clk: scmi: add is_prepared hook

Some clocks maybe default enabled by hardware. For clocks that don't
have users, that will be left in hardware default state, because prepare
count and enable count is zero,if there is no is_prepared hook to get
the hardware state. So add is_prepared hook to detect the hardware
state. Then when disabling the unused clocks, they can be simply
turned OFF to save power during kernel boot.

Reviewed-by: Dhruva Gole <[email protected]>
Signed-off-by: Peng Fan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Sudeep Holla <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>

Author: MrVan

drivers/clk/clk-scmi.c

@@ -156,20 +156,30 @@ static void scmi_clk_atomic_disable(struct clk_hw *hw)
 	scmi_proto_clk_ops->disable(clk->ph, clk->id, ATOMIC);
 }
 
-static int scmi_clk_atomic_is_enabled(struct clk_hw *hw)
+static int __scmi_clk_is_enabled(struct clk_hw *hw, bool atomic)
 {
 	int ret;
 	bool enabled = false;
 	struct scmi_clk *clk = to_scmi_clk(hw);
 
-	ret = scmi_proto_clk_ops->state_get(clk->ph, clk->id, &enabled, ATOMIC);
+	ret = scmi_proto_clk_ops->state_get(clk->ph, clk->id, &enabled, atomic);
 	if (ret)
 		dev_warn(clk->dev,
 			 "Failed to get state for clock ID %d\n", clk->id);
 
 	return !!enabled;
 }
 
+static int scmi_clk_atomic_is_enabled(struct clk_hw *hw)
+{
+	return __scmi_clk_is_enabled(hw, ATOMIC);
+}
+
+static int scmi_clk_is_enabled(struct clk_hw *hw)
+{
+	return __scmi_clk_is_enabled(hw, NOT_ATOMIC);
+}
+
 static int scmi_clk_get_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
 {
 	int ret;
@@ -285,6 +295,8 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
 
 	if (feats_key & BIT(SCMI_CLK_ATOMIC_SUPPORTED))
 		ops->is_enabled = scmi_clk_atomic_is_enabled;
+	else
+		ops->is_prepared = scmi_clk_is_enabled;
 
 	/* Rate ops */
 	ops->recalc_rate = scmi_clk_recalc_rate;