[PATCH hwmon 1/1] hwmon: (pmbus) Fix sensors readouts for MPS Multi-phase mp2888 controller

[Oleksandr Shamray <oleksandrs@nvidia.com>]

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Fix scale factors for reading MPS Multi-phase mp2888 controller.
Fixed sensors:
    - PIN/POUT: based on vendor documentation, set bscale factor 0.5W/LSB
    - IOUT: based on vendor documentation, set scale factor 0.25 A/LSB

Fixes: e4db7719d037 ("hwmon: (pmbus) Add support for MPS Multi-phase mp2888 controller")
Signed-off-by: Oleksandr Shamray <oleksandrs@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
---
 drivers/hwmon/pmbus/mp2888.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/pmbus/mp2888.c b/drivers/hwmon/pmbus/mp2888.c
index 8ecd4adfef40..529eb3c95bb6 100644
--- a/drivers/hwmon/pmbus/mp2888.c
+++ b/drivers/hwmon/pmbus/mp2888.c
@@ -109,7 +109,7 @@ mp2888_read_phase(struct i2c_client *client, struct mp2888_data *data, int page,
 	 * - Kcs is the DrMOS current sense gain of power stage, which is obtained from the
 	 *   register MP2888_MFR_VR_CONFIG1, bits 13-12 with the following selection of DrMOS
 	 *   (data->curr_sense_gain):
-	 *   00b - 5µA/A, 01b - 8.5µA/A, 10b - 9.7µA/A, 11b - 10µA/A.
+	 *   00b - 8.5µA/A, 01b - 9.7µA/A, 1b - 10µA/A, 11b - 5µA/A.
 	 * - Rcs is the internal phase current sense resistor. This parameter depends on hardware
 	 *   assembly. By default it is set to 1kΩ. In case of different assembly, user should
 	 *   scale this parameter by dividing it by Rcs.
@@ -118,10 +118,9 @@ mp2888_read_phase(struct i2c_client *client, struct mp2888_data *data, int page,
 	 * because sampling of current occurrence of bit weight has a big deviation, especially for
 	 * light load.
 	 */
-	ret = DIV_ROUND_CLOSEST(ret * 100 - 9800, data->curr_sense_gain);
-	ret = (data->phase_curr_resolution) ? ret * 2 : ret;
+	ret = DIV_ROUND_CLOSEST(ret * 200 - 19600, data->curr_sense_gain);
 	/* Scale according to total current resolution. */
-	ret = (data->total_curr_resolution) ? ret * 8 : ret * 4;
+	ret = (data->total_curr_resolution) ? ret * 2 : ret;
 	return ret;
 }
 
@@ -212,7 +211,7 @@ static int mp2888_read_word_data(struct i2c_client *client, int page, int phase,
 		ret = pmbus_read_word_data(client, page, phase, reg);
 		if (ret < 0)
 			return ret;
-		ret = data->total_curr_resolution ? ret * 2 : ret;
+		ret = data->total_curr_resolution ? ret  : DIV_ROUND_CLOSEST(ret, 2);
 		break;
 	case PMBUS_POUT_OP_WARN_LIMIT:
 		ret = pmbus_read_word_data(client, page, phase, reg);
@@ -223,7 +222,7 @@ static int mp2888_read_word_data(struct i2c_client *client, int page, int phase,
 		 * set 1. Actual power is reported with 0.5W or 1W respectively resolution. Scaling
 		 * is needed to match both.
 		 */
-		ret = data->total_curr_resolution ? ret * 4 : ret * 2;
+		ret = data->total_curr_resolution ? ret * 2 : ret;
 		break;
 	/*
 	 * The below registers are not implemented by device or implemented not according to the
-- 
2.14.1