z2_battery.c 7.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Battery measurement code for Zipit Z2
  4. *
  5. * Copyright (C) 2009 Peter Edwards <sweetlilmre@gmail.com>
  6. */
  7. #include <linux/module.h>
  8. #include <linux/gpio.h>
  9. #include <linux/i2c.h>
  10. #include <linux/interrupt.h>
  11. #include <linux/irq.h>
  12. #include <linux/power_supply.h>
  13. #include <linux/slab.h>
  14. #include <linux/z2_battery.h>
  15. #define Z2_DEFAULT_NAME "Z2"
  16. struct z2_charger {
  17. struct z2_battery_info *info;
  18. int bat_status;
  19. struct i2c_client *client;
  20. struct power_supply *batt_ps;
  21. struct power_supply_desc batt_ps_desc;
  22. struct mutex work_lock;
  23. struct work_struct bat_work;
  24. };
  25. static unsigned long z2_read_bat(struct z2_charger *charger)
  26. {
  27. int data;
  28. data = i2c_smbus_read_byte_data(charger->client,
  29. charger->info->batt_I2C_reg);
  30. if (data < 0)
  31. return 0;
  32. return data * charger->info->batt_mult / charger->info->batt_div;
  33. }
  34. static int z2_batt_get_property(struct power_supply *batt_ps,
  35. enum power_supply_property psp,
  36. union power_supply_propval *val)
  37. {
  38. struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  39. struct z2_battery_info *info = charger->info;
  40. switch (psp) {
  41. case POWER_SUPPLY_PROP_STATUS:
  42. val->intval = charger->bat_status;
  43. break;
  44. case POWER_SUPPLY_PROP_TECHNOLOGY:
  45. val->intval = info->batt_tech;
  46. break;
  47. case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  48. if (info->batt_I2C_reg >= 0)
  49. val->intval = z2_read_bat(charger);
  50. else
  51. return -EINVAL;
  52. break;
  53. case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  54. if (info->max_voltage >= 0)
  55. val->intval = info->max_voltage;
  56. else
  57. return -EINVAL;
  58. break;
  59. case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  60. if (info->min_voltage >= 0)
  61. val->intval = info->min_voltage;
  62. else
  63. return -EINVAL;
  64. break;
  65. case POWER_SUPPLY_PROP_PRESENT:
  66. val->intval = 1;
  67. break;
  68. default:
  69. return -EINVAL;
  70. }
  71. return 0;
  72. }
  73. static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
  74. {
  75. struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  76. schedule_work(&charger->bat_work);
  77. }
  78. static void z2_batt_update(struct z2_charger *charger)
  79. {
  80. int old_status = charger->bat_status;
  81. struct z2_battery_info *info;
  82. info = charger->info;
  83. mutex_lock(&charger->work_lock);
  84. charger->bat_status = (info->charge_gpio >= 0) ?
  85. (gpio_get_value(info->charge_gpio) ?
  86. POWER_SUPPLY_STATUS_CHARGING :
  87. POWER_SUPPLY_STATUS_DISCHARGING) :
  88. POWER_SUPPLY_STATUS_UNKNOWN;
  89. if (old_status != charger->bat_status) {
  90. pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name,
  91. old_status,
  92. charger->bat_status);
  93. power_supply_changed(charger->batt_ps);
  94. }
  95. mutex_unlock(&charger->work_lock);
  96. }
  97. static void z2_batt_work(struct work_struct *work)
  98. {
  99. struct z2_charger *charger;
  100. charger = container_of(work, struct z2_charger, bat_work);
  101. z2_batt_update(charger);
  102. }
  103. static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
  104. {
  105. struct z2_charger *charger = devid;
  106. schedule_work(&charger->bat_work);
  107. return IRQ_HANDLED;
  108. }
  109. static int z2_batt_ps_init(struct z2_charger *charger, int props)
  110. {
  111. int i = 0;
  112. enum power_supply_property *prop;
  113. struct z2_battery_info *info = charger->info;
  114. if (info->charge_gpio >= 0)
  115. props++; /* POWER_SUPPLY_PROP_STATUS */
  116. if (info->batt_tech >= 0)
  117. props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
  118. if (info->batt_I2C_reg >= 0)
  119. props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
  120. if (info->max_voltage >= 0)
  121. props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
  122. if (info->min_voltage >= 0)
  123. props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
  124. prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
  125. if (!prop)
  126. return -ENOMEM;
  127. prop[i++] = POWER_SUPPLY_PROP_PRESENT;
  128. if (info->charge_gpio >= 0)
  129. prop[i++] = POWER_SUPPLY_PROP_STATUS;
  130. if (info->batt_tech >= 0)
  131. prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
  132. if (info->batt_I2C_reg >= 0)
  133. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
  134. if (info->max_voltage >= 0)
  135. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
  136. if (info->min_voltage >= 0)
  137. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
  138. if (!info->batt_name) {
