[PATCH 2/2] serial: 8250-mtk: modify uart DMA rx

Long Cheng
2019-05-23T07:36:21Z

Modify uart rx and complete for DMA

Signed-off-by: Long Cheng <long.cheng@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