On Fri, Feb 27, 2026 at 12:00:55PM +0000, Biju Das wrote:

quoted

-----Original Message-----
From: linux-arm-kernel <redacted> On Behalf Of Brian Masney
Sent: 26 February 2026 18:17
Subject: [PATCH 01/13] clk: add new flag CLK_ROUNDING_FW_MANAGED

There are some clocks where the rounding is managed by the hardware, and the determine_rate() clk ops
is just a noop that simply returns 0. Add a new flag for these type of clocks, and update the clk core
so that the
determine_rate() clk op is not required when this flag is set.

Signed-off-by: Brian Masney <bmasney@redhat.com>

[snip]

quoted

 drivers/clk/clk.c            | 24 +++++++++++++++++++++---
 include/linux/clk-provider.h |  2 ++
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index

fd418dc988b1c60c49e3ac9c0c44aa132dd5da28..0a522a0817411c7f7c6e9cffd6f024e672a331a8 100644

--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c

@@ -1557,6 +1557,20 @@ static int __init clk_disable_unused(void)  }

late_initcall_sync(clk_disable_unused);

+/**
+ * clk_is_rounding_fw_managed - Check to see if clk rounding is handled
+by the
+ * firmware.
+ * @core: the clk to check
+ *
+ * Clks that have this flag enabled do not need to have a
+determine_rate() op
+ * set, and will always return success for any rounding operation since
+the
+ * firmware will deal with the rounding.
+ */
+static inline bool clk_is_rounding_fw_managed(struct clk_core *core) {
+	return core->flags & CLK_ROUNDING_FW_MANAGED; }
+
 static int clk_core_determine_round_nolock(struct clk_core *core,
 					   struct clk_rate_request *req)
 {

@@ -1589,6 +1603,8 @@ static int clk_core_determine_round_nolock(struct clk_core *core,
 		req->rate = core->rate;
 	} else if (core->ops->determine_rate) {
 		return core->ops->determine_rate(core->hw, req);
+	} else if (clk_is_rounding_fw_managed(core)) {
+		return 0;
 	} else {
 		return -EINVAL;
 	}

@@ -1673,7 +1689,7 @@ EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);

 static bool clk_core_can_round(struct clk_core * const core)  {
-	return core->ops->determine_rate;
+	return core->ops->determine_rate || clk_is_rounding_fw_managed(core);
 }

 static int clk_core_round_rate_nolock(struct clk_core *core, @@ -3528,6 +3544,7 @@ static const

struct {
 	ENTRY(CLK_IS_CRITICAL),
 	ENTRY(CLK_OPS_PARENT_ENABLE),
 	ENTRY(CLK_DUTY_CYCLE_PARENT),
+	ENTRY(CLK_ROUNDING_FW_MANAGED),
 #undef ENTRY
 };

@@ -3906,7 +3923,7 @@ static int __clk_core_init(struct clk_core *core)

 	/* check that clk_ops are sane.  See Documentation/driver-api/clk.rst */
 	if (core->ops->set_rate && !core->ops->determine_rate &&
-	      core->ops->recalc_rate) {
+	      core->ops->recalc_rate && !clk_is_rounding_fw_managed(core)) {
 		pr_err("%s: %s must implement .determine_rate in addition to .recalc_rate\n",
 		       __func__, core->name);
 		ret = -EINVAL;

@@ -3920,7 +3937,8 @@ static int __clk_core_init(struct clk_core *core)
 		goto out;
 	}

-	if (core->ops->set_parent && !core->ops->determine_rate) {
+	if (core->ops->set_parent && !core->ops->determine_rate &&
+	    !clk_is_rounding_fw_managed(core)) {

quoted

 		pr_err("%s: %s must implement .set_parent & .determine_rate\n",
 			__func__, core->name);
 		ret = -EINVAL;

After applying patch#11, I get a message as you removed .determine_rate, Also it breaks display.

[    0.096414] __clk_core_init: .pll5_foutpostdiv must implement .round_rate or .determine_rate in addition to .recalc_rate

Thanks for testing. This happens because rzg2l_cpg_pll_clk_register()
doesn't have the new flag set. I'll fix this, and go through all of the
others again just to make sure I don't miss any others.

Brian