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-rw-r--r--drivers/tty/serial/fsl_lpuart.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 3a2dd4d05a46..6abac7f92fa0 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1970,6 +1970,30 @@ static int lpuart_suspend(struct device *dev)
}
uart_suspend_port(&lpuart_reg, &sport->port);
+
+ if (sport->lpuart_dma_rx_use) {
+ /*
+ * EDMA driver during suspend will forcefully release any
+ * non-idle DMA channels. If port wakeup is enabled or if port
+ * is console port or 'no_console_suspend' is set the Rx DMA
+ * cannot resume as as expected, hence gracefully release the
+ * Rx DMA path before suspend and start Rx DMA path on resume.
+ */
+ if (sport->port.irq_wake) {
+ del_timer_sync(&sport->lpuart_timer);
+ lpuart_dma_rx_free(&sport->port);
+ }
+
+ /* Disable Rx DMA to use UART port as wakeup source */
+ writeb(readb(sport->port.membase + UARTCR5) & ~UARTCR5_RDMAS,
+ sport->port.membase + UARTCR5);
+ }
+
+ if (sport->lpuart_dma_tx_use) {
+ sport->dma_tx_in_progress = false;
+ dmaengine_terminate_all(sport->dma_tx_chan);
+ }
+
if (sport->port.suspended && !sport->port.irq_wake)
clk_disable_unprepare(sport->clk);
@@ -1997,6 +2021,31 @@ static int lpuart_resume(struct device *dev)
writeb(temp, sport->port.membase + UARTCR2);
}
+ if (sport->lpuart_dma_rx_use) {
+ if (sport->port.irq_wake) {
+ if (!lpuart_start_rx_dma(sport)) {
+ sport->lpuart_dma_rx_use = true;
+ setup_timer(&sport->lpuart_timer,
+ lpuart_timer_func,
+ (unsigned long)sport);
+ sport->lpuart_timer.expires = jiffies +
+ sport->dma_rx_timeout;
+ add_timer(&sport->lpuart_timer);
+ } else {
+ sport->lpuart_dma_rx_use = false;
+ }
+ }
+ }
+
+ if (sport->dma_tx_chan && !lpuart_dma_tx_request(&sport->port)) {
+ init_waitqueue_head(&sport->dma_wait);
+ sport->lpuart_dma_tx_use = true;
+ writeb(readb(sport->port.membase + UARTCR5) |
+ UARTCR5_TDMAS, sport->port.membase + UARTCR5);
+ } else {
+ sport->lpuart_dma_tx_use = false;
+ }
+
uart_resume_port(&lpuart_reg, &sport->port);
return 0;