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authorLudovic Desroches <ludovic.desroches@atmel.com>2013-06-13 10:39:38 +0200
committerNicolas Ferre <nicolas.ferre@atmel.com>2013-06-15 00:12:30 +0200
commitca79522c3f4430facefd63d0da408038d4b0f5fe (patch)
treed2b5260db6b5479de640571fd968e179f10056ed /include/dt-bindings
parent028633c238f91dc113520a7ad25d37b2ba9068af (diff)
ARM: at91: dt: add header to define at_hdmac configuration
DMA-cell content is a concatenation of several values. In order to keep this stuff human readable, macros are introduced. The values for the FIFO configuration are not the same as the ones used in the configuration register in order to keep backward compatibility. Most devices use the half FIFO configuration but USART ones have to use the ASAP configuration. This parameter was not initially planed to be into the at91 dma dt binding. The third cell will be used to store this parameter, it will become a concatenation of the FIFO configuration and of the peripheral ID. In order to keep backward compatibility i.e. FIFO configuration is equal to 0, we have to perform a translation since the value to put in the register to set half FIFO is 1. Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Diffstat (limited to 'include/dt-bindings')
-rw-r--r--include/dt-bindings/dma/at91.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/include/dt-bindings/dma/at91.h b/include/dt-bindings/dma/at91.h
new file mode 100644
index 00000000000..e835037a77b
--- /dev/null
+++ b/include/dt-bindings/dma/at91.h
@@ -0,0 +1,27 @@
+/*
+ * This header provides macros for at91 dma bindings.
+ *
+ * Copyright (C) 2013 Ludovic Desroches <ludovic.desroches@atmel.com>
+ *
+ * GPLv2 only
+ */
+
+#ifndef __DT_BINDINGS_AT91_DMA_H__
+#define __DT_BINDINGS_AT91_DMA_H__
+
+/*
+ * Source and/or destination peripheral ID
+ */
+#define AT91_DMA_CFG_PER_ID_MASK (0xff)
+#define AT91_DMA_CFG_PER_ID(id) (id & AT91_DMA_CFG_PER_ID_MASK)
+
+/*
+ * FIFO configuration: it defines when a request is serviced.
+ */
+#define AT91_DMA_CFG_FIFOCFG_OFFSET (8)
+#define AT91_DMA_CFG_FIFOCFG_MASK (0xf << AT91_DMA_CFG_FIFOCFG_OFFSET)
+#define AT91_DMA_CFG_FIFOCFG_HALF (0x0 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* half FIFO (default behavior) */
+#define AT91_DMA_CFG_FIFOCFG_ALAP (0x1 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* largest defined AHB burst */
+#define AT91_DMA_CFG_FIFOCFG_ASAP (0x2 << AT91_DMA_CFG_FIFOCFG_OFFSET) /* single AHB access */
+
+#endif /* __DT_BINDINGS_AT91_DMA_H__ */