From c6fdea96646dcc868ef0d565c527823ac30ef234 Mon Sep 17 00:00:00 2001 From: Pavel Machek Date: Sun, 10 Jan 2021 21:53:54 +0200 Subject: [PATCH] power: supply: cpcap-charger: Limiting charge current on Droid 4 Droid 4 has same problem as N900: it is often necessary to manually tweak current draw from USB, for example when using thin charging cable. Cc: Arthur Demchenkov Cc: Carl Philipp Klemm Cc: Merlijn Wajer Cc: Pavel Machek Signed-off-by: Pavel Machek [tony@atomide.com: rebased, cleaned up whitespace issues, updated comments] Signed-off-by: Tony Lindgren Signed-off-by: Sebastian Reichel --- drivers/power/supply/cpcap-charger.c | 49 +++++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 6 deletions(-) diff --git a/drivers/power/supply/cpcap-charger.c b/drivers/power/supply/cpcap-charger.c index 5a00815..81270ed 100644 --- a/drivers/power/supply/cpcap-charger.c +++ b/drivers/power/supply/cpcap-charger.c @@ -89,6 +89,8 @@ * CPCAP_REG_CRM charge currents. These seem to match MC13783UG.pdf * values in "Table 8-3. Charge Path Regulator Current Limit * Characteristics" for the nominal values. + * + * Except 70mA and 1.596A and unlimited, these are simply 88.7mA / step. */ #define CPCAP_REG_CRM_ICHRG(val) (((val) & 0xf) << 0) #define CPCAP_REG_CRM_ICHRG_0A000 CPCAP_REG_CRM_ICHRG(0x0) @@ -140,6 +142,7 @@ struct cpcap_charger_ddata { int status; int state; int voltage; + int limit_current; }; struct cpcap_interrupt_desc { @@ -166,6 +169,7 @@ static enum power_supply_property cpcap_charger_props[] = { POWER_SUPPLY_PROP_STATUS, POWER_SUPPLY_PROP_ONLINE, POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE, + POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_CURRENT_NOW, }; @@ -229,6 +233,9 @@ static int cpcap_charger_get_property(struct power_supply *psy, case POWER_SUPPLY_PROP_STATUS: val->intval = ddata->status; break; + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT: + val->intval = ddata->limit_current; + break; case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE: val->intval = ddata->voltage; break; @@ -300,6 +307,26 @@ cpcap_charger_get_bat_const_charge_voltage(struct cpcap_charger_ddata *ddata) return voltage; } +static int cpcap_charger_current_to_regval(int microamp) +{ + int miliamp = microamp / 1000; + int res; + + if (miliamp < 0) + return -EINVAL; + if (miliamp < 70) + return CPCAP_REG_CRM_ICHRG(0x0); + if (miliamp < 177) + return CPCAP_REG_CRM_ICHRG(0x1); + if (miliamp > 1596) + return CPCAP_REG_CRM_ICHRG(0xe); + + res = microamp / 88666; + if (res > 0xd) + res = 0xd; + return CPCAP_REG_CRM_ICHRG(res); +} + static int cpcap_charger_set_property(struct power_supply *psy, enum power_supply_property psp, const union power_supply_propval *val) @@ -308,6 +335,12 @@ static int cpcap_charger_set_property(struct power_supply *psy, int voltage, batvolt; switch (psp) { + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT: + if (cpcap_charger_current_to_regval(val->intval) < 0) + return -EINVAL; + ddata->limit_current = val->intval; + schedule_delayed_work(&ddata->detect_work, 0); + break; case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE: voltage = cpcap_charger_match_voltage(val->intval); batvolt = cpcap_charger_get_bat_const_charge_voltage(ddata); @@ -327,6 +360,7 @@ static int cpcap_charger_property_is_writeable(struct power_supply *psy, enum power_supply_property psp) { switch (psp) { + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT: case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE: return 1; default: @@ -652,18 +686,20 @@ static void cpcap_usb_detect(struct work_struct *work) if (!ddata->feeding_vbus && cpcap_charger_vbus_valid(ddata) && s.chrgcurr1) { - int max_current; - int vchrg; + int max_current = 532000; + int vchrg, ichrg; if (cpcap_charger_battery_found(ddata)) - max_current = CPCAP_REG_CRM_ICHRG_1A596; - else - max_current = CPCAP_REG_CRM_ICHRG_0A532; + max_current = 1596000; + + if (max_current > ddata->limit_current) + max_current = ddata->limit_current; + ichrg = cpcap_charger_current_to_regval(max_current); vchrg = cpcap_charger_voltage_to_regval(ddata->voltage); error = cpcap_charger_set_state(ddata, CPCAP_REG_CRM_VCHRG(vchrg), - max_current, 0); + ichrg, 0); if (error) goto out_err; cpcap_charger_update_state(ddata, @@ -837,6 +873,7 @@ static int cpcap_charger_probe(struct platform_device *pdev) ddata->dev = &pdev->dev; ddata->voltage = 4200000; + ddata->limit_current = 532000; ddata->reg = dev_get_regmap(ddata->dev->parent, NULL); if (!ddata->reg) -- 2.7.4