From 377dc5538c43052d2ee9bc89577cb07fe18f2520 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 25 Aug 2011 00:25:12 -0700 Subject: 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 Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/tsc2007.c | 150 ++++++++++++++++-------------------- 1 file changed, 66 insertions(+), 84 deletions(-) (limited to 'drivers/input/touchscreen/tsc2007.c') 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; -- cgit v1.2.3