lkml.org 
[lkml]   [2022]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/4] power: supply: max17042_battery: Add unit conversion macros
Date
Instead of sprinkling the code with magic numbers, put the unit
definitions used by the gauge into a set of macros. Macros are
used instead of simple defines in order to not require floating
point operations for divisions.

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
---
drivers/power/supply/max17042_battery.c | 40 +++++++++++++++----------
1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/power/supply/max17042_battery.c b/drivers/power/supply/max17042_battery.c
index ab031bbfbe78..c019d6c52363 100644
--- a/drivers/power/supply/max17042_battery.c
+++ b/drivers/power/supply/max17042_battery.c
@@ -51,6 +51,15 @@

#define MAX17042_VMAX_TOLERANCE 50 /* 50 mV */

+#define MAX17042_CURRENT_LSB 1562500ll /* µV */
+#define MAX17042_CURRENT_RSENSE(x) (x * MAX17042_CURRENT_LSB) /* µV */
+#define MAX17042_CAPACITY_LSB 5000000ll /* µVh */
+#define MAX17042_CAPACITY_RSENSE(x) (x * MAX17042_CAPACITY_LSB) /* µVh */
+#define MAX17042_TIME(x) (x * 5625 / 1000) /* s */
+#define MAX17042_VOLTAGE(x) (x * 625 / 8) /* µV */
+#define MAX17042_RESISTANCE(x) (x / 4096) /* Ω */
+#define MAX17042_TEMPERATURE(x) (x / 256) /* °C */
+
struct max17042_chip {
struct i2c_client *client;
struct regmap *regmap;
@@ -103,8 +112,7 @@ static int max17042_get_temperature(struct max17042_chip *chip, int *temp)

*temp = sign_extend32(data, 15);
/* The value is converted into deci-centigrade scale */
- /* Units of LSB = 1 / 256 degree Celsius */
- *temp = *temp * 10 / 256;
+ *temp = MAX17042_TEMPERATURE(*temp * 10);
return 0;
}

@@ -161,7 +169,7 @@ static int max17042_get_status(struct max17042_chip *chip, int *status)
return ret;

avg_current = sign_extend32(data, 15);
- avg_current *= 1562500 / chip->pdata->r_sns;
+ avg_current *= MAX17042_CURRENT_LSB / chip->pdata->r_sns;

if (avg_current > 0)
*status = POWER_SUPPLY_STATUS_CHARGING;
@@ -181,7 +189,7 @@ static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
goto health_error;

/* bits [0-3] unused */
- vavg = val * 625 / 8;
+ vavg = MAX17042_VOLTAGE(val);
/* Convert to millivolts */
vavg /= 1000;

@@ -190,7 +198,7 @@ static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
goto health_error;

/* bits [0-3] unused */
- vbatt = val * 625 / 8;
+ vbatt = MAX17042_VOLTAGE(val);
/* Convert to millivolts */
vbatt /= 1000;

@@ -297,21 +305,21 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = MAX17042_VOLTAGE(data);
break;
case POWER_SUPPLY_PROP_VOLTAGE_AVG:
ret = regmap_read(map, MAX17042_AvgVCELL, &data);
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = MAX17042_VOLTAGE(data);
break;
case POWER_SUPPLY_PROP_VOLTAGE_OCV:
ret = regmap_read(map, MAX17042_OCVInternal, &data);
if (ret < 0)
return ret;

- val->intval = data * 625 / 8;
+ val->intval = MAX17042_VOLTAGE(data);
break;
case POWER_SUPPLY_PROP_CAPACITY:
if (chip->pdata->enable_current_sense)
@@ -328,7 +336,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = MAX17042_CAPACITY_RSENSE(data);
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -337,7 +345,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = MAX17042_CAPACITY_RSENSE(data);
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -346,7 +354,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 5000000ll;
+ data64 = MAX17042_CAPACITY_RSENSE(data);
do_div(data64, chip->pdata->r_sns);
val->intval = data64;
break;
@@ -355,7 +363,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 5000000ll;
+ data64 = MAX17042_CAPACITY_RSENSE(sign_extend64(data, 15));
val->intval = div_s64(data64, chip->pdata->r_sns);
break;
case POWER_SUPPLY_PROP_TEMP:
@@ -397,7 +405,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 1562500ll;
+ data64 = MAX17042_CURRENT_RSENSE(sign_extend64(data, 15));
val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
@@ -409,7 +417,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = sign_extend64(data, 15) * 1562500ll;
+ data64 = MAX17042_CURRENT_RSENSE(sign_extend64(data, 15));
val->intval = div_s64(data64, chip->pdata->r_sns);
} else {
return -EINVAL;
@@ -420,7 +428,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- data64 = data * 1562500ll;
+ data64 = MAX17042_CURRENT_RSENSE(data);
val->intval = div_s64(data64, chip->pdata->r_sns);
break;
case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
@@ -428,7 +436,7 @@ static int max17042_get_property(struct power_supply *psy,
if (ret < 0)
return ret;

- val->intval = data * 5625 / 1000;
+ val->intval = MAX17042_TIME(data);
break;
default:
return -EINVAL;
--
2.35.1
\
 
 \ /
  Last update: 2022-03-18 01:12    [W:0.095 / U:0.932 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site