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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2011-08-25 11:25:12 +0400
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2011-08-27 10:21:53 +0400
commit377dc5538c43052d2ee9bc89577cb07fe18f2520 (patch)
tree2183ea64740210993786f49f0e3561e814c41c52 /drivers/input/touchscreen/tsc2007.c
parent6a20baa9a40116715ebc99afe5b79b92f637ec23 (diff)
downloadlinux-377dc5538c43052d2ee9bc89577cb07fe18f2520.tar.xz
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>
Diffstat (limited to 'drivers/input/touchscreen/tsc2007.c')
-rw-r--r--drivers/input/touchscreen/tsc2007.c150
1 files changed, 66 insertions, 84 deletions
diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index fadc11545b1e..e3aaf50ee8d3 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -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)
-{
- 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)
+static bool tsc2007_is_pen_down(struct tsc2007 *ts)
{
- 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);
+ return ts->get_pendown_state();
+}
- 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;
+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);
- if (rt) {
- struct input_dev *input = ts->input;
+ rt = tsc2007_calculate_pressure(ts, &tc);
- if (!ts->pendown) {
- dev_dbg(&ts->client->dev, "DOWN\n");
+ 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);
- 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);
+
+ } 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);
}
- input_report_abs(input, ABS_X, tc.x);
- input_report_abs(input, ABS_Y, tc.y);
- input_report_abs(input, ABS_PRESSURE, rt);
+ wait_event_timeout(ts->wait, ts->stopped,
+ msecs_to_jiffies(ts->poll_period));
+ }
- input_sync(input);
+ dev_dbg(&ts->client->dev, "UP\n");
- dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
- tc.x, tc.y, rt);
+ input_report_key(input, BTN_TOUCH, 0);
+ input_report_abs(input, ABS_PRESSURE, 0);
+ input_sync(input);
- } 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;
- }
+ if (ts->clear_penirq)
+ ts->clear_penirq();
- out:
- if (ts->pendown || debounced)
- schedule_delayed_work(&ts->work,
- msecs_to_jiffies(ts->poll_period));
- else
- enable_irq(ts->irq);
+ return IRQ_HANDLED;
}
-static irqreturn_t tsc2007_irq(int irq, void *handle)
+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;