gpio-charger.c 11 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
  4. * Driver for chargers which report their online status through a GPIO pin
  5. */
  6. #include <linux/device.h>
  7. #include <linux/init.h>
  8. #include <linux/interrupt.h>
  9. #include <linux/kernel.h>
  10. #include <linux/module.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/power_supply.h>
  13. #include <linux/slab.h>
  14. #include <linux/of.h>
  15. #include <linux/gpio/consumer.h>
  16. #include <linux/power/gpio-charger.h>
  17. struct gpio_mapping {
  18. u32 limit_ua;
  19. u32 gpiodata;
  20. } __packed;
  21. struct gpio_charger {
  22. struct device *dev;
  23. unsigned int irq;
  24. unsigned int charge_status_irq;
  25. bool wakeup_enabled;
  26. struct power_supply *charger;
  27. struct power_supply_desc charger_desc;
  28. struct gpio_desc *gpiod;
  29. struct gpio_desc *charge_status;
  30. struct gpio_descs *current_limit_gpios;
  31. struct gpio_mapping *current_limit_map;
  32. u32 current_limit_map_size;
  33. u32 charge_current_limit;
  34. };
  35. static irqreturn_t gpio_charger_irq(int irq, void *devid)
  36. {
  37. struct power_supply *charger = devid;
  38. power_supply_changed(charger);
  39. return IRQ_HANDLED;
  40. }
  41. static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy)
  42. {
  43. return power_supply_get_drvdata(psy);
  44. }
  45. static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val)
  46. {
  47. struct gpio_mapping mapping;
  48. int ndescs = gpio_charger->current_limit_gpios->ndescs;
  49. struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc;
  50. int i;
  51. if (!gpio_charger->current_limit_map_size)
  52. return -EINVAL;
  53. for (i = 0; i < gpio_charger->current_limit_map_size; i++) {
  54. if (gpio_charger->current_limit_map[i].limit_ua <= val)
  55. break;
  56. }
  57. mapping = gpio_charger->current_limit_map[i];
  58. for (i = 0; i < ndescs; i++) {
  59. bool val = (mapping.gpiodata >> i) & 1;
  60. gpiod_set_value_cansleep(gpios[ndescs-i-1], val);
  61. }
  62. gpio_charger->charge_current_limit = mapping.limit_ua;
  63. dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n",
  64. gpio_charger->charge_current_limit, val);
  65. return 0;
  66. }
  67. static int gpio_charger_get_property(struct power_supply *psy,
  68. enum power_supply_property psp, union power_supply_propval *val)
  69. {
  70. struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
  71. switch (psp) {
  72. case POWER_SUPPLY_PROP_ONLINE:
  73. val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
  74. break;
  75. case POWER_SUPPLY_PROP_STATUS:
  76. if (gpiod_get_value_cansleep(gpio_charger->charge_status))
  77. val->intval = POWER_SUPPLY_STATUS_CHARGING;
  78. else
  79. val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
  80. break;
  81. case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
  82. val->intval = gpio_charger->charge_current_limit;
  83. break;
  84. default:
  85. return -EINVAL;
  86. }
  87. return 0;
  88. }
  89. static int gpio_charger_set_property(struct power_supply *psy,
  90. enum power_supply_property psp, const union power_supply_propval *val)
  91. {
  92. struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy);
  93. switch (psp) {
  94. case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
  95. return set_charge_current_limit(gpio_charger, val->intval);
  96. default:
  97. return -EINVAL;
  98. }
  99. return 0;
  100. }
  101. static int gpio_charger_property_is_writeable(struct power_supply *psy,
  102. enum power_supply_property psp)
  103. {
  104. switch (psp) {
  105. case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
  106. return 1;
  107. default:
  108. break;
  109. }
  110. return 0;
  111. }
  112. static enum power_supply_type gpio_charger_get_type(struct device *dev)
  113. {
  114. const char *chargetype;
  115. if (!device_property_read_string(dev, "charger-type", &chargetype)) {
  116. if (!strcmp("unknown", chargetype))
  117. return POWER_SUPPLY_TYPE_UNKNOWN;
  118. if (!strcmp("battery", chargetype))
  119. return POWER_SUPPLY_TYPE_BATTERY;
