drivers/power/max14577_charger.c

   1 /*
   2  * Battery charger driver for the Maxim 14577
   3  *
   4  * Copyright (C) 2013 Samsung Electronics
   5  * Krzysztof Kozlowski <k.kozlowski@samsung.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/power_supply.h>
  21 #include <linux/mfd/max14577-private.h>
  22
  23 struct max14577_charger {
  24         struct device *dev;
  25         struct max14577 *max14577;
  26         struct power_supply     charger;
  27
  28         unsigned int    charging_state;
  29         unsigned int    battery_state;
  30 };
  31
  32 static int max14577_get_charger_state(struct max14577_charger *chg)
  33 {
  34         struct regmap *rmap = chg->max14577->regmap;
  35         int state = POWER_SUPPLY_STATUS_DISCHARGING;
  36         u8 reg_data;
  37
  38         /*
  39          * Charging occurs only if:
  40          *  - CHGCTRL2/MBCHOSTEN == 1
  41          *  - STATUS2/CGMBC == 1
  42          *
  43          * TODO:
  44          *  - handle FULL after Top-off timer (EOC register may be off
  45          *    and the charger won't be charging although MBCHOSTEN is on)
  46          *  - handle properly dead-battery charging (respect timer)
  47          *  - handle timers (fast-charge and prequal) /MBCCHGERR/
  48          */
  49         max14577_read_reg(rmap, MAX14577_CHG_REG_CHG_CTRL2, &reg_data);
  50         if ((reg_data & CHGCTRL2_MBCHOSTEN_MASK) == 0)
  51                 goto state_set;
  52
  53         max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
  54         if (reg_data & STATUS3_CGMBC_MASK) {
  55                 /* Charger or USB-cable is connected */
  56                 if (reg_data & STATUS3_EOC_MASK)
  57                         state = POWER_SUPPLY_STATUS_FULL;
  58                 else
  59                         state = POWER_SUPPLY_STATUS_CHARGING;
  60                 goto state_set;
  61         }
  62
  63 state_set:
  64         chg->charging_state = state;
  65         return state;
  66 }
  67
  68 /*
  69  * Supported charge types:
  70  *  - POWER_SUPPLY_CHARGE_TYPE_NONE
  71  *  - POWER_SUPPLY_CHARGE_TYPE_FAST
  72  */
  73 static int max14577_get_charge_type(struct max14577_charger *chg)
  74 {
  75         /*
  76          * TODO: CHARGE_TYPE_TRICKLE (VCHGR_RC or EOC)?
  77          * As spec says:
  78          * [after reaching EOC interrupt]
  79          * "When the battery is fully charged, the 30-minute (typ)
  80          *  top-off timer starts. The device continues to trickle
  81          *  charge the battery until the top-off timer runs out."
  82          */
  83         if (max14577_get_charger_state(chg) == POWER_SUPPLY_STATUS_CHARGING)
  84                 return POWER_SUPPLY_CHARGE_TYPE_FAST;
  85         return POWER_SUPPLY_CHARGE_TYPE_NONE;
  86 }
  87
  88 static int max14577_get_online(struct max14577_charger *chg)
  89 {
  90         struct regmap *rmap = chg->max14577->regmap;
  91         u8 reg_data;
  92
  93         max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
  94         reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
  95         switch (reg_data) {
  96         case MAX14577_CHARGER_TYPE_USB:
  97         case MAX14577_CHARGER_TYPE_DEDICATED_CHG:
  98         case MAX14577_CHARGER_TYPE_SPECIAL_500MA:
  99         case MAX14577_CHARGER_TYPE_SPECIAL_1A:
 100         case MAX14577_CHARGER_TYPE_DEAD_BATTERY:
 101                 return 1;
 102         case MAX14577_CHARGER_TYPE_NONE:
 103         case MAX14577_CHARGER_TYPE_DOWNSTREAM_PORT:
 104         case MAX14577_CHARGER_TYPE_RESERVED:
 105         default:
 106                 return 0;
 107         }
 108 }
 109
 110 /*
 111  * Supported health statuses:
 112  *  - POWER_SUPPLY_HEALTH_DEAD
 113  *  - POWER_SUPPLY_HEALTH_OVERVOLTAGE
 114  *  - POWER_SUPPLY_HEALTH_GOOD
 115  */
 116 static int max14577_get_battery_health(struct max14577_charger *chg)
 117 {
 118         struct regmap *rmap = chg->max14577->regmap;
 119         int state = POWER_SUPPLY_HEALTH_GOOD;
 120         u8 reg_data;
 121
 122         max14577_read_reg(rmap, MAX14577_MUIC_REG_STATUS2, &reg_data);
 123         reg_data = ((reg_data & STATUS2_CHGTYP_MASK) >> STATUS2_CHGTYP_SHIFT);
 124         if (reg_data == MAX14577_CHARGER_TYPE_DEAD_BATTERY) {
 125                 state = POWER_SUPPLY_HEALTH_DEAD;
 126                 goto state_set;
 127         }
 128
 129         max14577_read_reg(rmap, MAX14577_CHG_REG_STATUS3, &reg_data);
 130         if (reg_data & STATUS3_OVP_MASK) {
 131                 state = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
 132                 goto state_set;
 133         }
 134
 135 state_set:
 136         chg->battery_state = state;
 137         return state;
 138 }
 139
 140 /*
 141  * Always returns 1.
