From patchwork Fri Jun 23 09:00:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quentin Schulz X-Patchwork-Id: 9805997 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id EEF0860349 for ; Fri, 23 Jun 2017 09:02:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DF86A280FC for ; Fri, 23 Jun 2017 09:02:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D3E7F28437; Fri, 23 Jun 2017 09:02:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 57971280FC for ; Fri, 23 Jun 2017 09:02:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=UKWUeIgUy4bZqSYZLN1I/aqScI+2LkPfokd6+3C/Sxw=; b=tswOev3X/m+FD7BhVFQrNqhQho 6XmflSXjJclqxgKsNOLRRKw1ZFnV4jqIyH9tzYpgnzUrQM51xIkZt9ne3Qh67wE9JUgdjpPcmNm10 jEQGA3aEeHmVLEib4QN9E2Mk371PYP8QCsfO5+WTWUr1L56olRYIq2l+0NU3JVWdxDLwbvyTWLR4Z tNLgQS8trzNlWm6uFNfqGSM0BBPj1j1DN/+L1A4xPmNzz86uShW0chxsO243WBictBIRHi7YWCbw0 j4sKoYxK5kAis2kyRLmtVs48epWst0yuJ9AekwXarp9dDCZA0AMzJ9UIpHrU0vj5uroOiza5AnYdt 75iCw7WA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dOKUP-0007Lo-OB; Fri, 23 Jun 2017 09:02:53 +0000 Received: from mail.free-electrons.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dOKTa-00066R-U2 for linux-arm-kernel@lists.infradead.org; Fri, 23 Jun 2017 09:02:15 +0000 Received: by mail.free-electrons.com (Postfix, from userid 110) id 7AAA720981; Fri, 23 Jun 2017 11:01:19 +0200 (CEST) Received: from localhost.localdomain (LStLambert-657-1-97-87.w90-63.abo.wanadoo.fr [90.63.216.87]) by mail.free-electrons.com (Postfix) with ESMTPSA id 1C8CA20922; Fri, 23 Jun 2017 11:01:19 +0200 (CEST) From: Quentin Schulz To: mturquette@baylibre.com, sboyd@codeaurora.org, robh+dt@kernel.org, mark.rutland@arm.com, nicolas.ferre@microchip.com, alexandre.belloni@free-electrons.com, linux@armlinux.org.uk, boris.brezillon@free-electrons.com, lgirdwood@gmail.com, broonie@kernel.org, perex@perex.cz, tiwai@suse.com Subject: [PATCH 5/6] clk: at91: clk-generated: make gclk determine audio_pll rate Date: Fri, 23 Jun 2017 11:00:58 +0200 Message-Id: <20170623090059.8371-6-quentin.schulz@free-electrons.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170623090059.8371-1-quentin.schulz@free-electrons.com> References: <20170623090059.8371-1-quentin.schulz@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170623_020203_421323_728C7888 X-CRM114-Status: GOOD ( 18.01 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: thomas.petazzoni@free-electrons.com, devicetree@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Quentin Schulz , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This allows gclk to determine audio_pll rate and set the parent rate accordingly. However, there are multiple children clocks that could technically change the rate of audio_pll. Since the clock rate is usually critical for IPs, it isn't a good idea to have multiple clocks changing audio_pll clock rate. There isn't any rate locking system for the moment, thus we enforce that classd_gclk be the only one allowed to change audio_pll rate. To remain consistent, we deny other clocks to be children of audio_pll so classd_gclk altering audio_pll rate does not impact any other device. This needs to be re-worked once we have a rate locking system so two clocks could be children of the same clock and be sure the clock rate isn't changed by one or the other. Signed-off-by: Quentin Schulz --- drivers/clk/at91/clk-generated.c | 41 ++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c index 6530a2e7e84d..e66ee735a569 100644 --- a/drivers/clk/at91/clk-generated.c +++ b/drivers/clk/at91/clk-generated.c @@ -26,6 +26,9 @@ #define GENERATED_SOURCE_MAX 6 #define GENERATED_MAX_DIV 255 +#define GCK_ID_CLASSD 59 +#define GCK_INDEX_DT_AUDIO_PLL 5 + struct clk_generated { struct clk_hw hw; struct regmap *regmap; @@ -126,15 +129,14 @@ static int clk_generated_determine_rate(struct clk_hw *hw, { struct clk_generated *gck = to_clk_generated(hw); struct clk_hw *parent = NULL; + struct clk_rate_request req_parent = *req; long best_rate = -EINVAL; - unsigned long min_rate; + unsigned long min_rate, parent_rate; int best_diff = -1; int i; + u32 div; - for (i = 0; i < clk_hw_get_num_parents(hw); i++) { - u32 div; - unsigned long parent_rate; - + for (i = 0; i < clk_hw_get_num_parents(hw) - 1; i++) { parent = clk_hw_get_parent_by_index(hw, i); if (!parent) continue; @@ -150,11 +152,37 @@ static int clk_generated_determine_rate(struct clk_hw *hw, clk_generated_best_diff(req, parent, parent_rate, div, &best_diff, &best_rate); + if (!best_diff) + break; + } + + /* + * The audio_pll rate can be modified unlike the five others clocks that + * should never be altered. + * The audio_pll can technically be used by multiple consumers. However, + * they all are likely to want to modify its rate while the rate is + * critical for each one. Since we do not have a rate locking for the + * moment, let classd_gclk be the only consumer of the audio_pll clock. + */ + + if (gck->id != GCK_ID_CLASSD) + goto end; + + parent = clk_hw_get_parent_by_index(hw, GCK_INDEX_DT_AUDIO_PLL); + if (!parent) + goto end; + + for (div = 1; div < GENERATED_MAX_DIV + 2; div++) { + req_parent.rate = req->rate * div; + __clk_determine_rate(parent, &req_parent); + clk_generated_best_diff(req, parent, req_parent.rate, div, + &best_diff, &best_rate); if (!best_diff) break; } +end: pr_debug("GCLK: %s, best_rate = %ld, parent clk: %s @ %ld\n", __func__, best_rate, __clk_get_name((req->best_parent_hw)->clk), @@ -264,7 +292,8 @@ at91_clk_register_generated(struct regmap *regmap, spinlock_t *lock, init.ops = &generated_ops; init.parent_names = parent_names; init.num_parents = num_parents; - init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE; + init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE | + CLK_SET_RATE_PARENT; gck->id = id; gck->hw.init = &init;