target/linux/xburst/files-2.6.32/drivers/power/gpio-charger.c

   1 /*
   2  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *      Driver for chargers indicating their 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/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/types.h>
  20 #include <linux/device.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/power_supply.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/gpio.h>
  25
  26 #include <linux/power/gpio-charger.h>
  27
  28 struct gpio_charger {
  29         const struct gpio_charger_platform_data *pdata;
  30
  31         int irq;
  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         power_supply_changed(charger);
  40
  41         return IRQ_HANDLED;
  42 }
  43
  44 static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
  45 {
  46         return container_of(psy, struct gpio_charger, charger);
  47 }
  48
  49 static int gpio_charger_get_property(struct power_supply *psy,
  50                                      enum power_supply_property psp,
  51                                      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(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 __devinit 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
  79         if (!pdata) {
  80                 dev_err(&pdev->dev, "No platform data");
  81                 return -EINVAL;
  82         }
  83
  84         gpio_charger = kzalloc(sizeof(*gpio_charger), GFP_KERNEL);
  85
  86         charger = &gpio_charger->charger;
  87
  88         charger->name = pdata->name;
  89         charger->type = pdata->type;
  90         charger->properties = gpio_charger_properties;
  91         charger->num_properties = ARRAY_SIZE(gpio_charger_properties);
  92         charger->get_property  = gpio_charger_get_property;
  93         charger->supplied_to = pdata->batteries;
  94         charger->num_supplicants = pdata->num_batteries;
  95
  96         if (gpio_is_valid(pdata->gpio)) {
  97                 ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
  98                 if (ret) {
  99                         dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
 100                         goto err;
 101                 }
 102                 ret = gpio_direction_input(pdata->gpio);
 103                 if (ret) {
 104                         dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
 105                         goto err_gpio_free;
 106                 }
 107
 108                 gpio_charger->irq = gpio_to_irq(pdata->gpio);
 109                 if (gpio_charger->irq >= 0) {
 110                         ret = request_irq(gpio_charger->irq, gpio_charger_irq,
 111                         IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 112                         dev_name(&pdev->dev), charger);
 113                         if (ret) {
 114                                 dev_warn(&pdev->dev, "Failed to request online gpio irq: %d\n", ret);
 115                                 gpio_charger->irq = -1;
 116                         }
 117                 }
 118         }
 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", ret);
 123                 goto err_gpio_free;
 124         }
 125
 126         gpio_charger->pdata = pdata;
 127         platform_set_drvdata(pdev, gpio_charger);
 128
 129         return 0;
 130
 131 err_gpio_free:
 132         if (gpio_is_valid(pdata->gpio)) {
 133                 if (gpio_charger->irq >= 0)
 134                         free_irq(gpio_charger->irq, charger);
 135                 gpio_free(pdata->gpio);
 136         }
 137 err:
 138         return ret;
 139 }
 140
 141 static int __devexit gpio_charger_remove(struct platform_device *pdev)
 142 {
 143         struct gpio_charger *gpio_charger = platform_get_drvdata(pdev);
 144         const struct gpio_charger_platform_data *pdata = gpio_charger->pdata;
 145
 146         power_supply_unregister(&gpio_charger->charger);
 147
 148         if (gpio_is_valid(pdata->gpio)) {
 149                 if (gpio_charger->irq >= 0)
 150                         free_irq(gpio_charger->irq, &gpio_charger->charger);
 151                 gpio_free(pdata->gpio);
 152         }
 153
 154         platform_set_drvdata(pdev, NULL);
 155         kfree(gpio_charger);
 156
 157         return 0;
 158 }
 159
 160 static struct platform_driver  gpio_charger_driver = {
 161         .probe = gpio_charger_probe,
 162         .remove = __devexit_p(gpio_charger_remove),
 163         .driver = {
 164                 .name = "gpio-charger",
 165                 .owner = THIS_MODULE,
 166         },
 167 };
 168
 169 static int __init gpio_charger_init(void)
 170 {
 171         return platform_driver_register(&gpio_charger_driver);
 172 }
 173 module_init(gpio_charger_init);
 174
 175 static void gpio_charger_exit(void)
 176 {
 177         platform_driver_unregister(&gpio_charger_driver);
 178 }
 179 module_exit(gpio_charger_exit);
 180
 181 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 182 MODULE_DESCRIPTION("Driver for chargers indicating their status through a gpio");
 183 MODULE_LICENSE("GPL");
 184 MODULE_ALIAS("platform:gpio-charger");