On 4/17/25 1:35 AM, Adam Ford wrote:
[...]
if (!parent)
@@ -113,6 +114,9 @@ int clk_mux_fetch_parent_index(struct clk *clk,
struct clk *parent)
for (i = 0; i < mux->num_parents; i++) {
if (!strcmp(parent->dev->name, mux->parent_names[i]))
return i;
+ dev_read_string_index(parent->dev,
"clock-output-names", i, &name);
You are not supposed to use "clock-output-names" for clock look up.
You are supposed to use "clocks"/"clock-names" DT properties and then
resolve the remote clock from information in those.
+ if (!strcmp(name, mux->parent_names[i]))
+ return i;
if (!strcmp(parent->dev->name,
clk_resolve_parent_clk(clk->dev,
mux->parent_names[i])))
clk_resolve_parent_clk() is meant to look up the clocks in local DT node
"clock-names" property by name, and based on that, figure out which
phandle to use in local DT node "clocks" property to access those clock:
For example, in dts/upstream/src/arm64/freescale/imx8mp.dtsi
745 clk: clock-controller@30380000 {
746 compatible = "fsl,imx8mp-ccm";
747 reg = <0x30380000 0x10000>;
748 interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_HIGH>,
749 <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>;
750 #clock-cells = <1>;
751 clocks = <&osc_32k>, <&osc_24m>, <&clk_ext1>, <&clk_ext2>,
^^^^^^^^
752 <&clk_ext3>, <&clk_ext4>;
753 clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2",
^^^^^^^
This "osc_24m" is also the same osc_24m referenced in
drivers/clk/imx/clk-imx8mp.c imx8mp_a53_sels[] and co.
Is then resolved to these clock:
188 osc_24m: clock-osc-24m {
189 compatible = "fixed-clock";
190 #clock-cells = <0>;
191 clock-frequency = <24000000>;
192 clock-output-names = "osc_24m";
^^^^^^^ Ignore this
193 };
