[PATCH v2 06/12] dmaengine: add dmaengine_get_cap_mask() and dmaengine_has_cap() helpers

[Frank . Li]

From: Frank Li <Frank.Li@xxxxxxx>

Add two new inline helpers to query DMA channel capabilities without
directly accessing the internal dma_device pointer:

  dmaengine_get_cap_mask(chan) - returns a const pointer to the
    capability mask of the DMA device backing the channel.

  dmaengine_has_cap(chan, tx_type) - returns true if the channel
    supports the given transaction type.

These complement the existing dma_has_cap() macro which operates on
a dma_cap_mask_t directly.

Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 include/linux/dmaengine.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 615eeb708dcda..7fce44bd7c049 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -1585,6 +1585,18 @@ dmaengine_get_fill_align(struct dma_chan *chan)
 	return chan->device->fill_align;
 }
 
+/**
+ * dmaengine_get_cap_mask - get capability mask of a DMA channel
+ * @chan: DMA channel
+ *
+ * Return a pointer to the capability mask of the DMA device backing @chan.
+ */
+static inline const dma_cap_mask_t *
+dmaengine_get_cap_mask(struct dma_chan *chan)
+{
+	return &chan->device->cap_mask;
+}
+
 /**
  * dmaengine_is_copy_aligned - test copy alignment
  * @chan: DMA channel
@@ -1810,6 +1822,19 @@ __dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
 	return test_bit(tx_type, srcp->bits);
 }
 
+/**
+ * dmaengine_has_cap - test whether a DMA channel supports a transaction type
+ * @chan: DMA channel
+ * @tx_type: transaction type to test
+ *
+ * Return true if @chan supports @tx_type, false otherwise.
+ */
+static inline bool
+dmaengine_has_cap(struct dma_chan *chan, enum dma_transaction_type tx_type)
+{
+	return dma_has_cap(tx_type, chan->device->cap_mask);
+}
+
 #define for_each_dma_cap_mask(cap, mask) \
 	for_each_set_bit(cap, mask.bits, DMA_TX_TYPE_END)
 

-- 
2.43.0