drivers/power/supply/gpio-charger.c

   1 /*
   2  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *  Driver for chargers which report their online status through a GPIO pin
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/gpio.h> /* For legacy platform data */
  18 #include <linux/init.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/power_supply.h>
  24 #include <linux/slab.h>
  25 #include <linux/of.h>
  26 #include <linux/gpio/consumer.h>
  27
  28 #include <linux/power/gpio-charger.h>
  29
  30 struct gpio_charger {
  31         unsigned int irq;
  32         bool wakeup_enabled;
  33
  34         struct power_supply *charger;
  35         struct power_supply_desc charger_desc;
  36         struct gpio_desc *gpiod;
  37 };
  38
  39 static irqreturn_t gpio_charger_irq(int irq, void *devid)
  40 {
  41         struct power_supply *charger = devid;
  42
  43         power_supply_changed(charger);
  44
  45         return IRQ_HANDLED;
  46 }
  47
  48 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
  49 {
  50         return power_supply_get_drvdata(psy);
  51 }
  52
  53 static int gpio_charger_get_property(struct power_supply *psy,
  54                 enum power_supply_property psp, union power_supply_propval *val)
  55 {
  56         struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
  57
  58         switch (psp) {
  59         case POWER_SUPPLY_PROP_ONLINE:
  60                 val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
  61                 break;
  62         default:
  63                 return -EINVAL;
  64         }
  65
  66         return 0;
  67 }
  68
  69 static enum power_supply_type gpio_charger_get_type(struct device *dev)
  70 {
  71         const char *chargetype;
  72
  73         if (!device_property_read_string(dev, "charger-type", &chargetype)) {
  74                 if (!strcmp("unknown", chargetype))
  75                         return POWER_SUPPLY_TYPE_UNKNOWN;
  76                 if (!strcmp("battery", chargetype))
  77                         return POWER_SUPPLY_TYPE_BATTERY;
  78                 if (!strcmp("ups", chargetype))
  79                         return POWER_SUPPLY_TYPE_UPS;
  80                 if (!strcmp("mains", chargetype))
  81                         return POWER_SUPPLY_TYPE_MAINS;
  82                 if (!strcmp("usb-sdp", chargetype))
  83                         return POWER_SUPPLY_TYPE_USB;
  84                 if (!strcmp("usb-dcp", chargetype))
  85                         return POWER_SUPPLY_TYPE_USB_DCP;
  86                 if (!strcmp("usb-cdp", chargetype))
  87                         return POWER_SUPPLY_TYPE_USB_CDP;
  88                 if (!strcmp("usb-aca", chargetype))
  89                         return POWER_SUPPLY_TYPE_USB_ACA;
  90         }
  91         dev_warn(dev, "unknown charger type %s\n", chargetype);
  92
  93         return POWER_SUPPLY_TYPE_UNKNOWN;
  94 }
  95
  96 static enum power_supply_property gpio_charger_properties[] = {
  97         POWER_SUPPLY_PROP_ONLINE,
  98 };
  99
 100 static int gpio_charger_probe(struct platform_device *pdev)
 101 {
 102         struct device *dev = &pdev->dev;
 103         const struct gpio_charger_platform_data *pdata = dev->platform_data;
 104         struct power_supply_config psy_cfg = {};
 105         struct gpio_charger *gpio_charger;
 106         struct power_supply_desc *charger_desc;
 107         unsigned long flags;
 108         int irq, ret;
 109
 110         if (!pdata && !dev->of_node) {
 111                 dev_err(dev, "No platform data\n");
 112                 return -ENOENT;
 113         }
 114
 115         gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
 116         if (!gpio_charger)
 117                 return -ENOMEM;
 118
 119         /*
 120          * This will fetch a GPIO descriptor from device tree, ACPI or
 121          * boardfile descriptor tables. It's good to try this first.
 122          */
 123         gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN);
 124
 125         /*
 126          * If this fails and we're not using device tree, try the
 127          * legacy platform data method.
