power: pm8921-bms: use shutdown_soc to force power on soc
Experiments have shown that shutdown_soc is very accurate. However
upon a restart, the battery may be unsettled, leading to a significantly
different power on soc.
Update the code to force the value of shutdown soc on the power on
soc. To do this simply update the power on OCV (open circuit voltage)
value.
Change-Id: I1015b800e559cb08422364ffc8c8b981ddd4f07e
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
diff --git a/drivers/power/pm8921-bms.c b/drivers/power/pm8921-bms.c
index e544ec8..2612760 100644
--- a/drivers/power/pm8921-bms.c
+++ b/drivers/power/pm8921-bms.c
@@ -123,16 +123,25 @@
unsigned int rconn_mohm;
struct mutex last_ocv_uv_mutex;
int last_ocv_uv;
+ int pon_ocv_uv;
int last_cc_uah;
struct timeval t;
int last_uuc_uah;
int enable_fcc_learning;
int shutdown_soc;
+ int allow_soc_increase_without_chg;
+ int shutdown_soc_timer_expired;
+ struct delayed_work shutdown_soc_work;
int timer_uuc_expired;
struct delayed_work uuc_timer_work;
int uuc_uah_iavg_prev;
};
+/*
+ * protects against simultaneous adjustment of ocv based on shutdown soc and
+ * invalidating the shutdown soc
+ */
+static DEFINE_MUTEX(soc_invalidation_mutex);
static int shutdown_soc_invalid;
static struct pm8921_bms_chip *the_chip;
@@ -715,6 +724,82 @@
return 0;
}
+/* get ocv given a soc -- reverse lookup */
+static int interpolate_ocv(struct pm8921_bms_chip *chip,
+ int batt_temp_degc, int pc)
+{
+ int i, ocvrow1, ocvrow2, ocv;
+ int rows, cols;
+ int row1 = 0;
+ int row2 = 0;
+
+ rows = chip->pc_temp_ocv_lut->rows;
+ cols = chip->pc_temp_ocv_lut->cols;
+ if (pc > chip->pc_temp_ocv_lut->percent[0]) {
+ pr_debug("pc %d greater than known pc ranges for sfd\n", pc);
+ row1 = 0;
+ row2 = 0;
+ }
+ if (pc < chip->pc_temp_ocv_lut->percent[rows - 1]) {
+ pr_debug("pc %d less than known pc ranges for sf\n", pc);
+ row1 = rows - 1;
+ row2 = rows - 1;
+ }
+ for (i = 0; i < rows; i++) {
+ if (pc == chip->pc_temp_ocv_lut->percent[i]) {
+ row1 = i;
+ row2 = i;
+ break;
+ }
+ if (pc > chip->pc_temp_ocv_lut->percent[i]) {
+ row1 = i - 1;
+ row2 = i;
+ break;
+ }
+ }
+
+ if (batt_temp_degc < chip->pc_temp_ocv_lut->temp[0])
+ batt_temp_degc = chip->pc_temp_ocv_lut->temp[0];
+ if (batt_temp_degc > chip->pc_temp_ocv_lut->temp[cols - 1])
+ batt_temp_degc = chip->pc_temp_ocv_lut->temp[cols - 1];
+
+ for (i = 0; i < cols; i++)
+ if (batt_temp_degc <= chip->pc_temp_ocv_lut->temp[i])
+ break;
+ if (batt_temp_degc == chip->pc_temp_ocv_lut->temp[i]) {
+ ocv = linear_interpolate(
+ chip->pc_temp_ocv_lut->ocv[row1][i],
+ chip->pc_temp_ocv_lut->percent[row1],
+ chip->pc_temp_ocv_lut->ocv[row2][i],
+ chip->pc_temp_ocv_lut->percent[row2],
+ pc);
+ return ocv;
+ }
+
+ ocvrow1 = linear_interpolate(
+ chip->pc_temp_ocv_lut->ocv[row1][i - 1],
+ chip->pc_temp_ocv_lut->temp[i - 1],
+ chip->pc_temp_ocv_lut->ocv[row1][i],
+ chip->pc_temp_ocv_lut->temp[i],
+ batt_temp_degc);
+
+ ocvrow2 = linear_interpolate(
+ chip->pc_temp_ocv_lut->ocv[row2][i - 1],
+ chip->pc_temp_ocv_lut->temp[i - 1],
+ chip->pc_temp_ocv_lut->ocv[row2][i],
+ chip->pc_temp_ocv_lut->temp[i],
+ batt_temp_degc);
+
+ ocv = linear_interpolate(
+ ocvrow1,
+ chip->pc_temp_ocv_lut->percent[row1],
+ ocvrow2,
+ chip->pc_temp_ocv_lut->percent[row2],
+ pc);
+
+ return ocv;
