bcm6345_wdt.c 2.6 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
  4. *
  5. * Derived from linux/drivers/watchdog/bcm63xx_wdt.c:
  6. * Copyright (C) 2007 Miguel Gaio <miguel.gaio@efixo.com>
  7. * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
  8. */
  9. #include <common.h>
  10. #include <dm.h>
  11. #include <log.h>
  12. #include <wdt.h>
  13. #include <clk.h>
  14. #include <asm/io.h>
  15. /* WDT Value register */
  16. #define WDT_VAL_REG 0x0
  17. #define WDT_VAL_MIN 0x00000002
  18. #define WDT_VAL_MAX 0xfffffffe
  19. /* WDT Control register */
  20. #define WDT_CTL_REG 0x4
  21. #define WDT_CTL_START1_MASK 0x0000ff00
  22. #define WDT_CTL_START2_MASK 0x000000ff
  23. #define WDT_CTL_STOP1_MASK 0x0000ee00
  24. #define WDT_CTL_STOP2_MASK 0x000000ee
  25. struct bcm6345_wdt_priv {
  26. void __iomem *regs;
  27. unsigned long clk_rate;
  28. };
  29. static int bcm6345_wdt_reset(struct udevice *dev)
  30. {
  31. struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
  32. writel(WDT_CTL_START1_MASK, priv->regs + WDT_CTL_REG);
  33. writel(WDT_CTL_START2_MASK, priv->regs + WDT_CTL_REG);
  34. return 0;
  35. }
  36. static int bcm6345_wdt_start(struct udevice *dev, u64 timeout, ulong flags)
  37. {
  38. struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
  39. u32 val = priv->clk_rate / 1000 * timeout;
  40. if (val < WDT_VAL_MIN) {
  41. debug("watchdog won't fire with less than 2 ticks\n");
  42. val = WDT_VAL_MIN;
  43. } else if (val > WDT_VAL_MAX) {
  44. debug("maximum watchdog timeout exceeded\n");
  45. val = WDT_VAL_MAX;
  46. }
  47. writel(val, priv->regs + WDT_VAL_REG);
  48. return bcm6345_wdt_reset(dev);
  49. }
  50. static int bcm6345_wdt_expire_now(struct udevice *dev, ulong flags)
  51. {
  52. return bcm6345_wdt_start(dev, WDT_VAL_MIN, flags);
  53. }
  54. static int bcm6345_wdt_stop(struct udevice *dev)
  55. {
  56. struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
  57. writel(WDT_CTL_STOP1_MASK, priv->regs + WDT_CTL_REG);
  58. writel(WDT_CTL_STOP2_MASK, priv->regs + WDT_CTL_REG);
  59. return 0;
  60. }
  61. static const struct wdt_ops bcm6345_wdt_ops = {
  62. .expire_now = bcm6345_wdt_expire_now,
  63. .reset = bcm6345_wdt_reset,
  64. .start = bcm6345_wdt_start,
  65. .stop = bcm6345_wdt_stop,
  66. };
  67. static const struct udevice_id bcm6345_wdt_ids[] = {
  68. { .compatible = "brcm,bcm6345-wdt" },
  69. { /* sentinel */ }
  70. };
  71. static int bcm6345_wdt_probe(struct udevice *dev)
  72. {
  73. struct bcm6345_wdt_priv *priv = dev_get_priv(dev);
  74. struct clk clk;
  75. int ret;
  76. priv->regs = dev_remap_addr(dev);
  77. if (!priv->regs)
  78. return -EINVAL;
  79. ret = clk_get_by_index(dev, 0, &clk);
  80. if (!ret)
  81. priv->clk_rate = clk_get_rate(&clk);
  82. else
  83. return -EINVAL;
  84. bcm6345_wdt_stop(dev);
  85. return 0;
  86. }
  87. U_BOOT_DRIVER(wdt_bcm6345) = {
  88. .name = "wdt_bcm6345",
  89. .id = UCLASS_WDT,
  90. .of_match = bcm6345_wdt_ids,
  91. .ops = &bcm6345_wdt_ops,
  92. .priv_auto = sizeof(struct bcm6345_wdt_priv),
  93. .probe = bcm6345_wdt_probe,
  94. };