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From: Andrey Smirnov <andrew.smirnov@gmail.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Andrey Smirnov <andrew.smirnov@gmail.com>,
	Lucas Stach <l.stach@pengutronix.de>,
	Chris Healy <cphealy@gmail.com>,
	Eduardo Valentin <edubezval@gmail.com>,
	Angus Ainslie <angus@akkea.ca>,
	linux-imx@nxp.com, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v8 10/12] thermal: qoriq: Do not report invalid temperature reading
Date: Tue, 10 Dec 2019 08:41:51 -0800	[thread overview]
Message-ID: <20191210164153.10463-11-andrew.smirnov@gmail.com> (raw)
In-Reply-To: <20191210164153.10463-1-andrew.smirnov@gmail.com>

Before returning measured temperature data to upper layer we need to
make sure that the reading was marked as "valid" to avoid reporting
bogus data.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Lucas Stach <l.stach@pengutronix.de>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Angus Ainslie (Purism) <angus@akkea.ca>
Cc: linux-imx@nxp.com
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/thermal/qoriq_thermal.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/qoriq_thermal.c b/drivers/thermal/qoriq_thermal.c
index 6c5e53ea7711..b684d3ceda69 100644
--- a/drivers/thermal/qoriq_thermal.c
+++ b/drivers/thermal/qoriq_thermal.c
@@ -48,6 +48,7 @@
 #define REGS_TRITSR(n)	(0x100 + 16 * (n)) /* Immediate Temperature
 					    * Site Register
 					    */
+#define TRITSR_V	BIT(31)
 #define REGS_TTRnCR(n)	(0xf10 + 4 * (n)) /* Temperature Range n
 					   * Control Register
 					   */
@@ -80,8 +81,24 @@ static int tmu_get_temp(void *p, int *temp)
 	struct qoriq_sensor *qsensor = p;
 	struct qoriq_tmu_data *qdata = qoriq_sensor_to_data(qsensor);
 	u32 val;
+	/*
+	 * REGS_TRITSR(id) has the following layout:
+	 *
+	 * 31  ... 7 6 5 4 3 2 1 0
+	 *  V          TEMP
+	 *
+	 * Where V bit signifies if the measurement is ready and is
+	 * within sensor range. TEMP is an 8 bit value representing
+	 * temperature in C.
+	 */
+	if (regmap_read_poll_timeout(qdata->regmap,
+				     REGS_TRITSR(qsensor->id),
+				     val,
+				     val & TRITSR_V,
+				     USEC_PER_MSEC,
+				     10 * USEC_PER_MSEC))
+		return -ENODATA;
 
-	regmap_read(qdata->regmap, REGS_TRITSR(qsensor->id), &val);
 	*temp = (val & 0xff) * 1000;
 
 	return 0;
-- 
2.21.0


  parent reply	other threads:[~2019-12-10 16:42 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-10 16:41 [PATCH v8 00/12] QorIQ TMU multi-sensor and HWMON support Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 01/12] thermal: qoriq: Add local struct device pointer Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 02/12] thermal: qoriq: Don't store struct thermal_zone_device reference Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 03/12] thermal: qoriq: Add local struct qoriq_sensor pointer Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 04/12] thermal: qoriq: Embed per-sensor data into struct qoriq_tmu_data Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 05/12] thermal: qoriq: Pass data to qoriq_tmu_register_tmu_zone() directly Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 06/12] thermal: qoriq: Pass data to qoriq_tmu_calibration() directly Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 07/12] thermal: qoriq: Drop unnecessary drvdata cleanup Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 08/12] thermal: qoriq: Convert driver to use regmap API Andrey Smirnov
2019-12-13  6:16   ` [EXT] " Andy Tang
2019-12-13  7:47     ` Daniel Lezcano
2019-12-13  8:52       ` Andy Tang
2019-12-10 16:41 ` [PATCH v8 09/12] thermal: qoriq: Enable all sensors before registering them Andrey Smirnov
2019-12-10 16:41 ` Andrey Smirnov [this message]
2019-12-10 16:41 ` [PATCH v8 11/12] thermal_hwmon: Add devres wrapper for thermal_add_hwmon_sysfs() Andrey Smirnov
2019-12-10 16:41 ` [PATCH v8 12/12] thermal: qoriq: Add hwmon support Andrey Smirnov
2019-12-10 18:05 ` [PATCH v8 00/12] QorIQ TMU multi-sensor and HWMON support Daniel Lezcano

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