clk: scmi: Add support for state control restricted clocks

Some exposed SCMI Clocks could be marked as non-supporting state changes.
Configure a clk_ops descriptor which does not provide the state change
callbacks for such clocks when registering with CLK framework.

CC: Michael Turquette <mturquette@baylibre.com>
CC: Stephen Boyd <sboyd@kernel.org>
CC: linux-clk@vger.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20240415163649.895268-3-cristian.marussi@arm.com
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index 4b6c43d7f5f3bd898b545c8036e8f0ccb8f2b9b8..e707085739656757847a3bb63274f1e05685bfa0 100644 (file)
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -19,6 +19,7 @@
 
 enum scmi_clk_feats {
        SCMI_CLK_ATOMIC_SUPPORTED,
+       SCMI_CLK_STATE_CTRL_SUPPORTED,
        SCMI_CLK_FEATS_COUNT
 };
 
@@ -230,15 +231,19 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
         * only the prepare/unprepare API, as allowed by the clock framework
         * when atomic calls are not available.
         */
-       if (feats_key & BIT(SCMI_CLK_ATOMIC_SUPPORTED)) {
-               ops->enable = scmi_clk_atomic_enable;
-               ops->disable = scmi_clk_atomic_disable;
-               ops->is_enabled = scmi_clk_atomic_is_enabled;
-       } else {
-               ops->prepare = scmi_clk_enable;
-               ops->unprepare = scmi_clk_disable;
+       if (feats_key & BIT(SCMI_CLK_STATE_CTRL_SUPPORTED)) {
+               if (feats_key & BIT(SCMI_CLK_ATOMIC_SUPPORTED)) {
+                       ops->enable = scmi_clk_atomic_enable;
+                       ops->disable = scmi_clk_atomic_disable;
+               } else {
+                       ops->prepare = scmi_clk_enable;
+                       ops->unprepare = scmi_clk_disable;
+               }
        }
 
+       if (feats_key & BIT(SCMI_CLK_ATOMIC_SUPPORTED))
+               ops->is_enabled = scmi_clk_atomic_is_enabled;
+
        /* Rate ops */
        ops->recalc_rate = scmi_clk_recalc_rate;
        ops->round_rate = scmi_clk_round_rate;
@@ -294,6 +299,9 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
        if (atomic_capable && ci->enable_latency <= atomic_threshold_us)
                feats_key |= BIT(SCMI_CLK_ATOMIC_SUPPORTED);
 
+       if (!ci->state_ctrl_forbidden)
+               feats_key |= BIT(SCMI_CLK_STATE_CTRL_SUPPORTED);
+
        if (WARN_ON(feats_key >= db_size))
                return NULL;