reset-meson-audio-arb.c 4.9 KB

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  1. // SPDX-License-Identifier: (GPL-2.0 OR MIT)
  2. // Copyright (c) 2018 BayLibre, SAS.
  3. // Author: Jerome Brunet <jbrunet@baylibre.com>
  4. #include <linux/clk.h>
  5. #include <linux/io.h>
  6. #include <linux/module.h>
  7. #include <linux/of_platform.h>
  8. #include <linux/reset-controller.h>
  9. #include <linux/spinlock.h>
  10. #include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
  11. struct meson_audio_arb_data {
  12. struct reset_controller_dev rstc;
  13. void __iomem *regs;
  14. struct clk *clk;
  15. const unsigned int *reset_bits;
  16. spinlock_t lock;
  17. };
  18. struct meson_audio_arb_match_data {
  19. const unsigned int *reset_bits;
  20. unsigned int reset_num;
  21. };
  22. #define ARB_GENERAL_BIT 31
  23. static const unsigned int axg_audio_arb_reset_bits[] = {
  24. [AXG_ARB_TODDR_A] = 0,
  25. [AXG_ARB_TODDR_B] = 1,
  26. [AXG_ARB_TODDR_C] = 2,
  27. [AXG_ARB_FRDDR_A] = 4,
  28. [AXG_ARB_FRDDR_B] = 5,
  29. [AXG_ARB_FRDDR_C] = 6,
  30. };
  31. static const struct meson_audio_arb_match_data axg_audio_arb_match = {
  32. .reset_bits = axg_audio_arb_reset_bits,
  33. .reset_num = ARRAY_SIZE(axg_audio_arb_reset_bits),
  34. };
  35. static const unsigned int sm1_audio_arb_reset_bits[] = {
  36. [AXG_ARB_TODDR_A] = 0,
  37. [AXG_ARB_TODDR_B] = 1,
  38. [AXG_ARB_TODDR_C] = 2,
  39. [AXG_ARB_FRDDR_A] = 4,
  40. [AXG_ARB_FRDDR_B] = 5,
  41. [AXG_ARB_FRDDR_C] = 6,
  42. [AXG_ARB_TODDR_D] = 3,
  43. [AXG_ARB_FRDDR_D] = 7,
  44. };
  45. static const struct meson_audio_arb_match_data sm1_audio_arb_match = {
  46. .reset_bits = sm1_audio_arb_reset_bits,
  47. .reset_num = ARRAY_SIZE(sm1_audio_arb_reset_bits),
  48. };
  49. static int meson_audio_arb_update(struct reset_controller_dev *rcdev,
  50. unsigned long id, bool assert)
  51. {
  52. u32 val;
  53. struct meson_audio_arb_data *arb =
  54. container_of(rcdev, struct meson_audio_arb_data, rstc);
  55. spin_lock(&arb->lock);
  56. val = readl(arb->regs);
  57. if (assert)
  58. val &= ~BIT(arb->reset_bits[id]);
  59. else
  60. val |= BIT(arb->reset_bits[id]);
  61. writel(val, arb->regs);
  62. spin_unlock(&arb->lock);
  63. return 0;
  64. }
  65. static int meson_audio_arb_status(struct reset_controller_dev *rcdev,
  66. unsigned long id)
  67. {
  68. u32 val;
  69. struct meson_audio_arb_data *arb =
  70. container_of(rcdev, struct meson_audio_arb_data, rstc);
  71. val = readl(arb->regs);
  72. return !(val & BIT(arb->reset_bits[id]));
  73. }
  74. static int meson_audio_arb_assert(struct reset_controller_dev *rcdev,
  75. unsigned long id)
  76. {
  77. return meson_audio_arb_update(rcdev, id, true);
  78. }
  79. static int meson_audio_arb_deassert(struct reset_controller_dev *rcdev,
  80. unsigned long id)
  81. {
  82. return meson_audio_arb_update(rcdev, id, false);
  83. }
  84. static const struct reset_control_ops meson_audio_arb_rstc_ops = {
  85. .assert = meson_audio_arb_assert,
  86. .deassert = meson_audio_arb_deassert,
  87. .status = meson_audio_arb_status,
  88. };
  89. static const struct of_device_id meson_audio_arb_of_match[] = {
  90. {
  91. .compatible = "amlogic,meson-axg-audio-arb",
  92. .data = &axg_audio_arb_match,
  93. }, {
  94. .compatible = "amlogic,meson-sm1-audio-arb",
  95. .data = &sm1_audio_arb_match,
  96. },
  97. {}
  98. };
  99. MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match);
  100. static int meson_audio_arb_remove(struct platform_device *pdev)
  101. {
  102. struct meson_audio_arb_data *arb = platform_get_drvdata(pdev);
  103. /* Disable all access */
  104. spin_lock(&arb->lock);
  105. writel(0, arb->regs);
  106. spin_unlock(&arb->lock);
  107. clk_disable_unprepare(arb->clk);
  108. return 0;
  109. }
  110. static int meson_audio_arb_probe(struct platform_device *pdev)
  111. {
  112. struct device *dev = &pdev->dev;
  113. const struct meson_audio_arb_match_data *data;
  114. struct meson_audio_arb_data *arb;
  115. struct resource *res;
  116. int ret;
  117. data = of_device_get_match_data(dev);
  118. if (!data)
  119. return -EINVAL;
  120. arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
  121. if (!arb)
  122. return -ENOMEM;
  123. platform_set_drvdata(pdev, arb);
  124. arb->clk = devm_clk_get(dev, NULL);
  125. if (IS_ERR(arb->clk)) {
  126. if (PTR_ERR(arb->clk) != -EPROBE_DEFER)
  127. dev_err(dev, "failed to get clock\n");
  128. return PTR_ERR(arb->clk);
  129. }
  130. res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  131. arb->regs = devm_ioremap_resource(dev, res);
  132. if (IS_ERR(arb->regs))
  133. return PTR_ERR(arb->regs);
  134. spin_lock_init(&arb->lock);
  135. arb->reset_bits = data->reset_bits;
  136. arb->rstc.nr_resets = data->reset_num;
  137. arb->rstc.ops = &meson_audio_arb_rstc_ops;
  138. arb->rstc.of_node = dev->of_node;
  139. arb->rstc.owner = THIS_MODULE;
  140. /*
  141. * Enable general :
  142. * In the initial state, all memory interfaces are disabled
  143. * and the general bit is on
  144. */
  145. ret = clk_prepare_enable(arb->clk);
  146. if (ret) {
  147. dev_err(dev, "failed to enable arb clock\n");
  148. return ret;
  149. }
  150. writel(BIT(ARB_GENERAL_BIT), arb->regs);
  151. /* Register reset controller */
  152. ret = devm_reset_controller_register(dev, &arb->rstc);
  153. if (ret) {
  154. dev_err(dev, "failed to register arb reset controller\n");
  155. meson_audio_arb_remove(pdev);
  156. }
  157. return ret;
  158. }
  159. static struct platform_driver meson_audio_arb_pdrv = {
  160. .probe = meson_audio_arb_probe,
  161. .remove = meson_audio_arb_remove,
  162. .driver = {
  163. .name = "meson-audio-arb-reset",
  164. .of_match_table = meson_audio_arb_of_match,
  165. },
  166. };
  167. module_platform_driver(meson_audio_arb_pdrv);
  168. MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
  169. MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
  170. MODULE_LICENSE("GPL v2");