[PATCH v6 08/20] clk: scmi: check the clock state/parent/rate control permissions

[Marek Vasut]

On 2/28/25 11:53 AM, Alice Guo (OSS) wrote:
> From: Alice Guo <alice.guo at nxp.com>
> 
> Clock driver based on SCMI clock management protocol in Linux checks
> clock state, parent and rate control permissions. To be consistent with
> the kernel driver, add this check here.
> 
> When using common clock framework (CCF), use the clock signal ID to get
> the clock registered by clk_register() in scmi_clk_probe(), and then
> obatin the struct clk_scmi variable with container_of().
> 
> Signed-off-by: Alice Guo <alice.guo at nxp.com>
> Signed-off-by: Ye Li <ye.li at nxp.com>
> Reviewed-by: Peng Fan <peng.fan at nxp.com>
> ---
>   drivers/clk/clk_scmi.c   | 172 ++++++++++++++++++++++++++++++++++++++++++++---
>   include/scmi_protocols.h |  26 ++++++-
>   2 files changed, 187 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
> index 84333cdd0c..4fce92d064 100644
> --- a/drivers/clk/clk_scmi.c
> +++ b/drivers/clk/clk_scmi.c
> @@ -12,6 +12,56 @@
>   #include <asm/types.h>
>   #include <linux/clk-provider.h>
>   
> +struct clk_scmi {
> +	struct clk clk;
> +	u32 ctrl_flags;
> +};
> +
> +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) {
> +		debug("SCMI clock management protocol version is less than 3.0.\n");
> +		return -EINVAL;
> +	}
> +
> +	struct scmi_clk_get_permissions_in in = {
> +		.clock_id = clkid,
> +	};
> +	struct scmi_clk_get_permissions_out out;

Variable declarations should be at the start of this function.

> +	struct scmi_msg msg = {
> +		.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> +		.message_id = SCMI_CLOCK_GET_PERMISSIONS,
> +		.in_msg = (u8 *)&in,
> +		.in_msg_sz = sizeof(in),
> +		.out_msg = (u8 *)&out,
> +		.out_msg_sz = sizeof(out),
> +	};
> +
> +	ret = devm_scmi_process_msg(dev, &msg);
> +	if (ret) {
> +		debug("get SCMI clock management protocol permissions failed\n");

Either use log_debug() or dev_dbg() or something which includes __func__ 
and __LINE__ too.

> +		return ret;
> +	}
> +
> +	ret = scmi_to_linux_errno(out.status);
> +	if (ret < 0) {
> +		debug("the status code of getting permissions: %d\n", ret);
> +		return ret;
> +	}
> +
> +	*perm = out.permissions;
> +	return 0;
> +}
> +
>   static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
>   {
>   	struct scmi_clk_protocol_attr_out out;
> @@ -32,7 +82,8 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
>   	return 0;
>   }
>   
> -static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
> +static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name,
> +				 u32 *attr)
>   {
>   	struct scmi_clk_attribute_in in = {
>   		.clock_id = clkid,
> @@ -53,6 +104,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
>   		return ret;
>   
>   	*name = strdup(out.clock_name);
> +	*attr = out.attributes;
>   
>   	return 0;
>   }
> @@ -78,11 +130,49 @@ static int scmi_clk_gate(struct clk *clk, int enable)
>   
>   static int scmi_clk_enable(struct clk *clk)
>   {
> +	struct clk_scmi *clkscmi;
> +	struct clk *c;
> +	int ret;
> +
> +	if (CONFIG_IS_ENABLED(CLK_CCF)) {

if (!CONFIG_IS_ENABLED(CLK_CCF))
	return scmi_clk_gate(clk, 1);

Reduce indent.

> +		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_STAT_CONTROL)
> +			return scmi_clk_gate(clk, 1);
> +
> +		/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
> +		debug("SCMI CLOCK: the clock cannot be enabled by the agent.\n");
> +		return 0;
> +	}
> +
>   	return scmi_clk_gate(clk, 1);
>   }
>   
>   static int scmi_clk_disable(struct clk *clk)
>   {
> +	struct clk_scmi *clkscmi;
> +	struct clk *c;
> +	int ret;
> +
> +	if (CONFIG_IS_ENABLED(CLK_CCF)) {

DTTO

> +		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_STAT_CONTROL)
> +			return scmi_clk_gate(clk, 0);
> +
> +		/* Following Linux drivers/clk/clk-scmi.c, directly return 0 if agent has no permission. */
> +		debug("SCMI CLOCK: the clock cannot be disabled by the agent.\n");
> +		return 0;
> +	}
> +
>   	return scmi_clk_gate(clk, 0);
>   }
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