From patchwork Tue Jul 4 11:59:24 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Quentin Schulz X-Patchwork-Id: 9824729 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 A66A6602F0 for ; Tue, 4 Jul 2017 12:10:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 95D712022C for ; Tue, 4 Jul 2017 12:10:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 88F2726E54; Tue, 4 Jul 2017 12:10:29 +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 1F7D52022C for ; Tue, 4 Jul 2017 12:10:29 +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=/TLlbU0V/La3ZJeoa2NmovoB+m6xZ1QltEMoakigtig=; b=Vt9Pto7sbCS3augw4XyUuEcjv6 k8YnTSt7na7Wu7t5MPdolOGxvQ9iBeRxWweRmAly9N6011Jgh4q6as4ceFLrwlYfGHqQkegRKxCOG Sw4gYrHA2SeaCxUQo1WQOod+WRqPfk7PUXPLczqoFqp8oicIFlm87YvfaraBe5O3l3pByLx81gvWN olnP91nVbxDSqLk7gt+JlO8LXdgEJWZGMH9yyzwG6MUJuZWSLDX6cFnSezseWkA0gBKwDuZist7F7 RCuqlse27ZY+G16Wj/kN/g0jHZ4HDR3eFM9DJLayRNl59XuMOsOgKM3ZPgzkZwEl9YmKA3/Qsyz0t 3I7rlWEg==; 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 1dSMex-0003iD-Sb; Tue, 04 Jul 2017 12:10:27 +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 1dSMVM-0006IY-SR for linux-arm-kernel@lists.infradead.org; Tue, 04 Jul 2017 12:00:42 +0000 Received: by mail.free-electrons.com (Postfix, from userid 110) id 5E9BC21FC1; Tue, 4 Jul 2017 13:59:45 +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 F026721D40; Tue, 4 Jul 2017 13:59:44 +0200 (CEST) From: Quentin Schulz To: mturquette@baylibre.com, sboyd@codeaurora.org, robh+dt@kernel.org, mark.rutland@arm.com, lgirdwood@gmail.com, broonie@kernel.org, nicolas.ferre@microchip.com, alexandre.belloni@free-electrons.com, linux@armlinux.org.uk, boris.brezillon@free-electrons.com, perex@perex.cz, tiwai@suse.com Subject: [PATCH v2 6/9] clk: at91: clk-generated: make gclk determine audio_pll rate Date: Tue, 4 Jul 2017 13:59:24 +0200 Message-Id: <20170704115927.32662-7-quentin.schulz@free-electrons.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170704115927.32662-1-quentin.schulz@free-electrons.com> References: <20170704115927.32662-1-quentin.schulz@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170704_050033_655183_1372C298 X-CRM114-Status: GOOD ( 15.24 ) 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 , cyrille.pitchen@wedev4u.fr, 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 (via gck). With the rate locking, the first consumer to enable the clock will be the one definitely setting the rate of the clock. Since audio IPs are most likely to request the same rate, we enforce that the only clks able to modify gck rate are those of audio IPs. To remain consistent, we deny other clocks to be children of audio_pll. Signed-off-by: Quentin Schulz Acked-by: Boris Brezillon --- v2: - added conditions for audio pll rate setting restriction for SSC and I2S, drivers/clk/at91/clk-generated.c | 48 +++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 6 deletions(-) diff --git a/drivers/clk/at91/clk-generated.c b/drivers/clk/at91/clk-generated.c index 6530a2e7e84d..87866786a6ab 100644 --- a/drivers/clk/at91/clk-generated.c +++ b/drivers/clk/at91/clk-generated.c @@ -26,6 +26,13 @@ #define GENERATED_SOURCE_MAX 6 #define GENERATED_MAX_DIV 255 +#define GCK_ID_SSC0 43 +#define GCK_ID_SSC1 44 +#define GCK_ID_I2S0 54 +#define GCK_ID_I2S1 55 +#define GCK_ID_CLASSD 59 +#define GCK_INDEX_DT_AUDIO_PLL 5 + struct clk_generated { struct clk_hw hw; struct regmap *regmap; @@ -126,15 +133,14 @@ 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 +156,40 @@ 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, + * with the rate locking, the first consumer to enable to clock will be + * the one definitely setting the rate of the clock. + * Since audio IPs are most likely to request the same rate, we enforce + * that the only clks able to modify gck rate are those of audio IPs. + */ + + if (gck->id != GCK_ID_SSC0 && gck->id != GCK_ID_SSC1 && + gck->id != GCK_ID_I2S0 && gck->id != GCK_ID_I2S1 && + 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 +299,8 @@ 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;