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>

1 files changed, 42 insertions, 30 deletions

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index b512697b227..75fbd753a4d 100644
--- 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)