[PATCH v2 5/5] clk: scmi: register scmi clocks with CCF
Sean Anderson
seanga2 at gmail.com
Fri Feb 25 07:33:50 CET 2022
Hi Etienne,
On 2/21/22 3:22 AM, Etienne Carriere wrote:
> Implements SCMI APIs to retrieve the number exposed SCMI clocks using
> SCMI_PROTOCOL_ATTRIBUTES messages and the names of the clocks using
> SCMI_CLOCK_ATTRIBUTES messages.
>
> This change updates sandbox SCMI clock test driver to manage these
> 2 new message IDs.
>
> Cc: Lukasz Majewski <lukma at denx.de>
> Cc: Sean Anderson <seanga2 at gmail.com>
> Cc: Clement Leger <clement.leger at bootlin.com>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Signed-off-by: Gabriel Fernandez <gabriel.fernandez at st.com>
> Signed-off-by: Etienne Carriere <etienne.carriere at linaro.org>
> ---
> Changes since v1:
> - Remove Series-links tag and apply R-b tag.
> ---
> drivers/clk/clk_scmi.c | 90 ++++++++++++++++++++++
> drivers/firmware/scmi/sandbox-scmi_agent.c | 53 +++++++++++++
> include/scmi_protocols.h | 43 +++++++++++
> 3 files changed, 186 insertions(+)
>
> diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
> index 42fbab0d21..57022685e2 100644
> --- a/drivers/clk/clk_scmi.c
> +++ b/drivers/clk/clk_scmi.c
> @@ -11,6 +11,52 @@
> #include <scmi_agent.h>
> #include <scmi_protocols.h>
> #include <asm/types.h>
> +#include <linux/clk-provider.h>
> +
> +static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)
> +{
> + struct scmi_clk_protocol_attr_out out;
> + struct scmi_msg msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> + .message_id = SCMI_PROTOCOL_ATTRIBUTES,
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev, &msg);
> + if (ret)
> + return ret;
> +
> + *num_clocks = out.attributes & SCMI_CLK_PROTO_ATTR_COUNT_MASK;
> +
> + return 0;
> +}
> +
> +static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)
nit: scmi_clk_get_attribute
> +{
> + struct scmi_clk_attribute_in in = {
> + .clock_id = clkid,
> + };
> + struct scmi_clk_attribute_out out;
> + struct scmi_msg msg = {
> + .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
> + .message_id = SCMI_CLOCK_ATTRIBUTES,
> + .in_msg = (u8 *)&in,
> + .in_msg_sz = sizeof(in),
> + .out_msg = (u8 *)&out,
> + .out_msg_sz = sizeof(out),
> + };
> + int ret;
> +
> + ret = devm_scmi_process_msg(dev, &msg);
> + if (ret)
> + return ret;
> +
> + *name = out.clock_name;
> +
> + return 0;
> +}
>
> static int scmi_clk_gate(struct clk *clk, int enable)
> {
> @@ -88,6 +134,49 @@ static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
> return scmi_clk_get_rate(clk);
> }
>
> +static int scmi_clk_probe(struct udevice *dev)
> +{
> + struct clk *clk;
> + size_t num_clocks, i;
> + int ret;
> +
> + if (!CONFIG_IS_ENABLED(CLK_CCF))
> + return 0;
> +
> + /* register CCF children: CLK UCLASS, no probed again */
> + if (device_get_uclass_id(dev->parent) == UCLASS_CLK)
> + return 0;
> +
> + ret = scmi_clk_get_num_clock(dev, &num_clocks);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < num_clocks; i++) {
> + char *name;
> +
> + if (!scmi_clk_get_attibute(dev, i, &name)) {
> + char *clock_name = strdup(name);
> +
> + clk = kzalloc(sizeof(*clk), GFP_KERNEL);
> + if (!clk || !clock_name)
> + ret = -ENOMEM;
> + else
> + ret = clk_register(clk, dev->driver->name,
> + clock_name, dev->name);
> +
> + if (ret) {
> + free(clk);
> + free(clock_name);
> + return ret;
> + }
> +
> + clk_dm(i, clk);
> + }
> + }
> +
> + return 0;
> +}
> +
So why not call scmi_clk_get_num_clock during probe() and then check against
it in xlate? I don't really see why we need CCF. This also means you don't
have a driver with copies of itself as children, and is lighter on memory.
