z2_battery.c 7.7 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 <[email protected]>
  6. */
  7. #include <linux/module.h>
  8. #include <linux/gpio/consumer.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. struct gpio_desc *charge_gpiod;
  19. int bat_status;
  20. struct i2c_client *client;
  21. struct power_supply *batt_ps;
  22. struct power_supply_desc batt_ps_desc;
  23. struct mutex work_lock;
  24. struct work_struct bat_work;
  25. };
  26. static unsigned long z2_read_bat(struct z2_charger *charger)
  27. {
  28. int data;
  29. data = i2c_smbus_read_byte_data(charger->client,
  30. charger->info->batt_I2C_reg);
  31. if (data < 0)
  32. return 0;
  33. return data * charger->info->batt_mult / charger->info->batt_div;
  34. }
  35. static int z2_batt_get_property(struct power_supply *batt_ps,
  36. enum power_supply_property psp,
  37. union power_supply_propval *val)
  38. {
  39. struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  40. struct z2_battery_info *info = charger->info;
  41. switch (psp) {
  42. case POWER_SUPPLY_PROP_STATUS:
  43. val->intval = charger->bat_status;
  44. break;
  45. case POWER_SUPPLY_PROP_TECHNOLOGY:
  46. val->intval = info->batt_tech;
  47. break;
  48. case POWER_SUPPLY_PROP_VOLTAGE_NOW:
  49. if (info->batt_I2C_reg >= 0)
  50. val->intval = z2_read_bat(charger);
  51. else
  52. return -EINVAL;
  53. break;
  54. case POWER_SUPPLY_PROP_VOLTAGE_MAX:
  55. if (info->max_voltage >= 0)
  56. val->intval = info->max_voltage;
  57. else
  58. return -EINVAL;
  59. break;
  60. case POWER_SUPPLY_PROP_VOLTAGE_MIN:
  61. if (info->min_voltage >= 0)
  62. val->intval = info->min_voltage;
  63. else
  64. return -EINVAL;
  65. break;
  66. case POWER_SUPPLY_PROP_PRESENT:
  67. val->intval = 1;
  68. break;
  69. default:
  70. return -EINVAL;
  71. }
  72. return 0;
  73. }
  74. static void z2_batt_ext_power_changed(struct power_supply *batt_ps)
  75. {
  76. struct z2_charger *charger = power_supply_get_drvdata(batt_ps);
  77. schedule_work(&charger->bat_work);
  78. }
  79. static void z2_batt_update(struct z2_charger *charger)
  80. {
  81. int old_status = charger->bat_status;
  82. mutex_lock(&charger->work_lock);
  83. charger->bat_status = charger->charge_gpiod ?
  84. (gpiod_get_value(charger->charge_gpiod) ?
  85. POWER_SUPPLY_STATUS_CHARGING :
  86. POWER_SUPPLY_STATUS_DISCHARGING) :
  87. POWER_SUPPLY_STATUS_UNKNOWN;
  88. if (old_status != charger->bat_status) {
  89. pr_debug("%s: %i -> %i\n", charger->batt_ps->desc->name,
  90. old_status,
  91. charger->bat_status);
  92. power_supply_changed(charger->batt_ps);
  93. }
  94. mutex_unlock(&charger->work_lock);
  95. }
  96. static void z2_batt_work(struct work_struct *work)
  97. {
  98. struct z2_charger *charger;
  99. charger = container_of(work, struct z2_charger, bat_work);
  100. z2_batt_update(charger);
  101. }
  102. static irqreturn_t z2_charge_switch_irq(int irq, void *devid)
  103. {
  104. struct z2_charger *charger = devid;
  105. schedule_work(&charger->bat_work);
  106. return IRQ_HANDLED;
  107. }
  108. static int z2_batt_ps_init(struct z2_charger *charger, int props)
  109. {
  110. int i = 0;
  111. enum power_supply_property *prop;
  112. struct z2_battery_info *info = charger->info;
  113. if (charger->charge_gpiod)
  114. props++; /* POWER_SUPPLY_PROP_STATUS */
  115. if (info->batt_tech >= 0)
  116. props++; /* POWER_SUPPLY_PROP_TECHNOLOGY */
  117. if (info->batt_I2C_reg >= 0)
  118. props++; /* POWER_SUPPLY_PROP_VOLTAGE_NOW */
  119. if (info->max_voltage >= 0)
  120. props++; /* POWER_SUPPLY_PROP_VOLTAGE_MAX */
  121. if (info->min_voltage >= 0)
  122. props++; /* POWER_SUPPLY_PROP_VOLTAGE_MIN */
  123. prop = kcalloc(props, sizeof(*prop), GFP_KERNEL);
  124. if (!prop)
  125. return -ENOMEM;
  126. prop[i++] = POWER_SUPPLY_PROP_PRESENT;
  127. if (charger->charge_gpiod)
  128. prop[i++] = POWER_SUPPLY_PROP_STATUS;
  129. if (info->batt_tech >= 0)
  130. prop[i++] = POWER_SUPPLY_PROP_TECHNOLOGY;
  131. if (info->batt_I2C_reg >= 0)
  132. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_NOW;
  133. if (info->max_voltage >= 0)
  134. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MAX;
  135. if (info->min_voltage >= 0)
  136. prop[i++] = POWER_SUPPLY_PROP_VOLTAGE_MIN;
  137. if (!info->batt_name) {
  138. dev_info(&charger->client->dev,
  139. "Please consider setting proper battery "
  140. "name in platform definition file, falling "
