From 326cc42f9fdc3030676e949d5cea3ccc923fd1de Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Fri, 5 May 2023 13:26:10 +0200 Subject: [PATCH] clk: Forbid to register a mux without determine_rate MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The determine_rate hook allows to select the proper parent and its rate for a given clock configuration. On another hand, set_parent is there to change the parent of a mux. Some clocks provide a set_parent hook but don't implement determine_rate. In such a case, set_parent is pretty much useless since the clock framework will always assume the current parent is to be used, and we will thus never change it. This situation can be solved in two ways: - either we don't need to change the parent, and we thus shouldn't implement set_parent; - or we don't want to change the parent, in this case we should set CLK_SET_RATE_NO_REPARENT; - or we're missing a determine_rate implementation. The latter is probably just an oversight from the driver's author, and we should thus raise their awareness about the fact that the current state of the driver is confusing. All the drivers in-tree have been converted by now, so let's prevent any clock with set_parent but without determine_rate to register so that it can't sneak in again in the future. Cc: Abel Vesa Cc: Alessandro Zummo Cc: Alexandre Belloni Cc: Alexandre Torgue Cc: "Andreas Färber" Cc: AngeloGioacchino Del Regno Cc: Baolin Wang Cc: Charles Keepax Cc: Chen-Yu Tsai Cc: Chen-Yu Tsai Cc: Chunyan Zhang Cc: Claudiu Beznea Cc: Daniel Vetter Cc: David Airlie Cc: David Lechner Cc: Dinh Nguyen Cc: Fabio Estevam Cc: Geert Uytterhoeven Cc: Jaroslav Kysela Cc: Jernej Skrabec Cc: Jonathan Hunter Cc: Kishon Vijay Abraham I Cc: Liam Girdwood Cc: Linus Walleij Cc: Luca Ceresoli Cc: Manivannan Sadhasivam Cc: Mark Brown Cc: Markus Schneider-Pargmann Cc: Max Filippov Cc: Maxime Coquelin Cc: Mikko Perttunen Cc: Miles Chen Cc: Nicolas Ferre Cc: Orson Zhai Cc: Paul Cercueil Cc: Peng Fan Cc: Peter De Schrijver Cc: Prashant Gaikwad Cc: Richard Fitzgerald Cc: Samuel Holland Cc: Sascha Hauer Cc: Sekhar Nori Cc: Shawn Guo Cc: Takashi Iwai Cc: Thierry Reding Cc: Ulf Hansson Cc: Vinod Koul Cc: dri-devel@lists.freedesktop.org Cc: linux-actions@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-mips@vger.kernel.org Cc: linux-phy@lists.infradead.org Cc: linux-renesas-soc@vger.kernel.org Cc: linux-rtc@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com Cc: linux-sunxi@lists.linux.dev Cc: linux-tegra@vger.kernel.org Cc: NXP Linux Team Cc: patches@opensource.cirrus.com Cc: Pengutronix Kernel Team Reviewed-by: AngeloGioacchino Del Regno Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20221018-clk-range-checks-fixes-v4-68-971d5077e7d2@cerno.tech Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index ad4488dedd01..ffc9f03840b7 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -3776,6 +3776,13 @@ static int __clk_core_init(struct clk_core *core) goto out; } + if (core->ops->set_parent && !core->ops->determine_rate) { + pr_err("%s: %s must implement .set_parent & .determine_rate\n", + __func__, core->name); + ret = -EINVAL; + goto out; + } + if (core->num_parents > 1 && !core->ops->get_parent) { pr_err("%s: %s must implement .get_parent as it has multi parents\n", __func__, core->name);