From: Tom Levens <tom.levens@cern.ch>
To: <linux@roeck-us.net>
Cc: <jdelvare@suse.com>, <robh+dt@kernel.org>, <mark.rutland@arm.com>,
<linux-kernel@vger.kernel.org>, <linux-hwmon@vger.kernel.org>,
<devicetree@vger.kernel.org>, Tom Levens <tom.levens@cern.ch>
Subject: [PATCH v2 1/3] hwmon: ltc2990: refactor value conversion
Date: Thu, 17 Nov 2016 13:10:14 +0100 [thread overview]
Message-ID: <1479384616-12479-1-git-send-email-tom.levens@cern.ch> (raw)
Conversion from raw values to signed integers has been refactored using
the macros in bitops.h.
Signed-off-by: Tom Levens <tom.levens@cern.ch>
---
drivers/hwmon/ltc2990.c | 27 ++++++++++-----------------
1 files changed, 10 insertions(+), 17 deletions(-)
diff --git a/drivers/hwmon/ltc2990.c b/drivers/hwmon/ltc2990.c
index 8f8fe05..0ec4102 100644
--- a/drivers/hwmon/ltc2990.c
+++ b/drivers/hwmon/ltc2990.c
@@ -9,8 +9,12 @@
* This driver assumes the chip is wired as a dual current monitor, and
* reports the voltage drop across two series resistors. It also reports
* the chip's internal temperature and Vcc power supply voltage.
+ *
+ * Value conversion refactored
+ * by Tom Levens <tom.levens@cern.ch>
*/
+#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
@@ -34,19 +38,10 @@
#define LTC2990_CONTROL_MODE_CURRENT 0x06
#define LTC2990_CONTROL_MODE_VOLTAGE 0x07
-/* convert raw register value to sign-extended integer in 16-bit range */
-static int ltc2990_voltage_to_int(int raw)
-{
- if (raw & BIT(14))
- return -(0x4000 - (raw & 0x3FFF)) << 2;
- else
- return (raw & 0x3FFF) << 2;
-}
-
/* Return the converted value from the given register in uV or mC */
-static int ltc2990_get_value(struct i2c_client *i2c, u8 reg, int *result)
+static int ltc2990_get_value(struct i2c_client *i2c, u8 reg, s32 *result)
{
- int val;
+ s32 val;
val = i2c_smbus_read_word_swapped(i2c, reg);
if (unlikely(val < 0))
@@ -55,18 +50,16 @@ static int ltc2990_get_value(struct i2c_client *i2c, u8 reg, int *result)
switch (reg) {
case LTC2990_TINT_MSB:
/* internal temp, 0.0625 degrees/LSB, 13-bit */
- val = (val & 0x1FFF) << 3;
- *result = (val * 1000) >> 7;
+ *result = sign_extend32(val, 12) * 1000 / 16;
break;
case LTC2990_V1_MSB:
case LTC2990_V3_MSB:
/* Vx-Vy, 19.42uV/LSB. Depends on mode. */
- *result = ltc2990_voltage_to_int(val) * 1942 / (4 * 100);
+ *result = sign_extend32(val, 14) * 1942 / 100;
break;
case LTC2990_VCC_MSB:
/* Vcc, 305.18μV/LSB, 2.5V offset */
- *result = (ltc2990_voltage_to_int(val) * 30518 /
- (4 * 100 * 1000)) + 2500;
+ *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
break;
default:
return -EINVAL; /* won't happen, keep compiler happy */
@@ -79,7 +72,7 @@ static ssize_t ltc2990_show_value(struct device *dev,
struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
- int value;
+ s32 value;
int ret;
ret = ltc2990_get_value(dev_get_drvdata(dev), attr->index, &value);
--
1.7.1
next reply other threads:[~2016-11-17 23:43 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-17 12:10 Tom Levens [this message]
2016-11-17 12:10 ` [PATCH v2 2/3] hwmon: ltc2990: add devicetree binding Tom Levens
2016-11-18 14:50 ` Rob Herring
2016-11-18 15:36 ` Tom Levens
2016-11-17 12:10 ` [PATCH v2 3/3] hwmon: ltc2990: support all measurement modes Tom Levens
2016-11-17 16:56 ` Guenter Roeck
2016-11-17 17:40 ` Mike Looijmans
2016-11-17 18:56 ` Guenter Roeck
2016-11-17 19:52 ` Mike Looijmans
2016-11-17 21:54 ` Guenter Roeck
2016-11-17 23:25 ` Tom Levens
2016-11-17 23:40 ` Guenter Roeck
2016-11-18 12:23 ` Tom Levens
2016-11-18 14:16 ` Guenter Roeck
2017-06-28 14:24 ` Mike Looijmans
2017-06-28 15:01 ` Guenter Roeck
2017-06-28 15:29 ` Tom Levens
2017-06-28 16:00 ` Guenter Roeck
2017-06-28 17:02 ` Tom Levens
2017-06-28 17:33 ` Mike Looijmans
2017-06-28 17:55 ` Guenter Roeck
2017-06-29 7:45 ` Mike Looijmans
2017-06-29 11:46 ` Tom Levens
2016-11-17 15:06 ` [PATCH v2 1/3] hwmon: ltc2990: refactor value conversion Guenter Roeck
2016-11-17 16:23 ` Tom Levens
2016-11-17 16:36 ` Guenter Roeck
2016-11-18 8:18 ` Tom Levens
2016-11-18 14:09 ` Guenter Roeck
2016-11-18 14:17 ` Guenter Roeck
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1479384616-12479-1-git-send-email-tom.levens@cern.ch \
--to=tom.levens@cern.ch \
--cc=devicetree@vger.kernel.org \
--cc=jdelvare@suse.com \
--cc=linux-hwmon@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux@roeck-us.net \
--cc=mark.rutland@arm.com \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).