 142  * The max14577 chip doesn't report any status of battery presence.
 143  * Lets assume that it will always be used with some battery.
 144  */
 145 static int max14577_get_present(struct max14577_charger *chg)
 146 {
 147         return 1;
 148 }
 149
 150 /*
 151  * Sets charger registers to proper and safe default values.
 152  * Some of these values are equal to defaults in MAX14577E
 153  * data sheet but there are minor differences.
 154  */
 155 static void max14577_charger_reg_init(struct max14577_charger *chg)
 156 {
 157         struct regmap *rmap = chg->max14577->regmap;
 158         u8 reg_data;
 159
 160         /*
 161          * Charger-Type Manual Detection, default off (set CHGTYPMAN to 0)
 162          * Charger-Detection Enable, default on (set CHGDETEN to 1)
 163          * Combined mask of CHGDETEN and CHGTYPMAN will zero the CHGTYPMAN bit
 164          */
 165         reg_data = 0x1 << CDETCTRL1_CHGDETEN_SHIFT;
 166         max14577_update_reg(rmap, MAX14577_REG_CDETCTRL1,
 167                         CDETCTRL1_CHGDETEN_MASK | CDETCTRL1_CHGTYPMAN_MASK,
 168                         reg_data);
 169
 170         /* Battery Fast-Charge Timer, from SM-V700: 6hrs */
 171         reg_data = 0x3 << CHGCTRL1_TCHW_SHIFT;
 172         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL1, reg_data);
 173
 174         /*
 175          * Wall-Adapter Rapid Charge, default on
 176          * Battery-Charger, default on
 177          */
 178         reg_data = 0x1 << CHGCTRL2_VCHGR_RC_SHIFT;
 179         reg_data |= 0x1 << CHGCTRL2_MBCHOSTEN_SHIFT;
 180         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL2, reg_data);
 181
 182         /* Battery-Charger Constant Voltage (CV) Mode, from SM-V700: 4.35V */
 183         reg_data = 0xf << CHGCTRL3_MBCCVWRC_SHIFT;
 184         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL3, reg_data);
 185
 186         /*
 187          * Fast Battery-Charge Current Low, default 200-950mA
 188          * Fast Battery-Charge Current High, from SM-V700: 450mA
 189          */
 190         reg_data = 0x1 << CHGCTRL4_MBCICHWRCL_SHIFT;
 191         reg_data |= 0x5 << CHGCTRL4_MBCICHWRCH_SHIFT;
 192         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL4, reg_data);
 193
 194         /* End-of-Charge Current, from SM-V700: 50mA */
 195         reg_data = 0x0 << CHGCTRL5_EOCS_SHIFT;
 196         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL5, reg_data);
 197
 198         /* Auto Charging Stop, default off */
 199         reg_data = 0x0 << CHGCTRL6_AUTOSTOP_SHIFT;
 200         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL6, reg_data);
 201
 202         /* Overvoltage-Protection Threshold, from SM-V700: 6.5V */
 203         reg_data = 0x2 << CHGCTRL7_OTPCGHCVS_SHIFT;
 204         max14577_write_reg(rmap, MAX14577_REG_CHGCTRL7, reg_data);
 205 }
 206
 207 /* Support property from charger */
 208 static enum power_supply_property max14577_charger_props[] = {
 209         POWER_SUPPLY_PROP_STATUS,
 210         POWER_SUPPLY_PROP_CHARGE_TYPE,
 211         POWER_SUPPLY_PROP_HEALTH,
 212         POWER_SUPPLY_PROP_PRESENT,
 213         POWER_SUPPLY_PROP_ONLINE,
 214         POWER_SUPPLY_PROP_MODEL_NAME,
 215         POWER_SUPPLY_PROP_MANUFACTURER,
 216 };
 217
 218 static const char *model_name = "MAX14577";
 219 static const char *manufacturer = "Maxim Integrated";
 220