  120. if (!strcmp("ups", chargetype))
  121. return POWER_SUPPLY_TYPE_UPS;
  122. if (!strcmp("mains", chargetype))
  123. return POWER_SUPPLY_TYPE_MAINS;
  124. if (!strcmp("usb-sdp", chargetype))
  125. return POWER_SUPPLY_TYPE_USB;
  126. if (!strcmp("usb-dcp", chargetype))
  127. return POWER_SUPPLY_TYPE_USB;
  128. if (!strcmp("usb-cdp", chargetype))
  129. return POWER_SUPPLY_TYPE_USB;
  130. if (!strcmp("usb-aca", chargetype))
  131. return POWER_SUPPLY_TYPE_USB;
  132. }
  133. dev_warn(dev, "unknown charger type %s\n", chargetype);
  134. return POWER_SUPPLY_TYPE_UNKNOWN;
  135. }
  136. static int gpio_charger_get_irq(struct device *dev, void *dev_id,
  137. struct gpio_desc *gpio)
  138. {
  139. int ret, irq = gpiod_to_irq(gpio);
  140. if (irq > 0) {
  141. ret = devm_request_any_context_irq(dev, irq, gpio_charger_irq,
  142. IRQF_TRIGGER_RISING |
  143. IRQF_TRIGGER_FALLING,
  144. dev_name(dev),
  145. dev_id);
  146. if (ret < 0) {
  147. dev_warn(dev, "Failed to request irq: %d\n", ret);
  148. irq = 0;
  149. }
  150. }
  151. return irq;
  152. }
  153. static int init_charge_current_limit(struct device *dev,
  154. struct gpio_charger *gpio_charger)
  155. {
  156. int i, len;
  157. u32 cur_limit = U32_MAX;
  158. gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev,
  159. "charge-current-limit", GPIOD_OUT_LOW);
  160. if (IS_ERR(gpio_charger->current_limit_gpios)) {
  161. dev_err(dev, "error getting current-limit GPIOs\n");
  162. return PTR_ERR(gpio_charger->current_limit_gpios);
  163. }
  164. if (!gpio_charger->current_limit_gpios)
  165. return 0;
  166. len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
  167. NULL, 0);
  168. if (len < 0)
  169. return len;
  170. if (len == 0 || len % 2) {
  171. dev_err(dev, "invalid charge-current-limit-mapping length\n");
  172. return -EINVAL;
  173. }
  174. gpio_charger->current_limit_map = devm_kmalloc_array(dev,
  175. len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL);
  176. if (!gpio_charger->current_limit_map)
  177. return -ENOMEM;
  178. gpio_charger->current_limit_map_size = len / 2;
  179. len = device_property_read_u32_array(dev, "charge-current-limit-mapping",
  180. (u32*) gpio_charger->current_limit_map, len);
  181. if (len < 0)
  182. return len;
  183. for (i=0; i < gpio_charger->current_limit_map_size; i++) {
  184. if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) {
  185. dev_err(dev, "charge-current-limit-mapping not sorted by current in descending order\n");
  186. return -EINVAL;
  187. }
  188. cur_limit = gpio_charger->current_limit_map[i].limit_ua;
  189. }
  190. /* default to smallest current limitation for safety reasons */
  191. len = gpio_charger->current_limit_map_size - 1;
  192. set_charge_current_limit(gpio_charger,
  193. gpio_charger->current_limit_map[len].limit_ua);
  194. return 0;
  195. }
  196. /*
  197. * The entries will be overwritten by driver's probe routine depending
  198. * on the available features. This list ensures, that the array is big
  199. * enough for all optional features.
  200. */
  201. static enum power_supply_property gpio_charger_properties[] = {
  202. POWER_SUPPLY_PROP_ONLINE,
  203. POWER_SUPPLY_PROP_STATUS,
  204. POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
  205. };
  206. static int gpio_charger_probe(struct platform_device *pdev)
  207. {
  208. struct device *dev = &pdev->dev;
  209. const struct gpio_charger_platform_data *pdata = dev->platform_data;
  210. struct power_supply_config psy_cfg = {};
  211. struct gpio_charger *gpio_charger;
  212. struct power_supply_desc *charger_desc;
  213. struct gpio_desc *charge_status;
  214. int charge_status_irq;
  215. int ret;
  216. int num_props = 0;
  217. if (!pdata && !dev->of_node) {
  218. dev_err(dev, "No platform data\n");
  219. return -ENOENT;
  220. }
  221. gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL);
  222. if (!gpio_charger)
  223. return -ENOMEM;
  224. gpio_charger->dev = dev;
  225. /*
  226. * This will fetch a GPIO descriptor from device tree, ACPI or
  227. * boardfile descriptor tables. It's good to try this first.
