ARM: PL011: add DMA burst threshold support for ST variants

ST Micro variants has some specific dma burst threshold compensation,
which allows them to make better use of a DMA controller.  Add support
to set this up.

Based on a patch from Linus Walleij.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 15 insertions, 0 deletions

diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h
index 577f22eb9225..5479fdc849e9 100644
--- a/include/linux/amba/serial.h
+++ b/include/linux/amba/serial.h
@@ -113,6 +113,21 @@
 #define UART01x_LCRH_PEN        0x02
 #define UART01x_LCRH_BRK        0x01
 
+#define ST_UART011_DMAWM_RX_1   (0 << 3)
+#define ST_UART011_DMAWM_RX_2   (1 << 3)
+#define ST_UART011_DMAWM_RX_4   (2 << 3)
+#define ST_UART011_DMAWM_RX_8   (3 << 3)
+#define ST_UART011_DMAWM_RX_16  (4 << 3)
+#define ST_UART011_DMAWM_RX_32  (5 << 3)
+#define ST_UART011_DMAWM_RX_48  (6 << 3)
+#define ST_UART011_DMAWM_TX_1   0
+#define ST_UART011_DMAWM_TX_2   1
+#define ST_UART011_DMAWM_TX_4   2
+#define ST_UART011_DMAWM_TX_8   3
+#define ST_UART011_DMAWM_TX_16  4
+#define ST_UART011_DMAWM_TX_32  5
+#define ST_UART011_DMAWM_TX_48  6
+
 #define UART010_IIR_RTIS        0x08
 #define UART010_IIR_TIS         0x04
 #define UART010_IIR_RIS         0x02