[U-Boot] [PATCH 3/4] board: ti: am43xx-idk: Configure the CDCE913 clock synthesizer

Tero Kristo t-kristo at ti.com
Fri Sep 27 16:14:28 UTC 2019


AM43xx-IDK boards contain the CDCE913 clock synthesizer, and their
reset crystal capacitance load value of 10pF is wrong leading into
lost packets in certain networking tests. Add DT data for this
device, and probe it from the board file to program the crystal
capacitance load value to 0pF to avoid any problems.

Signed-off-by: Tero Kristo <t-kristo at ti.com>
---
 arch/arm/dts/am437x-idk-evm-u-boot.dtsi | 14 ++++++++++++++
 board/ti/am43xx/board.c                 |  5 +++++
 configs/am43xx_evm_defconfig            |  2 ++
 3 files changed, 21 insertions(+)

diff --git a/arch/arm/dts/am437x-idk-evm-u-boot.dtsi b/arch/arm/dts/am437x-idk-evm-u-boot.dtsi
index 3aa9195e44..50fe09cfc3 100644
--- a/arch/arm/dts/am437x-idk-evm-u-boot.dtsi
+++ b/arch/arm/dts/am437x-idk-evm-u-boot.dtsi
@@ -9,6 +9,12 @@
 	ocp {
 		u-boot,dm-spl;
 	};
+
+	xtal25mhz: xtal25mhz {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <25000000>;
+	};
 };
 
 &uart0 {
@@ -17,6 +23,14 @@
 
 &i2c0 {
 	u-boot,dm-spl;
+
+	cdce913: cdce913 at 65 {
+		compatible = "ti,cdce913";
+		reg = <0x65>;
+		clocks = <&xtal25mhz>;
+		#clock-cells = <1>;
+		xtal-load-pf = <0>;
+	};
 };
 
 &mmc1 {
diff --git a/board/ti/am43xx/board.c b/board/ti/am43xx/board.c
index 2e09cc20e8..f5ecf871bc 100644
--- a/board/ti/am43xx/board.c
+++ b/board/ti/am43xx/board.c
@@ -720,6 +720,7 @@ static int device_okay(const char *path)
 
 int board_late_init(void)
 {
+	struct udevice *dev;
 #ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 	set_board_info_env(NULL);
 
@@ -737,6 +738,10 @@ int board_late_init(void)
 	if (device_okay("/ocp/omap_dwc3 at 483c0000"))
 		enable_usb_clocks(1);
 #endif
+
+	/* Just probe the potentially supported cdce913 device */
+	uclass_get_device(UCLASS_CLK, 0, &dev);
+
 	return 0;
 }
 #endif
diff --git a/configs/am43xx_evm_defconfig b/configs/am43xx_evm_defconfig
index 7c74047f3a..7367c6952b 100644
--- a/configs/am43xx_evm_defconfig
+++ b/configs/am43xx_evm_defconfig
@@ -78,3 +78,5 @@ CONFIG_USB_GADGET_VENDOR_NUM=0x0403
 CONFIG_USB_GADGET_PRODUCT_NUM=0xbd00
 CONFIG_USB_GADGET_DOWNLOAD=y
 CONFIG_USB_ETHER=y
+CONFIG_CLK=y
+CONFIG_CLK_CDCE9XX=y
-- 
2.17.1

--
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