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
  26 #include <linux/power/gpio-charger.h>
  27
  28 struct gpio_charger {
  29         const struct gpio_charger_platform_data *pdata;
  30         unsigned int irq;
  31         bool wakeup_enabled;
  32
  33         struct power_supply charger;
  34 };
  35
  36 static irqreturn_t gpio_charger_irq(int irq, void *devid)
  37 {
  38         struct power_supply *charger = devid;
  39
  40         power_supply_changed(charger);
  41
  42         return IRQ_HANDLED;
  43 }
  44
  45 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
  46 {
  47         return container_of(psy, struct gpio_charger, charger);
  48 }
  49
  50 static int gpio_charger_get_property(struct power_supply *psy,
  51                 enum power_supply_property psp, union power_supply_propval *val)
  52 {
  53         struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
  54         const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
  55
  56         switch (psp) {
  57         case POWER_SUPPLY_PROP_ONLINE:
  58                 val->intval = gpio_get_value_cansleep(pdata->gpio);
  59                 val->intval ^= pdata->gpio_active_low;
  60                 break;
  61         default:
  62                 return -EINVAL;
  63         }
  64
  65         return 0;
  66 }
  67
  68 static enum power_supply_property gpio_charger_properties[] = {
  69         POWER_SUPPLY_PROP_ONLINE,
  70 };
  71
  72 static int gpio_charger_probe(struct platform_device *pdev)
  73 {
  74         const struct gpio_charger_platform_data *pdata = pdev->dev.platform_data;
  75         struct gpio_charger *gpio_charger;
  76         struct power_supply *charger;
  77         int ret;
  78         int irq;
  79
  80         if (!pdata) {
  81                 dev_err(&pdev->dev, "No platform data\n");
  82                 return -EINVAL;
  83         }
  84
  85         if (!gpio_is_valid(pdata->gpio)) {
  86                 dev_err(&pdev->dev, "Invalid gpio pin\n");
  87                 return -EINVAL;
  88         }
  89
  90         gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
  91                                         GFP_KERNEL);
  92         if (!gpio_charger) {
  93                 dev_err(&pdev->dev, "Failed to alloc driver structure\n");
  94                 return -ENOMEM;
  95         }
  96
  97         charger = &gpio_charger->charger;
  98
  99         charger->name = pdata->name ? pdata->name : "gpio-charger";
 100         charger->type = pdata->type;
 101         charger->properties = gpio_charger_properties;
 102         charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
 103         charger->get_property = gpio_charger_get_property;
 104         charger->supplied_to = pdata->supplied_to;
 105         charger->num_supplicants = pdata->num_supplicants;
 106
 107         ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
 108         if (ret) {
 109                 dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
 110                 goto err_free;
 111         }
 112         ret = gpio_direction_input(pdata->gpio);
 113         if (ret) {
 114                 dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
 115                 goto err_gpio_free;
 116         }
 117
 118         gpio_charger->pdata = pdata;
 119
 120         ret = power_supply_register(&pdev->dev, charger);
 121         if (ret < 0) {
 122                 dev_err(&pdev->dev, "Failed to register power supply: %d\n",
 123                         ret);
 124                 goto err_gpio_free;
 125         }
 126
 127         irq = gpio_to_irq(pdata->gpio);
 128         if (irq > 0) {
 129                 ret = request_any_context_irq(irq, gpio_charger_irq,
 130                                 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 131                                 dev_name(&pdev->dev), charger);
 132                 if (ret < 0)
 133                         dev_warn(&pdev->dev, "Failed to request irq: %d\n", ret);
 134                 else
 135                         gpio_charger->irq = irq;
 136         }
 137
 138         platform_set_drvdata(pdev, gpio_charger);
 139
 140         device_init_wakeup(&pdev->dev, 1);
 141
 142         return 0;
 143
 144 err_gpio_free:
 145         gpio_free(pdata->gpio);
 146 err_free:
 147         return ret;
 148 }
 149
 150 static int gpio_charger_remove(struct platform_device *pdev)
 151 {
 152         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 153
 154         if (gpio_charger->irq)
 155                 free_irq(gpio_charger->irq, &gpio_charger->charger);
 156
 157         power_supply_unregister(&gpio_charger->charger);
 158
 159         gpio_free(gpio_charger->pdata->gpio);
 160
 161         return 0;
 162 }
 163
 164 #ifdef CONFIG_PM_SLEEP
 165 static int gpio_charger_suspend(struct device *dev)
 166 {
 167         struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
 168
 169         if (device_may_wakeup(dev))
 170                 gpio_charger->wakeup_enabled =
 171                         enable_irq_wake(gpio_charger->irq);
 172
 173         return 0;
 174 }
 175
 176 static int gpio_charger_resume(struct device *dev)
 177 {
 178         struct platform_device *pdev = to_platform_device(dev);
 179         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 180
 181         if (gpio_charger->wakeup_enabled)
 182                 disable_irq_wake(gpio_charger->irq);
 183         power_supply_changed(&gpio_charger->charger);
 184
 185         return 0;
 186 }
 187 #endif
 188
 189 static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
 190                 gpio_charger_suspend, gpio_charger_resume);
 191
 192 static struct platform_driver gpio_charger_driver = {
 193         .probe = gpio_charger_probe,
 194         .remove = gpio_charger_remove,
 195         .driver = {
 196                 .name = "gpio-charger",
 197                 .owner = THIS_MODULE,
 198                 .pm = &gpio_charger_pm_ops,
 199         },
 200 };
 201
 202 module_platform_driver(gpio_charger_driver);
 203
 204 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 205 MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO");
 206 MODULE_LICENSE("GPL");
 207 MODULE_ALIAS("platform:gpio-charger");