mm: factor out memory isolate functions

[firefly-linux-kernel-4.4.55.git] / drivers / iio / industrialio-buffer.c

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index 2f35db93cdb6ef3a8594b74effb93e0f64e971ea..4add9bb40eeb32a2cf032775fc7b357085af49c1 100644 (file)
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -285,11 +285,14 @@ int iio_buffer_register(struct iio_dev *indio_dev,
        if (channels) {
                /* new magic */
                for (i = 0; i < num_channels; i++) {
+                       if (channels[i].scan_index < 0)
+                               continue;
+
                        /* Establish necessary mask length */
                        if (channels[i].scan_index >
                            (int)indio_dev->masklength - 1)
                                indio_dev->masklength
-                                       = indio_dev->channels[i].scan_index + 1;
+                                       = channels[i].scan_index + 1;
 
                        ret = iio_buffer_add_channel_sysfs(indio_dev,
                                                         &channels[i]);
@@ -567,6 +570,31 @@ int iio_sw_buffer_preenable(struct iio_dev *indio_dev)
 }
 EXPORT_SYMBOL(iio_sw_buffer_preenable);
 
+/**
+ * iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
+ * @indio_dev: the iio device
+ * @mask: scan mask to be checked
+ *
+ * Return true if exactly one bit is set in the scan mask, false otherwise. It
+ * can be used for devices where only one channel can be active for sampling at
+ * a time.
+ */
+bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
+       const unsigned long *mask)
+{
+       return bitmap_weight(mask, indio_dev->masklength) == 1;
+}
+EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
+
+static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
+       const unsigned long *mask)
+{
+       if (!indio_dev->setup_ops->validate_scan_mask)
+               return true;
+
+       return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
+}
+
 /**
  * iio_scan_mask_set() - set particular bit in the scan mask
  * @buffer: the buffer whose scan mask we are interested in
@@ -586,27 +614,31 @@ int iio_scan_mask_set(struct iio_dev *indio_dev,
                return -ENOMEM;
        if (!indio_dev->masklength) {
                WARN_ON("trying to set scanmask prior to registering buffer\n");
-               kfree(trialmask);
-               return -EINVAL;
+               goto err_invalid_mask;
        }
        bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
        set_bit(bit, trialmask);
 
+       if (!iio_validate_scan_mask(indio_dev, trialmask))
+               goto err_invalid_mask;
+
        if (indio_dev->available_scan_masks) {
                mask = iio_scan_mask_match(indio_dev->available_scan_masks,
                                           indio_dev->masklength,
                                           trialmask);
-               if (!mask) {
-                       kfree(trialmask);
-                       return -EINVAL;
-               }
+               if (!mask)
+                       goto err_invalid_mask;
        }
        bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
 
        kfree(trialmask);
 
        return 0;
-};
+
+err_invalid_mask:
+       kfree(trialmask);
+       return -EINVAL;
+}
 EXPORT_SYMBOL_GPL(iio_scan_mask_set);
 
 int iio_scan_mask_query(struct iio_dev *indio_dev,