--Sean
> static const struct clk_ops scmi_clk_ops = {
> .enable = scmi_clk_enable,
> .disable = scmi_clk_disable,
> @@ -99,4 +188,5 @@ U_BOOT_DRIVER(scmi_clock) = {
> .name = "scmi_clk",
> .id = UCLASS_CLK,
> .ops = &scmi_clk_ops,
> + .probe = &scmi_clk_probe,
> };
> diff --git a/drivers/firmware/scmi/sandbox-scmi_agent.c b/drivers/firmware/scmi/sandbox-scmi_agent.c
> index fc717a8aea..c555164d19 100644
> --- a/drivers/firmware/scmi/sandbox-scmi_agent.c
> +++ b/drivers/firmware/scmi/sandbox-scmi_agent.c
> @@ -114,6 +114,55 @@ static struct sandbox_scmi_voltd *get_scmi_voltd_state(uint domain_id)
> * Sandbox SCMI agent ops
> */
>
> +static int sandbox_scmi_clock_protocol_attribs(struct udevice *dev,
> + struct scmi_msg *msg)
> +{
> + struct scmi_clk_protocol_attr_out *out = NULL;
> +
> + if (!msg->out_msg || msg->out_msg_sz < sizeof(*out))
> + return -EINVAL;
> +
> + out = (struct scmi_clk_protocol_attr_out *)msg->out_msg;
> + out->attributes = ARRAY_SIZE(scmi_clk);
> + out->status = SCMI_SUCCESS;
> +
> + return 0;
> +}
> +
> +static int sandbox_scmi_clock_attribs(struct udevice *dev, struct scmi_msg *msg)
> +{
> + struct scmi_clk_attribute_in *in = NULL;
> + struct scmi_clk_attribute_out *out = NULL;
> + struct sandbox_scmi_clk *clk_state = NULL;
> + int ret;
> +
> + if (!msg->in_msg || msg->in_msg_sz < sizeof(*in) ||
> + !msg->out_msg || msg->out_msg_sz < sizeof(*out))
> + return -EINVAL;
> +
> + in = (struct scmi_clk_attribute_in *)msg->in_msg;
> + out = (struct scmi_clk_attribute_out *)msg->out_msg;
> +
> + clk_state = get_scmi_clk_state(in->clock_id);
> + if (!clk_state) {
> + dev_err(dev, "Unexpected clock ID %u\n", in->clock_id);
> +
> + out->status = SCMI_NOT_FOUND;
> + } else {
> + memset(out, 0, sizeof(*out));
> +
> + if (clk_state->enabled)
> + out->attributes = 1;
> +
> + ret = snprintf(out->clock_name, sizeof(out->clock_name),
> + "clk%u", in->clock_id);
> + assert(ret > 0 && ret < sizeof(out->clock_name));
> +
> + out->status = SCMI_SUCCESS;
> + }
> +
> + return 0;
> +}
> static int sandbox_scmi_clock_rate_set(struct udevice *dev,
> struct scmi_msg *msg)
> {
> @@ -427,6 +476,10 @@ static int sandbox_scmi_test_process_msg(struct udevice *dev,
> switch (msg->protocol_id) {
> case SCMI_PROTOCOL_ID_CLOCK:
> switch (msg->message_id) {
> + case SCMI_PROTOCOL_ATTRIBUTES:
> + return sandbox_scmi_clock_protocol_attribs(dev, msg);
> + case SCMI_CLOCK_ATTRIBUTES:
> + return sandbox_scmi_clock_attribs(dev, msg);
> case SCMI_CLOCK_RATE_SET:
> return sandbox_scmi_clock_rate_set(dev, msg);
> case SCMI_CLOCK_RATE_GET:
> diff --git a/include/scmi_protocols.h b/include/scmi_protocols.h
> index ef26e72176..a220cb2a91 100644
> --- a/include/scmi_protocols.h
> +++ b/include/scmi_protocols.h
> @@ -40,22 +40,65 @@ enum scmi_status_code {
> SCMI_PROTOCOL_ERROR = -10,
> };
>
> +/*
> + * Generic message IDs
> + */
> +enum scmi_discovery_id {
> + SCMI_PROTOCOL_VERSION = 0x0,
> + SCMI_PROTOCOL_ATTRIBUTES = 0x1,
> + SCMI_PROTOCOL_MESSAGE_ATTRIBUTES = 0x2,
> +};
> +
> /*
> * SCMI Clock Protocol
> */
>
> enum scmi_clock_message_id {
> + SCMI_CLOCK_ATTRIBUTES = 0x3,
> SCMI_CLOCK_RATE_SET = 0x5,
> SCMI_CLOCK_RATE_GET = 0x6,
> SCMI_CLOCK_CONFIG_SET = 0x7,
> };
>
> +#define SCMI_CLK_PROTO_ATTR_COUNT_MASK GENMASK(15, 0)
> #define SCMI_CLK_RATE_ASYNC_NOTIFY BIT(0)
> #define SCMI_CLK_RATE_ASYNC_NORESP (BIT(0) | BIT(1))
> #define SCMI_CLK_RATE_ROUND_DOWN 0
> #define SCMI_CLK_RATE_ROUND_UP BIT(2)
> #define SCMI_CLK_RATE_ROUND_CLOSEST BIT(3)
>
> +#define SCMI_CLOCK_NAME_LENGTH_MAX 16
> +
> +/**
> + * struct scmi_clk_get_nb_out - Response for SCMI_PROTOCOL_ATTRIBUTES command
> + * @status: SCMI command status
> + * @attributes: Attributes of the clock protocol, mainly number of clocks exposed
> + */
> +struct scmi_clk_protocol_attr_out {
> + s32 status;
> + u32 attributes;
> +};
> +
> +/**
> + * struct scmi_clk_attribute_in - Message payload for SCMI_CLOCK_ATTRIBUTES command
> + * @clock_id: SCMI clock ID
> + */
> +struct scmi_clk_attribute_in {
> + u32 clock_id;
> +};
> +
> +/**
> + * struct scmi_clk_get_nb_out - Response payload for SCMI_CLOCK_ATTRIBUTES command
> + * @status: SCMI command status
> + * @attributes: clock attributes
> + * @clock_name: name of the clock
> + */
> +struct scmi_clk_attribute_out {
> + s32 status;
> + u32 attributes;
> + char clock_name[SCMI_CLOCK_NAME_LENGTH_MAX];
> +};
> +
> /**
> * struct scmi_clk_state_in - Message payload for CLOCK_CONFIG_SET command
> * @clock_id: SCMI clock ID
>
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