linux-kernel - [PATCH 14/15] drivers: thermal: tsens: Create function to return sign-extended temperature

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Message-Id: <07de61a57cf2362169d3b128405d7305eb20785f.1564091601.git.amit.kucheria@linaro.org>
Date:   Fri, 26 Jul 2019 03:48:49 +0530
From:   Amit Kucheria <amit.kucheria@...aro.org>
To:     linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        bjorn.andersson@...aro.org, edubezval@...il.com,
        andy.gross@...aro.org, Andy Gross <agross@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Mark Rutland <mark.rutland@....com>,
        Rob Herring <robh+dt@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>
Cc:     linux-pm@...r.kernel.org
Subject: [PATCH 14/15] drivers: thermal: tsens: Create function to return sign-extended temperature

Hide the details of how to convert values read from TSENS HW to mCelsius
behind a function. All versions of the IP can be supported as a result.

Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
---
 drivers/thermal/qcom/tsens-common.c | 34 ++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
index 7ab2e740a1da..13a875b99094 100644
--- a/drivers/thermal/qcom/tsens-common.c
+++ b/drivers/thermal/qcom/tsens-common.c
@@ -84,13 +84,35 @@ static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
 	return degc;
 }
 
+/**
+ * tsens_hw_to_mC - Return properly sign extended temperature in mCelsius,
+ * whether in ADC code or deciCelsius depending on IP version.
+ * This function handles the different widths of the signed integer across IPs.
+ */
+static int tsens_hw_to_mC(char *str, struct tsens_sensor *s, int field, int temp)
+{
+	struct tsens_priv *priv = s->priv;
+	u32 mask;
+
+	if (priv->feat->adc) {
+		/* Convert temperature from ADC code to milliCelsius */
+		return code_to_degc(temp, s) * 1000;
+	} else {
+		mask = GENMASK(priv->fields[field].msb,
+			       priv->fields[field].lsb) >> priv->fields[field].lsb;
+		dev_dbg(priv->dev, "%s: mask: %d\n", str, fls(mask));
+		/* Convert temperature from deciCelsius to milliCelsius */
+		return sign_extend32(temp, fls(mask) - 1) * 100;
+	}
+}
+
 int get_temp_tsens_valid(struct tsens_sensor *s, int *temp)
 {
 	struct tsens_priv *priv = s->priv;
 	int hw_id = s->hw_id;
 	u32 temp_idx = LAST_TEMP_0 + hw_id;
 	u32 valid_idx = VALID_0 + hw_id;
-	u32 last_temp = 0, valid, mask;
+	u32 last_temp = 0, valid;
 	int ret;
 
 	ret = regmap_field_read(priv->rf[valid_idx], &valid);
@@ -112,15 +134,7 @@ int get_temp_tsens_valid(struct tsens_sensor *s, int *temp)
 	if (ret)
 		return ret;
 
-	if (priv->feat->adc) {
-		/* Convert temperature from ADC code to milliCelsius */
-		*temp = code_to_degc(last_temp, s) * 1000;
-	} else {
-		mask = GENMASK(priv->fields[LAST_TEMP_0].msb,
-			       priv->fields[LAST_TEMP_0].lsb);
-		/* Convert temperature from deciCelsius to milliCelsius */
-		*temp = sign_extend32(last_temp, fls(mask) - 1) * 100;
-	}
+	*temp = tsens_hw_to_mC("get_temp", s, LAST_TEMP_0, last_temp);
 
 	return 0;
 }
-- 
2.17.1