 128          */
 129         if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) {
 130                 /* Non-DT: use legacy GPIO numbers */
 131                 if (!gpio_is_valid(pdata->gpio)) {
 132                         dev_err(dev, "Invalid gpio pin in pdata\n");
 133                         return -EINVAL;
 134                 }
 135                 flags = GPIOF_IN;
 136                 if (pdata->gpio_active_low)
 137                         flags |= GPIOF_ACTIVE_LOW;
 138                 ret = devm_gpio_request_one(dev, pdata->gpio, flags,
 139                                             dev_name(dev));
 140                 if (ret) {
 141                         dev_err(dev, "Failed to request gpio pin: %d\n", ret);
 142                         return ret;
 143                 }
 144                 /* Then convert this to gpiod for now */
 145                 gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
 146         } else if (IS_ERR(gpio_charger->gpiod)) {
 147                 /* Just try again if this happens */
 148                 if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
 149                         return -EPROBE_DEFER;
 150                 dev_err(dev, "error getting GPIO descriptor\n");
 151                 return PTR_ERR(gpio_charger->gpiod);
 152         }
 153
 154         charger_desc = &gpio_charger->charger_desc;
 155         charger_desc->properties = gpio_charger_properties;
 156         charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties);
 157         charger_desc->get_property = gpio_charger_get_property;
 158
 159         psy_cfg.of_node = dev->of_node;
 160         psy_cfg.drv_data = gpio_charger;
 161
 162         if (pdata) {
 163                 charger_desc->name = pdata->name;
 164                 charger_desc->type = pdata->type;
 165                 psy_cfg.supplied_to = pdata->supplied_to;
 166                 psy_cfg.num_supplicants = pdata->num_supplicants;
 167         } else {
 168                 charger_desc->name = dev->of_node->name;
 169                 charger_desc->type = gpio_charger_get_type(dev);
 170         }
 171
 172         if (!charger_desc->name)
 173                 charger_desc->name = pdev->name;
 174
 175         gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
 176                                                            &psy_cfg);
 177         if (IS_ERR(gpio_charger->charger)) {
 178                 ret = PTR_ERR(gpio_charger->charger);
 179                 dev_err(dev, "Failed to register power supply: %d\n", ret);
 180                 return ret;
 181         }
 182
 183         irq = gpiod_to_irq(gpio_charger->gpiod);
 184         if (irq > 0) {
 185                 ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
 186                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 187                                 dev_name(dev), gpio_charger->charger);
 188                 if (ret < 0)
 189                         dev_warn(dev, "Failed to request irq: %d\n", ret);
 190                 else
 191                         gpio_charger->irq = irq;
 192         }
 193
 194         platform_set_drvdata(pdev, gpio_charger);
 195
 196         device_init_wakeup(dev, 1);
 197
 198         return 0;
 199 }
 200
 201 #ifdef CONFIG_PM_SLEEP
 202 static int gpio_charger_suspend(struct device *dev)
 203 {
 204         struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
 205
 206         if (device_may_wakeup(dev))
 207                 gpio_charger->wakeup_enabled =
 208                         !enable_irq_wake(gpio_charger->irq);
 209
 210         return 0;
 211 }
 212
 213 static int gpio_charger_resume(struct device *dev)
 214 {
 215         struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
 216
 217         if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
 218                 disable_irq_wake(gpio_charger->irq);
 219         power_supply_changed(gpio_charger->charger);
 220
 221         return 0;
 222 }
 223 #endif
 224
 225 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
 226                 gpio_charger_suspend, gpio_charger_resume);
 227
 228 static const struct of_device_id gpio_charger_match[] = {
 229         { .compatible = "gpio-charger" },
 230         { }
 231 };
 232 MODULE_DEVICE_TABLE(of, gpio_charger_match);
 233
 234 static struct platform_driver gpio_charger_driver = {
 235         .probe = gpio_charger_probe,
 236         .driver = {
 237                 .name = "gpio-charger",
 238                 .pm = &gpio_charger_pm_ops,
 239                 .of_match_table = gpio_charger_match,
 240         },
 241 };
 242
 243 module_platform_driver(gpio_charger_driver);
 244
 245 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 246 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
 247 MODULE_LICENSE("GPL");
 248 MODULE_ALIAS("platform:gpio-charger");