Modify uart rx and complete for DMA

Signed-off-by: Long Cheng <long.ch...@mediatek.com>
---
 drivers/tty/serial/8250/8250_mtk.c |   49 +++++++++++++++---------------------
 1 file changed, 20 insertions(+), 29 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_mtk.c 
b/drivers/tty/serial/8250/8250_mtk.c
index 417c7c8..f470ded 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -47,7 +47,6 @@
 #define MTK_UART_DMA_EN_RX     0x5
 
 #define MTK_UART_ESCAPE_CHAR   0x77    /* Escape char added under sw fc */
-#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
@@ -89,28 +88,30 @@ 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, total, cnt;
        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);
+       total = dma->rx_size - state.residue;
+       cnt = total;
 
-       if (data->rx_status == DMA_RX_SHUTDOWN)
-               return;
+       if ((data->rx_pos + cnt) > dma->rx_size)
+               cnt = 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, cnt);
+       data->rx_pos += cnt;
+
+       if (total > cnt) {
                ptr = (unsigned char *)(dma->rx_buf);
-               copied += tty_insert_flip_string(tty_port, ptr,
-                               data->rx_pos + state.residue - dma->rx_size);
+               cnt = total - cnt;
+               copied += tty_insert_flip_string(tty_port, ptr, cnt);
+               data->rx_pos = cnt;
        }
+
        up->port.icount.rx += copied;
 
        tty_flip_buffer_push(tty_port);
@@ -121,9 +122,7 @@ 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,
@@ -138,12 +137,6 @@ 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);
 }
 
@@ -156,13 +149,11 @@ 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.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.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);
-- 
1.7.9.5

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