[PATCH 10/14] clk: scmi: support SCMI multi-channel

[Sean Anderson]

On 5/13/22 2:26 AM, Etienne Carriere wrote:
> Update SCMI clock driver to get its assigned SCMI channel during
> initialization. This change allows SCMI clock protocol to use a
> dedicated channel when defined in the DT. The reference is saved
> in SCMI clock driver private data.
> 
> Cc: Lukasz Majewski <lukma at denx.de>
> Cc: Sean Anderson <seanga2 at gmail.com>
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
>   drivers/clk/clk_scmi.c | 23 +++++++++++++++++------
>   1 file changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
> index 0d0bb72eaf7..5cf7bd73df5 100644
> --- a/drivers/clk/clk_scmi.c
> +++ b/drivers/clk/clk_scmi.c
> @@ -15,6 +15,7 @@
>   
>   static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
>   	struct scmi_clk_protocol_attr_out out;
>   	struct scmi_msg msg = {
>   		.protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> @@ -24,7 +25,7 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
>   	};
>   	int ret;
>   
> -	ret = devm_scmi_process_msg(dev, NULL, &msg);
> +	ret = devm_scmi_process_msg(dev, *scmi_channel_ref, &msg);
>   	if (ret)
>   		return ret;
>   
> @@ -35,6 +36,7 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
>   
>   static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
>   	struct scmi_clk_attribute_in in = {
>   		.clock_id = clkid,
>   	};
> @@ -49,7 +51,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
>   	};
>   	int ret;
>   
> -	ret = devm_scmi_process_msg(dev, NULL, &msg);
> +	ret = devm_scmi_process_msg(dev, *scmi_channel_ref, &msg);
>   	if (ret)
>   		return ret;
>   
> @@ -60,6 +62,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
>   
>   static int scmi_clk_gate(struct clk *clk, int enable)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
>   	struct scmi_clk_state_in in = {
>   		.clock_id = clk->id,
>   		.attributes = enable,
> @@ -70,7 +73,7 @@ static int scmi_clk_gate(struct clk *clk, int enable)
>   					  in, out);
>   	int ret;
>   
> -	ret = devm_scmi_process_msg(clk->dev, NULL, &msg);
> +	ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
>   	if (ret)
>   		return ret;
>   
> @@ -89,6 +92,7 @@ static int scmi_clk_disable(struct clk *clk)
>   
>   static ulong scmi_clk_get_rate(struct clk *clk)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
>   	struct scmi_clk_rate_get_in in = {
>   		.clock_id = clk->id,
>   	};
> @@ -98,7 +102,7 @@ static ulong scmi_clk_get_rate(struct clk *clk)
>   					  in, out);
>   	int ret;
>   
> -	ret = devm_scmi_process_msg(clk->dev, NULL, &msg);
> +	ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
>   	if (ret < 0)
>   		return ret;
>   
> @@ -111,6 +115,7 @@ static ulong scmi_clk_get_rate(struct clk *clk)
>   
>   static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
>   	struct scmi_clk_rate_set_in in = {
>   		.clock_id = clk->id,
>   		.flags = SCMI_CLK_RATE_ROUND_CLOSEST,
> @@ -123,7 +128,7 @@ static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
>   					  in, out);
>   	int ret;
>   
> -	ret = devm_scmi_process_msg(clk->dev, NULL, &msg);
> +	ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
>   	if (ret < 0)
>   		return ret;
>   
> @@ -136,10 +141,15 @@ static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
>   
>   static int scmi_clk_probe(struct udevice *dev)
>   {
> +	struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
>   	struct clk *clk;
>   	size_t num_clocks, i;
>   	int ret;
>   
> +	ret = devm_scmi_of_get_channel(dev, scmi_channel_ref);
> +	if (ret)
> +		return ret;
> +
>   	if (!CONFIG_IS_ENABLED(CLK_CCF))
>   		return 0;
>   
> @@ -186,5 +196,6 @@ U_BOOT_DRIVER(scmi_clock) = {
>   	.name = "scmi_clk",
>   	.id = UCLASS_CLK,
>   	.ops = &scmi_clk_ops,
> -	.probe = &scmi_clk_probe,
> +	.probe = scmi_clk_probe,
> +	.priv_auto = sizeof(struct scmi_channel *),

Please create a priv struct to hold this. E.g.

/**
  * struct scmi_clk_priv - Private data for SCMI clocks
  * @channel: ...
  */
struct scmi_clk_priv {
	struct scmi_channel *channel;
};

This will allow for easier refactoring if it is necessary to add additional
per-device data in the future.

--Sean