From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: [PATCH v2] clk: tegra: divider: Check UART's divider enable-bit state on rate's recalculation Date: Wed, 30 Oct 2019 03:48:13 +0300 Message-ID: <20191030004813.9187-1-digetx@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Michael Turquette , Thierry Reding , Jonathan Hunter , Peter De Schrijver , Prashant Gaikwad , Stephen Boyd Cc: linux-clk@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org UART clock is divided using divisor values from DLM/DLL registers when enable-bit is unset in clk register and clk's divider configuration isn't taken onto account in this case. This doesn't cause any problems, but let's add a check for the divider's enable-bit state, for consistency. Acked-by: Peter De Schrijver Signed-off-by: Dmitry Osipenko --- Changelog: v2: In the comment to v1 Peter De Schrijver pointed out that UART's DLM/DLL registers configuration is used when enable bit is unset, thus the commit's title and message are changed accordingly. drivers/clk/tegra/clk-divider.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c index e76731fb7d69..f33c19045386 100644 --- a/drivers/clk/tegra/clk-divider.c +++ b/drivers/clk/tegra/clk-divider.c @@ -40,8 +40,13 @@ static unsigned long clk_frac_div_recalc_rate(struct clk_hw *hw, int div, mul; u64 rate = parent_rate; - reg = readl_relaxed(divider->reg) >> divider->shift; - div = reg & div_mask(divider); + reg = readl_relaxed(divider->reg); + + if ((divider->flags & TEGRA_DIVIDER_UART) && + !(reg & PERIPH_CLK_UART_DIV_ENB)) + return rate; + + div = (reg >> divider->shift) & div_mask(divider); mul = get_mul(divider); div += mul; -- 2.23.0