[PATCH v3 3/6] serial: imx: Simplify DMA disablement

From: Martyn Welch
Date: Thu Sep 21 2017 - 12:18:30 EST


From: Nandor Han <nandor.han@xxxxxx>

This commits simplify the function imx_disable_dma() by moving
the code for disabling RX and TX DMAs to dedicated functions.
This is a preparation for the next commit.

Signed-off-by: Nandor Han <nandor.han@xxxxxx>
Signed-off-by: Romain Perier <romain.perier@xxxxxxxxxxxxx>
Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/imx.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 7835279..2fb3210 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -350,6 +350,24 @@ static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)
*ucr2 |= UCR2_CTSC;
}

+static void imx_stop_tx_dma(struct imx_port *sport)
+{
+ unsigned long temp;
+
+ temp = readl(sport->port.membase + UCR1);
+ temp &= ~UCR1_TDMAEN;
+ writel(temp, sport->port.membase + UCR1);
+}
+
+static void imx_stop_rx_dma(struct imx_port *sport)
+{
+ unsigned long temp;
+
+ temp = readl(sport->port.membase + UCR1);
+ temp &= ~(UCR1_RDMAEN | UCR1_ATDMAEN);
+ writel(temp, sport->port.membase + UCR1);
+}
+
/*
* interrupts disabled on entry
*/
@@ -1217,13 +1235,8 @@ static void imx_enable_dma(struct imx_port *sport)

static void imx_disable_dma(struct imx_port *sport)
{
- unsigned long temp;
-
- /* clear UCR1 */
- temp = readl(sport->port.membase + UCR1);
- temp &= ~(UCR1_RDMAEN | UCR1_TDMAEN | UCR1_ATDMAEN);
- writel(temp, sport->port.membase + UCR1);
-
+ imx_stop_rx_dma(sport);
+ imx_stop_tx_dma(sport);
imx_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);

sport->dma_is_enabled = 0;
--
1.8.3.1