drivers/power/pda_power.c

   1 /*
   2  * Common power driver for PDAs and phones with one or two external
   3  * power supplies (AC/USB) connected to main and backup batteries,
   4  * and optional builtin charger.
   5  *
   6  * Copyright © 2007 Anton Vorontsov <cbou@mail.ru>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/power_supply.h>
  17 #include <linux/pda_power.h>
  18 #include <linux/timer.h>
  19 #include <linux/jiffies.h>
  20
  21 static inline unsigned int get_irq_flags(struct resource *res)
  22 {
  23         unsigned int flags = IRQF_DISABLED | IRQF_SHARED;
  24
  25         flags |= res->flags & IRQF_TRIGGER_MASK;
  26
  27         return flags;
  28 }
  29
  30 static struct device *dev;
  31 static struct pda_power_pdata *pdata;
  32 static struct resource *ac_irq, *usb_irq;
  33 static struct timer_list charger_timer;
  34 static struct timer_list supply_timer;
  35 static struct timer_list polling_timer;
  36 static int polling;
  37
  38 enum {
  39         PDA_PSY_OFFLINE = 0,
  40         PDA_PSY_ONLINE = 1,
  41         PDA_PSY_TO_CHANGE,
  42 };
  43 static int new_ac_status = -1;
  44 static int new_usb_status = -1;
  45 static int ac_status = -1;
  46 static int usb_status = -1;
  47
  48 static int pda_power_get_property(struct power_supply *psy,
  49                                   enum power_supply_property psp,
  50                                   union power_supply_propval *val)
  51 {
  52         switch (psp) {
  53         case POWER_SUPPLY_PROP_ONLINE:
  54                 if (psy->type == POWER_SUPPLY_TYPE_MAINS)
  55                         val->intval = pdata->is_ac_online ?
  56                                       pdata->is_ac_online() : 0;
  57                 else
  58                         val->intval = pdata->is_usb_online ?
  59                                       pdata->is_usb_online() : 0;
  60                 break;
  61         default:
  62                 return -EINVAL;
  63         }
  64         return 0;
  65 }
  66
  67 static enum power_supply_property pda_power_props[] = {
  68         POWER_SUPPLY_PROP_ONLINE,
  69 };
  70
  71 static char *pda_power_supplied_to[] = {
  72         "main-battery",
  73         "backup-battery",
  74 };
  75
  76 static struct power_supply pda_psy_ac = {
  77         .name = "ac",
  78         .type = POWER_SUPPLY_TYPE_MAINS,
  79         .supplied_to = pda_power_supplied_to,
  80         .num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
  81         .properties = pda_power_props,
  82         .num_properties = ARRAY_SIZE(pda_power_props),
  83         .get_property = pda_power_get_property,
  84 };
  85
  86 static struct power_supply pda_psy_usb = {
  87         .name = "usb",
  88         .type = POWER_SUPPLY_TYPE_USB,
  89         .supplied_to = pda_power_supplied_to,
  90         .num_supplicants = ARRAY_SIZE(pda_power_supplied_to),
  91         .properties = pda_power_props,
  92         .num_properties = ARRAY_SIZE(pda_power_props),
  93         .get_property = pda_power_get_property,
  94 };
  95
  96 static void update_status(void)
  97 {
  98         if (pdata->is_ac_online)
  99                 new_ac_status = !!pdata->is_ac_online();
 100
 101         if (pdata->is_usb_online)
 102                 new_usb_status = !!pdata->is_usb_online();
 103 }
 104
 105 static void update_charger(void)
 106 {
 107         if (!pdata->set_charge)
 108                 return;
 109
 110         if (new_ac_status > 0) {
 111                 dev_dbg(dev, "charger on (AC)\n");
 112                 pdata->set_charge(PDA_POWER_CHARGE_AC);
 113         } else if (new_usb_status > 0) {
 114                 dev_dbg(dev, "charger on (USB)\n");
 115                 pdata->set_charge(PDA_POWER_CHARGE_USB);
 116         } else {
 117                 dev_dbg(dev, "charger off\n");
 118                 pdata->set_charge(0);
 119         }
 120 }
 121
 122 static void supply_timer_func(unsigned long unused)
 123 {
 124         if (ac_status == PDA_PSY_TO_CHANGE) {
 125                 ac_status = new_ac_status;
 126                 power_supply_changed(&pda_psy_ac);
 127         }
 128
 129         if (usb_status == PDA_PSY_TO_CHANGE) {
 130                 usb_status = new_usb_status;
 131                 power_supply_changed(&pda_psy_usb);
 132         }
 133 }
 134
 135 static void psy_changed(void)
 136 {
 137         update_charger();
 138
 139         /*
 140          * Okay, charger set. Now wait a bit before notifying supplicants,
 141          * charge power should stabilize.
