drivers/power/supply/max8903_charger.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * max8903_charger.c - Maxim 8903 USB/Adapter Charger Driver
   4  *
   5  * Copyright (C) 2011 Samsung Electronics
   6  * MyungJoo Ham <myungjoo.ham@samsung.com>
   7  */
   8
   9 #include <linux/gpio/consumer.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/slab.h>
  14 #include <linux/power_supply.h>
  15 #include <linux/platform_device.h>
  16
  17 struct max8903_data {
  18         struct device *dev;
  19         struct power_supply *psy;
  20         struct power_supply_desc psy_desc;
  21         /*
  22          * GPIOs
  23          * chg, flt, dcm and usus are optional.
  24          * dok or uok must be present.
  25          * If dok is present, cen must be present.
  26          */
  27         struct gpio_desc *cen; /* Charger Enable input */
  28         struct gpio_desc *dok; /* DC (Adapter) Power OK output */
  29         struct gpio_desc *uok; /* USB Power OK output */
  30         struct gpio_desc *chg; /* Charger status output */
  31         struct gpio_desc *flt; /* Fault output */
  32         struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */
  33         struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */
  34         bool fault;
  35         bool usb_in;
  36         bool ta_in;
  37 };
  38
  39 static enum power_supply_property max8903_charger_props[] = {
  40         POWER_SUPPLY_PROP_STATUS, /* Charger status output */
  41         POWER_SUPPLY_PROP_ONLINE, /* External power source */
  42         POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
  43 };
  44
  45 static int max8903_get_property(struct power_supply *psy,
  46                 enum power_supply_property psp,
  47                 union power_supply_propval *val)
  48 {
  49         struct max8903_data *data = power_supply_get_drvdata(psy);
  50
  51         switch (psp) {
  52         case POWER_SUPPLY_PROP_STATUS:
  53                 val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
  54                 if (data->chg) {
  55                         if (gpiod_get_value(data->chg))
  56                                 /* CHG asserted */
  57                                 val->intval = POWER_SUPPLY_STATUS_CHARGING;
  58                         else if (data->usb_in || data->ta_in)
  59                                 val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
  60                         else
  61                                 val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
  62                 }
  63                 break;
  64         case POWER_SUPPLY_PROP_ONLINE:
  65                 val->intval = 0;
  66                 if (data->usb_in || data->ta_in)
  67                         val->intval = 1;
  68                 break;
  69         case POWER_SUPPLY_PROP_HEALTH:
  70                 val->intval = POWER_SUPPLY_HEALTH_GOOD;
  71                 if (data->fault)
  72                         val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
  73                 break;
  74         default:
  75                 return -EINVAL;
  76         }
  77
  78         return 0;
  79 }
  80
  81 static irqreturn_t max8903_dcin(int irq, void *_data)
  82 {
  83         struct max8903_data *data = _data;
  84         bool ta_in;
  85         enum power_supply_type old_type;
  86
  87         /*
  88          * This means the line is asserted.
  89          *
  90          * The signal is active low, but the inversion is handled in the GPIO
  91          * library as the line should be flagged GPIO_ACTIVE_LOW in the device
  92          * tree.
  93          */
  94         ta_in = gpiod_get_value(data->dok);
  95
  96         if (ta_in == data->ta_in)
  97                 return IRQ_HANDLED;
  98
  99         data->ta_in = ta_in;
 100
 101         /* Set Current-Limit-Mode 1:DC 0:USB */
 102         if (data->dcm)
 103                 gpiod_set_value(data->dcm, ta_in);
 104
 105         /* Charger Enable / Disable */
 106         if (data->cen) {
 107                 int val;
 108
 109                 if (ta_in)
 110                         /* Certainly enable if DOK is asserted */
 111                         val = 1;
 112                 else if (data->usb_in)
 113                         /* Enable if the USB charger is enabled */
 114                         val = 1;
 115                 else
 116                         /* Else default-disable */
 117                         val = 0;
 118
 119                 gpiod_set_value(data->cen, val);
 120         }
 121
 122         dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
 123                         "Connected" : "Disconnected");
 124
 125         old_type = data->psy_desc.type;
 126
 127         if (data->ta_in)
 128                 data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
 129         else if (data->usb_in)
 130                 data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
 131         else
 132                 data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 133
 134         if (old_type != data->psy_desc.type)
 135                 power_supply_changed(data->psy);
 136
 137         return IRQ_HANDLED;
 138 }
 139
 140 static irqreturn_t max8903_usbin(int irq, void *_data)
 141 {
 142         struct max8903_data *data = _data;
 143         bool usb_in;
 144         enum power_supply_type old_type;
 145
 146         /*
 147          * This means the line is asserted.
