[PATCH v3 1/2] firmware: arm_scmi: clock: support clock parents

Peng Fan (OSS)
2023-10-01T04:34:58Z

From: Peng Fan <peng.fan@nxp.com>

SCMI v3.2 spec introduces CLOCK_POSSIBLE_PARENTS_GET, CLOCK_PARENT_SET
and CLOCK_PARENT_GET. This patch is to add the upper three new
commands.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
drivers/firmware/arm_scmi/clock.c | 182 ++++++++++++++++++++++++++++++++++++--
include/linux/scmi_protocol.h | 6 ++
2 files changed, 182 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index d18bf789fc24..9b95239d63ae 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -22,6 +22,9 @@ enum scmi_clock_protocol_cmd {
CLOCK_RATE_NOTIFY = 0x9,
CLOCK_RATE_CHANGE_REQUESTED_NOTIFY = 0xA,
CLOCK_CONFIG_GET = 0xB,
+ CLOCK_POSSIBLE_PARENTS_GET = 0xC,
+ CLOCK_PARENT_SET = 0xD,
+ CLOCK_PARENT_GET = 0xE,
};

enum clk_state {
@@ -42,10 +45,28 @@ struct scmi_msg_resp_clock_attributes {
#define SUPPORTS_RATE_CHANGED_NOTIF(x) ((x) & BIT(31))
#define SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(x) ((x) & BIT(30))
#define SUPPORTS_EXTENDED_NAMES(x) ((x) & BIT(29))
+#define SUPPORTS_PARENT_CLOCK(x) ((x) & BIT(28))
u8 name[SCMI_SHORT_NAME_MAX_SIZE];
__le32 clock_enable_latency;
};

+struct scmi_msg_clock_possible_parents {
+ __le32 id;
+ __le32 skip_parents;
+};
+
+struct scmi_msg_resp_clock_possible_parents {
+ __le32 num_parent_flags;
+#define NUM_PARENTS_RETURNED(x) ((x) & 0xff)
+#define NUM_PARENTS_REMAINING(x) ((x) >> 24)
+ u32 possible_parents[];
+};
+
+struct scmi_msg_clock_set_parent {
+ __le32 id;
+ __le32 parent_id;
+};
+
struct scmi_msg_clock_config_set_v2 {
__le32 id;
__le32 attributes;
@@ -167,6 +188,99 @@ scmi_clock_protocol_attributes_get(const struct scmi_protocol_handle *ph,
return ret;
}

+struct scmi_clk_ipriv {
+ struct device *dev;
+ u32 clk_id;
+ struct scmi_clock_info *clk;
+};
+
+static void iter_clk_possible_parents_prepare_message(void *message, unsigned int desc_index,
+ const void *priv)
+{
+ struct scmi_msg_clock_possible_parents *msg = message;
+ const struct scmi_clk_ipriv *p = priv;
+
+ msg->id = cpu_to_le32(p->clk_id);
+ /* Set the number of OPPs to be skipped/already read */
+ msg->skip_parents = cpu_to_le32(desc_index);
+}
+
+static int iter_clk_possible_parents_update_state(struct scmi_iterator_state *st,
+ const void *response, void *priv)
+{
+ const struct scmi_msg_resp_clock_possible_parents *r = response;
+ struct scmi_clk_ipriv *p = priv;
+ struct device *dev = ((struct scmi_clk_ipriv *)p)->dev;
+ u32 flags;
+
+ flags = le32_to_cpu(r->num_parent_flags);
+ st->num_returned = NUM_PARENTS_RETURNED(flags);
+ st->num_remaining = NUM_PARENTS_REMAINING(flags);
+
+ /*
+ * num parents is not declared previously anywhere so we
+ * assume it's returned+remaining on first call.
+ */
+ if (!st->max_resources) {
+ p->clk->num_parents = st->num_returned + st->num_remaining;
+ p->clk->parents = devm_kcalloc(dev, p->clk->num_parents,
+ sizeof(*p->clk->parents),
+ GFP_KERNEL);
+ if (!p->clk->parents) {
+ p->clk->num_parents = 0;
+ return -ENOMEM;
+ }
+
+ st->max_resources = st->num_returned + st->num_remaining;
+ };
+
+ return 0;
+}
+
+static int iter_clk_possible_parents_process_response(const struct scmi_protocol_handle *ph,
+ const void *response,
+ struct scmi_iterator_state *st,
+ void *priv)
+{
+ const struct scmi_msg_resp_clock_possible_parents *r = response;
+ struct scmi_clk_ipriv *p = priv;
+
+ u32 *parent = &p->clk->parents[st->desc_index + st->loop_idx];
+
+ *parent = le32_to_cpu(r->possible_parents[st->loop_idx]);
+
+ return 0;
+}
+
+static int scmi_clock_possible_parents(const struct scmi_protocol_handle *ph, u32 clk_id,
+ struct scmi_clock_info *clk)
+{
+ struct scmi_iterator_ops ops = {
+ .prepare_message = iter_clk_possible_parents_prepare_message,
+ .update_state = iter_clk_possible_parents_update_state,
+ .process_response = iter_clk_possible_parents_process_response,
+ };
+
+ struct scmi_clk_ipriv ppriv = {
+ .clk_id = clk_id,
+ .clk = clk,
+ .dev = ph->dev,
+ };
+ void *iter;
+ int ret;
+
+ iter = ph->hops->iter_response_init(ph, &ops, 0,
+ CLOCK_POSSIBLE_PARENTS_GET,
+ sizeof(struct scmi_msg_clock_possible_parents),
+ &ppriv);
+ if (IS_ERR(iter))
+ return PTR_ERR(iter);
+
+ ret = ph->hops->iter_response_run(iter);
+
+ return ret;
+}
+
static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
u32 clk_id, struct scmi_clock_info *clk,
u32 version)
@@ -211,6 +325,8 @@ static int scmi_clock_attributes_get(const struct scmi_protocol_handle *ph,
clk->rate_changed_notifications = true;
if (SUPPORTS_RATE_CHANGE_REQUESTED_NOTIF(attributes))
clk->rate_change_requested_notifications = true;
+ if (SUPPORTS_PARENT_CLOCK(attributes))
+ scmi_clock_possible_parents(ph, clk_id, clk);
}

