linux-kernel - [PATCH v2 2/5] clk: scmi: Add support for state control restricted clocks

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Date: Mon, 25 Mar 2024 21:00:22 +0000
From: Cristian Marussi <cristian.marussi@....com>
To: linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-clk@...r.kernel.org
Cc: sudeep.holla@....com,
	james.quinlan@...adcom.com,
	f.fainelli@...il.com,
	vincent.guittot@...aro.org,
	peng.fan@....nxp.com,
	michal.simek@....com,
	quic_sibis@...cinc.com,
	quic_nkela@...cinc.com,
	souvik.chakravarty@....com,
	mturquette@...libre.com,
	sboyd@...nel.org,
	Cristian Marussi <cristian.marussi@....com>
Subject: [PATCH v2 2/5] 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@...libre.com>
CC: Stephen Boyd <sboyd@...nel.org>
CC: linux-clk@...r.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi@....com>
---
 drivers/clk/clk-scmi.c | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index d5d369b052bd..fc9603988d91 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -18,6 +18,7 @@
 
 enum scmi_clk_feats {
 	SCMI_CLK_ATOMIC_SUPPORTED,
+	SCMI_CLK_STATE_CTRL_FORBIDDEN,
 	SCMI_CLK_MAX_FEATS
 };
 
@@ -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_FORBIDDEN))) {
+		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;
@@ -288,6 +293,9 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
 	if (atomic_capable && ci->enable_latency <= atomic_threshold)
 		feats_key |= BIT(SCMI_CLK_ATOMIC_SUPPORTED);
 
+	if (ci->state_ctrl_forbidden)
+		feats_key |= BIT(SCMI_CLK_STATE_CTRL_FORBIDDEN);
+
 	/* Lookup previously allocated ops */
 	ops = clk_ops_db[feats_key];
 	if (!ops) {
-- 
2.44.0