[PATCH v4] Fix dcan driver probe failed on am437x platform

[dillon.minfei@gmail.com]

From: dillon min <dillon.minfei@gmail.com>

Got following d_can probe errors with kernel 5.8-rc1 on am437x

[   10.730822] CAN device driver interface
Starting Wait for Network to be Configured...
[  OK  ] Reached target Network.
[   10.787363] c_can_platform 481cc000.can: probe failed
[   10.792484] c_can_platform: probe of 481cc000.can failed with
error -2
[   10.799457] c_can_platform 481d0000.can: probe failed
[   10.804617] c_can_platform: probe of 481d0000.can failed with
error -2

actually, Tony has fixed this issue on am335x with the patch [3]

Since am437x has the same clock structure with am335x
[1][2], so reuse the code from Tony Lindgren's patch [3] to fix it.


[1]: https://www.ti.com/lit/pdf/spruh73 Chapter-23, Figure 23-1. DCAN
Integration
[2]: https://www.ti.com/lit/pdf/spruhl7 Chapter-25, Figure 25-1. DCAN
Integration
[3]: commit 516f1117d0fb ("ARM: dts: Configure osc clock for d_can on am335x")

Fixes: 1a5cd7c23cc5 ("bus: ti-sysc: Enable all clocks directly during init to read revision")
Signed-off-by: dillon min <dillon.minfei@gmail.com>
---

Hi Stephen,

This changes correct commit messages based on your reviewing.
make Fixes tags to oneline.
make all commit message tags at the end of commit message
make Fixes tags before Signed-off-by line.
add probe failed log to commit message.

 arch/arm/boot/dts/am437x-l4.dtsi | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/am437x-l4.dtsi b/arch/arm/boot/dts/am437x-l4.dtsi
index 0d0f9fe4a882..4129affde54e 100644
--- a/arch/arm/boot/dts/am437x-l4.dtsi
+++ b/arch/arm/boot/dts/am437x-l4.dtsi
@@ -1541,8 +1541,9 @@
 			reg = <0xcc020 0x4>;
 			reg-names = "rev";
 			/* Domains (P, C): per_pwrdm, l4ls_clkdm */
-			clocks = <&l4ls_clkctrl AM4_L4LS_D_CAN0_CLKCTRL 0>;
-			clock-names = "fck";
+			clocks = <&l4ls_clkctrl AM4_L4LS_D_CAN0_CLKCTRL 0>,
+			<&dcan0_fck>;
+			clock-names = "fck", "osc";
 			#address-cells = <1>;
 			#size-cells = <1>;
 			ranges = <0x0 0xcc000 0x2000>;
@@ -1550,6 +1551,8 @@
 			dcan0: can@0 {
 				compatible = "ti,am4372-d_can", "ti,am3352-d_can";
 				reg = <0x0 0x2000>;
+				clocks = <&dcan0_fck>;
+				clock-names = "fck";
 				syscon-raminit = <&scm_conf 0x644 0>;
 				interrupts = <GIC_SPI 52 IRQ_TYPE_LEVEL_HIGH>;
 				status = "disabled";
@@ -1561,8 +1564,9 @@
 			reg = <0xd0020 0x4>;
 			reg-names = "rev";
 			/* Domains (P, C): per_pwrdm, l4ls_clkdm */
-			clocks = <&l4ls_clkctrl AM4_L4LS_D_CAN1_CLKCTRL 0>;
-			clock-names = "fck";
+			clocks = <&l4ls_clkctrl AM4_L4LS_D_CAN1_CLKCTRL 0>,
+			<&dcan1_fck>;
+			clock-names = "fck", "osc";
 			#address-cells = <1>;
 			#size-cells = <1>;
 			ranges = <0x0 0xd0000 0x2000>;
@@ -1570,6 +1574,8 @@
 			dcan1: can@0 {
 				compatible = "ti,am4372-d_can", "ti,am3352-d_can";
 				reg = <0x0 0x2000>;
+				clocks = <&dcan1_fck>;
+				clock-name = "fck";
 				syscon-raminit = <&scm_conf 0x644 1>;
 				interrupts = <GIC_SPI 49 IRQ_TYPE_LEVEL_HIGH>;
 				status = "disabled";
-- 
2.7.4