  141. "back to name \" Z2_DEFAULT_NAME \"\n");
  142. charger->batt_ps_desc.name = Z2_DEFAULT_NAME;
  143. } else
  144. charger->batt_ps_desc.name = info->batt_name;
  145. charger->batt_ps_desc.properties = prop;
  146. charger->batt_ps_desc.num_properties = props;
  147. charger->batt_ps_desc.type = POWER_SUPPLY_TYPE_BATTERY;
  148. charger->batt_ps_desc.get_property = z2_batt_get_property;
  149. charger->batt_ps_desc.external_power_changed =
  150. z2_batt_ext_power_changed;
  151. charger->batt_ps_desc.use_for_apm = 1;
  152. return 0;
  153. }
  154. static int z2_batt_probe(struct i2c_client *client,
  155. const struct i2c_device_id *id)
  156. {
  157. int ret = 0;
  158. int props = 1; /* POWER_SUPPLY_PROP_PRESENT */
  159. struct z2_charger *charger;
  160. struct z2_battery_info *info = client->dev.platform_data;
  161. struct power_supply_config psy_cfg = {};
  162. if (info == NULL) {
  163. dev_err(&client->dev,
  164. "Please set platform device platform_data"
  165. " to a valid z2_battery_info pointer!\n");
  166. return -EINVAL;
  167. }
  168. charger = kzalloc(sizeof(*charger), GFP_KERNEL);
  169. if (charger == NULL)
  170. return -ENOMEM;
  171. charger->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
  172. charger->info = info;
  173. charger->client = client;
  174. i2c_set_clientdata(client, charger);
  175. psy_cfg.drv_data = charger;
  176. mutex_init(&charger->work_lock);
  177. charger->charge_gpiod = devm_gpiod_get_optional(&client->dev,
  178. NULL, GPIOD_IN);
  179. if (IS_ERR(charger->charge_gpiod)) {
  180. ret = dev_err_probe(&client->dev,
  181. PTR_ERR(charger->charge_gpiod),
  182. "failed to get charge GPIO\n");
  183. goto err;
  184. }
  185. if (charger->charge_gpiod) {
  186. gpiod_set_consumer_name(charger->charge_gpiod, "BATT CHRG");
  187. irq_set_irq_type(gpiod_to_irq(charger->charge_gpiod),
  188. IRQ_TYPE_EDGE_BOTH);
  189. ret = request_irq(gpiod_to_irq(charger->charge_gpiod),
  190. z2_charge_switch_irq, 0,
  191. "AC Detect", charger);
  192. if (ret)
  193. goto err;
  194. }
  195. ret = z2_batt_ps_init(charger, props);
  196. if (ret)
  197. goto err3;
  198. INIT_WORK(&charger->bat_work, z2_batt_work);
  199. charger->batt_ps = power_supply_register(&client->dev,
  200. &charger->batt_ps_desc,
  201. &psy_cfg);
  202. if (IS_ERR(charger->batt_ps)) {
  203. ret = PTR_ERR(charger->batt_ps);
  204. goto err4;
  205. }
  206. schedule_work(&charger->bat_work);
  207. return 0;
  208. err4:
  209. kfree(charger->batt_ps_desc.properties);
  210. err3:
  211. if (charger->charge_gpiod)
  212. free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
  213. err:
  214. kfree(charger);
  215. return ret;
  216. }
  217. static void z2_batt_remove(struct i2c_client *client)
  218. {
  219. struct z2_charger *charger = i2c_get_clientdata(client);
  220. cancel_work_sync(&charger->bat_work);
  221. power_supply_unregister(charger->batt_ps);
  222. kfree(charger->batt_ps_desc.properties);
  223. if (charger->charge_gpiod)
  224. free_irq(gpiod_to_irq(charger->charge_gpiod), charger);
  225. kfree(charger);
  226. }
  227. #ifdef CONFIG_PM
  228. static int z2_batt_suspend(struct device *dev)
  229. {
  230. struct i2c_client *client = to_i2c_client(dev);
  231. struct z2_charger *charger = i2c_get_clientdata(client);
  232. flush_work(&charger->bat_work);
  233. return 0;
  234. }
  235. static int z2_batt_resume(struct device *dev)
  236. {
  237. struct i2c_client *client = to_i2c_client(dev);
  238. struct z2_charger *charger = i2c_get_clientdata(client);
  239. schedule_work(&charger->bat_work);
  240. return 0;
  241. }
  242. static const struct dev_pm_ops z2_battery_pm_ops = {
  243. .suspend = z2_batt_suspend,
  244. .resume = z2_batt_resume,
  245. };
  246. #define Z2_BATTERY_PM_OPS (&z2_battery_pm_ops)
  247. #else
  248. #define Z2_BATTERY_PM_OPS (NULL)
  249. #endif
  250. static const struct i2c_device_id z2_batt_id[] = {
  251. { "aer915", 0 },
  252. { }
  253. };
  254. MODULE_DEVICE_TABLE(i2c, z2_batt_id);
  255. static struct i2c_driver z2_batt_driver = {
  256. .driver = {
  257. .name = "z2-battery",
  258. .pm = Z2_BATTERY_PM_OPS
  259. },
  260. .probe = z2_batt_probe,
  261. .remove = z2_batt_remove,
  262. .id_table = z2_batt_id,
  263. };
  264. module_i2c_driver(z2_batt_driver);
  265. MODULE_LICENSE("GPL");
  266. MODULE_AUTHOR("Peter Edwards <[email protected]>");
  267. MODULE_DESCRIPTION("Zipit Z2 battery driver");