palmas-pwrbutton.c 7.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Texas Instruments' Palmas Power Button Input Driver
  4. *
  5. * Copyright (C) 2012-2014 Texas Instruments Incorporated - http://www.ti.com/
  6. * Girish S Ghongdemath
  7. * Nishanth Menon
  8. */
  9. #include <linux/bitfield.h>
  10. #include <linux/init.h>
  11. #include <linux/input.h>
  12. #include <linux/interrupt.h>
  13. #include <linux/kernel.h>
  14. #include <linux/mfd/palmas.h>
  15. #include <linux/module.h>
  16. #include <linux/of.h>
  17. #include <linux/platform_device.h>
  18. #include <linux/slab.h>
  19. #define PALMAS_LPK_TIME_MASK 0x0c
  20. #define PALMAS_PWRON_DEBOUNCE_MASK 0x03
  21. #define PALMAS_PWR_KEY_Q_TIME_MS 20
  22. /**
  23. * struct palmas_pwron - Palmas power on data
  24. * @palmas: pointer to palmas device
  25. * @input_dev: pointer to input device
  26. * @input_work: work for detecting release of key
  27. * @irq: irq that we are hooked on to
  28. */
  29. struct palmas_pwron {
  30. struct palmas *palmas;
  31. struct input_dev *input_dev;
  32. struct delayed_work input_work;
  33. int irq;
  34. };
  35. /**
  36. * struct palmas_pwron_config - configuration of palmas power on
  37. * @long_press_time_val: value for long press h/w shutdown event
  38. * @pwron_debounce_val: value for debounce of power button
  39. */
  40. struct palmas_pwron_config {
  41. u8 long_press_time_val;
  42. u8 pwron_debounce_val;
  43. };
  44. /**
  45. * palmas_power_button_work() - Detects the button release event
  46. * @work: work item to detect button release
  47. */
  48. static void palmas_power_button_work(struct work_struct *work)
  49. {
  50. struct palmas_pwron *pwron = container_of(work,
  51. struct palmas_pwron,
  52. input_work.work);
  53. struct input_dev *input_dev = pwron->input_dev;
  54. unsigned int reg;
  55. int error;
  56. error = palmas_read(pwron->palmas, PALMAS_INTERRUPT_BASE,
  57. PALMAS_INT1_LINE_STATE, &reg);
  58. if (error) {
  59. dev_err(input_dev->dev.parent,
  60. "Cannot read palmas PWRON status: %d\n", error);
  61. } else if (reg & BIT(1)) {
  62. /* The button is released, report event. */
  63. input_report_key(input_dev, KEY_POWER, 0);
  64. input_sync(input_dev);
  65. } else {
  66. /* The button is still depressed, keep checking. */
  67. schedule_delayed_work(&pwron->input_work,
  68. msecs_to_jiffies(PALMAS_PWR_KEY_Q_TIME_MS));
  69. }
  70. }
  71. /**
  72. * pwron_irq() - button press isr
  73. * @irq: irq
  74. * @palmas_pwron: pwron struct
  75. *
  76. * Return: IRQ_HANDLED
  77. */
  78. static irqreturn_t pwron_irq(int irq, void *palmas_pwron)
  79. {
  80. struct palmas_pwron *pwron = palmas_pwron;
  81. struct input_dev *input_dev = pwron->input_dev;