+}
+
static int interpolate_pc(struct pm8921_bms_chip *chip,
int batt_temp, int ocv)
{
@@ -895,6 +980,7 @@
convert_vbatt_raw_to_uv(chip, usb_chg,
raw->last_good_ocv_raw, &raw->last_good_ocv_uv);
chip->last_ocv_uv = raw->last_good_ocv_uv;
+ pr_debug("PON_OCV_UV = %d\n", chip->last_ocv_uv);
} else if (chip->prev_last_good_ocv_raw != raw->last_good_ocv_raw) {
chip->prev_last_good_ocv_raw = raw->last_good_ocv_raw;
convert_vbatt_raw_to_uv(chip, usb_chg,
@@ -1469,46 +1555,16 @@
return soc;
}
-#define MAX_SHUTDOWN_ADJUST_SECONDS 1800
-static int adjust_for_shutdown_soc(struct pm8921_bms_chip *chip, int soc)
+#define IGNORE_SOC_TEMP_DECIDEG 50
+static void backup_soc(struct pm8921_bms_chip *chip, int batt_temp, int soc)
{
- struct timespec uptime;
- int val;
+ if (soc == 0)
+ soc = 0xFF;
- /* value of zero means the shutdown soc should not be used */
- if (chip->shutdown_soc == 0)
- return soc;
+ if (batt_temp < IGNORE_SOC_TEMP_DECIDEG)
+ soc = 0;
- if (shutdown_soc_invalid) {
- chip->shutdown_soc = 0;
- return soc;
- }
-
- do_posix_clock_monotonic_gettime(&uptime);
-
- if (uptime.tv_sec >= MAX_SHUTDOWN_ADJUST_SECONDS) {
- /*
- * adjusted for a long time now, switch to reporting the
- * calculated soc
- */
- chip->shutdown_soc = 0;
- return soc;
- }
-
- val = ((MAX_SHUTDOWN_ADJUST_SECONDS - uptime.tv_sec)
- * chip->shutdown_soc
- + uptime.tv_sec * soc);
- val /= MAX_SHUTDOWN_ADJUST_SECONDS;
- pr_debug("shutdown_soc = %d, adj soc = %d, calc soc = %d\n",
- chip->shutdown_soc, val, soc);
-
- return val;
-}
-
-static void backup_soc(struct pm8921_bms_chip *chip, int last_soc)
-{
- /* TODO: if 0x107 is free for all variants 8917, 8038 etc */
- pm8xxx_writeb(the_chip->dev->parent, TEMP_SOC_STORAGE, last_soc);
+ pm8xxx_writeb(the_chip->dev->parent, TEMP_SOC_STORAGE, soc);
}
static void read_shutdown_soc(struct pm8921_bms_chip *chip)
@@ -1528,12 +1584,107 @@
void pm8921_bms_invalidate_shutdown_soc(void)
{
pr_debug("Invalidating shutdown soc - the battery was removed\n");
+ mutex_lock(&soc_invalidation_mutex);
shutdown_soc_invalid = 1;
- if (the_chip)
- the_chip->shutdown_soc = 0;
+ last_soc = -EINVAL;
+ if (the_chip) {
+ /* reset to pon ocv undoing what the adjusting did */
+ if (the_chip->pon_ocv_uv) {
+ the_chip->last_ocv_uv = the_chip->pon_ocv_uv;
+ pr_debug("resetting ocv to pon_ocv = %d\n",
+ the_chip->pon_ocv_uv);
+ }
+ }
+ mutex_unlock(&soc_invalidation_mutex);
}
EXPORT_SYMBOL(pm8921_bms_invalidate_shutdown_soc);
+static int adjust_remaining_charge_for_shutdown_soc(
+ struct pm8921_bms_chip *chip,
+ int batt_temp,
+ int chargecycles,
+ int fcc_uah,
+ int uuc_uah,
+ int cc_uah,
+ int remaining_charge_uah)
+{
+ s64 rc;
+ int pc;
+ int ocv, ocv_uv;
+ int batt_temp_degc = batt_temp / 10;
+ int new_pc;
+ int shutdown_soc;
+
+ mutex_lock(&soc_invalidation_mutex);
+ shutdown_soc = chip->shutdown_soc;
+ /*
+ * value of zero means the shutdown soc should not be used, the battery
+ * was removed for extended period, the coincell capacitor could have
+ * drained
+ */
+ if (shutdown_soc == 0) {
+ rc = remaining_charge_uah;
+ goto out;
+ }
+
+ /*
+ * shutdown_soc_invalid means the shutdown soc should not be used,
+ * the battery was removed for a small period
+ */
+ if (shutdown_soc_invalid) {
+ rc = remaining_charge_uah;
+ goto out;
+ }
+