 142          */
 143         mod_timer(&supply_timer,
 144                   jiffies + msecs_to_jiffies(pdata->wait_for_charger));
 145 }
 146
 147 static void charger_timer_func(unsigned long unused)
 148 {
 149         update_status();
 150         psy_changed();
 151 }
 152
 153 static irqreturn_t power_changed_isr(int irq, void *power_supply)
 154 {
 155         if (power_supply == &pda_psy_ac)
 156                 ac_status = PDA_PSY_TO_CHANGE;
 157         else if (power_supply == &pda_psy_usb)
 158                 usb_status = PDA_PSY_TO_CHANGE;
 159         else
 160                 return IRQ_NONE;
 161
 162         /*
 163          * Wait a bit before reading ac/usb line status and setting charger,
 164          * because ac/usb status readings may lag from irq.
 165          */
 166         mod_timer(&charger_timer,
 167                   jiffies + msecs_to_jiffies(pdata->wait_for_status));
 168
 169         return IRQ_HANDLED;
 170 }
 171
 172 static void polling_timer_func(unsigned long unused)
 173 {
 174         int changed = 0;
 175
 176         dev_dbg(dev, "polling...\n");
 177
 178         update_status();
 179
 180         if (!ac_irq && new_ac_status != ac_status) {
 181                 ac_status = PDA_PSY_TO_CHANGE;
 182                 changed = 1;
 183         }
 184
 185         if (!usb_irq && new_usb_status != usb_status) {
 186                 usb_status = PDA_PSY_TO_CHANGE;
 187                 changed = 1;
 188         }
 189
 190         if (changed)
 191                 psy_changed();
 192
 193         mod_timer(&polling_timer,
 194                   jiffies + msecs_to_jiffies(pdata->polling_interval));
 195 }
 196
 197 static int pda_power_probe(struct platform_device *pdev)
 198 {
 199         int ret = 0;
 200
 201         dev = &pdev->dev;
 202
 203         if (pdev->id != -1) {
 204                 dev_err(dev, "it's meaningless to register several "
 205                         "pda_powers; use id = -1\n");
 206                 ret = -EINVAL;
 207                 goto wrongid;
 208         }
 209
 210         pdata = pdev->dev.platform_data;
 211
 212         update_status();
 213         update_charger();
 214
 215         if (!pdata->wait_for_status)
 216                 pdata->wait_for_status = 500;
 217
 218         if (!pdata->wait_for_charger)
 219                 pdata->wait_for_charger = 500;
 220
 221         if (!pdata->polling_interval)
 222                 pdata->polling_interval = 2000;
 223
 224         setup_timer(&charger_timer, charger_timer_func, 0);
 225         setup_timer(&supply_timer, supply_timer_func, 0);
 226
 227         ac_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "ac");
 228         usb_irq = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "usb");
 229
 230         if (pdata->supplied_to) {
 231                 pda_psy_ac.supplied_to = pdata->supplied_to;
 232                 pda_psy_ac.num_supplicants = pdata->num_supplicants;
 233                 pda_psy_usb.supplied_to = pdata->supplied_to;
 234                 pda_psy_usb.num_supplicants = pdata->num_supplicants;
 235         }
 236
 237         if (pdata->is_ac_online) {
 238                 ret = power_supply_register(&pdev->dev, &pda_psy_ac);
 239                 if (ret) {
 240                         dev_err(dev, "failed to register %s power supply\n",
 241                                 pda_psy_ac.name);
 242                         goto ac_supply_failed;
 243                 }
 244
 245                 if (ac_irq) {
 246                         ret = request_irq(ac_irq->start, power_changed_isr,
 247                                           get_irq_flags(ac_irq), ac_irq->name,
 248                                           &pda_psy_ac);
 249                         if (ret) {
 250                                 dev_err(dev, "request ac irq failed\n");
 251                                 goto ac_irq_failed;
 252                         }
 253                 } else {
 254                         polling = 1;
 255                 }
 256         }
 257
 258         if (pdata->is_usb_online) {
