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Subject[PATCH v11 4/4] serial: 8250-mtk: modify uart DMA rx
Date
Modify uart rx and complete for DMA.

Signed-off-by: Long Cheng <long.cheng@mediatek.com>
---
drivers/tty/serial/8250/8250_mtk.c | 53 ++++++++++++++++--------------------
1 file changed, 23 insertions(+), 30 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index e2c4076..f9b2fd5 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -30,7 +30,6 @@
#define MTK_UART_DMA_EN_TX 0x2
#define MTK_UART_DMA_EN_RX 0x5

-#define MTK_UART_TX_SIZE UART_XMIT_SIZE
#define MTK_UART_RX_SIZE 0x8000
#define MTK_UART_TX_TRIGGER 1
#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE
@@ -64,28 +63,30 @@ static void mtk8250_dma_rx_complete(void *param)
struct mtk8250_data *data = up->port.private_data;
struct tty_port *tty_port = &up->port.state->port;
struct dma_tx_state state;
+ int copied, cnt, tmp;
unsigned char *ptr;
- int copied;

- dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
- dma->rx_size, DMA_FROM_DEVICE);
+ if (data->rx_status == DMA_RX_SHUTDOWN)
+ return;

dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+ cnt = dma->rx_size - state.residue;
+ tmp = cnt;

- if (data->rx_status == DMA_RX_SHUTDOWN)
- return;
+ if ((data->rx_pos + cnt) > dma->rx_size)
+ tmp = dma->rx_size - data->rx_pos;

- if ((data->rx_pos + state.residue) <= dma->rx_size) {
- ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
- copied = tty_insert_flip_string(tty_port, ptr, state.residue);
- } else {
- ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
- copied = tty_insert_flip_string(tty_port, ptr,
- dma->rx_size - data->rx_pos);
+ ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+ copied = tty_insert_flip_string(tty_port, ptr, tmp);
+ data->rx_pos += tmp;
+
+ if (cnt > tmp) {
ptr = (unsigned char *)(dma->rx_buf);
- copied += tty_insert_flip_string(tty_port, ptr,
- data->rx_pos + state.residue - dma->rx_size);
+ tmp = cnt - tmp;
+ copied += tty_insert_flip_string(tty_port, ptr, tmp);
+ data->rx_pos = tmp;
}
+
up->port.icount.rx += copied;

tty_flip_buffer_push(tty_port);
@@ -96,9 +97,7 @@ static void mtk8250_dma_rx_complete(void *param)
static void mtk8250_rx_dma(struct uart_8250_port *up)
{
struct uart_8250_dma *dma = up->dma;
- struct mtk8250_data *data = up->port.private_data;
struct dma_async_tx_descriptor *desc;
- struct dma_tx_state state;

desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
dma->rx_size, DMA_DEV_TO_MEM,
@@ -113,12 +112,6 @@ static void mtk8250_rx_dma(struct uart_8250_port *up)

dma->rx_cookie = dmaengine_submit(desc);

- dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
- data->rx_pos = state.residue;
-
- dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
- dma->rx_size, DMA_FROM_DEVICE);
-
dma_async_issue_pending(dma->rxchan);
}

@@ -131,13 +124,13 @@ static void mtk8250_dma_enable(struct uart_8250_port *up)
if (data->rx_status != DMA_RX_START)
return;

- dma->rxconf.direction = DMA_DEV_TO_MEM;
- dma->rxconf.src_addr_width = dma->rx_size / 1024;
- dma->rxconf.src_addr = dma->rx_addr;
+ dma->rxconf.direction = DMA_DEV_TO_MEM;
+ dma->rxconf.src_port_window_size = dma->rx_size;
+ dma->rxconf.src_addr = dma->rx_addr;

- dma->txconf.direction = DMA_MEM_TO_DEV;
- dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024;
- dma->txconf.dst_addr = dma->tx_addr;
+ dma->txconf.direction = DMA_MEM_TO_DEV;
+ dma->txconf.dst_port_window_size = UART_XMIT_SIZE;
+ dma->txconf.dst_addr = dma->tx_addr;

serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT);
@@ -217,7 +210,7 @@ static void mtk8250_shutdown(struct uart_port *port)
* Mediatek UARTs use an extra highspeed register (UART_MTK_HIGHS)
*
* We need to recalcualte the quot register, as the claculation depends
- * on the vaule in the highspeed register.
+ * on the value in the highspeed register.
*
* Some baudrates are not supported by the chip, so we use the next
* lower rate supported and update termios c_flag.
--
1.7.9.5
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