From patchwork Mon Jul 17 13:34:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Frank Oltmanns X-Patchwork-Id: 13316470 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mout-p-202.mailbox.org ([2001:67c:2050:0:465::202]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qLONK-0048Ts-2D for linux-arm-kernel@lists.infradead.org; Mon, 17 Jul 2023 13:35:07 +0000 From: Frank Oltmanns Date: Mon, 17 Jul 2023 15:34:30 +0200 Subject: [PATCH v4 06/11] clk: sunxi-ng: Add helper function to find closest rate MIME-Version: 1.0 Message-Id: <20230717-pll-mipi_set_rate_parent-v4-6-04acf1d39765@oltmanns.dev> References: <20230717-pll-mipi_set_rate_parent-v4-0-04acf1d39765@oltmanns.dev> In-Reply-To: <20230717-pll-mipi_set_rate_parent-v4-0-04acf1d39765@oltmanns.dev> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+lwn-linux-arm-kernel=archive.lwn.net@lists.infradead.org List-Archive: To: Maxime Ripard , Michael Turquette , Stephen Boyd , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Andre Przywara , Roman Beranek Cc: linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org, Frank Oltmanns The default behaviour of clocks in the sunxi-ng driver is to select a clock rate that is closest to but less than the requested rate. Add the ccu_is_better_rate() helper function that - depending on the fact if thc CCU_FEATURE_CLOSEST_RATE flag is set - decides if a rate is closer than another rate. Signed-off-by: Frank Oltmanns Acked-by: Maxime Ripard --- drivers/clk/sunxi-ng/ccu_common.c | 12 ++++++++++++ drivers/clk/sunxi-ng/ccu_common.h | 5 +++++ 2 files changed, 17 insertions(+) diff --git a/drivers/clk/sunxi-ng/ccu_common.c b/drivers/clk/sunxi-ng/ccu_common.c index 8d28a7a079d0..8babce55302f 100644 --- a/drivers/clk/sunxi-ng/ccu_common.c +++ b/drivers/clk/sunxi-ng/ccu_common.c @@ -39,6 +39,18 @@ void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock) } EXPORT_SYMBOL_NS_GPL(ccu_helper_wait_for_lock, SUNXI_CCU); +bool ccu_is_better_rate(struct ccu_common *common, + unsigned long target_rate, + unsigned long current_rate, + unsigned long best_rate) +{ + if (common->features & CCU_FEATURE_CLOSEST_RATE) + return abs(current_rate - target_rate) < abs(best_rate - target_rate); + + return current_rate <= target_rate && current_rate > best_rate; +} +EXPORT_SYMBOL_NS_GPL(ccu_is_better_rate, SUNXI_CCU); + /* * This clock notifier is called when the frequency of a PLL clock is * changed. In common PLL designs, changes to the dividers take effect diff --git a/drivers/clk/sunxi-ng/ccu_common.h b/drivers/clk/sunxi-ng/ccu_common.h index 5ad219f041d5..942a72c09437 100644 --- a/drivers/clk/sunxi-ng/ccu_common.h +++ b/drivers/clk/sunxi-ng/ccu_common.h @@ -53,6 +53,11 @@ struct sunxi_ccu_desc { void ccu_helper_wait_for_lock(struct ccu_common *common, u32 lock); +bool ccu_is_better_rate(struct ccu_common *common, + unsigned long target_rate, + unsigned long current_rate, + unsigned long best_rate); + struct ccu_pll_nb { struct notifier_block clk_nb; struct ccu_common *common;