power: qpnp-fg-gen3: Limit how frequently fg data can be queried

Querying the fuelgauge for data is expensive, so doing it frequently can
result in a significant increase in power consumption.

Limit how frequently data queries can be sent to 5 seconds in order to
prevent fuelgauge queries from consuming too much power. Only do this while
there is no USB cable connected to the device, since the charger drivers
need fresh statistics when there's a USB cable connected.

Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>

drivers/power/supply/qcom/fg-core.h

@@ -412,6 +412,11 @@ static const struct fg_pt fg_tsmc_osc_table[] = {
 	{  90,		444992 },
 };
 
+struct fg_saved_data {
+	union power_supply_propval val;
+	unsigned long last_req_expires;
+};
+
 struct fg_chip {
 	struct thermal_zone_device	*tz_dev;
 	struct device		*dev;
@@ -496,6 +501,7 @@ struct fg_chip {
 	struct work_struct	esr_filter_work;
 	struct alarm		esr_filter_alarm;
 	ktime_t			last_delta_temp_time;
+	struct fg_saved_data	saved_data[POWER_SUPPLY_PROP_MAX];
 };
 
 /* Debugfs data structures are below */

drivers/power/supply/qcom/qpnp-fg-gen3.c

@@ -417,6 +417,8 @@ module_param_named(
 static int fg_restart;
 static bool fg_sram_dump;
 
+#define FG_RATE_LIM_MS (5 * MSEC_PER_SEC)
+
 /* All getters HERE */
 
 #define VOLTAGE_15BIT_MASK	GENMASK(14, 0)
@@ -3874,8 +3876,36 @@ static int fg_psy_get_property(struct power_supply *psy,
 				       union power_supply_propval *pval)
 {
 	struct fg_chip *chip = power_supply_get_drvdata(psy);
+	struct fg_saved_data *sd = chip->saved_data + psp;
+	union power_supply_propval typec_sts = { .intval = -1 };
 	int rc = 0;
 
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_RESISTANCE_ID:
+	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+	case POWER_SUPPLY_PROP_CYCLE_COUNT_ID:
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+	case POWER_SUPPLY_PROP_SOC_REPORTING_READY:
+		/* These props don't require a fg query; don't ratelimit them */
+		break;
+	default:
+		if (!sd->last_req_expires)
+			break;
+
+		if (usb_psy_initialized(chip))
+			power_supply_get_property(chip->usb_psy,
+				POWER_SUPPLY_PROP_TYPEC_MODE, &typec_sts);
+
+		if (typec_sts.intval == POWER_SUPPLY_TYPEC_NONE &&
+			time_before(jiffies, sd->last_req_expires)) {
+			*pval = sd->val;
+			return 0;
+		}
+		break;
+	}
+
 	switch (psp) {
 	case POWER_SUPPLY_PROP_CAPACITY:
 		rc = fg_get_prop_capacity(chip, &pval->intval);
@@ -4006,6 +4036,9 @@ static int fg_psy_get_property(struct power_supply *psy,
 	if (rc < 0)
 		return -ENODATA;
 
+	sd->val = *pval;
+	sd->last_req_expires = jiffies + msecs_to_jiffies(FG_RATE_LIM_MS);
+
 	return 0;
 }
 

include/linux/power_supply.h

@@ -304,6 +304,7 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 	POWER_SUPPLY_PROP_BATTERY_TYPE,
 	POWER_SUPPLY_PROP_CYCLE_COUNTS,
+	POWER_SUPPLY_PROP_MAX
 };
 
 enum power_supply_type {