  228. */
  229. gpio_charger->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN);
  230. if (IS_ERR(gpio_charger->gpiod)) {
  231. /* Just try again if this happens */
  232. return dev_err_probe(dev, PTR_ERR(gpio_charger->gpiod),
  233. "error getting GPIO descriptor\n");
  234. }
  235. if (gpio_charger->gpiod) {
  236. gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_ONLINE;
  237. num_props++;
  238. }
  239. charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN);
  240. if (IS_ERR(charge_status))
  241. return PTR_ERR(charge_status);
  242. if (charge_status) {
  243. gpio_charger->charge_status = charge_status;
  244. gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_STATUS;
  245. num_props++;
  246. }
  247. ret = init_charge_current_limit(dev, gpio_charger);
  248. if (ret < 0)
  249. return ret;
  250. if (gpio_charger->current_limit_map) {
  251. gpio_charger_properties[num_props] =
  252. POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX;
  253. num_props++;
  254. }
  255. charger_desc = &gpio_charger->charger_desc;
  256. charger_desc->properties = gpio_charger_properties;
  257. charger_desc->num_properties = num_props;
  258. charger_desc->get_property = gpio_charger_get_property;
  259. charger_desc->set_property = gpio_charger_set_property;
  260. charger_desc->property_is_writeable =
  261. gpio_charger_property_is_writeable;
  262. psy_cfg.of_node = dev->of_node;
  263. psy_cfg.drv_data = gpio_charger;
  264. if (pdata) {
  265. charger_desc->name = pdata->name;
  266. charger_desc->type = pdata->type;
  267. psy_cfg.supplied_to = pdata->supplied_to;
  268. psy_cfg.num_supplicants = pdata->num_supplicants;
  269. } else {
  270. charger_desc->name = dev->of_node->name;
  271. charger_desc->type = gpio_charger_get_type(dev);
  272. }
  273. if (!charger_desc->name)
  274. charger_desc->name = pdev->name;
  275. gpio_charger->charger = devm_power_supply_register(dev, charger_desc,
  276. &psy_cfg);
  277. if (IS_ERR(gpio_charger->charger)) {
  278. ret = PTR_ERR(gpio_charger->charger);
  279. dev_err(dev, "Failed to register power supply: %d\n", ret);
  280. return ret;
  281. }
  282. gpio_charger->irq = gpio_charger_get_irq(dev, gpio_charger->charger,
  283. gpio_charger->gpiod);
  284. charge_status_irq = gpio_charger_get_irq(dev, gpio_charger->charger,
  285. gpio_charger->charge_status);
  286. gpio_charger->charge_status_irq = charge_status_irq;
  287. platform_set_drvdata(pdev, gpio_charger);
  288. device_init_wakeup(dev, 1);
  289. return 0;
  290. }
  291. #ifdef CONFIG_PM_SLEEP
  292. static int gpio_charger_suspend(struct device *dev)
  293. {
  294. struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
  295. if (device_may_wakeup(dev))
  296. gpio_charger->wakeup_enabled =
  297. !enable_irq_wake(gpio_charger->irq);
  298. return 0;
  299. }
  300. static int gpio_charger_resume(struct device *dev)
  301. {
  302. struct gpio_charger *gpio_charger = dev_get_drvdata(dev);
  303. if (device_may_wakeup(dev) && gpio_charger->wakeup_enabled)
  304. disable_irq_wake(gpio_charger->irq);
  305. power_supply_changed(gpio_charger->charger);
  306. return 0;
  307. }
  308. #endif
  309. static SIMPLE_DEV_PM_OPS(gpio_charger_pm_ops,
  310. gpio_charger_suspend, gpio_charger_resume);
  311. static const struct of_device_id gpio_charger_match[] = {
  312. { .compatible = "gpio-charger" },
  313. { }
  314. };
  315. MODULE_DEVICE_TABLE(of, gpio_charger_match);
  316. static struct platform_driver gpio_charger_driver = {
  317. .probe = gpio_charger_probe,
  318. .driver = {
  319. .name = "gpio-charger",
  320. .pm = &gpio_charger_pm_ops,
  321. .of_match_table = gpio_charger_match,
  322. },
  323. };
  324. module_platform_driver(gpio_charger_driver);
  325. MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
  326. MODULE_DESCRIPTION("Driver for chargers only communicating via GPIO(s)");
  327. MODULE_LICENSE("GPL");
  328. MODULE_ALIAS("platform:gpio-charger");