commit 8c306bec2d09c8436eea989b1be2a381cae93418
author Dong Aisheng <aisheng.dong@nxp.com> Thu Dec 13 07:08:00 2018 +0000
committer Marc Kleine-Budde <mkl@pengutronix.de> Wed Jul 24 10:31:55 2019 +0200
tree ba985d49c5bd51db29eb86923934eac84904701e
parent 9d733992772dc04ce5e8839f867b4ff83ee75c34

can: flexcan: add support for PE clock source select

Add support to select the clock source for CAN Protocol Engine (PE).
It's SoC Implementation dependent. Refer to RM for detailed definition
of each SoC. We select clock source 1 (peripheral clock) by default in
driver now, this patch adds support to parse the clock source from the DT.

Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/flexcan.c

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 228ac5d..bcc3951 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -275,6 +275,8 @@ struct flexcan_priv {
 	u8 tx_mb_idx;
 	u8 mb_count;
 	u8 mb_size;
+	u8 clk_src;	/* clock source of CAN Protocol Engine */
+
 	u32 reg_ctrl_default;
 	u32 reg_imask1_default;
 	u32 reg_imask2_default;
@@ -1369,7 +1371,10 @@ static int register_flexcandev(struct net_device *dev)
 		goto out_clks_disable;
 
 	reg = priv->read(&regs->ctrl);
-	reg |= FLEXCAN_CTRL_CLK_SRC;
+	if (priv->clk_src)
+		reg |= FLEXCAN_CTRL_CLK_SRC;
+	else
+		reg &= ~FLEXCAN_CTRL_CLK_SRC;
 	priv->write(reg, &regs->ctrl);
 
 	err = flexcan_chip_enable(priv);
@@ -1501,6 +1506,7 @@ static int flexcan_probe(struct platform_device *pdev)
 	struct clk *clk_ipg = NULL, *clk_per = NULL;
 	struct flexcan_regs __iomem *regs;
 	int err, irq;
+	u8 clk_src = 1;
 	u32 clock_freq = 0;
 
 	reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
@@ -1509,9 +1515,12 @@ static int flexcan_probe(struct platform_device *pdev)
 	else if (IS_ERR(reg_xceiver))
 		reg_xceiver = NULL;
 
-	if (pdev->dev.of_node)
+	if (pdev->dev.of_node) {
 		of_property_read_u32(pdev->dev.of_node,
 				     "clock-frequency", &clock_freq);
+		of_property_read_u8(pdev->dev.of_node,
+				    "fsl,clk-source", &clk_src);
+	}
 
 	if (!clock_freq) {
 		clk_ipg = devm_clk_get(&pdev->dev, "ipg");
@@ -1580,6 +1589,7 @@ static int flexcan_probe(struct platform_device *pdev)
 	priv->regs = regs;
 	priv->clk_ipg = clk_ipg;
 	priv->clk_per = clk_per;
+	priv->clk_src = clk_src;
 	priv->devtype_data = devtype_data;
 	priv->reg_xceiver = reg_xceiver;