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Input: tsc2007 - convert to threaded IRQ 

Instead of using hard IRQ and workqueue solution switch to using threaded
interrupt handler to simplify the code and locking rules.

Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2011-08-25 00:25:12 -07:00
parent 6a20baa9a4
commit 377dc5538c
1 changed files with 78 additions and 96 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

174
drivers/input/touchscreen/tsc2007.c
View File

@ -66,7 +66,6 @@ struct ts_event {
struct tsc2007 {
struct input_dev *input;
char phys[32];
struct delayed_work work;
struct i2c_client *client;
@ -76,9 +75,11 @@ struct tsc2007 {
unsigned long poll_delay;
unsigned long poll_period;
bool pendown;
int irq;
wait_queue_head_t wait;
bool stopped;
int (*get_pendown_state)(void);
void (*clear_penirq)(void);
};
@ -141,25 +142,8 @@ static u32 tsc2007_calculate_pressure(struct tsc2007 *tsc, struct ts_event *tc)
return rt;
}
static void tsc2007_send_up_event(struct tsc2007 *tsc)
static bool tsc2007_is_pen_down(struct tsc2007 *ts)
{
struct input_dev *input = tsc->input;
dev_dbg(&tsc->client->dev, "UP\n");
input_report_key(input, BTN_TOUCH, 0);
input_report_abs(input, ABS_PRESSURE, 0);
input_sync(input);
}
static void tsc2007_work(struct work_struct *work)
{
struct tsc2007 *ts =
container_of(to_delayed_work(work), struct tsc2007, work);
bool debounced = false;
struct ts_event tc;
u32 rt;
/*
* NOTE: We can't rely on the pressure to determine the pen down
* state, even though this controller has a pressure sensor.
@ -170,79 +154,82 @@ static void tsc2007_work(struct work_struct *work)
* The only safe way to check for the pen up condition is in the
* work function by reading the pen signal state (it's a GPIO
* and IRQ). Unfortunately such callback is not always available,
* in that case we have rely on the pressure anyway.
* in that case we assume that the pen is down and expect caller
* to fall back on the pressure reading.
*/
if (ts->get_pendown_state) {
if (unlikely(!ts->get_pendown_state())) {
tsc2007_send_up_event(ts);
ts->pendown = false;
goto out;
}
dev_dbg(&ts->client->dev, "pen is still down\n");
}
if (!ts->get_pendown_state)
return true;
tsc2007_read_values(ts, &tc);
rt = tsc2007_calculate_pressure(ts, &tc);
if (rt > ts->max_rt) {
/*
* Sample found inconsistent by debouncing or pressure is
* beyond the maximum. Don't report it to user space,
* repeat at least once more the measurement.
*/
dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
debounced = true;
goto out;
}
if (rt) {
struct input_dev *input = ts->input;
if (!ts->pendown) {
dev_dbg(&ts->client->dev, "DOWN\n");
input_report_key(input, BTN_TOUCH, 1);
ts->pendown = true;
}
input_report_abs(input, ABS_X, tc.x);
input_report_abs(input, ABS_Y, tc.y);
input_report_abs(input, ABS_PRESSURE, rt);
input_sync(input);
dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
tc.x, tc.y, rt);
} else if (!ts->get_pendown_state && ts->pendown) {
/*
* We don't have callback to check pendown state, so we
* have to assume that since pressure reported is 0 the
* pen was lifted up.
*/
tsc2007_send_up_event(ts);
ts->pendown = false;
}
out:
if (ts->pendown || debounced)
schedule_delayed_work(&ts->work,
msecs_to_jiffies(ts->poll_period));
else
enable_irq(ts->irq);
return ts->get_pendown_state();
}
static irqreturn_t tsc2007_irq(int irq, void *handle)
static irqreturn_t tsc2007_soft_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;
struct input_dev *input = ts->input;
struct ts_event tc;
u32 rt;
while (!ts->stopped && tsc2007_is_pen_down(ts)) {
/* pen is down, continue with the measurement */
tsc2007_read_values(ts, &tc);
rt = tsc2007_calculate_pressure(ts, &tc);
if (rt == 0 && !ts->get_pendown_state) {
/*
* If pressure reported is 0 and we don't have
* callback to check pendown state, we have to
* assume that pen was lifted up.
*/
break;
}
if (rt <= ts->max_rt) {
dev_dbg(&ts->client->dev,
"DOWN point(%4d,%4d), pressure (%4u)\n",
tc.x, tc.y, rt);
input_report_key(input, BTN_TOUCH, 1);
input_report_abs(input, ABS_X, tc.x);
input_report_abs(input, ABS_Y, tc.y);
input_report_abs(input, ABS_PRESSURE, rt);
input_sync(input);
} else {
/*
* Sample found inconsistent by debouncing or pressure is
* beyond the maximum. Don't report it to user space,
* repeat at least once more the measurement.
*/
dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
}
wait_event_timeout(ts->wait, ts->stopped,
msecs_to_jiffies(ts->poll_period));
}
dev_dbg(&ts->client->dev, "UP\n");
input_report_key(input, BTN_TOUCH, 0);
input_report_abs(input, ABS_PRESSURE, 0);
input_sync(input);
if (ts->clear_penirq)
ts->clear_penirq();
return IRQ_HANDLED;
}
static irqreturn_t tsc2007_hard_irq(int irq, void *handle)
{
struct tsc2007 *ts = handle;
if (!ts->get_pendown_state || likely(ts->get_pendown_state())) {
disable_irq_nosync(ts->irq);
schedule_delayed_work(&ts->work,
msecs_to_jiffies(ts->poll_delay));
}
if (!ts->get_pendown_state || likely(ts->get_pendown_state()))
return IRQ_WAKE_THREAD;
if (ts->clear_penirq)
ts->clear_penirq();
@ -252,15 +239,10 @@ static irqreturn_t tsc2007_irq(int irq, void *handle)
static void tsc2007_free_irq(struct tsc2007 *ts)
{
ts->stopped = true;
mb();
wake_up(&ts->wait);
free_irq(ts->irq, ts);
if (cancel_delayed_work_sync(&ts->work)) {
/*
* Work was pending, therefore we need to enable
* IRQ here to balance the disable_irq() done in the
* interrupt handler.
*/
enable_irq(ts->irq);
}
}
static int __devinit tsc2007_probe(struct i2c_client *client,
@ -290,7 +272,7 @@ static int __devinit tsc2007_probe(struct i2c_client *client,
ts->client = client;
ts->irq = client->irq;
ts->input = input_dev;
INIT_DELAYED_WORK(&ts->work, tsc2007_work);
init_waitqueue_head(&ts->wait);
ts->model = pdata->model;
ts->x_plate_ohms = pdata->x_plate_ohms;
@ -318,8 +300,8 @@ static int __devinit tsc2007_probe(struct i2c_client *client,
if (pdata->init_platform_hw)
pdata->init_platform_hw();
err = request_irq(ts->irq, tsc2007_irq, 0,
client->dev.driver->name, ts);
err = request_threaded_irq(ts->irq, tsc2007_hard_irq, tsc2007_soft_irq,
IRQF_ONESHOT, client->dev.driver->name, ts);
if (err < 0) {
dev_err(&client->dev, "irq %d busy?\n", ts->irq);
goto err_free_mem;