[PATCH v2 1/2] hwmon: (amd_energy) Use unified function to read energy data

[Guenter Roeck <linux@roeck-us.net>]

The driver implements two separate functions to read and update
energy values. One function is called periodically and updates
cached enery information to avoid loss of data, the other reads
energy data on demand to report it to userspace. The second
function reads current energy data, adds the difference to the
data previously obtained by the first function, and then discards
the updated data.

Simplify the code and always call the first function, then report
the energy data obtained by this function to userspace.

Cc: Naveen Krishna Chatradhi <nchatrad@amd.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
v2: Added patch, simplification

 drivers/hwmon/amd_energy.c | 31 ++++++-------------------------
 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/drivers/hwmon/amd_energy.c b/drivers/hwmon/amd_energy.c
index a86cc8d6d93d..93bad64039f1 100644
--- a/drivers/hwmon/amd_energy.c
+++ b/drivers/hwmon/amd_energy.c
@@ -118,35 +118,12 @@ static void read_accumulate(struct amd_energy_data *data)
 	data->core_id++;
 }
 
-static void amd_add_delta(struct amd_energy_data *data, int ch,
-			  int cpu, long *val, u32 reg)
-{
-	struct sensor_accumulator *accum;
-	u64 input;
-
-	mutex_lock(&data->lock);
-	rdmsrl_safe_on_cpu(cpu, reg, &input);
-	input &= AMD_ENERGY_MASK;
-
-	accum = &data->accums[ch];
-	if (input >= accum->prev_value)
-		input += accum->energy_ctr -
-				accum->prev_value;
-	else
-		input += UINT_MAX - accum->prev_value +
-				accum->energy_ctr;
-
-	/* Energy consumed = (1/(2^ESU) * RAW * 1000000UL) μJoules */
-	*val = div64_ul(input * 1000000UL, BIT(data->energy_units));
-
-	mutex_unlock(&data->lock);
-}
-
 static int amd_energy_read(struct device *dev,
 			   enum hwmon_sensor_types type,
 			   u32 attr, int channel, long *val)
 {
 	struct amd_energy_data *data = dev_get_drvdata(dev);
+	struct sensor_accumulator *accum;
 	u32 reg;
 	int cpu;
 
@@ -162,7 +139,11 @@ static int amd_energy_read(struct device *dev,
 
 		reg = ENERGY_CORE_MSR;
 	}
-	amd_add_delta(data, channel, cpu, val, reg);
+
+	accumulate_delta(data, channel, cpu, reg);
+	accum = &data->accums[channel];
+
+	*val = div64_ul(accum->energy_ctr * 1000000UL, BIT(data->energy_units));
 
 	return 0;
 }
-- 
2.17.1