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authorNicolin Chen <nicoleotsuka@gmail.com>2019-04-17 16:12:09 -0700
committerGuenter Roeck <linux@roeck-us.net>2019-04-18 06:37:25 -0700
commit521c0b6116ef60e4b96ba42dbf285b2ad69071d4 (patch)
tree5531a43aec4f8fe58c96764af8761bcdd84096ec /drivers
parent7ebd8b66dd9e5a0b65e5ee5e2b8e7ca382ec97b7 (diff)
hwmon: (ina3221) Do not read-back to cache reg_config
Reading back the CONFIG register increases an extra I2C transaction. This's not necessary and could be replaced with a local variable caching the register settings. So this patch replaces two readback regmap_read() calls with a tmp variable. Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hwmon/ina3221.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index 74d39d212931..62040aac653c 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -309,21 +309,22 @@ static int ina3221_write_chip(struct device *dev, u32 attr, long val)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int ret, idx;
+ u32 tmp;
switch (attr) {
case hwmon_chip_samples:
idx = find_closest(val, ina3221_avg_samples,
ARRAY_SIZE(ina3221_avg_samples));
- ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
- INA3221_CONFIG_AVG_MASK,
- idx << INA3221_CONFIG_AVG_SHIFT);
+ tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
+ (idx << INA3221_CONFIG_AVG_SHIFT);
+ ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
if (ret)
return ret;
/* Update reg_config accordingly */
- return regmap_read(ina->regmap, INA3221_CONFIG,
- &ina->reg_config);
+ ina->reg_config = tmp;
+ return 0;
default:
return -EOPNOTSUPP;
}
@@ -359,6 +360,7 @@ static int ina3221_write_enable(struct device *dev, int channel, bool enable)
struct ina3221_data *ina = dev_get_drvdata(dev);
u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
u16 config_old = ina->reg_config & mask;
+ u32 tmp;
int ret;
config = enable ? mask : 0;
@@ -377,14 +379,13 @@ static int ina3221_write_enable(struct device *dev, int channel, bool enable)
}
/* Enable or disable the channel */
- ret = regmap_update_bits(ina->regmap, INA3221_CONFIG, mask, config);
+ tmp = (ina->reg_config & ~mask) | (config & mask);
+ ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
if (ret)
goto fail;
/* Cache the latest config register value */
- ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
- if (ret)
- goto fail;
+ ina->reg_config = tmp;
/* For disabling routine, decrease refcount or suspend() at last */
if (!enable)