[PATCH v4 01/10] dmaengine: Move enum dma_slave_buswidth to a new header

[Nuno Sá]

In preparation for the bitmap based bus width capabilities, move
enum dma_slave_buswidth out of linux/dmaengine.h into a new
include/linux/dma/engine/types.h.

linux/dmaengine.h is included nearly everywhere, so growing it with the
new interface would make every one of its users pay for it. Keeping the
basic types in a separate header lets the new interface live next to it
without that cost. linux/dmaengine.h includes the new header, so its
users are unaffected.

While at it, add the missing kernel-doc for the enum members. The block
already opened with /**, so kernel-doc expected every member to be
described and warned about each one of them. Describe the UNDEFINED case
in particular, as its meaning depends on where the value is used.

No functional change intended.

Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
---
 include/linux/dma/engine/types.h | 41 ++++++++++++++++++++++++++++++++++++++++
 include/linux/dmaengine.h        | 20 +++-----------------
 2 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/include/linux/dma/engine/types.h b/include/linux/dma/engine/types.h
new file mode 100644
index 000000000000..2e8a266e42ef
--- /dev/null
+++ b/include/linux/dma/engine/types.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Basic types shared by the DMA engine interfaces.
+ */
+#ifndef LINUX_DMA_ENGINE_TYPES_H
+#define LINUX_DMA_ENGINE_TYPES_H
+
+#include <linux/types.h>
+
+/**
+ * enum dma_slave_buswidth - defines bus width of the DMA slave
+ * device, source or target buses
+ * @DMA_SLAVE_BUSWIDTH_UNDEFINED: no bus width specified. In a
+ *	&struct dma_slave_config it lets the controller pick a width, typically
+ *	derived from the transfer itself. In a bus width mask it is a width a
+ *	controller genuinely accepts, meaning it imposes no constraint of its
+ *	own.
+ * @DMA_SLAVE_BUSWIDTH_1_BYTE: 1 byte wide bus
+ * @DMA_SLAVE_BUSWIDTH_2_BYTES: 2 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_3_BYTES: 3 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_4_BYTES: 4 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_8_BYTES: 8 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_16_BYTES: 16 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_32_BYTES: 32 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_64_BYTES: 64 bytes wide bus
+ * @DMA_SLAVE_BUSWIDTH_128_BYTES: 128 bytes wide bus
+ */
+enum dma_slave_buswidth {
+	DMA_SLAVE_BUSWIDTH_UNDEFINED = 0,
+	DMA_SLAVE_BUSWIDTH_1_BYTE = 1,
+	DMA_SLAVE_BUSWIDTH_2_BYTES = 2,
+	DMA_SLAVE_BUSWIDTH_3_BYTES = 3,
+	DMA_SLAVE_BUSWIDTH_4_BYTES = 4,
+	DMA_SLAVE_BUSWIDTH_8_BYTES = 8,
+	DMA_SLAVE_BUSWIDTH_16_BYTES = 16,
+	DMA_SLAVE_BUSWIDTH_32_BYTES = 32,
+	DMA_SLAVE_BUSWIDTH_64_BYTES = 64,
+	DMA_SLAVE_BUSWIDTH_128_BYTES = 128,
+};
+
+#endif /* LINUX_DMA_ENGINE_TYPES_H */
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index fe33a20abc61..573e5ea34707 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -12,6 +12,9 @@
 #include <linux/scatterlist.h>
 #include <linux/bitmap.h>
 #include <linux/types.h>
+
+#include <linux/dma/engine/types.h>
+
 #include <asm/page.h>
 
 /**
@@ -384,23 +387,6 @@ struct dma_chan_dev {
 	bool chan_dma_dev;
 };
 
-/**
- * enum dma_slave_buswidth - defines bus width of the DMA slave
- * device, source or target buses
- */
-enum dma_slave_buswidth {
-	DMA_SLAVE_BUSWIDTH_UNDEFINED = 0,
-	DMA_SLAVE_BUSWIDTH_1_BYTE = 1,
-	DMA_SLAVE_BUSWIDTH_2_BYTES = 2,
-	DMA_SLAVE_BUSWIDTH_3_BYTES = 3,
-	DMA_SLAVE_BUSWIDTH_4_BYTES = 4,
-	DMA_SLAVE_BUSWIDTH_8_BYTES = 8,
-	DMA_SLAVE_BUSWIDTH_16_BYTES = 16,
-	DMA_SLAVE_BUSWIDTH_32_BYTES = 32,
-	DMA_SLAVE_BUSWIDTH_64_BYTES = 64,
-	DMA_SLAVE_BUSWIDTH_128_BYTES = 128,
-};
-
 /**
  * struct dma_slave_config - dma slave channel runtime config
  * @direction: whether the data shall go in or out on this slave

-- 
2.55.0