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From:   Ansuel Smith <ansuelsmth@gmail.com>
To:     Amit Kucheria <amitk@kernel.org>
Cc:     Ansuel Smith <ansuelsmth@gmail.com>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Zhang Rui <rui.zhang@intel.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Rob Herring <robh+dt@kernel.org>, linux-pm@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v10 5/8] drivers: thermal: tsens: Fix bug in sensor enable for msm8960
Date:   Wed, 17 Feb 2021 20:40:07 +0100
Message-Id: <20210217194011.22649-6-ansuelsmth@gmail.com>
In-Reply-To: <20210217194011.22649-1-ansuelsmth@gmail.com>
References: <20210217194011.22649-1-ansuelsmth@gmail.com>
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It's present a hardware bug in tsens VER_0 where if sensors upper to id
6 are enabled selectively, underfined results are expected. Fix this by
enabling all the remaining sensor in one step.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
---
 drivers/thermal/qcom/tsens-8960.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/thermal/qcom/tsens-8960.c b/drivers/thermal/qcom/tsens-8960.c
index 86585f439985..248aaa65b5b0 100644
--- a/drivers/thermal/qcom/tsens-8960.c
+++ b/drivers/thermal/qcom/tsens-8960.c
@@ -27,9 +27,9 @@
 #define EN			BIT(0)
 #define SW_RST			BIT(1)
 #define SENSOR0_EN		BIT(3)
+#define MEASURE_PERIOD		BIT(18)
 #define SLP_CLK_ENA		BIT(26)
 #define SLP_CLK_ENA_8660	BIT(24)
-#define MEASURE_PERIOD		1
 #define SENSOR0_SHIFT		3
 
 /* INT_STATUS_ADDR bitmasks */
@@ -132,11 +132,26 @@ static int enable_8960(struct tsens_priv *priv, int id)
 	if (ret)
 		return ret;
 
-	mask = BIT(id + SENSOR0_SHIFT);
+	/* HARDWARE BUG:
+	 * On platform with more than 5 sensors, all the remaining
+	 * sensors needs to be enabled all togheder or underfined
+	 * results are expected. (Sensor 6-7 disabled, Sensor 3
+	 * disabled...) In the original driver, all the sensors
+	 * are enabled in one step hence this bug is not triggered.
+	 */
+	if (id > 5)
+		mask = GENMASK(10, 6);
+	else
+		mask = BIT(id);
+
+	mask <<= SENSOR0_SHIFT;
+
 	ret = regmap_write(priv->tm_map, CNTL_ADDR, reg | SW_RST);
 	if (ret)
 		return ret;
 
+	reg |= MEASURE_PERIOD;
+
 	if (priv->num_sensors > 1)
 		reg |= mask | SLP_CLK_ENA | EN;
 	else
-- 
2.30.0