RE: [PATCH 01/13] clk: add new flag CLK_ROUNDING_FW_MANAGED
From: Biju Das <biju.das.jz@bp.renesas.com>
Date: 2026-02-27 12:00:58
Also in:
arm-scmi, imx, linux-arm-msm, linux-clk, linux-renesas-soc, linux-samsung-soc, lkml
Hi Brain, Thanks for the patch
quoted hunk ↗ jump to hunk
-----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> --- 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 indexfd418dc988b1c60c49e3ac9c0c44aa132dd5da28..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 conststruct { 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;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 Cheers, Biju