+ /* value of 0xFF means shutdown soc was 0% */
+ if (shutdown_soc == 0xFF)
+ shutdown_soc = 0;
+
+ pr_debug("shutdown_soc = %d forcing it now\n", shutdown_soc);
+
+ rc = (s64)shutdown_soc * (fcc_uah - uuc_uah);
+ rc = div_s64(rc, 100) + cc_uah + uuc_uah;
+ pc = DIV_ROUND_CLOSEST((int)rc * 100, fcc_uah);
+ pc = clamp(pc, 0, 100);
+
+ ocv = interpolate_ocv(chip, batt_temp_degc, pc);
+
+ pr_debug("To force shutdown_soc = %d, rc = %d, pc = %d, ocv mv = %d\n",
+ shutdown_soc, (int)rc, pc, ocv);
+ new_pc = interpolate_pc(chip, batt_temp_degc, ocv);
+ pr_debug("test revlookup pc = %d for ocv = %d\n", new_pc, ocv);
+
+ while (abs(new_pc - pc) > 1) {
+ int delta_mv = 5;
+
+ if (new_pc > pc)
+ delta_mv = -1 * delta_mv;
+
+ ocv = ocv + delta_mv;
+ new_pc = interpolate_pc(chip, batt_temp_degc, ocv);
+ pr_debug("test revlookup pc = %d for ocv = %d\n", new_pc, ocv);
+ }
+
+ ocv_uv = ocv * 1000;
+
+ chip->pon_ocv_uv = chip->last_ocv_uv;
+ chip->last_ocv_uv = ocv_uv;
+out:
+ mutex_unlock(&soc_invalidation_mutex);
+ return (int)rc;
+}
+
+#define SHOW_SHUTDOWN_SOC_MS 30000
+static void shutdown_soc_work(struct work_struct *work)
+{
+ struct pm8921_bms_chip *chip = container_of(work,
+ struct pm8921_bms_chip, shutdown_soc_work.work);
+
+ pr_debug("not forcing shutdown soc anymore\n");
+ /* it has been 30 seconds since init, no need to show shutdown soc */
+ chip->shutdown_soc_timer_expired = 1;
+}
+
/*
* Remaining Usable Charge = remaining_charge (charge at ocv instance)
* - coloumb counter charge
@@ -1548,7 +1699,6 @@
int remaining_charge_uah, soc;
int cc_uah;
int rbatt;
- int shutdown_adjusted_soc;
int iavg_ua;
int delta_time_us;
@@ -1561,6 +1711,17 @@
&iavg_ua,
&delta_time_us);
+ if (delta_time_us == 0)
+ /*
+ * soc for the first time - use shutdown soc
+ * to adjust pon ocv
+ */
+ remaining_charge_uah = adjust_remaining_charge_for_shutdown_soc(
+ chip,
+ batt_temp, chargecycles,
+ fcc_uah, unusable_charge_uah,
+ cc_uah, remaining_charge_uah);
+
/* calculate remaining usable charge */
remaining_usable_charge_uah = remaining_charge_uah
- cc_uah
@@ -1578,7 +1739,7 @@
if (soc > 100)
soc = 100;
- pr_debug("SOC = %u%%\n", soc);
+ pr_debug("SOC = %d%%\n", soc);
if (bms_fake_battery != -EINVAL) {
pr_debug("Returning Fake SOC = %d%%\n", bms_fake_battery);
@@ -1618,10 +1779,25 @@
last_soc);
}
- shutdown_adjusted_soc = adjust_for_shutdown_soc(chip, last_soc);
- backup_soc(chip, shutdown_adjusted_soc);
+ if (chip->shutdown_soc != 0
+ && !shutdown_soc_invalid
+ && !chip->shutdown_soc_timer_expired) {
+ /*
+ * force shutdown soc if it is valid and the shutdown soc show
+ * timer has not expired
+ */
+ if (chip->shutdown_soc != 0xFF)
+ last_soc = chip->shutdown_soc;
+ else
+ last_soc = 0;
- return shutdown_adjusted_soc;
+ pr_debug("Forcing SHUTDOWN_SOC = %d\n", last_soc);
+ }
+
+ backup_soc(chip, batt_temp, last_soc);
+ pr_debug("Reported SOC = %d\n", last_soc);
+
+ return last_soc;
}
#define MIN_DELTA_625_UV 1000
@@ -2661,6 +2837,12 @@
pr_info("OK battery_capacity_at_boot=%d volt = %d ocv = %d\n",
pm8921_bms_get_percent_charge(),
vbatt, chip->last_ocv_uv);
+
+ INIT_DELAYED_WORK(&chip->shutdown_soc_work, shutdown_soc_work);
+ schedule_delayed_work(&chip->shutdown_soc_work,
+ round_jiffies_relative(msecs_to_jiffies
+ (SHOW_SHUTDOWN_SOC_MS)));
+
return 0;
free_irqs: