drivers/power/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>
  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/of_gpio.h>
  27
  28 #include <linux/power/gpio-charger.h>
  29
  30 struct gpio_charger {
  31         const struct gpio_charger_platform_data *pdata;
  32         unsigned int irq;
  33         bool wakeup_enabled;
  34
  35         struct power_supply charger;
  36 };
  37
  38 static irqreturn_t gpio_charger_irq(int irq, void *devid)
  39 {
  40         struct power_supply *charger = devid;
  41
  42         power_supply_changed(charger);
  43
  44         return IRQ_HANDLED;
  45 }
  46
  47 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
  48 {
  49         return container_of(psy, struct gpio_charger, charger);
  50 }
  51
  52 static int gpio_charger_get_property(struct power_supply *psy,
  53                 enum power_supply_property psp, union power_supply_propval *val)
  54 {
  55         struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
  56         const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
  57
  58         switch (psp) {
  59         case POWER_SUPPLY_PROP_ONLINE:
  60                 val->intval = !!gpio_get_value_cansleep(pdata->gpio);
  61                 val->intval ^= pdata->gpio_active_low;
  62                 break;
  63         default:
  64                 return -EINVAL;
  65         }
  66
  67         return 0;
  68 }
  69
  70 static enum power_supply_property gpio_charger_properties[] = {
  71         POWER_SUPPLY_PROP_ONLINE,
  72 };
  73
  74 static
  75 struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
  76 {
  77         struct device_node *np = dev->of_node;
  78         struct gpio_charger_platform_data *pdata;
  79         const char *chargetype;
  80         enum of_gpio_flags flags;
  81         int ret;
  82
  83         if (!np)
  84                 return ERR_PTR(-ENOENT);
  85
  86         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
  87         if (!pdata)
  88                 return ERR_PTR(-ENOMEM);
  89
  90         pdata->name = np->name;
  91
  92         pdata->gpio = of_get_gpio_flags(np, 0, &flags);
  93         if (pdata->gpio < 0) {
  94                 if (pdata->gpio != -EPROBE_DEFER)
  95                         dev_err(dev, "could not get charger gpio\n");
  96                 return ERR_PTR(pdata->gpio);
  97         }
  98
  99         pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);
 100
 101         pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
 102         ret = of_property_read_string(np, "charger-type", &chargetype);
 103         if (ret >= 0) {
 104                 if (!strncmp("unknown", chargetype, 7))
 105                         pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
 106                 else if (!strncmp("battery", chargetype, 7))
 107                         pdata->type = POWER_SUPPLY_TYPE_BATTERY;
 108                 else if (!strncmp("ups", chargetype, 3))
 109                         pdata->type = POWER_SUPPLY_TYPE_UPS;
 110                 else if (!strncmp("mains", chargetype, 5))
 111                         pdata->type = POWER_SUPPLY_TYPE_MAINS;
 112                 else if (!strncmp("usb-sdp", chargetype, 7))
 113                         pdata->type = POWER_SUPPLY_TYPE_USB;
 114                 else if (!strncmp("usb-dcp", chargetype, 7))
 115                         pdata->type = POWER_SUPPLY_TYPE_USB_DCP;
 116                 else if (!strncmp("usb-cdp", chargetype, 7))
 117                         pdata->type = POWER_SUPPLY_TYPE_USB_CDP;
 118                 else if (!strncmp("usb-aca", chargetype, 7))
 119                         pdata->type = POWER_SUPPLY_TYPE_USB_ACA;
 120                 else
 121                         dev_warn(dev, "unknown charger type %s\n", chargetype);
 122         }
 123
 124         return pdata;
 125 }
 126
 127 static int gpio_charger_probe(struct platform_device *pdev)
 128 {
 129         const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
 130         struct gpio_charger *gpio_charger;
 131         struct power_supply *charger;
 132         int ret;
 133         int irq;
 134
 135         if (!pdata) {
 136                 pdata = gpio_charger_parse_dt(&pdev->dev);
 137                 if (IS_ERR(pdata)) {
 138                         ret = PTR_ERR(pdata);
 139                         if (ret != -EPROBE_DEFER)
 140                                 dev_err(&pdev->dev, "No platform data\n");
 141                         return ret;
 142                 }
 143         }
 144
