power: pm8921-bms: charging curve adjustments
It was observed that while charging the reported soc sometimes reaches
100% before end of charging happens. At other times it does not reach
100% at end of charge and a abrupt jump to 100% soc happens.
Fix this by linearly increasing soc based on battery charge current
after constant voltage phase is reached. Constant voltage phase is
reached when battery voltage reaches the max value.
Also once constant voltage phase is reached and the voltage or charge
current decreases keep reporting the earlier soc. This could be because
of a transient system load.
Change-Id: I14c2f42d7897041db038ce85ce1124cf1ef261af
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
diff --git a/drivers/power/pm8921-bms.c b/drivers/power/pm8921-bms.c
index 88e0948..86cdc5f 100644
--- a/drivers/power/pm8921-bms.c
+++ b/drivers/power/pm8921-bms.c
@@ -122,6 +122,7 @@
int cc_reading_at_100;
int max_voltage_uv;
+ int chg_term_ua;
int default_rbatt_mohm;
int amux_2_trim_delta;
uint16_t prev_last_good_ocv_raw;
@@ -144,6 +145,10 @@
int prev_uuc_iavg_ma;
int prev_pc_unusable;
int adjust_soc_low_threshold;
+
+ int ibat_at_cv_ua;
+ int soc_at_cv;
+ int prev_chg_soc;
};
/*
@@ -1510,6 +1515,53 @@
return soc;
}
+static int charging_adjustments(struct pm8921_bms_chip *chip,
+ int soc, int vbat_uv, int ibat_ua)
+{
+ int chg_soc;
+
+ if (chip->soc_at_cv == -EINVAL) {
+ /* In constant current charging return the calc soc */
+ if (vbat_uv <= chip->max_voltage_uv)
+ pr_debug("CC CHG SOC %d\n", soc);
+
+ /* Note the CC to CV point */
+ if (vbat_uv >= chip->max_voltage_uv) {
+ chip->soc_at_cv = soc;
+ chip->prev_chg_soc = soc;
+ chip->ibat_at_cv_ua = ibat_ua;
+ pr_debug("CC_TO_CV ibat_ua = %d CHG SOC %d\n",
+ ibat_ua, soc);
+ }
+ return soc;
+ }
+
+ /*
+ * battery is in CV phase - begin liner inerpolation of soc based on
+ * battery charge current
+ */
+
+ /*
+ * if voltage lessened (possibly because of a system load)
+ * keep reporting the prev chg soc
+ */
+ if (vbat_uv <= chip->max_voltage_uv) {
+ pr_debug("CC CHG SOC %d\n", chip->prev_chg_soc);
+ return chip->prev_chg_soc;
+ }
+
+ chg_soc = linear_interpolate(chip->soc_at_cv, chip->ibat_at_cv_ua,
+ 100, -100000,
+ ibat_ua);
+
+ /* always report a higher soc */
+ if (chg_soc > chip->prev_chg_soc)
+ chip->prev_chg_soc = chg_soc;
+
+ pr_debug("CHG SOC %d\n", chip->prev_chg_soc);
+ return chip->prev_chg_soc;
+}
+
static int last_soc_est = -EINVAL;
static int adjust_soc(struct pm8921_bms_chip *chip, int soc, int batt_temp,
int rbatt , int fcc_uah, int uuc_uah, int cc_uah)
@@ -1534,9 +1586,6 @@
}
- if (ibat_ua < 0)
- goto out;
-
delta_ocv_uv_limit = DIV_ROUND_CLOSEST(ibat_ua, 1000);
ocv_est_uv = vbat_uv + (ibat_ua * rbatt)/1000;
@@ -1545,6 +1594,11 @@
(s64)fcc_uah - uuc_uah);
soc_est = bound_soc(soc_est);
+ if (ibat_ua < 0) {
+ soc = charging_adjustments(chip, soc, vbat_uv, ibat_ua);
+ goto out;
+ }
+
/*
* do not adjust
* if soc is same as what bms calculated
@@ -1628,10 +1682,10 @@
out:
pr_debug("ibat_ua = %d, vbat_uv = %d, ocv_est_uv = %d, pc_est = %d, "
"soc_est = %d, n = %d, delta_ocv_uv = %d, last_ocv_uv = %d, "
- "pc_new = %d, soc_new = %d\n",
+ "pc_new = %d, soc_new = %d, rbatt = %d, m = %d\n",
ibat_ua, vbat_uv, ocv_est_uv, pc_est,
soc_est, n, delta_ocv_uv, chip->last_ocv_uv,
- pc_new, soc_new);
+ pc_new, soc_new, rbatt, m);
return soc;
}
@@ -2402,6 +2456,9 @@
IBAT_TOL_MASK, IBAT_TOL_DEFAULT);
the_chip->charge_time_us = 0;
the_chip->catch_up_time_us = 0;
+
+ the_chip->soc_at_cv = -EINVAL;
+ the_chip->prev_chg_soc = -EINVAL;
pr_debug("start_percent = %u%%\n", the_chip->start_percent);
}
EXPORT_SYMBOL_GPL(pm8921_bms_charging_began);
@@ -2507,6 +2564,8 @@
the_chip->end_percent = -EINVAL;
the_chip->charge_time_us = 0;
the_chip->catch_up_time_us = 0;
+ the_chip->soc_at_cv = -EINVAL;
+ the_chip->prev_chg_soc = -EINVAL;
pm_bms_masked_write(the_chip, BMS_TOLERANCES,
IBAT_TOL_MASK, IBAT_TOL_NOCHG);
}
@@ -3107,6 +3166,7 @@
chip->r_sense = pdata->r_sense;
chip->v_cutoff = pdata->v_cutoff;
chip->max_voltage_uv = pdata->max_voltage_uv;
+ chip->chg_term_ua = pdata->chg_term_ua;
chip->batt_type = pdata->battery_type;
chip->rconn_mohm = pdata->rconn_mohm;
chip->start_percent = -EINVAL;