rtc-88pm860x.c 10 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Real Time Clock driver for Marvell 88PM860x PMIC
  4. *
  5. * Copyright (c) 2010 Marvell International Ltd.
  6. * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
  7. */
  8. #include <linux/kernel.h>
  9. #include <linux/module.h>
  10. #include <linux/of.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/slab.h>
  13. #include <linux/mutex.h>
  14. #include <linux/rtc.h>
  15. #include <linux/delay.h>
  16. #include <linux/mfd/core.h>
  17. #include <linux/mfd/88pm860x.h>
  18. #define VRTC_CALIBRATION
  19. struct pm860x_rtc_info {
  20. struct pm860x_chip *chip;
  21. struct i2c_client *i2c;
  22. struct rtc_device *rtc_dev;
  23. struct device *dev;
  24. struct delayed_work calib_work;
  25. int irq;
  26. int vrtc;
  27. };
  28. #define REG_VRTC_MEAS1 0x7D
  29. #define REG0_ADDR 0xB0
  30. #define REG1_ADDR 0xB2
  31. #define REG2_ADDR 0xB4
  32. #define REG3_ADDR 0xB6
  33. #define REG0_DATA 0xB1
  34. #define REG1_DATA 0xB3
  35. #define REG2_DATA 0xB5
  36. #define REG3_DATA 0xB7
  37. /* bit definitions of Measurement Enable Register 2 (0x51) */
  38. #define MEAS2_VRTC (1 << 0)
  39. /* bit definitions of RTC Register 1 (0xA0) */
  40. #define ALARM_EN (1 << 3)
  41. #define ALARM_WAKEUP (1 << 4)
  42. #define ALARM (1 << 5)
  43. #define RTC1_USE_XO (1 << 7)
  44. #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */
  45. static irqreturn_t rtc_update_handler(int irq, void *data)
  46. {
  47. struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
  48. int mask;
  49. mask = ALARM | ALARM_WAKEUP;
  50. pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
  51. rtc_update_irq(info->rtc_dev, 1, RTC_AF);
  52. return IRQ_HANDLED;
  53. }
  54. static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  55. {
  56. struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  57. if (enabled)
  58. pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
  59. else
  60. pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
  61. return 0;
  62. }
  63. static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
  64. {
  65. struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  66. unsigned char buf[8];
  67. unsigned long ticks, base, data;
  68. pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
  69. dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
  70. buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
  71. base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
  72. (buf[5] << 8) | buf[7];
  73. /* load 32-bit read-only counter */
  74. pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
  75. data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
  76. (buf[1] << 8) | buf[0];
  77. ticks = base + data;
  78. dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
  79. base, data, ticks);
  80. rtc_time64_to_tm(ticks, tm);
  81. return 0;
  82. }
  83. static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
  84. {
  85. struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  86. unsigned char buf[4];
  87. unsigned long ticks, base, data;
  88. ticks = rtc_tm_to_time64(tm);
  89. /* load 32-bit read-only counter */
  90. pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
  91. data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
  92. (buf[1] << 8) | buf[0];
  93. base = ticks - data;
  94. dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
  95. base, data, ticks);
  96. pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
  97. pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
  98. pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
  99. pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
  100. return 0;
  101. }
  102. static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  103. {
  104. struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  105. unsigned char buf[8];
  106. unsigned long ticks, base, data;
  107. int ret;
  108. pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
  109. dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
  110. buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
  111. base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
  112. (buf[5] << 8) | buf[7];
  113. pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
  114. data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
  115. (buf[1] << 8) | buf[0];
  116. ticks = base + data;
  117. dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
  118. base, data, ticks);
  119. rtc_time64_to_tm(ticks, &alrm->time);
  120. ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
  121. alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
  122. alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
  123. return 0;
  124. }
  125. static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  126. {
  127. struct pm860x_rtc_info *info = dev_get_drvdata(dev);
  128. unsigned long ticks, base, data;
  129. unsigned char buf[8];
  130. int mask;
  131. pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
  132. pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
  133. dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
  134. buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
  135. base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
  136. (buf[5] << 8) | buf[7];
  137. ticks = rtc_tm_to_time64(&alrm->time);
  138. data = ticks - base;
  139. buf[0] = data & 0xff;
  140. buf[1] = (data >> 8) & 0xff;
  141. buf[2] = (data >> 16) & 0xff;
  142. buf[3] = (data >> 24) & 0xff;
  143. pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
  144. if (alrm->enabled) {
  145. mask = ALARM | ALARM_WAKEUP | ALARM_EN;
  146. pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
  147. } else {
  148. mask = ALARM | ALARM_WAKEUP | ALARM_EN;
  149. pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
  150. ALARM | ALARM_WAKEUP);
  151. }
  152. return 0;
  153. }
  154. static const struct rtc_class_ops pm860x_rtc_ops = {
  155. .read_time = pm860x_rtc_read_time,
  156. .set_time = pm860x_rtc_set_time,