 145         if (!gpio_is_valid(pdata->gpio)) {
 146                 dev_err(&pdev->dev, "Invalid gpio pin\n");
 147                 return -EINVAL;
 148         }
 149
 150         gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
 151                                         GFP_KERNEL);
 152         if (!gpio_charger) {
 153                 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
 154                 return -ENOMEM;
 155         }
 156
 157         charger = &gpio_charger->charger;
 158
 159         charger->name = pdata->name ? pdata->name : "gpio-charger";
 160         charger->type = pdata->type;
 161         charger->properties = gpio_charger_properties;
 162         charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
 163         charger->get_property = gpio_charger_get_property;
 164         charger->supplied_to = pdata->supplied_to;
 165         charger->num_supplicants = pdata->num_supplicants;
 166         charger->of_node = pdev->dev.of_node;
 167
 168         ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
 169         if (ret) {
 170                 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
 171                 goto err_free;
 172         }
 173         ret = gpio_direction_input(pdata->gpio);
 174         if (ret) {
 175                 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
 176                 goto err_gpio_free;
 177         }
 178
 179         gpio_charger->pdata = pdata;
 180
 181         ret = power_supply_register(&pdev->dev, charger);
 182         if (ret < 0) {
 183                 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
 184                         ret);
 185                 goto err_gpio_free;
 186         }
 187
 188         irq = gpio_to_irq(pdata->gpio);
 189         if (irq > 0) {
 190                 ret = request_any_context_irq(irq, gpio_charger_irq,
 191                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 192                                 dev_name(&pdev->dev), charger);
 193                 if (ret < 0)
 194                         dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
 195                 else
 196                         gpio_charger->irq = irq;
 197         }
 198
 199         platform_set_drvdata(pdev, gpio_charger);
 200
 201         device_init_wakeup(&pdev->dev, 1);
 202
 203         return 0;
 204
 205 err_gpio_free:
 206         gpio_free(pdata->gpio);
 207 err_free:
 208         return ret;
 209 }
 210
 211 static int gpio_charger_remove(struct platform_device *pdev)
 212 {
 213         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 214
 215         if (gpio_charger->irq)
 216                 free_irq(gpio_charger->irq, &gpio_charger->charger);
 217
 218         power_supply_unregister(&gpio_charger->charger);
 219
 220         gpio_free(gpio_charger->pdata->gpio);
 221
 222         return 0;
 223 }
 224
 225 #ifdef CONFIG_PM_SLEEP
 226 static int gpio_charger_suspend(struct device *dev)
 227 {
 228         struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
 229
 230         if (device_may_wakeup(dev))
 231                 gpio_charger->wakeup_enabled =
 232                         enable_irq_wake(gpio_charger->irq);
 233
 234         return 0;
 235 }
 236
 237 static int gpio_charger_resume(struct device *dev)
 238 {
 239         struct platform_device *pdev = to_platform_device(dev);
 240         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 241
 242         if (gpio_charger->wakeup_enabled)
 243                 disable_irq_wake(gpio_charger->irq);
 244         power_supply_changed(&gpio_charger->charger);
 245
 246         return 0;
 247 }
 248 #endif
 249
 250 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
 251                 gpio_charger_suspend, gpio_charger_resume);
 252
 253 static const struct of_device_id gpio_charger_match[] = {
 254         { .compatible = "gpio-charger" },
 255         { }
 256 };
 257 MODULE_DEVICE_TABLE(of, gpio_charger_match);
 258
 259 static struct platform_driver gpio_charger_driver = {
 260         .probe = gpio_charger_probe,
 261         .remove = gpio_charger_remove,
 262         .driver = {
 263                 .name = "gpio-charger",
 264                 .pm = &gpio_charger_pm_ops,
 265                 .of_match_table = gpio_charger_match,
 266         },
 267 };
 268
 269 module_platform_driver(gpio_charger_driver);
 270
 271 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 272 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
 273 MODULE_LICENSE("GPL");
 274 MODULE_ALIAS("platform:gpio-charger");