[PATCH v2 4/5] clk: scmi: Add support for re-parenting restricted clocks

Cristian Marussi cristian.marussi at arm.com
Mon Mar 25 14:00:24 PDT 2024


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

CC: Michael Turquette <mturquette at baylibre.com>
CC: Stephen Boyd <sboyd at kernel.org>
CC: linux-clk at vger.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi at arm.com>
---
 drivers/clk/clk-scmi.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index d20dcc60f9d1..87e968b6c095 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -20,6 +20,7 @@ enum scmi_clk_feats {
 	SCMI_CLK_ATOMIC_SUPPORTED,
 	SCMI_CLK_STATE_CTRL_FORBIDDEN,
 	SCMI_CLK_RATE_CTRL_FORBIDDEN,
+	SCMI_CLK_PARENT_CTRL_FORBIDDEN,
 	SCMI_CLK_MAX_FEATS
 };
 
@@ -254,7 +255,8 @@ scmi_clk_ops_alloc(struct device *dev, unsigned long feats_key)
 
 	/* Parent ops */
 	ops->get_parent = scmi_clk_get_parent;
-	ops->set_parent = scmi_clk_set_parent;
+	if (!(feats_key & BIT(SCMI_CLK_PARENT_CTRL_FORBIDDEN)))
+		ops->set_parent = scmi_clk_set_parent;
 
 	return ops;
 }
@@ -301,6 +303,9 @@ scmi_clk_ops_select(struct scmi_clk *sclk, bool atomic_capable,
 	if (ci->rate_ctrl_forbidden)
 		feats_key |= BIT(SCMI_CLK_RATE_CTRL_FORBIDDEN);
 
+	if (ci->parent_ctrl_forbidden)
+		feats_key |= BIT(SCMI_CLK_PARENT_CTRL_FORBIDDEN);
+
 	/* Lookup previously allocated ops */
 	ops = clk_ops_db[feats_key];
 	if (!ops) {
-- 
2.44.0




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