linux-kernel - [PATCH 26/40] hwmon: (lm90) Let lm90_read16() handle 8-bit read operations

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Message-Id: <20220525135758.2944744-27-linux@roeck-us.net>
Date:   Wed, 25 May 2022 06:57:44 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     linux-hwmon@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, Jean Delvare <jdelvare@...e.com>,
        Slawomir Stepien <sst@...zta.fm>,
        Guenter Roeck <linux@...ck-us.net>
Subject: [PATCH 26/40] hwmon: (lm90) Let lm90_read16() handle 8-bit read operations

Simplify the code a bit by handling single-register read operations
in lm90_read16(). All we need to do is to skip the low-byte read
operation if the register address is 0.

Signed-off-by: Guenter Roeck <linux@...ck-us.net>
---
 drivers/hwmon/lm90.c | 47 ++++++++++++++++----------------------------
 1 file changed, 17 insertions(+), 30 deletions(-)

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index 78eda648d960..20208f127508 100644
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -673,6 +673,10 @@ static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl,
 	oldh = lm90_read_reg(client, regh);
 	if (oldh < 0)
 		return oldh;
+
+	if (!regl)
+		return oldh << 8;
+
 	l = lm90_read_reg(client, regl);
 	if (l < 0)
 		return l;
@@ -804,29 +808,19 @@ static int lm90_update_limits(struct device *dev)
 		data->temp_hyst = val;
 	}
 
-	val = lm90_read_reg(client, LM90_REG_REMOTE_LOWH);
+	val = lm90_read16(client, LM90_REG_REMOTE_LOWH,
+			  (data->flags & LM90_HAVE_REM_LIMIT_EXT) ? LM90_REG_REMOTE_LOWL : 0,
+			  false);
 	if (val < 0)
 		return val;
-	data->temp[REMOTE_LOW] = val << 8;
+	data->temp[REMOTE_LOW] = val;
 
-	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
-		val = lm90_read_reg(client, LM90_REG_REMOTE_LOWL);
-		if (val < 0)
-			return val;
-		data->temp[REMOTE_LOW] |= val;
-	}
-
-	val = lm90_read_reg(client, LM90_REG_REMOTE_HIGHH);
+	val = lm90_read16(client, LM90_REG_REMOTE_HIGHH,
+			  (data->flags & LM90_HAVE_REM_LIMIT_EXT) ? LM90_REG_REMOTE_HIGHL : 0,
+			  false);
 	if (val < 0)
 		return val;
-	data->temp[REMOTE_HIGH] = val << 8;
-
-	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
-		val = lm90_read_reg(client, LM90_REG_REMOTE_HIGHL);
-		if (val < 0)
-			return val;
-		data->temp[REMOTE_HIGH] |= val;
-	}
+	data->temp[REMOTE_HIGH] = val;
 
 	if (data->flags & LM90_HAVE_OFFSET) {
 		val = lm90_read16(client, LM90_REG_REMOTE_OFFSH,
@@ -1063,18 +1057,11 @@ static int lm90_update_device(struct device *dev)
 			return val;
 		data->temp[LOCAL_HIGH] = val << 8;
 
-		if (data->reg_local_ext) {
-			val = lm90_read16(client, LM90_REG_LOCAL_TEMP,
-					  data->reg_local_ext, true);
-			if (val < 0)
-				return val;
-			data->temp[LOCAL_TEMP] = val;
-		} else {
-			val = lm90_read_reg(client, LM90_REG_LOCAL_TEMP);
-			if (val < 0)
-				return val;
-			data->temp[LOCAL_TEMP] = val << 8;
-		}
+		val = lm90_read16(client, LM90_REG_LOCAL_TEMP,
+				  data->reg_local_ext, true);
+		if (val < 0)
+			return val;
+		data->temp[LOCAL_TEMP] = val;
 		val = lm90_read16(client, LM90_REG_REMOTE_TEMPH,
 				  LM90_REG_REMOTE_TEMPL, true);
 		if (val < 0)
-- 
2.35.1