ni903x_wdt.c 6.2 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * Copyright (C) 2016 National Instruments Corp.
  4. */
  5. #include <linux/acpi.h>
  6. #include <linux/device.h>
  7. #include <linux/interrupt.h>
  8. #include <linux/io.h>
  9. #include <linux/module.h>
  10. #include <linux/watchdog.h>
  11. #define NIWD_CONTROL 0x01
  12. #define NIWD_COUNTER2 0x02
  13. #define NIWD_COUNTER1 0x03
  14. #define NIWD_COUNTER0 0x04
  15. #define NIWD_SEED2 0x05
  16. #define NIWD_SEED1 0x06
  17. #define NIWD_SEED0 0x07
  18. #define NIWD_IO_SIZE 0x08
  19. #define NIWD_CONTROL_MODE 0x80
  20. #define NIWD_CONTROL_PROC_RESET 0x20
  21. #define NIWD_CONTROL_PET 0x10
  22. #define NIWD_CONTROL_RUNNING 0x08
  23. #define NIWD_CONTROL_CAPTURECOUNTER 0x04
  24. #define NIWD_CONTROL_RESET 0x02
  25. #define NIWD_CONTROL_ALARM 0x01
  26. #define NIWD_PERIOD_NS 30720
  27. #define NIWD_MIN_TIMEOUT 1
  28. #define NIWD_MAX_TIMEOUT 515
  29. #define NIWD_DEFAULT_TIMEOUT 60
  30. #define NIWD_NAME "ni903x_wdt"
  31. struct ni903x_wdt {
  32. struct device *dev;
  33. u16 io_base;
  34. struct watchdog_device wdd;
  35. };
  36. static unsigned int timeout;
  37. module_param(timeout, uint, 0);
  38. MODULE_PARM_DESC(timeout,
  39. "Watchdog timeout in seconds. (default="
  40. __MODULE_STRING(NIWD_DEFAULT_TIMEOUT) ")");
  41. static int nowayout = WATCHDOG_NOWAYOUT;
  42. module_param(nowayout, int, S_IRUGO);
  43. MODULE_PARM_DESC(nowayout,
  44. "Watchdog cannot be stopped once started (default="
  45. __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  46. static void ni903x_start(struct ni903x_wdt *wdt)
  47. {
  48. u8 control = inb(wdt->io_base + NIWD_CONTROL);
  49. outb(control | NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
  50. outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
  51. }
  52. static int ni903x_wdd_set_timeout(struct watchdog_device *wdd,
  53. unsigned int timeout)
  54. {
  55. struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  56. u32 counter = timeout * (1000000000 / NIWD_PERIOD_NS);
  57. outb(((0x00FF0000 & counter) >> 16), wdt->io_base + NIWD_SEED2);
  58. outb(((0x0000FF00 & counter) >> 8), wdt->io_base + NIWD_SEED1);
  59. outb((0x000000FF & counter), wdt->io_base + NIWD_SEED0);
  60. wdd->timeout = timeout;
  61. return 0;
  62. }
  63. static unsigned int ni903x_wdd_get_timeleft(struct watchdog_device *wdd)
  64. {
  65. struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  66. u8 control, counter0, counter1, counter2;
  67. u32 counter;
  68. control = inb(wdt->io_base + NIWD_CONTROL);
  69. control |= NIWD_CONTROL_CAPTURECOUNTER;
  70. outb(control, wdt->io_base + NIWD_CONTROL);
  71. counter2 = inb(wdt->io_base + NIWD_COUNTER2);
  72. counter1 = inb(wdt->io_base + NIWD_COUNTER1);
  73. counter0 = inb(wdt->io_base + NIWD_COUNTER0);
  74. counter = (counter2 << 16) | (counter1 << 8) | counter0;
  75. return counter / (1000000000 / NIWD_PERIOD_NS);
  76. }
  77. static int ni903x_wdd_ping(struct watchdog_device *wdd)
  78. {
  79. struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  80. u8 control;
  81. control = inb(wdt->io_base + NIWD_CONTROL);
  82. outb(control | NIWD_CONTROL_PET, wdt->io_base + NIWD_CONTROL);
  83. return 0;
  84. }
  85. static int ni903x_wdd_start(struct watchdog_device *wdd)
  86. {
  87. struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  88. outb(NIWD_CONTROL_RESET | NIWD_CONTROL_PROC_RESET,
  89. wdt->io_base + NIWD_CONTROL);
  90. ni903x_wdd_set_timeout(wdd, wdd->timeout);
  91. ni903x_start(wdt);
  92. return 0;
  93. }
  94. static int ni903x_wdd_stop(struct watchdog_device *wdd)
  95. {
