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| author | Anton Staaf <robotboy@chromium.org> | 2015-07-21 12:04:42 -0700 |
|---|---|---|
| committer | ChromeOS Commit Bot <chromeos-commit-bot@chromium.org> | 2015-08-24 19:08:35 +0000 |
| commit | 69bd4ce351ca56a3141281bf25431a07ea10512f (patch) | |
| tree | 4486849beac1b26caf5d6ff8ac691a568869651f /board/discovery | |
| parent | 16f63703c9ccc46ec48abcc586a595456e99fc9a (diff) | |
| download | chrome-ec-69bd4ce351ca56a3141281bf25431a07ea10512f.tar.gz | |
USART: Add DMA based receiver
This DMA receiver uses a separate small circular buffer to DMA into.
This allows the DMA transaction to be made circular, and thus it does
not require the interrupt latency to be low enough to setup the next
transfer before the next character comes in.
Additional diagnostics output have been added to the usart_info console
command to facilitate tuning of the FIFO size.
Signed-off-by: Anton Staaf <robotboy@chromium.org>
BRANCH=None
BUG=None
TEST=make buildall -j
Verify DMA works by cross connecting two discovery boards
Change-Id: Idcdf95a47fadf21ec2154f0c9128cd3586e568ec
Reviewed-on: https://chromium-review.googlesource.com/292870
Tested-by: Anton Staaf <robotboy@chromium.org>
Reviewed-by: Anton Staaf <robotboy@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>
Trybot-Ready: Anton Staaf <robotboy@chromium.org>
Diffstat (limited to 'board/discovery')
| -rw-r--r-- | board/discovery/board.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/board/discovery/board.c b/board/discovery/board.c index eb58434aa7..81fe437850 100644 --- a/board/discovery/board.c +++ b/board/discovery/board.c @@ -11,6 +11,7 @@ #include "registers.h" #include "task.h" #include "usart-stm32f0.h" +#include "usart_rx_dma.h" #include "usart_tx_dma.h" #include "util.h" @@ -43,12 +44,15 @@ static struct queue const loopback_queue = loopback_usart.producer, loopback_usart.consumer); +static struct usart_rx_dma const loopback_rx_dma = + USART_RX_DMA(STM32_DMAC_CH6, 32); + static struct usart_tx_dma const loopback_tx_dma = USART_TX_DMA(STM32_DMAC_CH7, 16); static struct usart_config const loopback_usart = USART_CONFIG(usart2_hw, - usart_rx_interrupt, + loopback_rx_dma.usart_rx, loopback_tx_dma.usart_tx, 115200, loopback_queue, |