MLK-16757-1 can: flexcan: disable clocks during suspend

Flexcan will be stopped during suspend if no wakeup function required
and enabled after resume accordingly. During this period, we could
explicitly disable clocks.

We do this by moving the clk_prepare_enable/clk_disable_unprepare into
flexcan_chip_start and flexcan_chip_stop functions which will be called
during suspend/resume function.

Reviewed-by: Frank Li <frank.li@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>

1 files changed, 44 insertions, 31 deletions

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 4f86c2547952..b70d77b5ed5e 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -454,6 +454,27 @@ static inline void flexcan_mb_write(const struct flexcan_priv *priv,
 }
 #endif
 
+static int flexcan_clks_enable(const struct flexcan_priv *priv)
+{
+	int err;
+
+	err = clk_prepare_enable(priv->clk_ipg);
+	if (err)
+		return err;
+
+	err = clk_prepare_enable(priv->clk_per);
+	if (err)
+		clk_disable_unprepare(priv->clk_ipg);
+
+	return err;
+}
+
+static void flexcan_clks_disable(const struct flexcan_priv *priv)
+{
+	clk_disable_unprepare(priv->clk_ipg);
+	clk_disable_unprepare(priv->clk_per);
+}
+
 static inline void flexcan_enter_stop_mode(struct flexcan_priv *priv)
 {
 	/* enable stop request */
@@ -612,19 +633,13 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
 	const struct flexcan_priv *priv = netdev_priv(dev);
 	int err;
 
-	err = clk_prepare_enable(priv->clk_ipg);
+	err = flexcan_clks_enable(priv);
 	if (err)
 		return err;
 
-	err = clk_prepare_enable(priv->clk_per);
-	if (err)
-		goto out_disable_ipg;
-
 	err = __flexcan_get_berr_counter(dev, bec);
 
-	clk_disable_unprepare(priv->clk_per);
- out_disable_ipg:
-	clk_disable_unprepare(priv->clk_ipg);
+	flexcan_clks_disable(priv);
 
 	return err;
 }
@@ -1030,10 +1045,14 @@ static int flexcan_chip_start(struct net_device *dev)
 	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr, reg_fdctrl;
 	int err, i;
 
+	err = flexcan_clks_enable(priv);
+	if (err)
+		return err;
+
 	/* enable module */
 	err = flexcan_chip_enable(priv);
 	if (err)
-		return err;
+		goto out_clocks_disable;
 
 	/* soft reset */
 	err = flexcan_chip_softreset(priv);
@@ -1211,6 +1230,9 @@ static int flexcan_chip_start(struct net_device *dev)
 	flexcan_transceiver_disable(priv);
  out_chip_disable:
 	flexcan_chip_disable(priv);
+ out_clocks_disable:
+	flexcan_clks_disable(priv);
+
 	return err;
 }
 
@@ -1231,6 +1253,8 @@ static void flexcan_chip_stop(struct net_device *dev)
 	flexcan_write(priv, FLEXCAN_CTRL, priv->reg_ctrl_default &
 		      ~FLEXCAN_CTRL_ERR_ALL);
 
+	flexcan_clks_disable(priv);
+
 	flexcan_transceiver_disable(priv);
 	priv->can.state = CAN_STATE_STOPPED;
 }
@@ -1240,17 +1264,13 @@ static int flexcan_open(struct net_device *dev)
 	struct flexcan_priv *priv = netdev_priv(dev);
 	int err;
 
-	err = clk_prepare_enable(priv->clk_ipg);
+	err = flexcan_clks_enable(priv);
 	if (err)
 		return err;
 
-	err = clk_prepare_enable(priv->clk_per);
-	if (err)
-		goto out_disable_ipg;
-
 	err = open_candev(dev);
 	if (err)
-		goto out_disable_per;
+		goto out_clocks_disable;
 
 	err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
 	if (err)
@@ -1272,10 +1292,9 @@ static int flexcan_open(struct net_device *dev)
 	free_irq(dev->irq, dev);
  out_close:
 	close_candev(dev);
- out_disable_per:
-	clk_disable_unprepare(priv->clk_per);
- out_disable_ipg:
-	clk_disable_unprepare(priv->clk_ipg);
+
+ out_clocks_disable:
+	flexcan_clks_disable(priv);
 
 	return err;
 }
@@ -1289,13 +1308,13 @@ static int flexcan_close(struct net_device *dev)
 	flexcan_chip_stop(dev);
 
 	free_irq(dev->irq, dev);
-	clk_disable_unprepare(priv->clk_per);
-	clk_disable_unprepare(priv->clk_ipg);
 
 	close_candev(dev);
 
 	can_led_event(dev, CAN_LED_EVENT_STOP);
 
+	flexcan_clks_disable(priv);
+
 	return 0;
 }
 
@@ -1331,18 +1350,14 @@ static int register_flexcandev(struct net_device *dev)
 	struct flexcan_priv *priv = netdev_priv(dev);
 	u32 reg, err;
 
-	err = clk_prepare_enable(priv->clk_ipg);
+	err = flexcan_clks_enable(priv);
 	if (err)
 		return err;
 
-	err = clk_prepare_enable(priv->clk_per);
-	if (err)
-		goto out_disable_ipg;
-
 	/* select "bus clock", chip must be disabled */
 	err = flexcan_chip_disable(priv);
 	if (err)
-		goto out_disable_per;
+		goto out_clocks_disable;
 	reg = flexcan_read(priv, FLEXCAN_CTRL);
 	reg |= FLEXCAN_CTRL_CLK_SRC;
 	flexcan_write(priv, FLEXCAN_CTRL, reg);
@@ -1379,10 +1394,8 @@ static int register_flexcandev(struct net_device *dev)
 	/* disable core and turn off clocks */
  out_chip_disable:
 	flexcan_chip_disable(priv);
- out_disable_per:
-	clk_disable_unprepare(priv->clk_per);
- out_disable_ipg:
-	clk_disable_unprepare(priv->clk_ipg);
+ out_clocks_disable:
+	flexcan_clks_disable(priv);
 
 	return err;
 }