  82. input_report_key(input_dev, KEY_POWER, 1);
  83. pm_wakeup_event(input_dev->dev.parent, 0);
  84. input_sync(input_dev);
  85. mod_delayed_work(system_wq, &pwron->input_work,
  86. msecs_to_jiffies(PALMAS_PWR_KEY_Q_TIME_MS));
  87. return IRQ_HANDLED;
  88. }
  89. /**
  90. * palmas_pwron_params_ofinit() - device tree parameter parser
  91. * @dev: palmas button device
  92. * @config: configuration params that this fills up
  93. */
  94. static void palmas_pwron_params_ofinit(struct device *dev,
  95. struct palmas_pwron_config *config)
  96. {
  97. struct device_node *np;
  98. u32 val;
  99. int i, error;
  100. static const u8 lpk_times[] = { 6, 8, 10, 12 };
  101. static const int pwr_on_deb_ms[] = { 15, 100, 500, 1000 };
  102. memset(config, 0, sizeof(*config));
  103. /* Default config parameters */
  104. config->long_press_time_val = ARRAY_SIZE(lpk_times) - 1;
  105. np = dev->of_node;
  106. if (!np)
  107. return;
  108. error = of_property_read_u32(np, "ti,palmas-long-press-seconds", &val);
  109. if (!error) {
  110. for (i = 0; i < ARRAY_SIZE(lpk_times); i++) {
  111. if (val <= lpk_times[i]) {
  112. config->long_press_time_val = i;
  113. break;
  114. }
  115. }
  116. }
  117. error = of_property_read_u32(np,
  118. "ti,palmas-pwron-debounce-milli-seconds",
  119. &val);
  120. if (!error) {
  121. for (i = 0; i < ARRAY_SIZE(pwr_on_deb_ms); i++) {
  122. if (val <= pwr_on_deb_ms[i]) {
  123. config->pwron_debounce_val = i;
  124. break;
  125. }
  126. }
  127. }
  128. dev_info(dev, "h/w controlled shutdown duration=%d seconds\n",
  129. lpk_times[config->long_press_time_val]);
  130. }
  131. /**
  132. * palmas_pwron_probe() - probe
  133. * @pdev: platform device for the button
  134. *
  135. * Return: 0 for successful probe else appropriate error
  136. */
  137. static int palmas_pwron_probe(struct platform_device *pdev)
  138. {
  139. struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
  140. struct device *dev = &pdev->dev;
  141. struct input_dev *input_dev;
  142. struct palmas_pwron *pwron;
  143. struct palmas_pwron_config config;
  144. int val;
  145. int error;
  146. palmas_pwron_params_ofinit(dev, &config);
  147. pwron = kzalloc(sizeof(*pwron), GFP_KERNEL);
  148. if (!pwron)
  149. return -ENOMEM;
  150. input_dev = input_allocate_device();
  151. if (!input_dev) {
  152. dev_err(dev, "Can't allocate power button\n");
  153. error = -ENOMEM;
  154. goto err_free_mem;
  155. }
  156. input_dev->name = "palmas_pwron";
  157. input_dev->phys = "palmas_pwron/input0";
  158. input_dev->dev.parent = dev;
  159. input_set_capability(input_dev, EV_KEY, KEY_POWER);
  160. /*
  161. * Setup default hardware shutdown option (long key press)
  162. * and debounce.
