clk: scmi: Add support for get/set duty_cycle operations

Provide the CLK framework callbacks related to get/set clock duty cycle if
the related SCMI clock supports OEM extended configurations.

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/20240415163649.895268-6-cristian.marussi@arm.com
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: cris-ma

drivers/clk/clk-scmi.c

@@ -22,6 +22,7 @@ enum scmi_clk_feats {
 	SCMI_CLK_STATE_CTRL_SUPPORTED,
 	SCMI_CLK_RATE_CTRL_SUPPORTED,
 	SCMI_CLK_PARENT_CTRL_SUPPORTED,
+	SCMI_CLK_DUTY_CYCLE_SUPPORTED,
 	SCMI_CLK_FEATS_COUNT
 };
 
@@ -169,6 +170,45 @@ static int scmi_clk_atomic_is_enabled(struct clk_hw *hw)
 	return !!enabled;
 }
 
+static int scmi_clk_get_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
+{
+	int ret;
+	u32 val;
+	struct scmi_clk *clk = to_scmi_clk(hw);
+
+	ret = scmi_proto_clk_ops->config_oem_get(clk->ph, clk->id,
+						 SCMI_CLOCK_CFG_DUTY_CYCLE,
+						 &val, NULL, false);
+	if (!ret) {
+		duty->num = val;
+		duty->den = 100;
+	} else {
+		dev_warn(clk->dev,
+			 "Failed to get duty cycle for clock ID %d\n", clk->id);
+	}
+
+	return ret;
+}
+
+static int scmi_clk_set_duty_cycle(struct clk_hw *hw, struct clk_duty *duty)
+{
+	int ret;
+	u32 val;
+	struct scmi_clk *clk = to_scmi_clk(hw);
+
+	/* SCMI OEM Duty Cycle is expressed as a percentage */
+	val = (duty->num * 100) / duty->den;
+	ret = scmi_proto_clk_ops->config_oem_set(clk->ph, clk->id,
+						 SCMI_CLOCK_CFG_DUTY_CYCLE,
+						 val, false);
+	if (ret)
+		dev_warn(clk->dev,
+			 "Failed to set duty cycle(%u/%u) for clock ID %d\n",
+			 duty->num, duty->den, clk->id);
+
+	return ret;
+}
+
 static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk,
 			     const struct clk_ops *scmi_ops)
 {
@@ -258,6 +298,12 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
 	if (feats_key & BIT(SCMI_CLK_PARENT_CTRL_SUPPORTED))
 		ops->set_parent = scmi_clk_set_parent;
 
+	/* Duty cycle */
+	if (feats_key & BIT(SCMI_CLK_DUTY_CYCLE_SUPPORTED)) {
+		ops->get_duty_cycle = scmi_clk_get_duty_cycle;
+		ops->set_duty_cycle = scmi_clk_set_duty_cycle;
+	}
+
 	return ops;
 }
 
@@ -312,6 +358,9 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
 	if (!ci->parent_ctrl_forbidden)
 		feats_key |= BIT(SCMI_CLK_PARENT_CTRL_SUPPORTED);
 
+	if (ci->extended_config)
+		feats_key |= BIT(SCMI_CLK_DUTY_CYCLE_SUPPORTED);
+
 	if (WARN_ON(feats_key >= db_size))
 		return NULL;