 221 static int max14577_charger_get_property(struct power_supply *psy,
 222                             enum power_supply_property psp,
 223                             union power_supply_propval *val)
 224 {
 225         struct max14577_charger *chg = container_of(psy,
 226                                                   struct max14577_charger,
 227                                                   charger);
 228         int ret = 0;
 229
 230         switch (psp) {
 231         case POWER_SUPPLY_PROP_STATUS:
 232                 val->intval = max14577_get_charger_state(chg);
 233                 break;
 234         case POWER_SUPPLY_PROP_CHARGE_TYPE:
 235                 val->intval = max14577_get_charge_type(chg);
 236                 break;
 237         case POWER_SUPPLY_PROP_HEALTH:
 238                 val->intval = max14577_get_battery_health(chg);
 239                 break;
 240         case POWER_SUPPLY_PROP_PRESENT:
 241                 val->intval = max14577_get_present(chg);
 242                 break;
 243         case POWER_SUPPLY_PROP_ONLINE:
 244                 val->intval = max14577_get_online(chg);
 245                 break;
 246         case POWER_SUPPLY_PROP_MODEL_NAME:
 247                 val->strval = model_name;
 248                 break;
 249         case POWER_SUPPLY_PROP_MANUFACTURER:
 250                 val->strval = manufacturer;
 251                 break;
 252         default:
 253                 return -EINVAL;
 254         }
 255
 256         return ret;
 257 }
 258
 259 static int max14577_charger_probe(struct platform_device *pdev)
 260 {
 261         struct max14577_charger *chg;
 262         struct max14577 *max14577 = dev_get_drvdata(pdev->dev.parent);
 263         int ret;
 264
 265         chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
 266         if (!chg)
 267                 return -ENOMEM;
 268
 269         platform_set_drvdata(pdev, chg);
 270         chg->dev = &pdev->dev;
 271         chg->max14577 = max14577;
 272
 273         max14577_charger_reg_init(chg);
 274
 275         chg->charger.name = "max14577-charger",
 276         chg->charger.type = POWER_SUPPLY_TYPE_BATTERY,
 277         chg->charger.properties = max14577_charger_props,
 278         chg->charger.num_properties = ARRAY_SIZE(max14577_charger_props),
 279         chg->charger.get_property = max14577_charger_get_property,
 280
 281         ret = power_supply_register(&pdev->dev, &chg->charger);
 282         if (ret) {
 283                 dev_err(&pdev->dev, "failed: power supply register\n");
 284                 return ret;
 285         }
 286
 287         return 0;
 288 }
 289
 290 static int max14577_charger_remove(struct platform_device *pdev)
 291 {
 292         struct max14577_charger *chg = platform_get_drvdata(pdev);
 293
 294         power_supply_unregister(&chg->charger);
 295
 296         return 0;
 297 }
 298
 299 static struct platform_driver max14577_charger_driver = {
 300         .driver = {
 301                 .owner  = THIS_MODULE,
 302                 .name   = "max14577-charger",
 303         },
 304         .probe          = max14577_charger_probe,
 305         .remove         = max14577_charger_remove,
 306 };
 307 module_platform_driver(max14577_charger_driver);
 308
 309 MODULE_AUTHOR("Krzysztof Kozlowski <k.kozlowski@samsung.com>");
 310 MODULE_DESCRIPTION("MAXIM 14577 charger driver");
 311 MODULE_LICENSE("GPL");