From mboxrd@z Thu Jan 1 00:00:00 1970 From: Weiyi Lu Subject: [PATCH v3 12/12] clk: mediatek: Allow changing PLL rate when it is off Date: Mon, 10 Dec 2018 15:32:40 +0800 Message-ID: <20181210073240.32278-14-weiyi.lu@mediatek.com> References: <20181210073240.32278-1-weiyi.lu@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20181210073240.32278-1-weiyi.lu@mediatek.com> Sender: linux-kernel-owner@vger.kernel.org To: Nicolas Boichat , Matthias Brugger , Stephen Boyd , Rob Herring Cc: James Liao , Fan Chen , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-clk@vger.kernel.org, srv_heupstream@mediatek.com, stable@vger.kernel.org, Weiyi Lu List-Id: linux-mediatek@lists.infradead.org From: James Liao Some modules may need to change its clock rate before turn on it. So changing PLL's rate when it is off should be allowed. This patch removes PLL enabled check before set rate, so that PLLs can set new frequency even if they are off. On MT8173 for example, ARMPLL's enable bit can be controlled by other HW. That means ARMPLL may be turned on even if we (CPU / SW) set ARMPLL's enable bit as 0. In this case, SW may want and can still change ARMPLL's rate by changing its pcw and postdiv settings. But without this patch, new pcw setting will not be applied because its enable bit is 0. (am from https://patchwork.kernel.org/patch/9411983/) Signed-off-by: James Liao Acked-by: Michael Turquette Signed-off-by: Weiyi Lu --- drivers/clk/mediatek/clk-pll.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/clk/mediatek/clk-pll.c b/drivers/clk/mediatek/clk-pll.c index 81400601f107..03b20e3bca4e 100644 --- a/drivers/clk/mediatek/clk-pll.c +++ b/drivers/clk/mediatek/clk-pll.c @@ -96,13 +96,10 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw, int postdiv) { u32 con1, val; - int pll_en; u32 tuner_en = 0; u32 tuner_en_mask; void __iomem *tuner_en_addr = NULL; - pll_en = readl(pll->base_addr + REG_CON0) & CON0_BASE_EN; - /* disable tuner */ if (pll->tuner_en_addr) { tuner_en_addr = pll->tuner_en_addr; @@ -141,8 +138,7 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw, con1 = readl(pll->base_addr + REG_CON1); - if (pll_en) - con1 |= CON1_PCW_CHG; + con1 |= CON1_PCW_CHG; writel(con1, pll->base_addr + REG_CON1); if (pll->tuner_addr) @@ -155,8 +151,7 @@ static void mtk_pll_set_rate_regs(struct mtk_clk_pll *pll, u32 pcw, writel(val, tuner_en_addr); } - if (pll_en) - udelay(20); + udelay(20); } /* -- 2.18.0