diff options
Diffstat (limited to 'drivers/tty/serial/fsl_lpuart.c')
| -rw-r--r-- | drivers/tty/serial/fsl_lpuart.c | 88 |
1 files changed, 57 insertions, 31 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index c31b8f3db6bf..33798df4d727 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1493,36 +1493,67 @@ static void rx_dma_timer_init(struct lpuart_port *sport) static void lpuart_tx_dma_startup(struct lpuart_port *sport) { u32 uartbaud; + int ret; - if (sport->dma_tx_chan && !lpuart_dma_tx_request(&sport->port)) { - init_waitqueue_head(&sport->dma_wait); - sport->lpuart_dma_tx_use = true; - if (lpuart_is_32(sport)) { - uartbaud = lpuart32_read(&sport->port, UARTBAUD); - lpuart32_write(&sport->port, - uartbaud | UARTBAUD_TDMAE, UARTBAUD); - } else { - writeb(readb(sport->port.membase + UARTCR5) | - UARTCR5_TDMAS, sport->port.membase + UARTCR5); - } + sport->dma_tx_chan = dma_request_chan(sport->port.dev, "tx"); + if (IS_ERR(sport->dma_tx_chan)) { + dev_info_once(sport->port.dev, + "DMA tx channel request failed, operating without tx DMA (%ld)\n", + PTR_ERR(sport->dma_tx_chan)); + sport->dma_tx_chan = NULL; + goto err; + } + + ret = lpuart_dma_tx_request(&sport->port); + if (!ret) + goto err; + + init_waitqueue_head(&sport->dma_wait); + sport->lpuart_dma_tx_use = true; + if (lpuart_is_32(sport)) { + uartbaud = lpuart32_read(&sport->port, UARTBAUD); + lpuart32_write(&sport->port, + uartbaud | UARTBAUD_TDMAE, UARTBAUD); } else { - sport->lpuart_dma_tx_use = false; + writeb(readb(sport->port.membase + UARTCR5) | + UARTCR5_TDMAS, sport->port.membase + UARTCR5); } + + return; + +err: + sport->lpuart_dma_tx_use = false; } static void lpuart_rx_dma_startup(struct lpuart_port *sport) { - if (sport->dma_rx_chan && !lpuart_start_rx_dma(sport)) { - /* set Rx DMA timeout */ - sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT); - if (!sport->dma_rx_timeout) - sport->dma_rx_timeout = 1; + int ret; - sport->lpuart_dma_rx_use = true; - rx_dma_timer_init(sport); - } else { - sport->lpuart_dma_rx_use = false; + sport->dma_rx_chan = dma_request_chan(sport->port.dev, "rx"); + if (IS_ERR(sport->dma_rx_chan)) { + dev_info_once(sport->port.dev, + "DMA rx channel request failed, operating without rx DMA (%ld)\n", + PTR_ERR(sport->dma_rx_chan)); + sport->dma_rx_chan = NULL; + goto err; } + + ret = lpuart_start_rx_dma(sport); + if (ret) + goto err; + + /* set Rx DMA timeout */ + sport->dma_rx_timeout = msecs_to_jiffies(DMA_RX_TIMEOUT); + if (!sport->dma_rx_timeout) + sport->dma_rx_timeout = 1; + + sport->lpuart_dma_rx_use = true; + rx_dma_timer_init(sport); + + return; + +err: + sport->lpuart_dma_rx_use = false; } static int lpuart_startup(struct uart_port *port) @@ -1615,6 +1646,11 @@ static void lpuart_dma_shutdown(struct lpuart_port *sport) dmaengine_terminate_all(sport->dma_tx_chan); } } + + if (sport->dma_tx_chan) + dma_release_channel(sport->dma_tx_chan); + if (sport->dma_rx_chan) + dma_release_channel(sport->dma_rx_chan); } static void lpuart_shutdown(struct uart_port *port) @@ -2520,16 +2556,6 @@ static int lpuart_probe(struct platform_device *pdev) sport->port.rs485_config(&sport->port, &sport->port.rs485); - sport->dma_tx_chan = dma_request_slave_channel(sport->port.dev, "tx"); - if (!sport->dma_tx_chan) - dev_info(sport->port.dev, "DMA tx channel request failed, " - "operating without tx DMA\n"); - - sport->dma_rx_chan = dma_request_slave_channel(sport->port.dev, "rx"); - if (!sport->dma_rx_chan) - dev_info(sport->port.dev, "DMA rx channel request failed, " - "operating without rx DMA\n"); - return 0; failed_attach_port: |