From patchwork Tue Aug 19 03:33:15 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tuomas Tynkkynen X-Patchwork-Id: 4740001 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 460039F8A9 for ; Tue, 19 Aug 2014 03:37:42 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5C90D20142 for ; Tue, 19 Aug 2014 03:37:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DA2B420123 for ; Tue, 19 Aug 2014 03:37:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJaD2-0007z4-Jh; Tue, 19 Aug 2014 03:35:44 +0000 Received: from script.cs.helsinki.fi ([128.214.11.1]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XJaC0-0006LD-Ee for linux-arm-kernel@lists.infradead.org; Tue, 19 Aug 2014 03:34:41 +0000 X-DKIM: Courier DKIM Filter v0.50+pk-2014-03-23 mail.cs.helsinki.fi Tue, 19 Aug 2014 06:34:10 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.helsinki.fi; h=from:to:cc:subject:date:message-id:in-reply-to:references; s= dkim20130528; bh=Im+SWWuNq7lRWF3NdGA5auvmWmGQ5bw1wBFXE5LWCsQ=; b= jrfe0xymEGSDdnLqIcnr2czs2/jTGimvhq0j5DXyyjTKINohBo/hvCdpZIfxRNkf MFFRPycMOoAsceEmSzuQpP0aIhlvA+lksVTlZNKuSbTA0CdxSY8eGhmWQe3d/aPe LF+7eja5PZNxRufaAQ2dx+thOPGYi7YMRe3X4IbZcJE= Received: from melkki.cs.helsinki.fi (melkki.cs.helsinki.fi [128.214.9.98]) (AUTH: PLAIN cs-relay, TLS: TLSv1/SSLv3,256bits,AES256-SHA) by mail.cs.helsinki.fi with ESMTPSA; Tue, 19 Aug 2014 06:34:10 +0300 id 0000000000080D98.0000000053F2C5B2.00005673 Received: by melkki.cs.helsinki.fi (Postfix, from userid 18244) id 60B9F1C9630; Tue, 19 Aug 2014 06:34:04 +0300 (EEST) From: Tuomas Tynkkynen To: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org Subject: [PATCH v3 05/15] clk: tegra: Add DFLL DVCO reset control for Tegra124 Date: Tue, 19 Aug 2014 06:33:15 +0300 Message-Id: <1408419205-10048-6-git-send-email-tuomas.tynkkynen@iki.fi> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1408419205-10048-1-git-send-email-tuomas.tynkkynen@iki.fi> References: <1408419205-10048-1-git-send-email-tuomas.tynkkynen@iki.fi> X-NVConfidentiality: public X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140818_203440_715400_D9DACF1F X-CRM114-Status: GOOD ( 10.59 ) X-Spam-Score: -0.7 (/) Cc: devicetree@vger.kernel.org, Prashant Gaikwad , Mike Turquette , Vince Hsu , Stephen Warren , Viresh Kumar , Peter De Schrijver , "Rafael J. Wysocki" , Thierry Reding , Tuomas Tynkkynen , Paul Walmsley X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_NONE,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Paul Walmsley The DVCO present in the DFLL IP block has a separate reset line, exposed via the CAR IP block. This reset line is asserted upon SoC reset. Unless something (such as the DFLL driver) deasserts this line, the DVCO will not oscillate, although reads and writes to the DFLL IP block will complete. Thanks to Aleksandr Frid for identifying this and saving hours of debugging time. Signed-off-by: Paul Walmsley [ttynkkynen: ported to tegra124 from tegra114] Signed-off-by: Tuomas Tynkkynen --- drivers/clk/tegra/clk-tegra124.c | 47 ++++++++++++++++++++++++++++++++++++++++ drivers/clk/tegra/clk.h | 3 +++ 2 files changed, 50 insertions(+) diff --git a/drivers/clk/tegra/clk-tegra124.c b/drivers/clk/tegra/clk-tegra124.c index 9525c68..cc81eab 100644 --- a/drivers/clk/tegra/clk-tegra124.c +++ b/drivers/clk/tegra/clk-tegra124.c @@ -31,6 +31,9 @@ #define CLK_SOURCE_CSITE 0x1d4 #define CLK_SOURCE_EMC 0x19c +#define RST_DFLL_DVCO 0x2f4 +#define DVFS_DFLL_RESET_SHIFT 0 + #define PLLC_BASE 0x80 #define PLLC_OUT 0x84 #define PLLC_MISC2 0x88 @@ -1386,6 +1389,50 @@ static void __init tegra124_clock_apply_init_table(void) tegra_init_from_table(init_table, clks, TEGRA124_CLK_CLK_MAX); } +/** + * tegra124_car_barrier - wait for pending writes to the CAR to complete + * + * Wait for any outstanding writes to the CAR MMIO space from this CPU + * to complete before continuing execution. No return value. + */ +static void tegra124_car_barrier(void) +{ + readl_relaxed(clk_base + RST_DFLL_DVCO); +} + +/** + * tegra124_clock_assert_dfll_dvco_reset - assert the DFLL's DVCO reset + * + * Assert the reset line of the DFLL's DVCO. No return value. + */ +void tegra124_clock_assert_dfll_dvco_reset(void) +{ + u32 v; + + v = readl_relaxed(clk_base + RST_DFLL_DVCO); + v |= (1 << DVFS_DFLL_RESET_SHIFT); + writel_relaxed(v, clk_base + RST_DFLL_DVCO); + tegra124_car_barrier(); +} +EXPORT_SYMBOL(tegra124_clock_assert_dfll_dvco_reset); + +/** + * tegra124_clock_deassert_dfll_dvco_reset - deassert the DFLL's DVCO reset + * + * Deassert the reset line of the DFLL's DVCO, allowing the DVCO to + * operate. No return value. + */ +void tegra124_clock_deassert_dfll_dvco_reset(void) +{ + u32 v; + + v = readl_relaxed(clk_base + RST_DFLL_DVCO); + v &= ~(1 << DVFS_DFLL_RESET_SHIFT); + writel_relaxed(v, clk_base + RST_DFLL_DVCO); + tegra124_car_barrier(); +} +EXPORT_SYMBOL(tegra124_clock_deassert_dfll_dvco_reset); + static void __init tegra124_clock_init(struct device_node *np) { struct device_node *node; diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 16ec8d6..4b3f3d0 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -627,6 +627,9 @@ void tegra114_clock_tune_cpu_trimmers_init(void); void tegra114_clock_assert_dfll_dvco_reset(void); void tegra114_clock_deassert_dfll_dvco_reset(void); +void tegra124_clock_assert_dfll_dvco_reset(void); +void tegra124_clock_deassert_dfll_dvco_reset(void); + typedef void (*tegra_clk_apply_init_table_func)(void); extern tegra_clk_apply_init_table_func tegra_clk_apply_init_table;