 148          *
 149          * The signal is active low, but the inversion is handled in the GPIO
 150          * library as the line should be flagged GPIO_ACTIVE_LOW in the device
 151          * tree.
 152          */
 153         usb_in = gpiod_get_value(data->uok);
 154
 155         if (usb_in == data->usb_in)
 156                 return IRQ_HANDLED;
 157
 158         data->usb_in = usb_in;
 159
 160         /* Do not touch Current-Limit-Mode */
 161
 162         /* Charger Enable / Disable */
 163         if (data->cen) {
 164                 int val;
 165
 166                 if (usb_in)
 167                         /* Certainly enable if UOK is asserted */
 168                         val = 1;
 169                 else if (data->ta_in)
 170                         /* Enable if the DC charger is enabled */
 171                         val = 1;
 172                 else
 173                         /* Else default-disable */
 174                         val = 0;
 175
 176                 gpiod_set_value(data->cen, val);
 177         }
 178
 179         dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
 180                         "Connected" : "Disconnected");
 181
 182         old_type = data->psy_desc.type;
 183
 184         if (data->ta_in)
 185                 data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
 186         else if (data->usb_in)
 187                 data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
 188         else
 189                 data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 190
 191         if (old_type != data->psy_desc.type)
 192                 power_supply_changed(data->psy);
 193
 194         return IRQ_HANDLED;
 195 }
 196
 197 static irqreturn_t max8903_fault(int irq, void *_data)
 198 {
 199         struct max8903_data *data = _data;
 200         bool fault;
 201
 202         /*
 203          * This means the line is asserted.
 204          *
 205          * The signal is active low, but the inversion is handled in the GPIO
 206          * library as the line should be flagged GPIO_ACTIVE_LOW in the device
 207          * tree.
 208          */
 209         fault = gpiod_get_value(data->flt);
 210
 211         if (fault == data->fault)
 212                 return IRQ_HANDLED;
 213
 214         data->fault = fault;
 215
 216         if (fault)
 217                 dev_err(data->dev, "Charger suffers a fault and stops.\n");
 218         else
 219                 dev_err(data->dev, "Charger recovered from a fault.\n");
 220
 221         return IRQ_HANDLED;
 222 }
 223
 224 static int max8903_setup_gpios(struct platform_device *pdev)
 225 {
 226         struct max8903_data *data = platform_get_drvdata(pdev);
 227         struct device *dev = &pdev->dev;
 228         bool ta_in = false;
 229         bool usb_in = false;
 230         enum gpiod_flags flags;
 231
 232         data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN);
 233         if (IS_ERR(data->dok))
 234                 return dev_err_probe(dev, PTR_ERR(data->dok),
 235                                      "failed to get DOK GPIO");
 236         if (data->dok) {
 237                 gpiod_set_consumer_name(data->dok, data->psy_desc.name);
 238                 /*
 239                  * The DC OK is pulled up to 1 and goes low when a charger
 240                  * is plugged in (active low) but in the device tree the
 241                  * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
 242                  * here if the DC charger is plugged in.
 243                  */
 244                 ta_in = gpiod_get_value(data->dok);
 245         }
 246
 247         data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN);
 248         if (IS_ERR(data->uok))
 249                 return dev_err_probe(dev, PTR_ERR(data->uok),
 250                                      "failed to get UOK GPIO");
 251         if (data->uok) {
 252                 gpiod_set_consumer_name(data->uok, data->psy_desc.name);
 253                 /*
 254                  * The USB OK is pulled up to 1 and goes low when a USB charger
 255                  * is plugged in (active low) but in the device tree the
 256                  * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
 257                  * here if the USB charger is plugged in.
 258                  */
 259                 usb_in = gpiod_get_value(data->uok);
 260         }
 261
 262         /* Either DC OK or USB OK must be provided */
 263         if (!data->dok && !data->uok) {
 264                 dev_err(dev, "no valid power source\n");
 265                 return -EINVAL;
 266         }
 267
 268         /*
 269          * If either charger is already connected at this point,
 270          * assert the CEN line and enable charging from the start.
 271          *
 272          * The line is active low but also marked with GPIO_ACTIVE_LOW
 273          * in the device tree, so when we assert the line with
 274          * GPIOD_OUT_HIGH the line will be driven low.
 275          */
 276         flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 277         /*
 278          * If DC OK is provided, Charger Enable CEN is compulsory
 279          * so this is not optional here.
 280          */
 281         data->cen = devm_gpiod_get(dev, "cen", flags);
 282         if (IS_ERR(data->cen))
 283                 return dev_err_probe(dev, PTR_ERR(data->cen),
 284                                      "failed to get CEN GPIO");
 285         gpiod_set_consumer_name(data->cen, data->psy_desc.name);
 286
 287         /*
 288          * If the DC charger is connected, then select it.