  163. */
  164. val = FIELD_PREP(PALMAS_LPK_TIME_MASK, config.long_press_time_val) |
  165. FIELD_PREP(PALMAS_PWRON_DEBOUNCE_MASK, config.pwron_debounce_val);
  166. error = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
  167. PALMAS_LONG_PRESS_KEY,
  168. PALMAS_LPK_TIME_MASK |
  169. PALMAS_PWRON_DEBOUNCE_MASK,
  170. val);
  171. if (error) {
  172. dev_err(dev, "LONG_PRESS_KEY_UPDATE failed: %d\n", error);
  173. goto err_free_input;
  174. }
  175. pwron->palmas = palmas;
  176. pwron->input_dev = input_dev;
  177. INIT_DELAYED_WORK(&pwron->input_work, palmas_power_button_work);
  178. pwron->irq = platform_get_irq(pdev, 0);
  179. if (pwron->irq < 0) {
  180. error = pwron->irq;
  181. goto err_free_input;
  182. }
  183. error = request_threaded_irq(pwron->irq, NULL, pwron_irq,
  184. IRQF_TRIGGER_HIGH |
  185. IRQF_TRIGGER_LOW |
  186. IRQF_ONESHOT,
  187. dev_name(dev), pwron);
  188. if (error) {
  189. dev_err(dev, "Can't get IRQ for pwron: %d\n", error);
  190. goto err_free_input;
  191. }
  192. error = input_register_device(input_dev);
  193. if (error) {
  194. dev_err(dev, "Can't register power button: %d\n", error);
  195. goto err_free_irq;
  196. }
  197. platform_set_drvdata(pdev, pwron);
  198. device_init_wakeup(dev, true);
  199. return 0;
  200. err_free_irq:
  201. cancel_delayed_work_sync(&pwron->input_work);
  202. free_irq(pwron->irq, pwron);
  203. err_free_input:
  204. input_free_device(input_dev);
  205. err_free_mem:
  206. kfree(pwron);
  207. return error;
  208. }
  209. /**
  210. * palmas_pwron_remove() - Cleanup on removal
  211. * @pdev: platform device for the button
  212. *
  213. * Return: 0
  214. */
  215. static int palmas_pwron_remove(struct platform_device *pdev)
  216. {
  217. struct palmas_pwron *pwron = platform_get_drvdata(pdev);
  218. free_irq(pwron->irq, pwron);
  219. cancel_delayed_work_sync(&pwron->input_work);
  220. input_unregister_device(pwron->input_dev);
  221. kfree(pwron);
  222. return 0;
  223. }
  224. /**
  225. * palmas_pwron_suspend() - suspend handler
  226. * @dev: power button device
  227. *
  228. * Cancel all pending work items for the power button, setup irq for wakeup
  229. *
  230. * Return: 0
  231. */
  232. static int __maybe_unused palmas_pwron_suspend(struct device *dev)
  233. {
  234. struct platform_device *pdev = to_platform_device(dev);
  235. struct palmas_pwron *pwron = platform_get_drvdata(pdev);
  236. cancel_delayed_work_sync(&pwron->input_work);
  237. if (device_may_wakeup(dev))
  238. enable_irq_wake(pwron->irq);
  239. return 0;
  240. }
  241. /**
  242. * palmas_pwron_resume() - resume handler
  243. * @dev: power button device
  244. *
  245. * Just disable the wakeup capability of irq here.
  246. *
  247. * Return: 0
  248. */
  249. static int __maybe_unused palmas_pwron_resume(struct device *dev)
  250. {
  251. struct platform_device *pdev = to_platform_device(dev);
  252. struct palmas_pwron *pwron = platform_get_drvdata(pdev);
  253. if (device_may_wakeup(dev))
  254. disable_irq_wake(pwron->irq);
  255. return 0;
  256. }
  257. static SIMPLE_DEV_PM_OPS(palmas_pwron_pm,
  258. palmas_pwron_suspend, palmas_pwron_resume);
  259. #ifdef CONFIG_OF
  260. static const struct of_device_id of_palmas_pwr_match[] = {
  261. { .compatible = "ti,palmas-pwrbutton" },
  262. { },
  263. };
  264. MODULE_DEVICE_TABLE(of, of_palmas_pwr_match);
  265. #endif
  266. static struct platform_driver palmas_pwron_driver = {
  267. .probe = palmas_pwron_probe,
  268. .remove = palmas_pwron_remove,
  269. .driver = {
  270. .name = "palmas_pwrbutton",
  271. .of_match_table = of_match_ptr(of_palmas_pwr_match),
  272. .pm = &palmas_pwron_pm,
  273. },
  274. };
  275. module_platform_driver(palmas_pwron_driver);
  276. MODULE_ALIAS("platform:palmas-pwrbutton");
  277. MODULE_DESCRIPTION("Palmas Power Button");
  278. MODULE_LICENSE("GPL v2");
  279. MODULE_AUTHOR("Texas Instruments Inc.");