  139. dev_info(&charger->client->dev,
  140. "Please consider setting proper battery "
  141. "name in platform definition file, falling "
  142. "back to name \" Z2_DEFAULT_NAME \"\n");
  143. charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
  144. } else
  145. charger->batt_ps_desc.name = info->batt_name;
  146. charger->batt_ps_desc.properties = prop;
  147. charger->batt_ps_desc.num_properties = props;
  148. charger->batt_ps_desc.type = POWER_SUPPLY_TYPE_BATTERY;
  149. charger->batt_ps_desc.get_property = z2_batt_get_property;
  150. charger->batt_ps_desc.external_power_changed =
  151. z2_batt_ext_power_changed;
  152. charger->batt_ps_desc.use_for_apm = 1;
  153. return 0;
  154. }
  155. static int z2_batt_probe(struct i2c_client *client,
  156. const struct i2c_device_id *id)
  157. {
  158. int ret = 0;
  159. int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
  160. struct z2_charger *charger;
  161. struct z2_battery_info *info = client->dev.platform_data;
  162. struct power_supply_config psy_cfg = {};
  163. if (info == NULL) {
  164. dev_err(&client->dev,
  165. "Please set platform device platform_data"
  166. " to a valid z2_battery_info pointer!\n");
  167. return -EINVAL;
  168. }
  169. charger = kzalloc(sizeof(*charger), GFP_KERNEL);
  170. if (charger == NULL)
  171. return -ENOMEM;
  172. charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  173. charger->info = info;
  174. charger->client = client;
  175. i2c_set_clientdata(client, charger);
  176. psy_cfg.drv_data = charger;
  177. mutex_init(&charger->work_lock);
  178. if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
  179. ret = gpio_request(info->charge_gpio, "BATT CHRG");
  180. if (ret)
  181. goto err;
  182. ret = gpio_direction_input(info->charge_gpio);
  183. if (ret)
  184. goto err2;
  185. irq_set_irq_type(gpio_to_irq(info->charge_gpio),
  186. IRQ_TYPE_EDGE_BOTH);
  187. ret = request_irq(gpio_to_irq(info->charge_gpio),
  188. z2_charge_switch_irq, 0,
  189. "AC Detect", charger);
  190. if (ret)
  191. goto err3;
  192. }
  193. ret = z2_batt_ps_init(charger, props);
  194. if (ret)
  195. goto err3;
  196. INIT_WORK(&charger->bat_work, z2_batt_work);
  197. charger->batt_ps = power_supply_register(&client->dev,
  198. &charger->batt_ps_desc,
  199. &psy_cfg);
  200. if (IS_ERR(charger->batt_ps)) {
  201. ret = PTR_ERR(charger->batt_ps);
  202. goto err4;
  203. }
  204. schedule_work(&charger->bat_work);
  205. return 0;
  206. err4:
  207. kfree(charger->batt_ps_desc.properties);
  208. err3:
  209. if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
  210. free_irq(gpio_to_irq(info->charge_gpio), charger);
  211. err2:
  212. if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio))
  213. gpio_free(info->charge_gpio);
  214. err:
  215. kfree(charger);
  216. return ret;
  217. }
  218. static int z2_batt_remove(struct i2c_client *client)
  219. {
  220. struct z2_charger *charger = i2c_get_clientdata(client);
  221. struct z2_battery_info *info = charger->info;
  222. cancel_work_sync(&charger->bat_work);
  223. power_supply_unregister(charger->batt_ps);
  224. kfree(charger->batt_ps_desc.properties);
  225. if (info->charge_gpio >= 0 && gpio_is_valid(info->charge_gpio)) {
  226. free_irq(gpio_to_irq(info->charge_gpio), charger);
  227. gpio_free(info->charge_gpio);
  228. }
  229. kfree(charger);
  230. return 0;
  231. }
  232. #ifdef CONFIG_PM
  233. static int z2_batt_suspend(struct device *dev)
  234. {
  235. struct i2c_client *client = to_i2c_client(dev);
  236. struct z2_charger *charger = i2c_get_clientdata(client);
  237. flush_work(&charger->bat_work);
  238. return 0;
  239. }
  240. static int z2_batt_resume(struct device *dev)
  241. {
  242. struct i2c_client *client = to_i2c_client(dev);
  243. struct z2_charger *charger = i2c_get_clientdata(client);
  244. schedule_work(&charger->bat_work);
  245. return 0;
  246. }
  247. static const struct dev_pm_ops z2_battery_pm_ops = {
  248. .suspend = z2_batt_suspend,
  249. .resume = z2_batt_resume,
  250. };
  251. #define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops)
  252. #else
  253. #define Z2_BATTERY_PM_OPS (NULL)
  254. #endif
  255. static const struct i2c_device_id z2_batt_id[] = {
  256. { "aer915", 0 },
  257. { }
  258. };
  259. MODULE_DEVICE_TABLE(i2c, z2_batt_id);
  260. static struct i2c_driver z2_batt_driver = {
  261. .driver = {
  262. .name = "z2-battery",
  263. .pm = Z2_BATTERY_PM_OPS
  264. },
  265. .probe = z2_batt_probe,
  266. .remove = z2_batt_remove,
  267. .id_table = z2_batt_id,
  268. };
  269. module_i2c_driver(z2_batt_driver);
  270. MODULE_LICENSE("GPL");
  271. MODULE_AUTHOR("Peter Edwards <sweetlilmre@gmail.com>");
  272. MODULE_DESCRIPTION("Zipit Z2 battery driver");