From: Peng Fan <peng.fan@nxp.com> To: "sboyd@kernel.org" <sboyd@kernel.org>, "shawnguo@kernel.org" <shawnguo@kernel.org>, "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>, "festevam@gmail.com" <festevam@gmail.com>, Abel Vesa <abel.vesa@nxp.com> Cc: "kernel@pengutronix.de" <kernel@pengutronix.de>, dl-linux-imx <linux-imx@nxp.com>, Aisheng Dong <aisheng.dong@nxp.com>, "linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, Leonard Crestez <leonard.crestez@nxp.com>, Alice Guo <alice.guo@nxp.com>, "will@kernel.org" <will@kernel.org>, Peng Fan <peng.fan@nxp.com> Subject: [PATCH V2 2/4] clk: imx: pll14xx: use readl to force write completed Date: Thu, 14 Nov 2019 03:38:17 +0000 [thread overview] Message-ID: <1573702559-2744-3-git-send-email-peng.fan@nxp.com> (raw) In-Reply-To: <1573702559-2744-1-git-send-email-peng.fan@nxp.com> From: Peng Fan <peng.fan@nxp.com> To ensure writes to clock registers have properly completed, add a readl after writel_relaxed. Then we could make sure when udelay, write has been completed. Signed-off-by: Peng Fan <peng.fan@nxp.com> Cc: Will Deacon <will@kernel.org> --- drivers/clk/imx/clk-pll14xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/clk/imx/clk-pll14xx.c b/drivers/clk/imx/clk-pll14xx.c index 5b7d41d43b3b..a8af949f0848 100644 --- a/drivers/clk/imx/clk-pll14xx.c +++ b/drivers/clk/imx/clk-pll14xx.c @@ -205,6 +205,12 @@ static int clk_pll1416x_set_rate(struct clk_hw *hw, unsigned long drate, (rate->sdiv << SDIV_SHIFT); writel_relaxed(div_val, pll->base + 0x4); + /* + * readl will force write completed. There is a udelay below, + * we need make sure before udelay, write has been completed + */ + readl(pll->base + 0x4); + /* * According to SPEC, t3 - t2 need to be greater than * 1us and 1/FREF, respectively. -- 2.16.4
WARNING: multiple messages have this Message-ID (diff)
From: Peng Fan <peng.fan@nxp.com> To: "sboyd@kernel.org" <sboyd@kernel.org>, "shawnguo@kernel.org" <shawnguo@kernel.org>, "s.hauer@pengutronix.de" <s.hauer@pengutronix.de>, "festevam@gmail.com" <festevam@gmail.com>, Abel Vesa <abel.vesa@nxp.com> Cc: Aisheng Dong <aisheng.dong@nxp.com>, Peng Fan <peng.fan@nxp.com>, Alice Guo <alice.guo@nxp.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, dl-linux-imx <linux-imx@nxp.com>, "kernel@pengutronix.de" <kernel@pengutronix.de>, Leonard Crestez <leonard.crestez@nxp.com>, "will@kernel.org" <will@kernel.org>, "linux-clk@vger.kernel.org" <linux-clk@vger.kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: [PATCH V2 2/4] clk: imx: pll14xx: use readl to force write completed Date: Thu, 14 Nov 2019 03:38:17 +0000 [thread overview] Message-ID: <1573702559-2744-3-git-send-email-peng.fan@nxp.com> (raw) In-Reply-To: <1573702559-2744-1-git-send-email-peng.fan@nxp.com> From: Peng Fan <peng.fan@nxp.com> To ensure writes to clock registers have properly completed, add a readl after writel_relaxed. Then we could make sure when udelay, write has been completed. Signed-off-by: Peng Fan <peng.fan@nxp.com> Cc: Will Deacon <will@kernel.org> --- drivers/clk/imx/clk-pll14xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/clk/imx/clk-pll14xx.c b/drivers/clk/imx/clk-pll14xx.c index 5b7d41d43b3b..a8af949f0848 100644 --- a/drivers/clk/imx/clk-pll14xx.c +++ b/drivers/clk/imx/clk-pll14xx.c @@ -205,6 +205,12 @@ static int clk_pll1416x_set_rate(struct clk_hw *hw, unsigned long drate, (rate->sdiv << SDIV_SHIFT); writel_relaxed(div_val, pll->base + 0x4); + /* + * readl will force write completed. There is a udelay below, + * we need make sure before udelay, write has been completed + */ + readl(pll->base + 0x4); + /* * According to SPEC, t3 - t2 need to be greater than * 1us and 1/FREF, respectively. -- 2.16.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-11-14 3:38 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-11-14 3:38 [PATCH V2 0/4] clk: imx: pll14/sccg use relaxed API Peng Fan 2019-11-14 3:38 ` Peng Fan 2019-11-14 3:38 ` [PATCH V2 1/4] clk: imx: pll14xx: use writel_relaxed Peng Fan 2019-11-14 3:38 ` Peng Fan 2019-11-14 3:38 ` Peng Fan [this message] 2019-11-14 3:38 ` [PATCH V2 2/4] clk: imx: pll14xx: use readl to force write completed Peng Fan 2019-11-14 3:38 ` [PATCH V2 3/4] clk: imx: sccg: use relaxed io api Peng Fan 2019-11-14 3:38 ` Peng Fan 2019-11-14 3:38 ` [PATCH V2 4/4] clk: imx: composite-8m: " Peng Fan 2019-11-14 3:38 ` Peng Fan 2019-12-12 5:36 ` [PATCH V2 0/4] clk: imx: pll14/sccg use relaxed API Peng Fan 2019-12-12 5:36 ` Peng Fan
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