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 4/4] clk: imx: composite-8m: use relaxed io api Date: Thu, 14 Nov 2019 03:38:28 +0000 [thread overview] Message-ID: <1573702559-2744-5-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> writel/readl has a barrier, however that barrier is not needed, because device memory mapping is nGnRE mapping and access is in order and clk driver has spin lock or other lock to make sure write finished. It is ok to use relaxed api here, no need to use stronger readl/writel Signed-off-by: Peng Fan <peng.fan@nxp.com> --- drivers/clk/imx/clk-composite-8m.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c index 20f7c91c03d2..513dc57483d0 100644 --- a/drivers/clk/imx/clk-composite-8m.c +++ b/drivers/clk/imx/clk-composite-8m.c @@ -31,14 +31,14 @@ static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw, unsigned int prediv_value; unsigned int div_value; - prediv_value = readl(divider->reg) >> divider->shift; + prediv_value = readl_relaxed(divider->reg) >> divider->shift; prediv_value &= clk_div_mask(divider->width); prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value, NULL, divider->flags, divider->width); - div_value = readl(divider->reg) >> PCG_DIV_SHIFT; + div_value = readl_relaxed(divider->reg) >> PCG_DIV_SHIFT; div_value &= clk_div_mask(PCG_DIV_WIDTH); return divider_recalc_rate(hw, prediv_rate, div_value, NULL, @@ -104,13 +104,13 @@ static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw, spin_lock_irqsave(divider->lock, flags); - val = readl(divider->reg); + val = readl_relaxed(divider->reg); val &= ~((clk_div_mask(divider->width) << divider->shift) | (clk_div_mask(PCG_DIV_WIDTH) << PCG_DIV_SHIFT)); val |= (u32)(prediv_value - 1) << divider->shift; val |= (u32)(div_value - 1) << PCG_DIV_SHIFT; - writel(val, divider->reg); + writel_relaxed(val, divider->reg); spin_unlock_irqrestore(divider->lock, flags); -- 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 4/4] clk: imx: composite-8m: use relaxed io api Date: Thu, 14 Nov 2019 03:38:28 +0000 [thread overview] Message-ID: <1573702559-2744-5-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> writel/readl has a barrier, however that barrier is not needed, because device memory mapping is nGnRE mapping and access is in order and clk driver has spin lock or other lock to make sure write finished. It is ok to use relaxed api here, no need to use stronger readl/writel Signed-off-by: Peng Fan <peng.fan@nxp.com> --- drivers/clk/imx/clk-composite-8m.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c index 20f7c91c03d2..513dc57483d0 100644 --- a/drivers/clk/imx/clk-composite-8m.c +++ b/drivers/clk/imx/clk-composite-8m.c @@ -31,14 +31,14 @@ static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw, unsigned int prediv_value; unsigned int div_value; - prediv_value = readl(divider->reg) >> divider->shift; + prediv_value = readl_relaxed(divider->reg) >> divider->shift; prediv_value &= clk_div_mask(divider->width); prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value, NULL, divider->flags, divider->width); - div_value = readl(divider->reg) >> PCG_DIV_SHIFT; + div_value = readl_relaxed(divider->reg) >> PCG_DIV_SHIFT; div_value &= clk_div_mask(PCG_DIV_WIDTH); return divider_recalc_rate(hw, prediv_rate, div_value, NULL, @@ -104,13 +104,13 @@ static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw, spin_lock_irqsave(divider->lock, flags); - val = readl(divider->reg); + val = readl_relaxed(divider->reg); val &= ~((clk_div_mask(divider->width) << divider->shift) | (clk_div_mask(PCG_DIV_WIDTH) << PCG_DIV_SHIFT)); val |= (u32)(prediv_value - 1) << divider->shift; val |= (u32)(div_value - 1) << PCG_DIV_SHIFT; - writel(val, divider->reg); + writel_relaxed(val, divider->reg); spin_unlock_irqrestore(divider->lock, flags); -- 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 ` [PATCH V2 2/4] clk: imx: pll14xx: use readl to force write completed Peng Fan 2019-11-14 3:38 ` 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 ` Peng Fan [this message] 2019-11-14 3:38 ` [PATCH V2 4/4] clk: imx: composite-8m: " 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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