7 @@ static int ad7877_read_adc(struct spi_device *spi, unsigned command)
return status ? : sample;
}
static int ad7877_rx(struct ad7877 *ts)
static int ad7877_process_data(struct ad7877 *ts)
{
struct input_dev *input_dev = ts->input;
unsigned Rt;
@ -374,6 +373,7 @@ static int ad7877_rx(struct ad7877 *ts)
input_report_abs(input_dev, ABS_Y, y);
input_report_abs(input_dev, ABS_PRESSURE, Rt);
input_sync(input_dev);
return 0;
}
@ -392,64 +392,49 @@ static inline void ad7877_ts_event_release(struct ad7877 *ts)
static void ad7877_timer(unsigned long handle)
{
struct ad7877 *ts = (void *)handle;
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
ad7877_ts_event_release(ts);
spin_unlock_irqrestore(&ts->lock, flags);
}
static irqreturn_t ad7877_irq(int irq, void *handle)
{
struct ad7877 *ts = handle;
unsigned long flags;
int status;
int error;
/*
* The repeated conversion sequencer controlled by TMR kicked off
* too fast. We ignore the last and process the sample sequence
* currently in the queue. It can't be older than 9.4ms, and we
* need to avoid that ts->msg doesn't get issued twice while in work.
*/
error = spi_sync(ts->spi, &ts->msg);
if (error) {
dev_err(&ts->spi->dev, "spi_sync --> %d\n", error);
goto out;
}
spin_lock_irqsave(&ts->lock, flags);
if (!ts->pending) {
ts->pending = 1;
status = spi_async(ts->spi, &ts->msg);
if (status)
dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
}
error = ad7877_process_data(ts);
if (!error)
mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
spin_unlock_irqrestore(&ts->lock, flags);
out:
return IRQ_HANDLED;
}
static void ad7877_callback(void *_ts)
{
struct ad7877 *ts = _ts;
spin_lock_irq(&ts->lock);
if (!ad7877_rx(ts))
mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
ts->pending = 0;
spin_unlock_irq(&ts->lock);
}
static void ad7877_disable(struct ad7877 *ts)
{
mutex_lock(&ts->mutex);
if (!ts->disabled) {
ts->disabled = 1;
ts->disabled = true;
disable_irq(ts->spi->irq);
/* Wait for spi_async callback */
while (ts->pending)
msleep(1);
if (del_timer_sync(&ts->timer))
ad7877_ts_event_release(ts);
}
/* we know the chip's in lowpower mode since we always
/*
* We know the chip's in lowpower mode since we always
* leave it that way after every request
*/
@ -461,7 +446,7 @@ static void ad7877_enable(struct ad7877 *ts)
mutex_lock(&ts->mutex);
if (ts->disabled) {
ts->disabled = 0;
ts->disabled = false;
enable_irq(ts->spi->irq);
}
@ -672,7 +657,6 @@ static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
spi_message_init(m);
m->complete = ad7877_callback;
m->context = ts;
ts->xfer[0].tx_buf = &ts->cmd_crtl1;
@ -795,8 +779,9 @@ static int __devinit ad7877_probe(struct spi_device *spi)
/* Request AD7877 /DAV GPIO interrupt */
err = request_irq(spi->irq, ad7877_irq, IRQF_TRIGGER_FALLING,
spi->dev.driver->name, ts);
err = request_threaded_irq(spi->irq, NULL, ad7877_irq,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
spi->dev.driver->name, ts);
if (err) {
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
goto err_free_mem;