[PATCH v3 2/2] clk: scmi: add compatibility for clock version 3.0 and onwards

[Kamlesh Gurudasani]

Maxim Kochetkov <fido_max at inbox.ru> writes:

> 08.10.2025 15:27, Kamlesh Gurudasani wrote:
>
>>>> Could you elaborate?
>>>> I think clk->dev should be fine, similar to other instances in the same
>>>> file. Maybe I am missing something?
>>>>
>>>
>>> clk->dev points to hw clock device. It has no struct scmi_clock_priv
>>> stored in priv data. So we have to step up to parent device to get SCMI
>>> protocol device to get struct scmi_clock_priv to get protocol version
>>> priv->version.
>> Hi Maxim,
>> 
>> in probe function, we are making sure that priv data is available
>> 	struct scmi_clock_priv *priv = dev_get_priv(dev);
>> 	size_t num_clocks, i;
>> 	int ret;
>> 
>> 	ret = devm_scmi_of_get_channel(dev);
>> 	if (ret)
>> 		return ret;
>> 
>> 	ret = scmi_generic_protocol_version(dev, SCMI_PROTOCOL_ID_CLOCK,
>> 					    &priv->version);
>> 
>> 
>> Also, the code is working just fine and returns correct version with
>> clk->dev
>> 
>> Let me know if I missed something
>
> Here is my debug path:
>
> --- a/drivers/clk/clk_scmi.c
> +++ b/drivers/clk/clk_scmi.c
> @@ -135,6 +135,10 @@ static int scmi_clk_gate(struct clk *clk, int enable)
>          struct scmi_clk_state_out out;
>          int ret;
>
> +       printf("%s name:%s dev:0x%px dev->priv:0x%px     parent->name:%s 
> parent->dev:0x%px parent->dev->priv:0x%px\n", __FUNCTION__,
> +               clk->dev->name, clk->dev, dev_get_priv(clk->dev),
> +               clk->dev->parent->name, clk->dev->parent, 
> dev_get_priv(clk->dev->parent));
> +
>          if (priv->version >= CLOCK_PROTOCOL_VERSION_3_0) {
>                  struct scmi_clk_state_in_v2 in = {
>                          .clock_id = clk_get_id(clk),
> @@ -288,6 +292,8 @@ static int scmi_clk_probe(struct udevice *dev)
>          size_t num_clocks, i;
>          int ret;
>
> +       printf("%s name:%s dev:0x%px dev->priv:0x%px\n", __FUNCTION__, 
> dev->name, dev, priv);
> +
>          ret = devm_scmi_of_get_channel(dev);
>          if (ret)
>                  return ret;
>
> And output:
>
> DRAM:  510 MiB
> scmi_clk_probe name:protocol at 14 dev:0x000000041f51fc50 
> dev->priv:0x000000041f520ae0
> scmi_clk_gate name:UART0 dev:0x000000041f522710 
> dev->priv:0x0000000000000000     parent->name:protocol at 14 
> parent->dev:0x000000041f51fc50 parent->dev->priv:0x000000041f520ae0
> Core:  132 devices, 22 uclasses, devicetree: board
> MMC:   scmi_clk_gate name:EMMC_S dev:0x000000041f521950 
> dev->priv:0x0000000000000000     parent->name:protocol at 14 
> parent->dev:0x000000041f51fc50 parent->dev->priv:0x000000041f520ae0
> sdhci at 0: 0
> Loading Environment from nowhere... OK
> In:    serial
> Out:   serial
> Err:   serial
>
> As we can see here, we have two different devs in scmi_clk_probe() and 
> scmi_clk_gate(). dev from scmi_clk_gate() have NULL in dev->priv. So we 
> can't get scmi version form clk->dev direcrly.
>
> P.S.: I have CONFIG_CLK_CCF=y
Thanks for the logs Maxim.

Looks like the behaviour is different for CCF and non CCF

We have parent->dev->priv as NULL. (and no prints from probe func for r5)

*r5 core logs*
U-Boot SPL 2025.01-00667-g8d2958a533ce-dirty (Oct 28 2025 - 18:43:57 +0530)
SPL initial stack usage: 1984 bytes
Trying to boot from DFU
scmi_clk_gate name:protocol at 14 dev:0x82b7a400x dev->priv:0x82b7a588x parent->name:scmi parent->dev:0x82b7a1d0x parent->dev->pr\
iv:0x0x
#####DOWNLOAD ... OK
Ctrl+C to exit ...
ERROR:   Agent 0 Protocol 0x10 Message 0x7: not supported

*A53 core logs*
U-Boot 2025.01-00667-g8d2958a533ce-dirty (Oct 28 2025 - 18:43:57 +0530)

SoC:   AM62LX SR1.0 HS-FS
Model: Texas Instruments AM62L3 Evaluation Module
DRAM:  2 GiB
ERROR:   Agent 0 Protocol 0x10 Message 0x7: not supported
scmi_clk_probe name:protocol at 14 dev:0x00000000fdeb65a0 dev->priv:0x00000000fdeb6f30
Core:  84 devices, 32 uclasses, devicetree: separate
MMC:   mmc at fa10000: 0, mmc at fa00000: 1
Loading Environment from nowhere... OK


If you have suggestion for solutions please let me know.

Regards,
Kamlesh