diff options
| -rw-r--r-- | drivers/tty/serial/stm32-usart.c | 69 |
1 files changed, 41 insertions, 28 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 7fd192e1e15d..ee3495c0abbb 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -761,6 +761,10 @@ static void stm32_usart_stop_rx(struct uart_port *port) struct stm32_port *stm32_port = to_stm32_port(port); const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; + /* Disable DMA request line. */ + if (stm32_port->rx_ch) + stm32_usart_clr_bits(port, ofs->cr3, USART_CR3_DMAR); + stm32_usart_clr_bits(port, ofs->cr1, stm32_port->cr1_irq); if (stm32_port->cr3_irq) stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq); @@ -777,6 +781,7 @@ static int stm32_usart_startup(struct uart_port *port) const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; const struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; + struct dma_async_tx_descriptor *desc; u32 val; int ret; @@ -797,6 +802,33 @@ static int stm32_usart_startup(struct uart_port *port) if (ofs->rqr != UNDEF_REG) writel_relaxed(USART_RQR_RXFRQ, port->membase + ofs->rqr); + if (stm32_port->rx_ch) { + stm32_port->last_res = RX_BUF_L; + /* Prepare a DMA cyclic transaction */ + desc = dmaengine_prep_dma_cyclic(stm32_port->rx_ch, + stm32_port->rx_dma_buf, + RX_BUF_L, RX_BUF_P, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!desc) { + dev_err(port->dev, "rx dma prep cyclic failed\n"); + ret = -ENODEV; + goto err; + } + + desc->callback = stm32_usart_rx_dma_complete; + desc->callback_param = port; + + /* Push current DMA transaction in the pending queue */ + ret = dma_submit_error(dmaengine_submit(desc)); + if (ret) { + dmaengine_terminate_sync(stm32_port->rx_ch); + goto err; + } + + /* Issue pending DMA requests */ + dma_async_issue_pending(stm32_port->rx_ch); + } /* * DMA request line not re-enabled at resume when port is throttled. * It will be re-enabled by unthrottle ops. @@ -809,6 +841,11 @@ static int stm32_usart_startup(struct uart_port *port) stm32_usart_set_bits(port, ofs->cr1, val); return 0; + +err: + free_irq(port->irq, port); + + return ret; } static void stm32_usart_shutdown(struct uart_port *port) @@ -836,6 +873,10 @@ static void stm32_usart_shutdown(struct uart_port *port) if (ret) dev_err(port->dev, "Transmission is not complete\n"); + /* Disable RX DMA. */ + if (stm32_port->rx_ch) + dmaengine_terminate_async(stm32_port->rx_ch); + /* flush RX & TX FIFO */ if (ofs->rqr != UNDEF_REG) writel_relaxed(USART_RQR_TXFRQ | USART_RQR_RXFRQ, @@ -1304,7 +1345,6 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port, struct uart_port *port = &stm32port->port; struct device *dev = &pdev->dev; struct dma_slave_config config; - struct dma_async_tx_descriptor *desc = NULL; int ret; /* @@ -1332,32 +1372,6 @@ static int stm32_usart_of_dma_rx_probe(struct stm32_port *stm32port, return ret; } - /* Prepare a DMA cyclic transaction */ - desc = dmaengine_prep_dma_cyclic(stm32port->rx_ch, - stm32port->rx_dma_buf, - RX_BUF_L, RX_BUF_P, DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT); - if (!desc) { - dev_err(dev, "rx dma prep cyclic failed\n"); - stm32_usart_of_dma_rx_remove(stm32port, pdev); - return -ENODEV; - } - - /* Set DMA callback */ - desc->callback = stm32_usart_rx_dma_complete; - desc->callback_param = port; - - /* Push current DMA transaction in the pending queue */ - ret = dma_submit_error(dmaengine_submit(desc)); - if (ret) { - dmaengine_terminate_sync(stm32port->rx_ch); - stm32_usart_of_dma_rx_remove(stm32port, pdev); - return ret; - } - - /* Issue pending DMA requests */ - dma_async_issue_pending(stm32port->rx_ch); - return 0; } @@ -1535,7 +1549,6 @@ static int stm32_usart_serial_remove(struct platform_device *pdev) } if (stm32_port->rx_ch) { - dmaengine_terminate_async(stm32_port->rx_ch); stm32_usart_of_dma_rx_remove(stm32_port, pdev); dma_release_channel(stm32_port->rx_ch); } |