  96. struct ni903x_wdt *wdt = watchdog_get_drvdata(wdd);
  97. outb(NIWD_CONTROL_RESET, wdt->io_base + NIWD_CONTROL);
  98. return 0;
  99. }
  100. static acpi_status ni903x_resources(struct acpi_resource *res, void *data)
  101. {
  102. struct ni903x_wdt *wdt = data;
  103. u16 io_size;
  104. switch (res->type) {
  105. case ACPI_RESOURCE_TYPE_IO:
  106. if (wdt->io_base != 0) {
  107. dev_err(wdt->dev, "too many IO resources\n");
  108. return AE_ERROR;
  109. }
  110. wdt->io_base = res->data.io.minimum;
  111. io_size = res->data.io.address_length;
  112. if (io_size < NIWD_IO_SIZE) {
  113. dev_err(wdt->dev, "memory region too small\n");
  114. return AE_ERROR;
  115. }
  116. if (!devm_request_region(wdt->dev, wdt->io_base, io_size,
  117. NIWD_NAME)) {
  118. dev_err(wdt->dev, "failed to get memory region\n");
  119. return AE_ERROR;
  120. }
  121. return AE_OK;
  122. case ACPI_RESOURCE_TYPE_END_TAG:
  123. default:
  124. /* Ignore unsupported resources, e.g. IRQ */
  125. return AE_OK;
  126. }
  127. }
  128. static const struct watchdog_info ni903x_wdd_info = {
  129. .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
  130. .identity = "NI Watchdog",
  131. };
  132. static const struct watchdog_ops ni903x_wdd_ops = {
  133. .owner = THIS_MODULE,
  134. .start = ni903x_wdd_start,
  135. .stop = ni903x_wdd_stop,
  136. .ping = ni903x_wdd_ping,
  137. .set_timeout = ni903x_wdd_set_timeout,
  138. .get_timeleft = ni903x_wdd_get_timeleft,
  139. };
  140. static int ni903x_acpi_add(struct acpi_device *device)
  141. {
  142. struct device *dev = &device->dev;
  143. struct watchdog_device *wdd;
  144. struct ni903x_wdt *wdt;
  145. acpi_status status;
  146. int ret;
  147. wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
  148. if (!wdt)
  149. return -ENOMEM;
  150. device->driver_data = wdt;
  151. wdt->dev = dev;
  152. status = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
  153. ni903x_resources, wdt);
  154. if (ACPI_FAILURE(status) || wdt->io_base == 0) {
  155. dev_err(dev, "failed to get resources\n");
  156. return -ENODEV;
  157. }
  158. wdd = &wdt->wdd;
  159. wdd->info = &ni903x_wdd_info;
  160. wdd->ops = &ni903x_wdd_ops;
  161. wdd->min_timeout = NIWD_MIN_TIMEOUT;
  162. wdd->max_timeout = NIWD_MAX_TIMEOUT;
  163. wdd->timeout = NIWD_DEFAULT_TIMEOUT;
  164. wdd->parent = dev;
  165. watchdog_set_drvdata(wdd, wdt);
  166. watchdog_set_nowayout(wdd, nowayout);
  167. watchdog_init_timeout(wdd, timeout, dev);
  168. ret = watchdog_register_device(wdd);
  169. if (ret)
  170. return ret;
  171. /* Switch from boot mode to user mode */
  172. outb(NIWD_CONTROL_RESET | NIWD_CONTROL_MODE,
  173. wdt->io_base + NIWD_CONTROL);
  174. dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
  175. wdt->io_base, timeout, nowayout);
  176. return 0;
  177. }
  178. static int ni903x_acpi_remove(struct acpi_device *device)
  179. {
  180. struct ni903x_wdt *wdt = acpi_driver_data(device);
  181. ni903x_wdd_stop(&wdt->wdd);
  182. watchdog_unregister_device(&wdt->wdd);
  183. return 0;
  184. }
  185. static const struct acpi_device_id ni903x_device_ids[] = {
  186. {"NIC775C", 0},
  187. {"", 0},
  188. };
  189. MODULE_DEVICE_TABLE(acpi, ni903x_device_ids);
  190. static struct acpi_driver ni903x_acpi_driver = {
  191. .name = NIWD_NAME,
  192. .ids = ni903x_device_ids,
  193. .ops = {
  194. .add = ni903x_acpi_add,
  195. .remove = ni903x_acpi_remove,
  196. },
  197. };
  198. module_acpi_driver(ni903x_acpi_driver);
  199. MODULE_DESCRIPTION("NI 903x Watchdog");
  200. MODULE_AUTHOR("Jeff Westfahl <jeff.westfahl@ni.com>");
  201. MODULE_AUTHOR("Kyle Roeschley <kyle.roeschley@ni.com>");
  202. MODULE_LICENSE("GPL");