rtc-tx4939.c 7.9 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * TX4939 internal RTC driver
  4. * Based on RBTX49xx patch from CELF patch archive.
  5. *
  6. * (C) Copyright TOSHIBA CORPORATION 2005-2007
  7. */
  8. #include <linux/rtc.h>
  9. #include <linux/platform_device.h>
  10. #include <linux/interrupt.h>
  11. #include <linux/module.h>
  12. #include <linux/io.h>
  13. #include <linux/gfp.h>
  14. #define TX4939_RTCCTL_ALME 0x00000080
  15. #define TX4939_RTCCTL_ALMD 0x00000040
  16. #define TX4939_RTCCTL_BUSY 0x00000020
  17. #define TX4939_RTCCTL_COMMAND 0x00000007
  18. #define TX4939_RTCCTL_COMMAND_NOP 0x00000000
  19. #define TX4939_RTCCTL_COMMAND_GETTIME 0x00000001
  20. #define TX4939_RTCCTL_COMMAND_SETTIME 0x00000002
  21. #define TX4939_RTCCTL_COMMAND_GETALARM 0x00000003
  22. #define TX4939_RTCCTL_COMMAND_SETALARM 0x00000004
  23. #define TX4939_RTCTBC_PM 0x00000080
  24. #define TX4939_RTCTBC_COMP 0x0000007f
  25. #define TX4939_RTC_REG_RAMSIZE 0x00000100
  26. #define TX4939_RTC_REG_RWBSIZE 0x00000006
  27. struct tx4939_rtc_reg {
  28. __u32 ctl;
  29. __u32 adr;
  30. __u32 dat;
  31. __u32 tbc;
  32. };
  33. struct tx4939rtc_plat_data {
  34. struct rtc_device *rtc;
  35. struct tx4939_rtc_reg __iomem *rtcreg;
  36. spinlock_t lock;
  37. };
  38. static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
  39. {
  40. int i = 0;
  41. __raw_writel(cmd, &rtcreg->ctl);
  42. /* This might take 30us (next 32.768KHz clock) */
  43. while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
  44. /* timeout on approx. 100us (@ GBUS200MHz) */
  45. if (i++ > 200 * 100)
  46. return -EBUSY;
  47. cpu_relax();
  48. }
  49. return 0;
  50. }
  51. static int tx4939_rtc_set_time(struct device *dev, struct rtc_time *tm)
  52. {
  53. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev);
  54. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  55. unsigned long secs = rtc_tm_to_time64(tm);
  56. int i, ret;
  57. unsigned char buf[6];
  58. buf[0] = 0;
  59. buf[1] = 0;
  60. buf[2] = secs;
  61. buf[3] = secs >> 8;
  62. buf[4] = secs >> 16;
  63. buf[5] = secs >> 24;
  64. spin_lock_irq(&pdata->lock);
  65. __raw_writel(0, &rtcreg->adr);
  66. for (i = 0; i < 6; i++)
  67. __raw_writel(buf[i], &rtcreg->dat);
  68. ret = tx4939_rtc_cmd(rtcreg,
  69. TX4939_RTCCTL_COMMAND_SETTIME |
  70. (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
  71. spin_unlock_irq(&pdata->lock);
  72. return ret;
  73. }
  74. static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
  75. {
  76. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev);
  77. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  78. int i, ret;
  79. unsigned long sec;
  80. unsigned char buf[6];
  81. spin_lock_irq(&pdata->lock);
  82. ret = tx4939_rtc_cmd(rtcreg,
  83. TX4939_RTCCTL_COMMAND_GETTIME |
  84. (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
  85. if (ret) {
  86. spin_unlock_irq(&pdata->lock);
  87. return ret;
  88. }
  89. __raw_writel(2, &rtcreg->adr);
  90. for (i = 2; i < 6; i++)
  91. buf[i] = __raw_readl(&rtcreg->dat);
  92. spin_unlock_irq(&pdata->lock);
  93. sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) |
  94. (buf[3] << 8) | buf[2];
  95. rtc_time64_to_tm(sec, tm);
  96. return 0;
  97. }
  98. static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  99. {
  100. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev);
  101. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  102. int i, ret;
  103. unsigned long sec;
  104. unsigned char buf[6];
  105. sec = rtc_tm_to_time64(&alrm->time);
  106. buf[0] = 0;
  107. buf[1] = 0;
  108. buf[2] = sec;
  109. buf[3] = sec >> 8;
  110. buf[4] = sec >> 16;
  111. buf[5] = sec >> 24;
  112. spin_lock_irq(&pdata->lock);
  113. __raw_writel(0, &rtcreg->adr);
  114. for (i = 0; i < 6; i++)
  115. __raw_writel(buf[i], &rtcreg->dat);
  116. ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
  117. (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
  118. spin_unlock_irq(&pdata->lock);
  119. return ret;
  120. }
  121. static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
  122. {
  123. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev);
  124. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  125. int i, ret;
  126. unsigned long sec;
  127. unsigned char buf[6];
  128. u32 ctl;
  129. spin_lock_irq(&pdata->lock);
  130. ret = tx4939_rtc_cmd(rtcreg,
  131. TX4939_RTCCTL_COMMAND_GETALARM |
  132. (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
  133. if (ret) {
  134. spin_unlock_irq(&pdata->lock);
  135. return ret;
  136. }
  137. __raw_writel(2, &rtcreg->adr);
  138. for (i = 2; i < 6; i++)
