From: Brian Masney <bmasney@redhat.com>
To: Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
Brian Masney <bmasney@redhat.com>,
Abel Vesa <abelvesa@kernel.org>,
Andrea della Porta <andrea.porta@suse.com>,
Baolin Wang <baolin.wang@linux.alibaba.com>,
Bjorn Andersson <andersson@kernel.org>,
Chanwoo Choi <cw00.choi@samsung.com>,
Frank Li <Frank.Li@nxp.com>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Krzysztof Kozlowski <krzk@kernel.org>,
Orson Zhai <orsonzhai@gmail.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
Sudeep Holla <sudeep.holla@kernel.org>,
Sylwester Nawrocki <s.nawrocki@samsung.com>,
Tudor Ambarus <tudor.ambarus@linaro.org>,
Alim Akhtar <alim.akhtar@samsung.com>,
arm-scmi@vger.kernel.org, Chunyan Zhang <zhang.lyra@gmail.com>,
Cristian Marussi <cristian.marussi@arm.com>,
Fabio Estevam <festevam@gmail.com>,
imx@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org,
linux-renesas-soc@vger.kernel.org,
linux-samsung-soc@vger.kernel.org, Peng Fan <peng.fan@nxp.com>,
Pengutronix Kernel Team <kernel@pengutronix.de>
Subject: [PATCH 01/13] clk: add new flag CLK_ROUNDING_FW_MANAGED
Date: Thu, 26 Feb 2026 13:16:45 -0500 [thread overview]
Message-ID: <20260226-clk-det-rate-fw-managed-v1-1-4421dd2f6dc6@redhat.com> (raw)
In-Reply-To: <20260226-clk-det-rate-fw-managed-v1-0-4421dd2f6dc6@redhat.com>
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>
---
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
To: Abel Vesa <abelvesa@kernel.org>
To: Andrea della Porta <andrea.porta@suse.com>
To: Baolin Wang <baolin.wang@linux.alibaba.com>
To: Bjorn Andersson <andersson@kernel.org>
To: Chanwoo Choi <cw00.choi@samsung.com>
To: Frank Li <Frank.Li@nxp.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>
To: Krzysztof Kozlowski <krzk@kernel.org>
To: Orson Zhai <orsonzhai@gmail.com>
To: Sascha Hauer <s.hauer@pengutronix.de>
To: Sudeep Holla <sudeep.holla@kernel.org>
To: Sylwester Nawrocki <s.nawrocki@samsung.com>
To: Tudor Ambarus <tudor.ambarus@linaro.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: arm-scmi@vger.kernel.org
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Cristian Marussi <cristian.marussi@arm.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: imx@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
---
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)) {
pr_err("%s: %s must implement .set_parent & .determine_rate\n",
__func__, core->name);
ret = -EINVAL;
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 1cda2c78dffaff037f0f16b0f11106b63b3a746f..187f8248a9c840c701cbbba99bb7cdeef7b654ee 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -32,6 +32,8 @@
#define CLK_OPS_PARENT_ENABLE BIT(12)
/* duty cycle call may be forwarded to the parent clock */
#define CLK_DUTY_CYCLE_PARENT BIT(13)
+/* clock rate rounding is managed by firmware, don't require determine_rate */
+#define CLK_ROUNDING_FW_MANAGED BIT(14)
struct clk;
struct clk_hw;
--
2.53.0
next prev parent reply other threads:[~2026-02-26 18:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-26 18:16 [PATCH 00/13] clk: add new flag CLK_ROUNDING_FW_MANAGED Brian Masney
2026-02-26 18:16 ` Brian Masney [this message]
2026-02-27 8:16 ` [PATCH 01/13] " Geert Uytterhoeven
2026-02-27 8:57 ` Biju Das
2026-02-27 12:00 ` Biju Das
2026-02-27 14:44 ` Brian Masney
2026-02-27 16:38 ` Brian Masney
2026-03-02 11:27 ` Sudeep Holla
2026-02-26 18:16 ` [PATCH 12/13] clk: samsung: acpm: drop determine_rate op and use CLK_ROUNDING_FW_MANAGED flag Brian Masney
2026-02-28 13:31 ` Krzysztof Kozlowski
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