return ret;
@@ -228,12 +344,6 @@ static int rate_cmp_func(const void *_r1, const void *_r2)
return 1;
}

-struct scmi_clk_ipriv {
- struct device *dev;
- u32 clk_id;
- struct scmi_clock_info *clk;
-};
-
static void iter_clk_describe_prepare_message(void *message,
const unsigned int desc_index,
const void *priv)
@@ -457,6 +567,64 @@ scmi_clock_config_set_v2(const struct scmi_protocol_handle *ph, u32 clk_id,
return ret;
}

+static int
+scmi_clock_set_parent(const struct scmi_protocol_handle *ph, u32 clk_id,
+ u32 parent_id)
+{
+ int ret;
+ struct scmi_xfer *t;
+ struct scmi_msg_clock_set_parent *cfg;
+ struct clock_info *ci = ph->get_priv(ph);
+ struct scmi_clock_info *clk;
+
+ if (clk_id >= ci->num_clocks)
+ return -EINVAL;
+
+ clk = ci->clk + clk_id;
+
+ if (parent_id >= clk->num_parents)
+ return -EINVAL;
+
+ ret = ph->xops->xfer_get_init(ph, CLOCK_PARENT_SET,
+ sizeof(*cfg), 0, &t);
+ if (ret)
+ return ret;
+
+ t->hdr.poll_completion = false;
+
+ cfg = t->tx.buf;
+ cfg->id = cpu_to_le32(clk_id);
+ cfg->parent_id = cpu_to_le32(clk->parents[parent_id]);
+
+ ret = ph->xops->do_xfer(ph, t);
+
+ ph->xops->xfer_put(ph, t);
+
+ return ret;
+}
+
+static int
+scmi_clock_get_parent(const struct scmi_protocol_handle *ph, u32 clk_id,
+ u32 *parent_id)
+{
+ int ret;
+ struct scmi_xfer *t;
+
+ ret = ph->xops->xfer_get_init(ph, CLOCK_PARENT_GET,
+ sizeof(__le32), sizeof(u32), &t);
+ if (ret)
+ return ret;
+
+ put_unaligned_le32(clk_id, t->tx.buf);
+
+ ret = ph->xops->do_xfer(ph, t);
+ if (!ret)
+ *parent_id = get_unaligned_le32(t->rx.buf);
+
+ ph->xops->xfer_put(ph, t);
+ return ret;
+}
+
static int
scmi_clock_config_set_v21(const struct scmi_protocol_handle *ph, u32 clk_id,
enum clk_state state, u8 oem_type, u32 oem_val,
@@ -647,6 +815,8 @@ static const struct scmi_clk_proto_ops clk_proto_ops = {
.state_get = scmi_clock_state_get,
.config_oem_get = scmi_clock_config_oem_get,
.config_oem_set = scmi_clock_config_oem_set,
+ .parent_set = scmi_clock_set_parent,
+ .parent_get = scmi_clock_get_parent,
};

static int scmi_clk_rate_notify(const struct scmi_protocol_handle *ph,
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 27bfa5a65b45..f2f05fb42d28 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -58,6 +58,8 @@ struct scmi_clock_info {
u64 step_size;
} range;
};
+ int num_parents;
+ u32 *parents;
};

enum scmi_power_scale {
@@ -83,6 +85,8 @@ struct scmi_protocol_handle;
* @state_get: get the status of the specified clock
* @config_oem_get: get the value of an OEM specific clock config
* @config_oem_set: set the value of an OEM specific clock config
+ * @parent_get: get the parent id of a clk
+ * @parent_set: set the parent of a clock
*/
struct scmi_clk_proto_ops {
int (*count_get)(const struct scmi_protocol_handle *ph);
@@ -104,6 +108,8 @@ struct scmi_clk_proto_ops {
bool atomic);
int (*config_oem_set)(const struct scmi_protocol_handle *ph, u32 clk_id,
u8 oem_type, u32 oem_val, bool atomic);
+ int (*parent_get)(const struct scmi_protocol_handle *ph, u32 clk_id, u32 *parent_id);
+ int (*parent_set)(const struct scmi_protocol_handle *ph, u32 clk_id, u32 parent_id);
};

struct scmi_perf_domain_info {

--
2.37.1