ice_wdt.c 4.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. #include <linux/clk.h>
  3. #include <linux/delay.h>
  4. #include <linux/err.h>
  5. #include <linux/init.h>
  6. #include <linux/io.h>
  7. #include <linux/kernel.h>
  8. #include <linux/module.h>
  9. #include <linux/moduleparam.h>
  10. #include <linux/of_device.h>
  11. #include <linux/platform_device.h>
  12. #include <linux/types.h>
  13. #include <linux/watchdog.h>
  14. #define DRV_NAME "ice-wdt"
  15. #define WDT_LOCK 0x0
  16. #define WDT_OT_LOAD_H 0x4
  17. #define WDT_OT_LOAD_L 0x8
  18. #define WDT_RMOD 0xC
  19. #define WDT_EN 0x10
  20. #define WDT_KNOCK 0x14
  21. #define WDT_EOI 0x18
  22. #define WDT_CUR_VALUE_H 0x1C
  23. #define WDT_CUR_VALUE_L 0x20
  24. #define WDT_INT_STATE 0x24
  25. #define REGS_WRITE_UNLOCK 0x5ada7200
  26. #define REGS_WRITE_LOCK 0x5ada7201
  27. #define TOUCH_WATCHDOG 0x55aadd22
  28. #define ICE_WDT_TIMEOUT 120
  29. #define DEFAULT_TIMEOUT 0xcccccccc
  30. static unsigned int timeout;
  31. struct ice_wdt_dev {
  32. struct watchdog_device wdt_dev;
  33. void __iomem *wdt_base;
  34. };
  35. static const struct watchdog_info ice_wdt_info = {
  36. .identity = DRV_NAME,
  37. .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
  38. };
  39. static void ice_wdt_change_timeout(struct watchdog_device *wdt_dev,
  40. unsigned int timeout)
  41. {
  42. struct ice_wdt_dev *ice_wdt = watchdog_get_drvdata(wdt_dev);
  43. u32 timetick;
  44. timetick = (DEFAULT_TIMEOUT/120) * timeout;
  45. writel(REGS_WRITE_UNLOCK, ice_wdt->wdt_base + WDT_LOCK);
  46. writel(timetick, ice_wdt->wdt_base + WDT_OT_LOAD_L);
  47. writel(REGS_WRITE_LOCK, ice_wdt->wdt_base + WDT_LOCK);
  48. }
  49. static int ice_wdt_restart(struct watchdog_device *wdt_dev,
  50. unsigned long action, void *data)
  51. {
  52. struct ice_wdt_dev *ice_wdt = watchdog_get_drvdata(wdt_dev);
  53. writel(REGS_WRITE_UNLOCK, ice_wdt->wdt_base + WDT_LOCK);
  54. writel(0, ice_wdt->wdt_base + WDT_EN);
  55. writel(0, ice_wdt->wdt_base + WDT_RMOD);
  56. writel(0, ice_wdt->wdt_base + WDT_OT_LOAD_H);
  57. writel(0xff, ice_wdt->wdt_base + WDT_OT_LOAD_L);
  58. writel(1, ice_wdt->wdt_base + WDT_EN);
  59. writel(REGS_WRITE_LOCK, ice_wdt->wdt_base + WDT_LOCK);
  60. while (1);
  61. return 0;
  62. }
  63. static int ice_wdt_ping(struct watchdog_device *wdt_dev)
  64. {
  65. struct ice_wdt_dev *ice_wdt = watchdog_get_drvdata(wdt_dev);
  66. writel(REGS_WRITE_UNLOCK, ice_wdt->wdt_base + WDT_LOCK);
  67. writel(TOUCH_WATCHDOG, ice_wdt->wdt_base + WDT_KNOCK);
  68. writel(REGS_WRITE_LOCK, ice_wdt->wdt_base + WDT_LOCK);
  69. return 0;
  70. }
  71. static int ice_wdt_set_timeout(struct watchdog_device *wdt_dev,
  72. unsigned int timeout)
  73. {
