linux/drivers/power/supply/max8903_charger.c
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   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/of_device.h>
  14#include <linux/slab.h>
  15#include <linux/power_supply.h>
  16#include <linux/platform_device.h>
  17
  18struct max8903_data {
  19        struct device *dev;
  20        struct power_supply *psy;
  21        struct power_supply_desc psy_desc;
  22        /*
  23         * GPIOs
  24         * chg, flt, dcm and usus are optional.
  25         * dok or uok must be present.
  26         * If dok is present, cen must be present.
  27         */
  28        struct gpio_desc *cen; /* Charger Enable input */
  29        struct gpio_desc *dok; /* DC (Adapter) Power OK output */
  30        struct gpio_desc *uok; /* USB Power OK output */
  31        struct gpio_desc *chg; /* Charger status output */
  32        struct gpio_desc *flt; /* Fault output */
  33        struct gpio_desc *dcm; /* Current-Limit Mode input (1: DC, 2: USB) */
  34        struct gpio_desc *usus; /* USB Suspend Input (1: suspended) */
  35        bool fault;
  36        bool usb_in;
  37        bool ta_in;
  38};
  39
  40static enum power_supply_property max8903_charger_props[] = {
  41        POWER_SUPPLY_PROP_STATUS, /* Charger status output */
  42        POWER_SUPPLY_PROP_ONLINE, /* External power source */
  43        POWER_SUPPLY_PROP_HEALTH, /* Fault or OK */
  44};
  45
  46static int max8903_get_property(struct power_supply *psy,
  47                enum power_supply_property psp,
  48                union power_supply_propval *val)
  49{
  50        struct max8903_data *data = power_supply_get_drvdata(psy);
  51
  52        switch (psp) {
  53        case POWER_SUPPLY_PROP_STATUS:
  54                val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
  55                if (data->chg) {
  56                        if (gpiod_get_value(data->chg))
  57                                /* CHG asserted */
  58                                val->intval = POWER_SUPPLY_STATUS_CHARGING;
  59                        else if (data->usb_in || data->ta_in)
  60                                val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
  61                        else
  62                                val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
  63                }
  64                break;
  65        case POWER_SUPPLY_PROP_ONLINE:
  66                val->intval = 0;
  67                if (data->usb_in || data->ta_in)
  68                        val->intval = 1;
  69                break;
  70        case POWER_SUPPLY_PROP_HEALTH:
  71                val->intval = POWER_SUPPLY_HEALTH_GOOD;
  72                if (data->fault)
  73                        val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
  74                break;
  75        default:
  76                return -EINVAL;
  77        }
  78
  79        return 0;
  80}
  81
  82static irqreturn_t max8903_dcin(int irq, void *_data)
  83{
  84        struct max8903_data *data = _data;
  85        bool ta_in;
  86        enum power_supply_type old_type;
  87
  88        /*
  89         * This means the line is asserted.
  90         *
  91         * The signal is active low, but the inversion is handled in the GPIO
  92         * library as the line should be flagged GPIO_ACTIVE_LOW in the device
  93         * tree.
  94         */
  95        ta_in = gpiod_get_value(data->dok);
  96
  97        if (ta_in == data->ta_in)
  98                return IRQ_HANDLED;
  99
 100        data->ta_in = ta_in;
 101
 102        /* Set Current-Limit-Mode 1:DC 0:USB */
 103        if (data->dcm)
 104                gpiod_set_value(data->dcm, ta_in);
 105
 106        /* Charger Enable / Disable */
 107        if (data->cen) {
 108                int val;
 109
 110                if (ta_in)
 111                        /* Certainly enable if DOK is asserted */
 112                        val = 1;
 113                else if (data->usb_in)
 114                        /* Enable if the USB charger is enabled */
 115                        val = 1;
 116                else
 117                        /* Else default-disable */
 118                        val = 0;
 119
 120                gpiod_set_value(data->cen, val);
 121        }
 122
 123        dev_dbg(data->dev, "TA(DC-IN) Charger %s.\n", ta_in ?
 124                        "Connected" : "Disconnected");
 125
 126        old_type = data->psy_desc.type;
 127
 128        if (data->ta_in)
 129                data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
 130        else if (data->usb_in)
 131                data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
 132        else
 133                data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 134
 135        if (old_type != data->psy_desc.type)
 136                power_supply_changed(data->psy);
 137
 138        return IRQ_HANDLED;
 139}
 140
 141static irqreturn_t max8903_usbin(int irq, void *_data)
 142{
 143        struct max8903_data *data = _data;
 144        bool usb_in;
 145        enum power_supply_type old_type;
 146
 147        /*
 148         * This means the line is asserted.
 149         *
 150         * The signal is active low, but the inversion is handled in the GPIO
 151         * library as the line should be flagged GPIO_ACTIVE_LOW in the device
 152         * tree.
