serial: mediatek: add support for bus clock and enable it

Upstream linux also provide the additional optional bus clock.

Add support for it and also enable the baud and bus clock on probe.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/serial/serial_mtk.c b/drivers/serial/serial_mtk.c
index 3f569c6..78e8d9d 100644
--- a/drivers/serial/serial_mtk.c
+++ b/drivers/serial/serial_mtk.c
@@ -76,6 +76,7 @@ struct mtk_serial_regs {
  *				driver
  * @regs:			Register base of the serial port
  * @clk:			The baud clock device
+ * @clk_bus:			The bus clock device
  * @fixed_clk_rate:		Fallback fixed baud clock rate if baud clock
  *				device is not specified
  * @force_highspeed:		Force using high-speed mode
@@ -83,6 +84,7 @@ struct mtk_serial_regs {
 struct mtk_serial_priv {
 	struct mtk_serial_regs __iomem *regs;
 	struct clk clk;
+	struct clk clk_bus;
 	u32 fixed_clk_rate;
 	bool force_highspeed;
 };
@@ -220,6 +222,10 @@ static int mtk_serial_probe(struct udevice *dev)
 	writel(UART_MCRVAL, &priv->regs->mcr);
 	writel(UART_FCRVAL, &priv->regs->fcr);
 
+	clk_enable(&priv->clk);
+	if (priv->clk_bus.dev)
+		clk_enable(&priv->clk_bus);
+
 	return 0;
 }
 
@@ -250,6 +256,8 @@ static int mtk_serial_of_to_plat(struct udevice *dev)
 		}
 	}
 
+	clk_get_by_name(dev, "bus", &priv->clk_bus);
+
 	priv->force_highspeed = dev_read_bool(dev, "mediatek,force-highspeed");
 
 	return 0;