 259                 ret = power_supply_register(&pdev->dev, &pda_psy_usb);
 260                 if (ret) {
 261                         dev_err(dev, "failed to register %s power supply\n",
 262                                 pda_psy_usb.name);
 263                         goto usb_supply_failed;
 264                 }
 265
 266                 if (usb_irq) {
 267                         ret = request_irq(usb_irq->start, power_changed_isr,
 268                                           get_irq_flags(usb_irq),
 269                                           usb_irq->name, &pda_psy_usb);
 270                         if (ret) {
 271                                 dev_err(dev, "request usb irq failed\n");
 272                                 goto usb_irq_failed;
 273                         }
 274                 } else {
 275                         polling = 1;
 276                 }
 277         }
 278
 279         if (polling) {
 280                 dev_dbg(dev, "will poll for status\n");
 281                 setup_timer(&polling_timer, polling_timer_func, 0);
 282                 mod_timer(&polling_timer,
 283                           jiffies + msecs_to_jiffies(pdata->polling_interval));
 284         }
 285
 286         if (ac_irq || usb_irq)
 287                 device_init_wakeup(&pdev->dev, 1);
 288
 289         return 0;
 290
 291 usb_irq_failed:
 292         if (pdata->is_usb_online)
 293                 power_supply_unregister(&pda_psy_usb);
 294 usb_supply_failed:
 295         if (pdata->is_ac_online && ac_irq)
 296                 free_irq(ac_irq->start, &pda_psy_ac);
 297 ac_irq_failed:
 298         if (pdata->is_ac_online)
 299                 power_supply_unregister(&pda_psy_ac);
 300 ac_supply_failed:
 301 wrongid:
 302         return ret;
 303 }
 304
 305 static int pda_power_remove(struct platform_device *pdev)
 306 {
 307         if (pdata->is_usb_online && usb_irq)
 308                 free_irq(usb_irq->start, &pda_psy_usb);
 309         if (pdata->is_ac_online && ac_irq)
 310                 free_irq(ac_irq->start, &pda_psy_ac);
 311
 312         if (polling)
 313                 del_timer_sync(&polling_timer);
 314         del_timer_sync(&charger_timer);
 315         del_timer_sync(&supply_timer);
 316
 317         if (pdata->is_usb_online)
 318                 power_supply_unregister(&pda_psy_usb);
 319         if (pdata->is_ac_online)
 320                 power_supply_unregister(&pda_psy_ac);
 321
 322         return 0;
 323 }
 324
 325 #ifdef CONFIG_PM
 326 static int pda_power_suspend(struct platform_device *pdev, pm_message_t state)
 327 {
 328         if (device_may_wakeup(&pdev->dev)) {
 329                 if (ac_irq)
 330                         enable_irq_wake(ac_irq->start);
 331                 if (usb_irq)
 332                         enable_irq_wake(usb_irq->start);
 333         }
 334
 335         return 0;
 336 }
 337
 338 static int pda_power_resume(struct platform_device *pdev)
 339 {
 340         if (device_may_wakeup(&pdev->dev)) {
 341                 if (usb_irq)
 342                         disable_irq_wake(usb_irq->start);
 343                 if (ac_irq)
 344                         disable_irq_wake(ac_irq->start);
 345         }
 346
 347         return 0;
 348 }
 349 #else
 350 #define pda_power_suspend NULL
 351 #define pda_power_resume NULL
 352 #endif /* CONFIG_PM */
 353
 354 static struct platform_driver pda_power_pdrv = {
 355         .driver = {
 356                 .name = "pda-power",
 357         },
 358         .probe = pda_power_probe,
 359         .remove = pda_power_remove,
 360         .suspend = pda_power_suspend,
 361         .resume = pda_power_resume,
 362 };
 363
 364 static int __init pda_power_init(void)
 365 {
 366         return platform_driver_register(&pda_power_pdrv);
 367 }
 368
 369 static void __exit pda_power_exit(void)
 370 {
 371         platform_driver_unregister(&pda_power_pdrv);
 372 }
 373
 374 module_init(pda_power_init);
 375 module_exit(pda_power_exit);
 376 MODULE_LICENSE("GPL");
 377 MODULE_AUTHOR("Anton Vorontsov <cbou@mail.ru>");