 153         */
 154        usb_in = gpiod_get_value(data->uok);
 155
 156        if (usb_in == data->usb_in)
 157                return IRQ_HANDLED;
 158
 159        data->usb_in = usb_in;
 160
 161        /* Do not touch Current-Limit-Mode */
 162
 163        /* Charger Enable / Disable */
 164        if (data->cen) {
 165                int val;
 166
 167                if (usb_in)
 168                        /* Certainly enable if UOK is asserted */
 169                        val = 1;
 170                else if (data->ta_in)
 171                        /* Enable if the DC charger is enabled */
 172                        val = 1;
 173                else
 174                        /* Else default-disable */
 175                        val = 0;
 176
 177                gpiod_set_value(data->cen, val);
 178        }
 179
 180        dev_dbg(data->dev, "USB Charger %s.\n", usb_in ?
 181                        "Connected" : "Disconnected");
 182
 183        old_type = data->psy_desc.type;
 184
 185        if (data->ta_in)
 186                data->psy_desc.type = POWER_SUPPLY_TYPE_MAINS;
 187        else if (data->usb_in)
 188                data->psy_desc.type = POWER_SUPPLY_TYPE_USB;
 189        else
 190                data->psy_desc.type = POWER_SUPPLY_TYPE_BATTERY;
 191
 192        if (old_type != data->psy_desc.type)
 193                power_supply_changed(data->psy);
 194
 195        return IRQ_HANDLED;
 196}
 197
 198static irqreturn_t max8903_fault(int irq, void *_data)
 199{
 200        struct max8903_data *data = _data;
 201        bool fault;
 202
 203        /*
 204         * This means the line is asserted.
 205         *
 206         * The signal is active low, but the inversion is handled in the GPIO
 207         * library as the line should be flagged GPIO_ACTIVE_LOW in the device
 208         * tree.
 209         */
 210        fault = gpiod_get_value(data->flt);
 211
 212        if (fault == data->fault)
 213                return IRQ_HANDLED;
 214
 215        data->fault = fault;
 216
 217        if (fault)
 218                dev_err(data->dev, "Charger suffers a fault and stops.\n");
 219        else
 220                dev_err(data->dev, "Charger recovered from a fault.\n");
 221
 222        return IRQ_HANDLED;
 223}
 224
 225static int max8903_setup_gpios(struct platform_device *pdev)
 226{
 227        struct max8903_data *data = platform_get_drvdata(pdev);
 228        struct device *dev = &pdev->dev;
 229        bool ta_in = false;
 230        bool usb_in = false;
 231        enum gpiod_flags flags;
 232
 233        data->dok = devm_gpiod_get_optional(dev, "dok", GPIOD_IN);
 234        if (IS_ERR(data->dok))
 235                return dev_err_probe(dev, PTR_ERR(data->dok),
 236                                     "failed to get DOK GPIO");
 237        if (data->dok) {
 238                gpiod_set_consumer_name(data->dok, data->psy_desc.name);
 239                /*
 240                 * The DC OK is pulled up to 1 and goes low when a charger
 241                 * is plugged in (active low) but in the device tree the
 242                 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
 243                 * here if the DC charger is plugged in.
 244                 */
 245                ta_in = gpiod_get_value(data->dok);
 246        }
 247
 248        data->uok = devm_gpiod_get_optional(dev, "uok", GPIOD_IN);
 249        if (IS_ERR(data->uok))
 250                return dev_err_probe(dev, PTR_ERR(data->uok),
 251                                     "failed to get UOK GPIO");
 252        if (data->uok) {
 253                gpiod_set_consumer_name(data->uok, data->psy_desc.name);
 254                /*
 255                 * The USB OK is pulled up to 1 and goes low when a USB charger
 256                 * is plugged in (active low) but in the device tree the
 257                 * line is marked as GPIO_ACTIVE_LOW so we get a 1 (asserted)
 258                 * here if the USB charger is plugged in.
 259                 */
 260                usb_in = gpiod_get_value(data->uok);
 261        }
 262
 263        /* Either DC OK or USB OK must be provided */
 264        if (!data->dok && !data->uok) {
 265                dev_err(dev, "no valid power source\n");
 266                return -EINVAL;
 267        }
 268
 269        /*
 270         * If either charger is already connected at this point,
 271         * assert the CEN line and enable charging from the start.
 272         *
 273         * The line is active low but also marked with GPIO_ACTIVE_LOW
 274         * in the device tree, so when we assert the line with
 275         * GPIOD_OUT_HIGH the line will be driven low.
 276         */
 277        flags = (ta_in || usb_in) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 278        /*
 279         * If DC OK is provided, Charger Enable CEN is compulsory
 280         * so this is not optional here.
 281         */
 282        data->cen = devm_gpiod_get(dev, "cen", flags);
 283        if (IS_ERR(data->cen))
 284                return dev_err_probe(dev, PTR_ERR(data->cen),
 285                                     "failed to get CEN GPIO");
 286        gpiod_set_consumer_name(data->cen, data->psy_desc.name);
 287
 288        /*
 289         * If the DC charger is connected, then select it.
 290         *
 291         * The DCM line should be marked GPIO_ACTIVE_HIGH in the
 292         * device tree. Driving it high will enable the DC charger
 293         * input over the USB charger input.
