From patchwork Mon Jun 4 13:27:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sascha Hauer X-Patchwork-Id: 162802 Return-Path: X-Original-To: incoming-imx@patchwork.ozlabs.org Delivered-To: patchwork-incoming-imx@bilbo.ozlabs.org Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:4978:20e::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id B14FCB6FCB for ; Mon, 4 Jun 2012 23:33:06 +1000 (EST) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SbXKF-0004NJ-RR; Mon, 04 Jun 2012 13:28:04 +0000 Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SbXKB-0004Mo-B3 for linux-arm-kernel@lists.infradead.org; Mon, 04 Jun 2012 13:28:00 +0000 Received: from dude.hi.pengutronix.de ([2001:6f8:1178:2:21e:67ff:fe11:9c5c]) by metis.ext.pengutronix.de with esmtp (Exim 4.72) (envelope-from ) id 1SbXK1-00051z-GT; Mon, 04 Jun 2012 15:27:49 +0200 Received: from sha by dude.hi.pengutronix.de with local (Exim 4.77) (envelope-from ) id 1SbXK0-0000cv-Ot; Mon, 04 Jun 2012 15:27:48 +0200 From: Sascha Hauer To: Subject: [PATCH 2/3] ARM i.MX pllv2: make round_rate accurate Date: Mon, 4 Jun 2012 15:27:45 +0200 Message-Id: <1338816466-2365-2-git-send-email-s.hauer@pengutronix.de> X-Mailer: git-send-email 1.7.10 In-Reply-To: <1338816466-2365-1-git-send-email-s.hauer@pengutronix.de> References: <1338816466-2365-1-git-send-email-s.hauer@pengutronix.de> X-SA-Exim-Connect-IP: 2001:6f8:1178:2:21e:67ff:fe11:9c5c X-SA-Exim-Mail-From: sha@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-arm-kernel@lists.infradead.org X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Sascha Hauer , shawn.guo@linaro.org, Richard Zhao X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+incoming-imx=patchwork.ozlabs.org@lists.infradead.org List-Id: linux-imx-kernel.lists.patchwork.ozlabs.org in round_rate we made the assumption that we can set arbitrary frequencies and thus returned the input rate. This is not correct, for certain frequencies after setting a frequency with set_rate, recalc_rate will return different values. To fix this, introduce set_rate/recalc_rate functions which work on variables instead of registers directly. This way we can call these in round_rate to get the exact rate which we would get if we call set_rate with this value. Signed-off-by: Sascha Hauer --- arch/arm/mach-imx/clk-pllv2.c | 78 ++++++++++++++++++++++++++++------------- 1 file changed, 54 insertions(+), 24 deletions(-) diff --git a/arch/arm/mach-imx/clk-pllv2.c b/arch/arm/mach-imx/clk-pllv2.c index 1b03071..0440379 100644 --- a/arch/arm/mach-imx/clk-pllv2.c +++ b/arch/arm/mach-imx/clk-pllv2.c @@ -74,24 +74,15 @@ struct clk_pllv2 { void __iomem *base; }; -static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, - unsigned long parent_rate) +static unsigned long __clk_pllv2_recalc_rate(unsigned long parent_rate, + u32 dp_ctl, u32 dp_op, u32 dp_mfd, u32 dp_mfn) { long mfi, mfn, mfd, pdf, ref_clk, mfn_abs; - unsigned long dp_op, dp_mfd, dp_mfn, dp_ctl, dbl; - void __iomem *pllbase; + unsigned long dbl; s64 temp; - struct clk_pllv2 *pll = to_clk_pllv2(hw); - - pllbase = pll->base; - dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); dbl = dp_ctl & MXC_PLL_DP_CTL_DPDCK0_2_EN; - dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP); - dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD); - dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN); - pdf = dp_op & MXC_PLL_DP_OP_PDF_MASK; mfi = (dp_op & MXC_PLL_DP_OP_MFI_MASK) >> MXC_PLL_DP_OP_MFI_OFFSET; mfi = (mfi <= 5) ? 5 : mfi; @@ -117,18 +108,30 @@ static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, return temp; } -static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, +static unsigned long clk_pllv2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { + u32 dp_op, dp_mfd, dp_mfn, dp_ctl; + void __iomem *pllbase; struct clk_pllv2 *pll = to_clk_pllv2(hw); + + pllbase = pll->base; + + dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); + dp_op = __raw_readl(pllbase + MXC_PLL_DP_OP); + dp_mfd = __raw_readl(pllbase + MXC_PLL_DP_MFD); + dp_mfn = __raw_readl(pllbase + MXC_PLL_DP_MFN); + + return __clk_pllv2_recalc_rate(parent_rate, dp_ctl, dp_op, dp_mfd, dp_mfn); +} + +static int __clk_pllv2_set_rate(unsigned long rate, unsigned long parent_rate, + u32 *dp_op, u32 *dp_mfd, u32 *dp_mfn) +{ u32 reg; - void __iomem *pllbase; long mfi, pdf, mfn, mfd = 999999; s64 temp64; unsigned long quad_parent_rate; - unsigned long dp_ctl; - - pllbase = pll->base; quad_parent_rate = 4 * parent_rate; pdf = mfi = -1; @@ -138,18 +141,41 @@ static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, return -EINVAL; pdf--; - temp64 = rate * (pdf+1) - quad_parent_rate * mfi; - do_div(temp64, quad_parent_rate/1000000); + temp64 = rate * (pdf + 1) - quad_parent_rate * mfi; + do_div(temp64, quad_parent_rate / 1000000); mfn = (long)temp64; + reg = mfi << 4 | pdf; + + *dp_op = reg; + *dp_mfd = mfd; + *dp_mfn = mfn; + + return 0; +} + +static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_pllv2 *pll = to_clk_pllv2(hw); + void __iomem *pllbase; + u32 dp_ctl, dp_op, dp_mfd, dp_mfn; + int ret; + + pllbase = pll->base; + + + ret = __clk_pllv2_set_rate(rate, parent_rate, &dp_op, &dp_mfd, &dp_mfn); + if (ret) + return ret; + dp_ctl = __raw_readl(pllbase + MXC_PLL_DP_CTL); /* use dpdck0_2 */ __raw_writel(dp_ctl | 0x1000L, pllbase + MXC_PLL_DP_CTL); - reg = mfi << 4 | pdf; - __raw_writel(reg, pllbase + MXC_PLL_DP_OP); - __raw_writel(mfd, pllbase + MXC_PLL_DP_MFD); - __raw_writel(mfn, pllbase + MXC_PLL_DP_MFN); + __raw_writel(dp_op, pllbase + MXC_PLL_DP_OP); + __raw_writel(dp_mfd, pllbase + MXC_PLL_DP_MFD); + __raw_writel(dp_mfn, pllbase + MXC_PLL_DP_MFN); return 0; } @@ -157,7 +183,11 @@ static int clk_pllv2_set_rate(struct clk_hw *hw, unsigned long rate, static long clk_pllv2_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate) { - return rate; + u32 dp_op, dp_mfd, dp_mfn; + + __clk_pllv2_set_rate(rate, *prate, &dp_op, &dp_mfd, &dp_mfn); + return __clk_pllv2_recalc_rate(*prate, MXC_PLL_DP_CTL_DPDCK0_2_EN, + dp_op, dp_mfd, dp_mfn); } static int clk_pllv2_prepare(struct clk_hw *hw)