[PATCH V2 2/5] arm64: dts: ti: k3-j721e*: Cleanup disabled nodes at SoC dtsi level
Nishanth Menon
nm at ti.com
Wed Nov 11 20:49:26 EST 2020
The device tree standard states that when the status property is
not present under a node, the okay value is assumed. There are many
reasons for doing the same, the number of strings in the device
tree, default power management functionality, etc. are a few of the
reasons.
In general, after a few rounds of discussions [1] there are few
options one could take when dealing with SoC dtsi and board dts
a. SoC dtsi provide nodes as a super-set default (aka enabled) state and
to prevent messy board files, when more boards are added per SoC, we
optimize and disable commonly un-used nodes in board-common.dtsi
b. SoC dtsi disables all hardware dependent nodes by default and board
dts files enable nodes based on a need basis.
c. Subjectively pick and choose which nodes we will disable by default
in SoC dtsi and over the years we can optimize things and change
default state depending on the need.
While there are pros and cons on each of these approaches, the right
thing to do will be to stick with device tree default standards and
work within those established rules. So, we choose to go with option
(a).
Lets cleanup defaults of j721e SoC dtsi before this gets more harder
to cleanup later on and new SoCs are added.
The only functional difference between the dtb generated is
status='okay' is no longer necessary for mcasp10 and depends on the
default state.
NOTE: There is a known risk of omission that new board dts developers
might miss reviewing both the board schematics in addition to all the
DT nodes of the SoC when setting appropriate nodes status to disable
or reserved in the board dts. This can expose issues in drivers that
may not anticipate an incomplete node (example: missing appropriate
board properties) being in an "okay" state. These cases are considered
bugs and need to be fixed in the drivers as and when identified.
[1] https://lore.kernel.org/linux-arm-kernel/20201027130701.GE5639@atomide.com/
Fixes: 1c4d35265fb2 ("arm64: dts: ti: k3-j721e-main: Add McASP nodes")
Fixes: 76921f15acc0 ("arm64: dts: ti: k3-j721e-main: Add DSS node")
Signed-off-by: Nishanth Menon <nm at ti.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
Cc: Jyri Sarha <jsarha at ti.com>
Cc: Tomi Valkeinen <tomi.valkeinen at ti.com>
Cc: Peter Ujfalusi <peter.ujfalusi at ti.com>
Cc: Tony Lindgren <tony at atomide.com>
---
Changes since v1:
- commit message update
V1: https://lore.kernel.org/linux-arm-kernel/20201104224356.18040-3-nm@ti.com/
.../dts/ti/k3-j721e-common-proc-board.dts | 48 ++++++++++++++++++-
arch/arm64/boot/dts/ti/k3-j721e-main.dtsi | 26 ----------
2 files changed, 47 insertions(+), 27 deletions(-)
diff --git a/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts b/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
index 52e121155563..9416528caa8a 100644
--- a/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
+++ b/arch/arm64/boot/dts/ti/k3-j721e-common-proc-board.dts
@@ -540,6 +540,46 @@ &dss {
<&k3_clks 152 18>; /* PLL23_HSDIV0 */
};
+&mcasp0 {
+ status = "disabled";
+};
+
+&mcasp1 {
+ status = "disabled";
+};
+
+&mcasp2 {
+ status = "disabled";
+};
+
+&mcasp3 {
+ status = "disabled";
+};
+
+&mcasp4 {
+ status = "disabled";
+};
+
+&mcasp5 {
+ status = "disabled";
+};
+
+&mcasp6 {
+ status = "disabled";
+};
+
+&mcasp7 {
+ status = "disabled";
+};
+
+&mcasp8 {
+ status = "disabled";
+};
+
+&mcasp9 {
+ status = "disabled";
+};
+
&mcasp10 {
#sound-dai-cells = <0>;
@@ -556,8 +596,10 @@ &mcasp10 {
>;
tx-num-evt = <0>;
rx-num-evt = <0>;
+};
- status = "okay";
+&mcasp11 {
+ status = "disabled";
};
&serdes0 {
@@ -639,3 +681,7 @@ &pcie3_rc {
&pcie3_ep {
status = "disabled";
};
+
+&dss {
+ status = "disabled";
+};
diff --git a/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi b/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
index e2a96b2c423c..b54332d6fdc5 100644
--- a/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-j721e-main.dtsi
@@ -1327,8 +1327,6 @@ dss: dss at 04a00000 {
"common_s1",
"common_s2";
- status = "disabled";
-
dss_ports: ports {
#address-cells = <1>;
#size-cells = <0>;
@@ -1350,8 +1348,6 @@ mcasp0: mcasp at 2b00000 {
clocks = <&k3_clks 174 1>;
clock-names = "fck";
power-domains = <&k3_pds 174 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp1: mcasp at 2b10000 {
@@ -1369,8 +1365,6 @@ mcasp1: mcasp at 2b10000 {
clocks = <&k3_clks 175 1>;
clock-names = "fck";
power-domains = <&k3_pds 175 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp2: mcasp at 2b20000 {
@@ -1388,8 +1382,6 @@ mcasp2: mcasp at 2b20000 {
clocks = <&k3_clks 176 1>;
clock-names = "fck";
power-domains = <&k3_pds 176 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp3: mcasp at 2b30000 {
@@ -1407,8 +1399,6 @@ mcasp3: mcasp at 2b30000 {
clocks = <&k3_clks 177 1>;
clock-names = "fck";
power-domains = <&k3_pds 177 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp4: mcasp at 2b40000 {
@@ -1426,8 +1416,6 @@ mcasp4: mcasp at 2b40000 {
clocks = <&k3_clks 178 1>;
clock-names = "fck";
power-domains = <&k3_pds 178 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp5: mcasp at 2b50000 {
@@ -1445,8 +1433,6 @@ mcasp5: mcasp at 2b50000 {
clocks = <&k3_clks 179 1>;
clock-names = "fck";
power-domains = <&k3_pds 179 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp6: mcasp at 2b60000 {
@@ -1464,8 +1450,6 @@ mcasp6: mcasp at 2b60000 {
clocks = <&k3_clks 180 1>;
clock-names = "fck";
power-domains = <&k3_pds 180 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp7: mcasp at 2b70000 {
@@ -1483,8 +1467,6 @@ mcasp7: mcasp at 2b70000 {
clocks = <&k3_clks 181 1>;
clock-names = "fck";
power-domains = <&k3_pds 181 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp8: mcasp at 2b80000 {
@@ -1502,8 +1484,6 @@ mcasp8: mcasp at 2b80000 {
clocks = <&k3_clks 182 1>;
clock-names = "fck";
power-domains = <&k3_pds 182 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp9: mcasp at 2b90000 {
@@ -1521,8 +1501,6 @@ mcasp9: mcasp at 2b90000 {
clocks = <&k3_clks 183 1>;
clock-names = "fck";
power-domains = <&k3_pds 183 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp10: mcasp at 2ba0000 {
@@ -1540,8 +1518,6 @@ mcasp10: mcasp at 2ba0000 {
clocks = <&k3_clks 184 1>;
clock-names = "fck";
power-domains = <&k3_pds 184 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
mcasp11: mcasp at 2bb0000 {
@@ -1559,8 +1535,6 @@ mcasp11: mcasp at 2bb0000 {
clocks = <&k3_clks 185 1>;
clock-names = "fck";
power-domains = <&k3_pds 185 TI_SCI_PD_EXCLUSIVE>;
-
- status = "disabled";
};
watchdog0: watchdog at 2200000 {
--
2.29.2
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