Input: tsc2007 - properly shut off interrupts/delayed work

Properly shut off interrupts/delayed work by free-ing IRQ first
and then ensuring that enable/disable is balanced. Also add
__devinit/__devexit markings, restore poll delay/period scheduling
logic, make sure we call exit_platform_hw() method when probe
fails.

Tested-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index b512697..75fbd75 100644 (file)
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -27,7 +27,8 @@
 #include <linux/i2c.h>
 #include <linux/i2c/tsc2007.h>
 
-#define TS_POLL_PERIOD msecs_to_jiffies(1) /* ms delay between samples */
+#define TS_POLL_DELAY                  1 /* ms delay between samples */
+#define TS_POLL_PERIOD                 1 /* ms delay between samples */
 
 #define TSC2007_MEASURE_TEMP0          (0x0 << 4)
 #define TSC2007_MEASURE_AUX            (0x2 << 4)
@@ -76,7 +77,7 @@ struct tsc2007 {
        u16                     model;
        u16                     x_plate_ohms;
 
-       unsigned                pendown;
+       bool                    pendown;
        int                     irq;
 
        int                     (*get_pendown_state)(void);
@@ -131,18 +132,18 @@ static void tsc2007_send_event(void *tsc)
        } else
                rt = 0;
 
-       /* Sample found inconsistent by debouncing or pressure is beyond
+       /*
+        * 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
         */
        if (rt > MAX_12BIT) {
                dev_dbg(&ts->client->dev, "ignored pressure %d\n", rt);
-
-               schedule_delayed_work(&ts->work, TS_POLL_PERIOD);
                return;
        }
 
-       /* NOTE: We can't rely on the pressure to determine the pen down
+       /*
+        * NOTE: We can't rely on the pressure to determine the pen down
         * state, even this controller has a pressure sensor.  The pressure
         * value can fluctuate for quite a while after lifting the pen and
         * in some cases may not even settle at the expected value.
@@ -157,7 +158,7 @@ static void tsc2007_send_event(void *tsc)
                        dev_dbg(&ts->client->dev, "DOWN\n");
 
                        input_report_key(input, BTN_TOUCH, 1);
-                       ts->pendown = 1;
+                       ts->pendown = true;
                }
 
                input_report_abs(input, ABS_X, x);
@@ -169,8 +170,6 @@ static void tsc2007_send_event(void *tsc)
                dev_dbg(&ts->client->dev, "point(%4d,%4d), pressure (%4u)\n",
                        x, y, rt);
        }
-
-       schedule_delayed_work(&ts->work, TS_POLL_PERIOD);
 }
 
 static int tsc2007_read_values(struct tsc2007 *tsc)
@@ -195,6 +194,7 @@ static void tsc2007_work(struct work_struct *work)
 {
        struct tsc2007 *ts =
                container_of(to_delayed_work(work), struct tsc2007, work);
+
        if (unlikely(!ts->get_pendown_state() && ts->pendown)) {
                struct input_dev *input = ts->input;
 
@@ -204,7 +204,7 @@ static void tsc2007_work(struct work_struct *work)
                input_report_abs(input, ABS_PRESSURE, 0);
                input_sync(input);
 
-               ts->pendown = 0;
+               ts->pendown = false;
                enable_irq(ts->irq);
        } else {
                /* pen is still down, continue with the measurement */
@@ -212,6 +212,9 @@ static void tsc2007_work(struct work_struct *work)
 
                tsc2007_read_values(ts);
                tsc2007_send_event(ts);
+
+               schedule_delayed_work(&ts->work,
+                                     msecs_to_jiffies(TS_POLL_PERIOD));
        }
 }
 
@@ -221,7 +224,8 @@ static irqreturn_t tsc2007_irq(int irq, void *handle)
 
        if (likely(ts->get_pendown_state())) {
                disable_irq_nosync(ts->irq);
-               schedule_delayed_work(&ts->work, 0);
+               schedule_delayed_work(&ts->work,
+                                     msecs_to_jiffies(TS_POLL_DELAY));
        }
 
        if (ts->clear_penirq)
@@ -230,8 +234,21 @@ static irqreturn_t tsc2007_irq(int irq, void *handle)
        return IRQ_HANDLED;
 }
 
-static int tsc2007_probe(struct i2c_client *client,
-                       const struct i2c_device_id *id)
+static void tsc2007_free_irq(struct tsc2007 *ts)
+{
+       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,
+                                  const struct i2c_device_id *id)
 {
        struct tsc2007 *ts;
        struct tsc2007_platform_data *pdata = pdata = client->dev.platform_data;
@@ -255,17 +272,15 @@ static int tsc2007_probe(struct i2c_client *client,
        }
 
        ts->client = client;
-       i2c_set_clientdata(client, ts);
-
+       ts->irq = client->irq;
        ts->input = input_dev;
+       INIT_DELAYED_WORK(&ts->work, tsc2007_work);
 
        ts->model             = pdata->model;
        ts->x_plate_ohms      = pdata->x_plate_ohms;
        ts->get_pendown_state = pdata->get_pendown_state;
        ts->clear_penirq      = pdata->clear_penirq;
 
-       pdata->init_platform_hw();
-
        snprintf(ts->phys, sizeof(ts->phys),
                 "%s/input0", dev_name(&client->dev));
 
@@ -280,11 +295,7 @@ static int tsc2007_probe(struct i2c_client *client,
        input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
        input_set_abs_params(input_dev, ABS_PRESSURE, 0, MAX_12BIT, 0, 0);
 
-       tsc2007_read_values(ts);
-
-       ts->irq = client->irq;
-
-       INIT_DELAYED_WORK(&ts->work, tsc2007_work);
+       pdata->init_platform_hw();
 
        err = request_irq(ts->irq, tsc2007_irq, 0,
                        client->dev.driver->name, ts);
@@ -297,29 +308,30 @@ static int tsc2007_probe(struct i2c_client *client,
        if (err)
                goto err_free_irq;
 
-       dev_info(&client->dev, "registered with irq (%d)\n", ts->irq);
+       i2c_set_clientdata(client, ts);
+
+       tsc2007_read_values(ts);
 
        return 0;
 
  err_free_irq:
-       free_irq(ts->irq, ts);
+       tsc2007_free_irq(ts);
+       pdata->exit_platform_hw();
  err_free_mem:
        input_free_device(input_dev);
        kfree(ts);
        return err;
 }
 
-static int tsc2007_remove(struct i2c_client *client)
+static int __devexit tsc2007_remove(struct i2c_client *client)
 {
        struct tsc2007  *ts = i2c_get_clientdata(client);
-       struct tsc2007_platform_data *pdata;
+       struct tsc2007_platform_data *pdata = client->dev.platform_data;
 
-       cancel_delayed_work_sync(&ts->work);
+       tsc2007_free_irq(ts);
 
-       pdata = client->dev.platform_data;
        pdata->exit_platform_hw();
 
-       free_irq(ts->irq, ts);
        input_unregister_device(ts->input);
        kfree(ts);
 
@@ -340,7 +352,7 @@ static struct i2c_driver tsc2007_driver = {
        },
        .id_table       = tsc2007_idtable,
        .probe          = tsc2007_probe,
-       .remove         = tsc2007_remove,
+       .remove         = __devexit_p(tsc2007_remove),
 };
 
 static int __init tsc2007_init(void)