  74. wdt_dev->timeout = timeout;
  75. ice_wdt_change_timeout(wdt_dev, timeout);
  76. ice_wdt_ping(wdt_dev);
  77. return 0;
  78. }
  79. static int ice_wdt_stop(struct watchdog_device *wdt_dev)
  80. {
  81. struct ice_wdt_dev *ice_wdt = watchdog_get_drvdata(wdt_dev);
  82. writel(REGS_WRITE_UNLOCK, ice_wdt->wdt_base + WDT_LOCK);
  83. writel(0, ice_wdt->wdt_base + WDT_EN);
  84. writel(REGS_WRITE_LOCK, ice_wdt->wdt_base + WDT_LOCK);
  85. return 0;
  86. }
  87. static int ice_wdt_start(struct watchdog_device *wdt_dev)
  88. {
  89. struct ice_wdt_dev *ice_wdt = watchdog_get_drvdata(wdt_dev);
  90. writel(REGS_WRITE_UNLOCK, ice_wdt->wdt_base + WDT_LOCK);
  91. writel(1, ice_wdt->wdt_base + WDT_RMOD);
  92. writel(1, ice_wdt->wdt_base + WDT_EN);
  93. writel(REGS_WRITE_LOCK, ice_wdt->wdt_base + WDT_LOCK);
  94. return 0;
  95. }
  96. static const struct watchdog_ops ice_wdt_ops = {
  97. .owner = THIS_MODULE,
  98. .start = ice_wdt_start,
  99. .stop = ice_wdt_stop,
  100. .ping = ice_wdt_ping,
  101. .set_timeout = ice_wdt_set_timeout,
  102. .restart = ice_wdt_restart,
  103. };
  104. static const struct of_device_id ice_wdt_dt_ids[] = {
  105. { .compatible = "ice,ice-wdt",},
  106. { }
  107. };
  108. static int ice_wdt_probe(struct platform_device *pdev)
  109. {
  110. struct device *dev = &pdev->dev;
  111. struct ice_wdt_dev *ice_wdt;
  112. int err;
  113. ice_wdt = devm_kzalloc(dev, sizeof(*ice_wdt), GFP_KERNEL);
  114. if (!ice_wdt) {
  115. return -ENOMEM;
  116. }
  117. ice_wdt->wdt_base = devm_platform_ioremap_resource(pdev, 0);
  118. if (IS_ERR(ice_wdt->wdt_base)) {
  119. return PTR_ERR(ice_wdt->wdt_base);
  120. }
  121. ice_wdt->wdt_dev.parent = dev;
  122. ice_wdt->wdt_dev.info = &ice_wdt_info;
  123. ice_wdt->wdt_dev.ops = &ice_wdt_ops;
  124. ice_wdt->wdt_dev.timeout = ICE_WDT_TIMEOUT;
  125. ice_wdt->wdt_dev.min_timeout = 2;
  126. watchdog_set_drvdata(&ice_wdt->wdt_dev, ice_wdt);
  127. watchdog_init_timeout(&ice_wdt->wdt_dev, timeout, dev);
  128. watchdog_set_restart_priority(&ice_wdt->wdt_dev, 128);
  129. ice_wdt_stop(&ice_wdt->wdt_dev);
  130. err = devm_watchdog_register_device(dev, &ice_wdt->wdt_dev);
  131. if (err)
  132. return err;
  133. dev_info(dev, "Watchdog enabled (timeout=%d sec)\n", ice_wdt->wdt_dev.timeout);
  134. return 0;
  135. }
  136. static struct platform_driver ice_wdt_driver = {
  137. .probe = ice_wdt_probe,
  138. .driver = {
  139. .name = DRV_NAME,
  140. .of_match_table = ice_wdt_dt_ids,
  141. },
  142. };
  143. module_platform_driver(ice_wdt_driver);
  144. module_param(timeout, uint, 0);
  145. MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
  146. MODULE_LICENSE("GPL");
  147. MODULE_DESCRIPTION("Ice Watchdog Timer Driver");