[PATCH v8 6/9] clk: tegra: cclk: Handle thermal DIV2 CPU frequency throttling

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>,
	"Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: Rob Herring <robh+dt@kernel.org>,
	linux-tegra@vger.kernel.org, linux-clk@vger.kernel.org,
	linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: [PATCH v8 6/9] clk: tegra: cclk: Handle thermal DIV2 CPU frequency throttling
Date: Sun, 16 May 2021 19:30:38 +0300	[thread overview]
Message-ID: <20210516163041.12818-7-digetx@gmail.com> (raw)
In-Reply-To: <20210516163041.12818-1-digetx@gmail.com>

Check whether thermal DIV2 throttle is active in order to report
the CPU frequency properly. This very useful for userspace tools
like cpufreq-info which show actual frequency asserted from hardware.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/clk/tegra/clk-tegra-super-cclk.c | 16 ++++++++++++++--
 drivers/clk/tegra/clk-tegra30.c          |  2 +-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/tegra/clk-tegra-super-cclk.c b/drivers/clk/tegra/clk-tegra-super-cclk.c
index a03119c30456..68d7bcd5fc8a 100644
--- a/drivers/clk/tegra/clk-tegra-super-cclk.c
+++ b/drivers/clk/tegra/clk-tegra-super-cclk.c
@@ -25,6 +25,8 @@
 
 #define SUPER_CDIV_ENB		BIT(31)
 
+#define TSENSOR_SLOWDOWN	BIT(23)
+
 static struct tegra_clk_super_mux *cclk_super;
 static bool cclk_on_pllx;
 
@@ -47,10 +49,20 @@ static int cclk_super_set_rate(struct clk_hw *hw, unsigned long rate,
 static unsigned long cclk_super_recalc_rate(struct clk_hw *hw,
 					    unsigned long parent_rate)
 {
+	struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
+	u32 val = readl_relaxed(super->reg);
+	unsigned int div2;
+
+	/* check whether thermal throttling is active */
+	if (val & TSENSOR_SLOWDOWN)
+		div2 = 1;
+	else
+		div2 = 0;
+
 	if (cclk_super_get_parent(hw) == PLLX_INDEX)
-		return parent_rate;
+		return parent_rate >> div2;
 
-	return tegra_clk_super_ops.recalc_rate(hw, parent_rate);
+	return tegra_clk_super_ops.recalc_rate(hw, parent_rate) >> div2;
 }
 
 static int cclk_super_determine_rate(struct clk_hw *hw,
diff --git a/drivers/clk/tegra/clk-tegra30.c b/drivers/clk/tegra/clk-tegra30.c
index a33688b2359e..5b6bd138be84 100644
--- a/drivers/clk/tegra/clk-tegra30.c
+++ b/drivers/clk/tegra/clk-tegra30.c
@@ -930,7 +930,7 @@ static void __init tegra30_super_clk_init(void)
 	/* CCLKG */
 	clk = tegra_clk_register_super_cclk("cclk_g", cclk_g_parents,
 				  ARRAY_SIZE(cclk_g_parents),
-				  CLK_SET_RATE_PARENT,
+				  CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE,
 				  clk_base + CCLKG_BURST_POLICY,
 				  0, NULL);
 	clks[TEGRA30_CLK_CCLK_G] = clk;
-- 
2.30.2