 294         */
 295        flags = ta_in ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 296        data->dcm = devm_gpiod_get_optional(dev, "dcm", flags);
 297        if (IS_ERR(data->dcm))
 298                return dev_err_probe(dev, PTR_ERR(data->dcm),
 299                                     "failed to get DCM GPIO");
 300        gpiod_set_consumer_name(data->dcm, data->psy_desc.name);
 301
 302        data->chg = devm_gpiod_get_optional(dev, "chg", GPIOD_IN);
 303        if (IS_ERR(data->chg))
 304                return dev_err_probe(dev, PTR_ERR(data->chg),
 305                                     "failed to get CHG GPIO");
 306        gpiod_set_consumer_name(data->chg, data->psy_desc.name);
 307
 308        data->flt = devm_gpiod_get_optional(dev, "flt", GPIOD_IN);
 309        if (IS_ERR(data->flt))
 310                return dev_err_probe(dev, PTR_ERR(data->flt),
 311                                     "failed to get FLT GPIO");
 312        gpiod_set_consumer_name(data->flt, data->psy_desc.name);
 313
 314        data->usus = devm_gpiod_get_optional(dev, "usus", GPIOD_IN);
 315        if (IS_ERR(data->usus))
 316                return dev_err_probe(dev, PTR_ERR(data->usus),
 317                                     "failed to get USUS GPIO");
 318        gpiod_set_consumer_name(data->usus, data->psy_desc.name);
 319
 320        data->fault = false;
 321        data->ta_in = ta_in;
 322        data->usb_in = usb_in;
 323
 324        return 0;
 325}
 326
 327static int max8903_probe(struct platform_device *pdev)
 328{
 329        struct max8903_data *data;
 330        struct device *dev = &pdev->dev;
 331        struct power_supply_config psy_cfg = {};
 332        int ret = 0;
 333
 334        data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
 335        if (!data)
 336                return -ENOMEM;
 337
 338        data->dev = dev;
 339        platform_set_drvdata(pdev, data);
 340
 341        ret = max8903_setup_gpios(pdev);
 342        if (ret)
 343                return ret;
 344
 345        data->psy_desc.name = "max8903_charger";
 346        data->psy_desc.type = (data->ta_in) ? POWER_SUPPLY_TYPE_MAINS :
 347                        ((data->usb_in) ? POWER_SUPPLY_TYPE_USB :
 348                         POWER_SUPPLY_TYPE_BATTERY);
 349        data->psy_desc.get_property = max8903_get_property;
 350        data->psy_desc.properties = max8903_charger_props;
 351        data->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
 352
 353        psy_cfg.of_node = dev->of_node;
 354        psy_cfg.drv_data = data;
 355
 356        data->psy = devm_power_supply_register(dev, &data->psy_desc, &psy_cfg);
 357        if (IS_ERR(data->psy)) {
 358                dev_err(dev, "failed: power supply register.\n");
 359                return PTR_ERR(data->psy);
 360        }
 361
 362        if (data->dok) {
 363                ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->dok),
 364                                        NULL, max8903_dcin,
 365                                        IRQF_TRIGGER_FALLING |
 366                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 367                                        "MAX8903 DC IN", data);
 368                if (ret) {
 369                        dev_err(dev, "Cannot request irq %d for DC (%d)\n",
 370                                        gpiod_to_irq(data->dok), ret);
 371                        return ret;
 372                }
 373        }
 374
 375        if (data->uok) {
 376                ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->uok),
 377                                        NULL, max8903_usbin,
 378                                        IRQF_TRIGGER_FALLING |
 379                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 380                                        "MAX8903 USB IN", data);
 381                if (ret) {
 382                        dev_err(dev, "Cannot request irq %d for USB (%d)\n",
 383                                        gpiod_to_irq(data->uok), ret);
 384                        return ret;
 385                }
 386        }
 387
 388        if (data->flt) {
 389                ret = devm_request_threaded_irq(dev, gpiod_to_irq(data->flt),
 390                                        NULL, max8903_fault,
 391                                        IRQF_TRIGGER_FALLING |
 392                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 393                                        "MAX8903 Fault", data);
 394                if (ret) {
 395                        dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
 396                                        gpiod_to_irq(data->flt), ret);
 397                        return ret;
 398                }
 399        }
 400
 401        return 0;
 402}
 403
 404static const struct of_device_id max8903_match_ids[] = {
 405        { .compatible = "maxim,max8903", },
 406        { /* sentinel */ }
 407};
 408MODULE_DEVICE_TABLE(of, max8903_match_ids);
 409
 410static struct platform_driver max8903_driver = {
 411        .probe  = max8903_probe,
 412        .driver = {
 413                .name   = "max8903-charger",
 414                .of_match_table = max8903_match_ids
 415        },
 416};
 417
 418module_platform_driver(max8903_driver);
 419
 420MODULE_LICENSE("GPL");
 421MODULE_DESCRIPTION("MAX8903 Charger Driver");
 422MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
 423MODULE_ALIAS("platform:max8903-charger");
 424