  157. .read_alarm = pm860x_rtc_read_alarm,
  158. .set_alarm = pm860x_rtc_set_alarm,
  159. .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
  160. };
  161. #ifdef VRTC_CALIBRATION
  162. static void calibrate_vrtc_work(struct work_struct *work)
  163. {
  164. struct pm860x_rtc_info *info = container_of(work,
  165. struct pm860x_rtc_info, calib_work.work);
  166. unsigned char buf[2];
  167. unsigned int sum, data, mean, vrtc_set;
  168. int i;
  169. for (i = 0, sum = 0; i < 16; i++) {
  170. msleep(100);
  171. pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
  172. data = (buf[0] << 4) | buf[1];
  173. data = (data * 5400) >> 12; /* convert to mv */
  174. sum += data;
  175. }
  176. mean = sum >> 4;
  177. vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
  178. dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
  179. sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
  180. data = sum & 0x3;
  181. if ((mean + 200) < vrtc_set) {
  182. /* try higher voltage */
  183. if (++data == 4)
  184. goto out;
  185. data = (sum & 0xf8) | (data & 0x3);
  186. pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
  187. } else if ((mean - 200) > vrtc_set) {
  188. /* try lower voltage */
  189. if (data-- == 0)
  190. goto out;
  191. data = (sum & 0xf8) | (data & 0x3);
  192. pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
  193. } else
  194. goto out;
  195. dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
  196. /* trigger next calibration since VRTC is updated */
  197. schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
  198. return;
  199. out:
  200. /* disable measurement */
  201. pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
  202. dev_dbg(info->dev, "finish VRTC calibration\n");
  203. return;
  204. }
  205. #endif
  206. #ifdef CONFIG_OF
  207. static int pm860x_rtc_dt_init(struct platform_device *pdev,
  208. struct pm860x_rtc_info *info)
  209. {
  210. struct device_node *np = pdev->dev.parent->of_node;
  211. int ret;
  212. if (!np)
  213. return -ENODEV;
  214. np = of_get_child_by_name(np, "rtc");
  215. if (!np) {
  216. dev_err(&pdev->dev, "failed to find rtc node\n");
  217. return -ENODEV;
  218. }
  219. ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
  220. if (ret)
  221. info->vrtc = 0;
  222. of_node_put(np);
  223. return 0;
  224. }
  225. #else
  226. #define pm860x_rtc_dt_init(x, y) do { } while (0)
  227. #endif
  228. static int pm860x_rtc_probe(struct platform_device *pdev)
  229. {
  230. struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
  231. struct pm860x_rtc_info *info;
  232. int ret;
  233. info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
  234. GFP_KERNEL);
  235. if (!info)
  236. return -ENOMEM;
  237. info->irq = platform_get_irq(pdev, 0);
  238. if (info->irq < 0)
  239. return info->irq;
  240. info->chip = chip;
  241. info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
  242. info->dev = &pdev->dev;
  243. dev_set_drvdata(&pdev->dev, info);
  244. info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
  245. if (IS_ERR(info->rtc_dev))
  246. return PTR_ERR(info->rtc_dev);
  247. ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
  248. rtc_update_handler, IRQF_ONESHOT, "rtc",
  249. info);
  250. if (ret < 0) {
  251. dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
  252. info->irq, ret);
  253. return ret;
  254. }
  255. /* set addresses of 32-bit base value for RTC time */
  256. pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
  257. pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
  258. pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
  259. pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
  260. pm860x_rtc_dt_init(pdev, info);
  261. info->rtc_dev->ops = &pm860x_rtc_ops;
  262. info->rtc_dev->range_max = U32_MAX;
  263. ret = rtc_register_device(info->rtc_dev);
  264. if (ret)
  265. return ret;
  266. /*
  267. * enable internal XO instead of internal 3.25MHz clock since it can
  268. * free running in PMIC power-down state.
  269. */
  270. pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
  271. #ifdef VRTC_CALIBRATION
  272. /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
  273. pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
  274. /* calibrate VRTC */
  275. INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
  276. schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
  277. #endif /* VRTC_CALIBRATION */
  278. device_init_wakeup(&pdev->dev, 1);
  279. return 0;
  280. }
  281. static int pm860x_rtc_remove(struct platform_device *pdev)
  282. {
  283. struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
  284. #ifdef VRTC_CALIBRATION
  285. cancel_delayed_work_sync(&info->calib_work);
  286. /* disable measurement */
  287. pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
  288. #endif /* VRTC_CALIBRATION */
  289. return 0;
  290. }
  291. #ifdef CONFIG_PM_SLEEP
  292. static int pm860x_rtc_suspend(struct device *dev)
  293. {
  294. struct platform_device *pdev = to_platform_device(dev);
  295. struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
  296. if (device_may_wakeup(dev))
  297. chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
  298. return 0;
  299. }
  300. static int pm860x_rtc_resume(struct device *dev)
  301. {
  302. struct platform_device *pdev = to_platform_device(dev);
  303. struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
  304. if (device_may_wakeup(dev))
  305. chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
  306. return 0;
  307. }
  308. #endif
  309. static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
  310. static struct platform_driver pm860x_rtc_driver = {
  311. .driver = {
  312. .name = "88pm860x-rtc",
  313. .pm = &pm860x_rtc_pm_ops,
  314. },
  315. .probe = pm860x_rtc_probe,
  316. .remove = pm860x_rtc_remove,
  317. };
  318. module_platform_driver(pm860x_rtc_driver);
  319. MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
  320. MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
  321. MODULE_LICENSE("GPL");