apds990x: Check gpio status after handling IRQ

BZ: 29351

Since apds990x's interrupt pin is level style and some GPIO controllers
don't support level trigger, we need to check gpio pin value to
see if there is another interupt occurs between the interrupt status
register read and interrupt ack. If that happens, we need to do the
IRQ handle again to avert interrupt missing.

Change-Id: I09dd0049a4a520a92e22ecd1476b688ab56e2864
Signed-off-by: Leo Yan <leo.yan@intel.com>
Reviewed-on: http://android.intel.com:8080/41856
Reviewed-by: Du, Alek <alek.du@intel.com>
Tested-by: Wang, Zhifeng <zhifeng.wang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/misc/apds990x.c b/drivers/misc/apds990x.c
index 381ed1f..4515409 100644 (file)
--- a/drivers/misc/apds990x.c
+++ b/drivers/misc/apds990x.c
@@ -122,6 +122,7 @@
 #define APDS_ALS_DISABLE       (1 << 2)
 #define APDS_PS_ENABLE         (1 << 3)
 #define APDS_PS_DISABLE        (1 << 4)
+#define APDS_GPIO_CHECK_MAX    5
 
 /* alsps_client.status bits */
 #define PS_DATA_READY     0
@@ -566,26 +567,6 @@ static void ps_handle_irq(struct apds990x_chip *chip)
        wake_up(&chip->ps_workq_head);
 }
 
-static irqreturn_t apds990x_irq(int irq, void *data)
-{
-       struct apds990x_chip *chip = data;
-       u8 status;
-
-       dev_dbg(&chip->client->dev, "Enter apds990x irq handler.\n");
-       apds990x_read_byte(chip, APDS990X_STATUS, &status);
-       apds990x_ack_int(chip, status);
-
-       mutex_lock(&chip->mutex);
-       if (status & APDS990X_ST_AINT)
-               als_handle_irq(chip);
-
-       if (status & APDS990X_ST_PINT)
-               ps_handle_irq(chip);
-       mutex_unlock(&chip->mutex);
-out:
-       return IRQ_HANDLED;
-}
-
 static int apds990x_configure(struct apds990x_chip *chip)
 {
        /* It is recommended to use disabled mode during these operations */
@@ -1060,7 +1041,6 @@ static int apds990x_switch(struct apds990x_chip *chip, int mode)
 /* mutex must be held when calling this function */
 static void apds990x_mode(struct alsps_client *client, int mode)
 {
-       struct alsps_client *list_tmp;
        struct apds990x_chip *chip = client->chip;
 
        switch (mode) {
@@ -1110,6 +1090,47 @@ static void apds990x_mode(struct alsps_client *client, int mode)
        apds990x_switch(chip, chip->alsps_switch);
 }
 
+static irqreturn_t apds990x_irq(int irq, void *data)
+{
+       u8 status;
+       int i, value;
+       struct apds990x_chip *chip = data;
+
+       mutex_lock(&chip->mutex);
+       for (i = 0; i < APDS_GPIO_CHECK_MAX; i++) {
+               apds990x_read_byte(chip, APDS990X_STATUS, &status);
+               apds990x_ack_int(chip, status);
+
+               if (status & APDS990X_ST_AINT)
+                       als_handle_irq(chip);
+               if (status & APDS990X_ST_PINT)
+                       ps_handle_irq(chip);
+
+               /* Since apds990x's interrupt pin is level type and some GPIO
+                * controllers don't support level trigger, we need to check
+                * gpio pin value to see if there is another interupt occurs
+                * in the time window that interrupt status register read and
+                * interrupt ack. If that happens, do irq handle again to
+                * avert interrupt missing.
+                */
+               value = gpio_get_value(chip->pdata->gpio_number);
+               dev_dbg(&chip->client->dev,
+                                       "%s: try=%d, GPIO value = 0x%x",
+                                       __func__, i, value);
+               if (value)
+                       break;
+       }
+       if (i == APDS_GPIO_CHECK_MAX) {
+               dev_dbg(&chip->client->dev,
+                               "GPIO check max, reset the sensor\n");
+               apds990x_switch(chip, APDS_POWER_DOWN);
+               apds990x_switch(chip, chip->alsps_switch);
+       }
+       mutex_unlock(&chip->mutex);
+
+       return IRQ_HANDLED;
+}
+
 static long ps_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        int ret = 0;
@@ -1413,6 +1434,7 @@ static int __devinit apds990x_probe(struct i2c_client *client,
                dev_err(&client->dev, "Setup IRQ error\n");
                goto fail5;
        }
+       enable_irq_wake(client->irq);
 
 #ifdef CONFIG_HAS_EARLYSUSPEND
        chip->es.level = EARLY_SUSPEND_LEVEL_DISABLE_FB + 10;
@@ -1443,6 +1465,7 @@ static int __devexit apds990x_remove(struct i2c_client *client)
 {
        struct apds990x_chip *chip = i2c_get_clientdata(client);
 
+       disable_irq_wake(client->irq);
        free_irq(client->irq, chip);
        sysfs_remove_group(&chip->client->dev.kobj,
                        apds990x_attribute_group);
@@ -1465,32 +1488,32 @@ static int apds990x_suspend(struct device *dev)
        struct i2c_client *i2c_client = to_i2c_client(dev);
        struct apds990x_chip *chip = i2c_get_clientdata(i2c_client);
        struct alsps_client *client;
-       int ret = 0;
 
+       dev_dbg(&i2c_client->dev, "%s: pm suspend", __func__);
+       disable_irq(i2c_client->irq);
        if (!mutex_trylock(&chip->mutex)) {
-               ret = -EBUSY;
                goto out1;
        }
        list_for_each_entry(client, &chip->ps_list, list) {
                if (test_bit(PS_DATA_READY, &client->status)) {
-                       ret = -EBUSY;
                        goto out2;
                }
        }
-       disable_irq(i2c_client->irq);
-       enable_irq_wake(i2c_client->irq);
+       mutex_unlock(&chip->mutex);
+       return 0;
 out2:
        mutex_unlock(&chip->mutex);
 out1:
-       return ret;
+       enable_irq(i2c_client->irq);
+       return -EBUSY;
 }
 
 static int apds990x_resume(struct device *dev)
 {
        struct i2c_client *client = to_i2c_client(dev);
 
+       dev_dbg(&client->dev, "%s: pm resume", __func__);
        enable_irq(client->irq);
-       disable_irq_wake(client->irq);
        return 0;
 }
 #else