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From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Peter De Schrijver <pdeschrijver@nvidia.com>,
	Prashant Gaikwad <pgaikwad@nvidia.com>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>
Cc: linux-tegra@vger.kernel.org, linux-clk@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH RESEND for 5.6 v1 1/3] clk: tegra: divider: Check UART's divider enable-bit state on rate's recalculation
Date: Wed, 18 Dec 2019 21:44:05 +0300
Message-ID: <20191218184407.25790-1-digetx@gmail.com> (raw)

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 <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 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 ca0de5f11f84..38daf483ddf1 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;
-- 
2.24.0


             reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-18 18:44 Dmitry Osipenko [this message]
2019-12-18 18:44 ` [PATCH RESEND for 5.6 v1 2/3] clk: tegra20/30: Don't pre-initialize displays parent clock Dmitry Osipenko
2020-01-07 23:21   ` Dmitry Osipenko
2019-12-18 18:44 ` [PATCH RESEND for 5.6 v1 3/3] clk: tegra20/30: Explicitly set parent clock for Video Decoder Dmitry Osipenko
2020-01-10 14:52 ` [PATCH RESEND for 5.6 v1 1/3] clk: tegra: divider: Check UART's divider enable-bit state on rate's recalculation Thierry Reding

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