iio: stx104: Unregister IIO device on remove callback

The devm_iio_device_register function should not be used if custom
operations must be performed in the remove callback. This patch replaces
the dem_iio_device_register call with a iio_device_register call and
respective iio_device_unregister call in the remove callback.

Fixes: 765550e4d98d ("iio: stx104: Add GPIO support for the Apex Embedded Systems STX104")
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 29 insertions, 9 deletions

diff --git a/drivers/iio/dac/stx104.c b/drivers/iio/dac/stx104.c
index 792a97164cb2..bebbd00304ce 100644
--- a/drivers/iio/dac/stx104.c
+++ b/drivers/iio/dac/stx104.c
@@ -65,6 +65,16 @@ struct stx104_gpio {
         unsigned int out_state;
 };
 
+/**
+ * struct stx104_dev - STX104 device private data structure
+ * @indio_dev:  IIO device
+ * @chip:       instance of the gpio_chip
+ */
+struct stx104_dev {
+        struct iio_dev *indio_dev;
+        struct gpio_chip *chip;
+};
+
 static int stx104_read_raw(struct iio_dev *indio_dev,
         struct iio_chan_spec const *chan, int *val, int *val2, long mask)
 {
@@ -107,6 +117,7 @@ static const struct iio_chan_spec stx104_channels[STX104_NUM_CHAN] = {
 static int stx104_gpio_get_direction(struct gpio_chip *chip,
         unsigned int offset)
 {
+        /* GPIO 0-3 are input only, while the rest are output only */
         if (offset < 4)
                 return 1;
 
@@ -169,6 +180,7 @@ static int stx104_probe(struct device *dev, unsigned int id)
         struct iio_dev *indio_dev;
         struct stx104_iio *priv;
         struct stx104_gpio *stx104gpio;
+        struct stx104_dev *stx104dev;
         int err;
 
         indio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
@@ -179,6 +191,10 @@ static int stx104_probe(struct device *dev, unsigned int id)
         if (!stx104gpio)
                 return -ENOMEM;
 
+        stx104dev = devm_kzalloc(dev, sizeof(*stx104dev), GFP_KERNEL);
+        if (!stx104dev)
+                return -ENOMEM;
+
         if (!devm_request_region(dev, base[id], STX104_EXTENT,
                 dev_name(dev))) {
                 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
@@ -199,12 +215,6 @@ static int stx104_probe(struct device *dev, unsigned int id)
         outw(0, base[id] + 4);
         outw(0, base[id] + 6);
 
-        err = devm_iio_device_register(dev, indio_dev);
-        if (err) {
-                dev_err(dev, "IIO device registering failed (%d)\n", err);
-                return err;
-        }
-
         stx104gpio->chip.label = dev_name(dev);
         stx104gpio->chip.parent = dev;
         stx104gpio->chip.owner = THIS_MODULE;
@@ -220,7 +230,9 @@ static int stx104_probe(struct device *dev, unsigned int id)
 
         spin_lock_init(&stx104gpio->lock);
 
-        dev_set_drvdata(dev, stx104gpio);
+        stx104dev->indio_dev = indio_dev;
+        stx104dev->chip = &stx104gpio->chip;
+        dev_set_drvdata(dev, stx104dev);
 
         err = gpiochip_add_data(&stx104gpio->chip, stx104gpio);
         if (err) {
@@ -228,14 +240,22 @@ static int stx104_probe(struct device *dev, unsigned int id)
                 return err;
         }
 
+        err = iio_device_register(indio_dev);
+        if (err) {
+                dev_err(dev, "IIO device registering failed (%d)\n", err);
+                gpiochip_remove(&stx104gpio->chip);
+                return err;
+        }
+
         return 0;
 }
 
 static int stx104_remove(struct device *dev, unsigned int id)
 {
-        struct stx104_gpio *const stx104gpio = dev_get_drvdata(dev);
+        struct stx104_dev *const stx104dev = dev_get_drvdata(dev);
 
-        gpiochip_remove(&stx104gpio->chip);
+        iio_device_unregister(stx104dev->indio_dev);
+        gpiochip_remove(stx104dev->chip);
 
         return 0;
 }