qpnp-fg-gen3: prime CC_SOC_SW when capacity learning begins

CC_SOC_SW can accumulate error over time and get saturated high
during capacity learning. Prime it to a value based on battery
SOC when capacity learning begins. This way, it can be ensured
that CC_SOC_SW doesn't saturate in a capacity learning cycle.

Change-Id: I2866ed6dadee84e84bf28fb08dc3a5a0ae353852
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>

1 files changed, 28 insertions, 21 deletions

diff --git a/drivers/power/supply/qcom/qpnp-fg-gen3.c b/drivers/power/supply/qcom/qpnp-fg-gen3.c
index d0e1340456a0..5ce74dab9aab 100644
--- a/drivers/power/supply/qcom/qpnp-fg-gen3.c
+++ b/drivers/power/supply/qcom/qpnp-fg-gen3.c
@@ -525,7 +525,7 @@ static int fg_get_sram_prop(struct fg_chip *chip, enum fg_sram_param_id id,
 }
 
 #define CC_SOC_30BIT	GENMASK(29, 0)
-static int fg_get_cc_soc(struct fg_chip *chip, int *val)
+static int fg_get_charge_raw(struct fg_chip *chip, int *val)
 {
 	int rc, cc_soc;
 
@@ -539,7 +539,7 @@ static int fg_get_cc_soc(struct fg_chip *chip, int *val)
 	return 0;
 }
 
-static int fg_get_cc_soc_sw(struct fg_chip *chip, int *val)
+static int fg_get_charge_counter(struct fg_chip *chip, int *val)
 {
 	int rc, cc_soc;
 
@@ -1241,7 +1241,7 @@ static void fg_cap_learning_post_process(struct fg_chip *chip)
 		chip->cl.final_cc_uah, old_cap, chip->cl.learned_cc_uah);
 }
 
-static int  fg_cap_learning_process_full_data(struct fg_chip *chip)
+static int fg_cap_learning_process_full_data(struct fg_chip *chip)
 {
 	int rc, cc_soc_sw, cc_soc_delta_pct;
 	int64_t delta_cc_uah;
@@ -1263,30 +1263,39 @@ static int  fg_cap_learning_process_full_data(struct fg_chip *chip)
 	return 0;
 }
 
-static int fg_cap_learning_begin(struct fg_chip *chip, int batt_soc)
+#define BATT_SOC_32BIT	GENMASK(31, 0)
+static int fg_cap_learning_begin(struct fg_chip *chip, u32 batt_soc)
 {
-	int rc, cc_soc_sw;
+	int rc, cc_soc_sw, batt_soc_msb;
 
-	if (DIV_ROUND_CLOSEST(batt_soc * 100, FULL_SOC_RAW) >
+	batt_soc_msb = batt_soc >> 24;
+	if (DIV_ROUND_CLOSEST(batt_soc_msb * 100, FULL_SOC_RAW) >
 		chip->dt.cl_start_soc) {
 		fg_dbg(chip, FG_CAP_LEARN, "Battery SOC %d is high!, not starting\n",
-			batt_soc);
+			batt_soc_msb);
 		return -EINVAL;
 	}
 
-	chip->cl.init_cc_uah = div64_s64(chip->cl.learned_cc_uah * batt_soc,
+	chip->cl.init_cc_uah = div64_s64(chip->cl.learned_cc_uah * batt_soc_msb,
 					FULL_SOC_RAW);
-	rc = fg_get_sram_prop(chip, FG_SRAM_CC_SOC_SW, &cc_soc_sw);
+
+	/* Prime cc_soc_sw with battery SOC when capacity learning begins */
+	cc_soc_sw = div64_s64((int64_t)batt_soc * CC_SOC_30BIT,
+				BATT_SOC_32BIT);
+	rc = fg_sram_write(chip, chip->sp[FG_SRAM_CC_SOC_SW].addr_word,
+		chip->sp[FG_SRAM_CC_SOC_SW].addr_byte, (u8 *)&cc_soc_sw,
+		chip->sp[FG_SRAM_CC_SOC_SW].len, FG_IMA_ATOMIC);
 	if (rc < 0) {
-		pr_err("Error in getting CC_SOC_SW, rc=%d\n", rc);
-		return rc;
+		pr_err("Error in writing cc_soc_sw, rc=%d\n", rc);
+		goto out;
 	}
 
 	chip->cl.init_cc_soc_sw = cc_soc_sw;
 	chip->cl.active = true;
 	fg_dbg(chip, FG_CAP_LEARN, "Capacity learning started @ battery SOC %d init_cc_soc_sw:%d\n",
-		batt_soc, chip->cl.init_cc_soc_sw);
-	return 0;
+		batt_soc_msb, chip->cl.init_cc_soc_sw);
+out:
+	return rc;
 }
 
 static int fg_cap_learning_done(struct fg_chip *chip)
@@ -1318,7 +1327,7 @@ out:
 #define FULL_SOC_RAW	255
 static void fg_cap_learning_update(struct fg_chip *chip)
 {
-	int rc, batt_soc;
+	int rc, batt_soc, batt_soc_msb;
 
 	mutex_lock(&chip->cl.lock);
 
@@ -1337,11 +1346,9 @@ static void fg_cap_learning_update(struct fg_chip *chip)
 		goto out;
 	}
 
-	/* We need only the most significant byte here */
-	batt_soc = (u32)batt_soc >> 24;
-
+	batt_soc_msb = (u32)batt_soc >> 24;
 	fg_dbg(chip, FG_CAP_LEARN, "Chg_status: %d cl_active: %d batt_soc: %d\n",
-		chip->charge_status, chip->cl.active, batt_soc);
+		chip->charge_status, chip->cl.active, batt_soc_msb);
 
 	/* Initialize the starting point of learning capacity */
 	if (!chip->cl.active) {
@@ -1363,7 +1370,7 @@ static void fg_cap_learning_update(struct fg_chip *chip)
 
 		if (chip->charge_status == POWER_SUPPLY_STATUS_NOT_CHARGING) {
 			fg_dbg(chip, FG_CAP_LEARN, "Capacity learning aborted @ battery SOC %d\n",
-				batt_soc);
+				batt_soc_msb);
 			chip->cl.active = false;
 			chip->cl.init_cc_uah = 0;
 		}
@@ -2821,7 +2828,7 @@ static int fg_psy_get_property(struct power_supply *psy,
 		pval->intval = chip->cyc_ctr.id;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_NOW_RAW:
-		rc = fg_get_cc_soc(chip, &pval->intval);
+		rc = fg_get_charge_raw(chip, &pval->intval);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_NOW:
 		pval->intval = chip->cl.init_cc_uah;
@@ -2830,7 +2837,7 @@ static int fg_psy_get_property(struct power_supply *psy,
 		pval->intval = chip->cl.learned_cc_uah;
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
-		rc = fg_get_cc_soc_sw(chip, &pval->intval);
+		rc = fg_get_charge_counter(chip, &pval->intval);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 		rc = fg_get_time_to_full(chip, &pval->intval);