lis3lv02d: avoid divide by zero due to unchecked

[pandora-kernel.git] / drivers / misc / lis3lv02d / lis3lv02d.c

diff --git a/drivers/misc/lis3lv02d/lis3lv02d.c b/drivers/misc/lis3lv02d/lis3lv02d.c
index 8b51cd6..1fc6715 100644 (file)
--- a/drivers/misc/lis3lv02d/lis3lv02d.c
+++ b/drivers/misc/lis3lv02d/lis3lv02d.c
@@ -206,6 +206,18 @@ static int lis3lv02d_get_odr(void)
        return lis3_dev.odrs[(ctrl >> shift)];
 }
 
+static int lis3lv02d_get_pwron_wait(struct lis3lv02d *lis3)
+{
+       int div = lis3lv02d_get_odr();
+
+       if (WARN_ONCE(div == 0, "device returned spurious data"))
+               return -ENXIO;
+
+       /* LIS3 power on delay is quite long */
+       msleep(lis3->pwron_delay / div);
+       return 0;
+}
+
 static int lis3lv02d_set_odr(int rate)
 {
        u8 ctrl;
@@ -266,7 +278,9 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 
        lis3->read(lis3, ctlreg, &reg);
        lis3->write(lis3, ctlreg, (reg | selftest));
-       msleep(lis3->pwron_delay / lis3lv02d_get_odr());
+       ret = lis3lv02d_get_pwron_wait(lis3);
+       if (ret)
+               goto fail;
 
        /* Read directly to avoid axis remap */
        x = lis3->read_data(lis3, OUTX);
@@ -275,7 +289,9 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 
        /* back to normal settings */
        lis3->write(lis3, ctlreg, reg);
-       msleep(lis3->pwron_delay / lis3lv02d_get_odr());
+       ret = lis3lv02d_get_pwron_wait(lis3);
+       if (ret)
+               goto fail;
 
        results[0] = x - lis3->read_data(lis3, OUTX);
        results[1] = y - lis3->read_data(lis3, OUTY);
@@ -363,8 +379,9 @@ void lis3lv02d_poweroff(struct lis3lv02d *lis3)
 }
 EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
 
-void lis3lv02d_poweron(struct lis3lv02d *lis3)
+int lis3lv02d_poweron(struct lis3lv02d *lis3)
 {
+       int err;
        u8 reg;
 
        lis3->init(lis3);
@@ -384,11 +401,14 @@ void lis3lv02d_poweron(struct lis3lv02d *lis3)
                lis3->write(lis3, CTRL_REG2, reg);
        }
 
-       /* LIS3 power on delay is quite long */
-       msleep(lis3->pwron_delay / lis3lv02d_get_odr());
+       err = lis3lv02d_get_pwron_wait(lis3);
+       if (err)
+               return err;
 
        if (lis3->reg_ctrl)
                lis3_context_restore(lis3);
+
+       return 0;
 }
 EXPORT_SYMBOL_GPL(lis3lv02d_poweron);
 
@@ -928,7 +948,11 @@ int lis3lv02d_init_device(struct lis3lv02d *dev)
        atomic_set(&dev->wake_thread, 0);
 
        lis3lv02d_add_fs(dev);
-       lis3lv02d_poweron(dev);
+       err = lis3lv02d_poweron(dev);
+       if (err) {
+               lis3lv02d_remove_fs(dev);
+               return err;
+       }
 
        if (dev->pm_dev) {
                pm_runtime_set_active(dev->pm_dev);