 289          *
 290          * The DCM line should be marked GPIO_ACTIVE_HIGH in the
 291          * device tree. Driving it high will enable the DC charger
 292          * input over the USB charger input.
 293          */
 294         flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 295         data->dcm = devm_gpiod_get_optional(dev, "dcm", flags);
 296         if (IS_ERR(data->dcm))
 297                 return dev_err_probe(dev, PTR_ERR(data->dcm),
 298                                      "failed to get DCM GPIO");
 299         gpiod_set_consumer_name(data->dcm, data->psy_desc.name);
 300
 301         data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN);
 302         if (IS_ERR(data->chg))
 303                 return dev_err_probe(dev, PTR_ERR(data->chg),
 304                                      "failed to get CHG GPIO");
 305         gpiod_set_consumer_name(data->chg, data->psy_desc.name);
 306
 307         data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN);
 308         if (IS_ERR(data->flt))
 309                 return dev_err_probe(dev, PTR_ERR(data->flt),
 310                                      "failed to get FLT GPIO");
 311         gpiod_set_consumer_name(data->flt, data->psy_desc.name);
 312
 313         data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN);
 314         if (IS_ERR(data->usus))
 315                 return dev_err_probe(dev, PTR_ERR(data->usus),
 316                                      "failed to get USUS GPIO");
 317         gpiod_set_consumer_name(data->usus, data->psy_desc.name);
 318
 319         data->fault = false;
 320         data->ta_in = ta_in;
 321         data->usb_in = usb_in;
 322
 323         return 0;
 324 }
 325
 326 static int max8903_probe(struct platform_device *pdev)
 327 {
 328         struct max8903_data *data;
 329         struct device *dev = &pdev->dev;
 330         struct power_supply_config psy_cfg = {};
 331         int ret = 0;
 332
 333         data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
 334         if (!data)
 335                 return -ENOMEM;
 336
 337         data->dev = dev;
 338         platform_set_drvdata(pdev, data);
 339
 340         ret = max8903_setup_gpios(pdev);
 341         if (ret)
 342                 return ret;
 343
 344         data->psy_desc.name = "max8903_charger";
 345         data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
 346                         ((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
 347                          POWER_SUPPLY_TYPE_BATTERY);
 348         data->psy_desc.get_property = max8903_get_property;
 349         data->psy_desc.properties = max8903_charger_props;
 350         data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
 351
 352         psy_cfg.of_node = dev->of_node;
 353         psy_cfg.drv_data = data;
 354
 355         data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
 356         if (IS_ERR(data->psy)) {
 357                 dev_err(dev, "failed: power supply register.\n");
 358                 return PTR_ERR(data->psy);
 359         }
 360
 361         if (data->dok) {
 362                 ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok),
 363                                         NULL, max8903_dcin,
 364                                         IRQF_TRIGGER_FALLING |
 365                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 366                                         "MAX8903 DC IN", data);
 367                 if (ret) {
 368                         dev_err(dev, "Cannot request irq %d for DC (%d)\n",
 369                                         gpiod_to_irq(data->dok), ret);
 370                         return ret;
 371                 }
 372         }
 373
 374         if (data->uok) {
 375                 ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok),
 376                                         NULL, max8903_usbin,
 377                                         IRQF_TRIGGER_FALLING |
 378                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 379                                         "MAX8903 USB IN", data);
 380                 if (ret) {
 381                         dev_err(dev, "Cannot request irq %d for USB (%d)\n",
 382                                         gpiod_to_irq(data->uok), ret);
 383                         return ret;
 384                 }
 385         }
 386
 387         if (data->flt) {
 388                 ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt),
 389                                         NULL, max8903_fault,
 390                                         IRQF_TRIGGER_FALLING |
 391                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 392                                         "MAX8903 Fault", data);
 393                 if (ret) {
 394                         dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
 395                                         gpiod_to_irq(data->flt), ret);
 396                         return ret;
 397                 }
 398         }
 399
 400         return 0;
 401 }
 402
 403 static const struct of_device_id max8903_match_ids[] = {
 404         { .compatible = "maxim,max8903", },
 405         { /* sentinel */ }
 406 };
 407 MODULE_DEVICE_TABLE(of, max8903_match_ids);
 408
 409 static struct platform_driver max8903_driver = {
 410         .probe  = max8903_probe,
 411         .driver = {
 412                 .name   = "max8903-charger",
 413                 .of_match_table = max8903_match_ids
 414         },
 415 };
 416
 417 module_platform_driver(max8903_driver);
 418
 419 MODULE_LICENSE("GPL");
 420 MODULE_DESCRIPTION("MAX8903 Charger Driver");
 421 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 422 MODULE_ALIAS("platform:max8903-charger");