[PATCH v4 08/20] clk: scmi: check the clock state/parent/rate control permissions

[Marek Vasut]

On 1/15/25 2:28 PM, Alice Guo wrote:

[...]

> +static int scmi_clk_get_permissions(struct udevice *dev, int clkid, u32 *perm)
> +{
> +	u32 version;
> +	int ret;
> +
> +	ret = scmi_generic_protocol_version(dev, SCMI_PROTOCOL_ID_CLOCK, &version);
> +	if (ret) {
> +		debug("get SCMI clock management protocol version failed\n");
> +		return ret;
> +	}
> +
> +	if (version >= CLOCK_PROTOCOL_VERSION_3_0) {

if (version < CLOCK_PROTOCOL_VERSION_3_0)
   return -EINVAL;

> +		struct scmi_clk_get_permissions_in in = {
> +			.clock_id = clkid,
> +		};

[...]

> +static int scmi_clk_set_parent(struct clk *clk, struct clk *parent)
> +{
> +	struct clk_scmi *clkscmi;
> +	struct clk *c;
> +	int ret;
> +
> +	if (CONFIG_IS_ENABLED(CLK_CCF)) {

Either do this to reduce indent:

if (!CONFIG_IS_ENABLED(CLK_CCF))
   return -ENOTSUPP;

Or even better, introduce dedicated clock ops structure for the CCF 
variant with these extra callbacks .

> +		ret = clk_get_by_id(clk->id, &c);
> +		if (ret)
> +			return ret;
> +
> +		clkscmi = container_of(c, struct clk_scmi, clk);
> +
> +		if (clkscmi->ctrl_flags & SUPPORT_CLK_PARENT_CONTROL)
> +			return __scmi_clk_set_parent(clk, parent);
> +
> +		/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
> +		debug("SCMI CLOCK: the clock's parent cannot be changed by the agent.\n");
> +		return 0;
> +	}
> +
> +	return -ENOTSUPP;
> +}

[...]

> @@ -858,6 +861,27 @@ struct scmi_clk_parent_set_out {
>   	s32 status;
>   };
>   
> +/**
> + * @clock_id:	Identifier for the clock device.
> + */
> +struct scmi_clk_get_permissions_in {
> +	u32 clock_id;
> +};
> +
> +/**
> + * @status:	Negative 32-bit integers are used to return error status codes.
> + * @permissions:	Bit[31] Clock state control, Bit[30] Clock parent control,
> + * 					Bit[29] Clock rate control, Bits[28:0] Reserved, must be zero

Please make sure the indent is consistent (it seems there are too many 
tabs here) and does not overflow 80 characters line length .