  139. buf[i] = __raw_readl(&rtcreg->dat);
  140. ctl = __raw_readl(&rtcreg->ctl);
  141. alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
  142. alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
  143. spin_unlock_irq(&pdata->lock);
  144. sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) |
  145. (buf[3] << 8) | buf[2];
  146. rtc_time64_to_tm(sec, &alrm->time);
  147. return rtc_valid_tm(&alrm->time);
  148. }
  149. static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
  150. {
  151. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev);
  152. spin_lock_irq(&pdata->lock);
  153. tx4939_rtc_cmd(pdata->rtcreg,
  154. TX4939_RTCCTL_COMMAND_NOP |
  155. (enabled ? TX4939_RTCCTL_ALME : 0));
  156. spin_unlock_irq(&pdata->lock);
  157. return 0;
  158. }
  159. static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
  160. {
  161. struct tx4939rtc_plat_data *pdata = dev_get_drvdata(dev_id);
  162. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  163. unsigned long events = RTC_IRQF;
  164. spin_lock(&pdata->lock);
  165. if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
  166. events |= RTC_AF;
  167. tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
  168. }
  169. spin_unlock(&pdata->lock);
  170. rtc_update_irq(pdata->rtc, 1, events);
  171. return IRQ_HANDLED;
  172. }
  173. static const struct rtc_class_ops tx4939_rtc_ops = {
  174. .read_time = tx4939_rtc_read_time,
  175. .read_alarm = tx4939_rtc_read_alarm,
  176. .set_alarm = tx4939_rtc_set_alarm,
  177. .set_time = tx4939_rtc_set_time,
  178. .alarm_irq_enable = tx4939_rtc_alarm_irq_enable,
  179. };
  180. static int tx4939_nvram_read(void *priv, unsigned int pos, void *val,
  181. size_t bytes)
  182. {
  183. struct tx4939rtc_plat_data *pdata = priv;
  184. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  185. u8 *buf = val;
  186. spin_lock_irq(&pdata->lock);
  187. for (; bytes; bytes--) {
  188. __raw_writel(pos++, &rtcreg->adr);
  189. *buf++ = __raw_readl(&rtcreg->dat);
  190. }
  191. spin_unlock_irq(&pdata->lock);
  192. return 0;
  193. }
  194. static int tx4939_nvram_write(void *priv, unsigned int pos, void *val,
  195. size_t bytes)
  196. {
  197. struct tx4939rtc_plat_data *pdata = priv;
  198. struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
  199. u8 *buf = val;
  200. spin_lock_irq(&pdata->lock);
  201. for (; bytes; bytes--) {
  202. __raw_writel(pos++, &rtcreg->adr);
  203. __raw_writel(*buf++, &rtcreg->dat);
  204. }
  205. spin_unlock_irq(&pdata->lock);
  206. return 0;
  207. }
  208. static int __init tx4939_rtc_probe(struct platform_device *pdev)
  209. {
  210. struct rtc_device *rtc;
  211. struct tx4939rtc_plat_data *pdata;
  212. int irq, ret;
  213. struct nvmem_config nvmem_cfg = {
  214. .name = "tx4939_nvram",
  215. .size = TX4939_RTC_REG_RAMSIZE,
  216. .reg_read = tx4939_nvram_read,
  217. .reg_write = tx4939_nvram_write,
  218. };
  219. irq = platform_get_irq(pdev, 0);
  220. if (irq < 0)
  221. return -ENODEV;
  222. pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
  223. if (!pdata)
  224. return -ENOMEM;
  225. platform_set_drvdata(pdev, pdata);
  226. pdata->rtcreg = devm_platform_ioremap_resource(pdev, 0);
  227. if (IS_ERR(pdata->rtcreg))
  228. return PTR_ERR(pdata->rtcreg);
  229. spin_lock_init(&pdata->lock);
  230. tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
  231. if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
  232. 0, pdev->name, &pdev->dev) < 0)
  233. return -EBUSY;
  234. rtc = devm_rtc_allocate_device(&pdev->dev);
  235. if (IS_ERR(rtc))
  236. return PTR_ERR(rtc);
  237. rtc->ops = &tx4939_rtc_ops;
  238. rtc->nvram_old_abi = true;
  239. rtc->range_max = U32_MAX;
  240. pdata->rtc = rtc;
  241. nvmem_cfg.priv = pdata;
  242. ret = rtc_nvmem_register(rtc, &nvmem_cfg);
  243. if (ret)
  244. return ret;
  245. return rtc_register_device(rtc);
  246. }
  247. static int __exit tx4939_rtc_remove(struct platform_device *pdev)
  248. {
  249. struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
  250. spin_lock_irq(&pdata->lock);
  251. tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
  252. spin_unlock_irq(&pdata->lock);
  253. return 0;
  254. }
  255. static struct platform_driver tx4939_rtc_driver = {
  256. .remove = __exit_p(tx4939_rtc_remove),
  257. .driver = {
  258. .name = "tx4939rtc",
  259. },
  260. };
  261. module_platform_driver_probe(tx4939_rtc_driver, tx4939_rtc_probe);
  262. MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
  263. MODULE_DESCRIPTION("TX4939 internal RTC driver");
  264. MODULE_LICENSE("GPL v2");
  265. MODULE_ALIAS("platform:tx4939rtc");