imx-iim.c 3.0 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * i.MX IIM driver
  4. *
  5. * Copyright (c) 2017 Pengutronix, Michael Grzeschik <[email protected]>
  6. *
  7. * Based on the barebox iim driver,
  8. * Copyright (c) 2010 Baruch Siach <[email protected]>,
  9. * Orex Computed Radiography
  10. */
  11. #include <linux/device.h>
  12. #include <linux/io.h>
  13. #include <linux/module.h>
  14. #include <linux/nvmem-provider.h>
  15. #include <linux/of.h>
  16. #include <linux/of_device.h>
  17. #include <linux/platform_device.h>
  18. #include <linux/slab.h>
  19. #include <linux/clk.h>
  20. #define IIM_BANK_BASE(n) (0x800 + 0x400 * (n))
  21. struct imx_iim_drvdata {
  22. unsigned int nregs;
  23. };
  24. struct iim_priv {
  25. void __iomem *base;
  26. struct clk *clk;
  27. };
  28. static int imx_iim_read(void *context, unsigned int offset,
  29. void *buf, size_t bytes)
  30. {
  31. struct iim_priv *iim = context;
  32. int i, ret;
  33. u8 *buf8 = buf;
  34. ret = clk_prepare_enable(iim->clk);
  35. if (ret)
  36. return ret;
  37. for (i = offset; i < offset + bytes; i++) {
  38. int bank = i >> 5;
  39. int reg = i & 0x1f;
  40. *buf8++ = readl(iim->base + IIM_BANK_BASE(bank) + reg * 4);
  41. }
  42. clk_disable_unprepare(iim->clk);
  43. return 0;
  44. }
  45. static struct imx_iim_drvdata imx27_drvdata = {
  46. .nregs = 2 * 32,
  47. };
  48. static struct imx_iim_drvdata imx25_imx31_imx35_drvdata = {
  49. .nregs = 3 * 32,
  50. };
  51. static struct imx_iim_drvdata imx51_drvdata = {
  52. .nregs = 4 * 32,
  53. };
  54. static struct imx_iim_drvdata imx53_drvdata = {
  55. .nregs = 4 * 32 + 16,
  56. };
  57. static const struct of_device_id imx_iim_dt_ids[] = {
  58. {
  59. .compatible = "fsl,imx25-iim",
  60. .data = &imx25_imx31_imx35_drvdata,
  61. }, {
  62. .compatible = "fsl,imx27-iim",
  63. .data = &imx27_drvdata,
  64. }, {
  65. .compatible = "fsl,imx31-iim",
  66. .data = &imx25_imx31_imx35_drvdata,
  67. }, {
  68. .compatible = "fsl,imx35-iim",
  69. .data = &imx25_imx31_imx35_drvdata,
  70. }, {
  71. .compatible = "fsl,imx51-iim",
  72. .data = &imx51_drvdata,
  73. }, {
  74. .compatible = "fsl,imx53-iim",
  75. .data = &imx53_drvdata,
  76. }, {
  77. /* sentinel */
  78. },
  79. };
  80. MODULE_DEVICE_TABLE(of, imx_iim_dt_ids);
  81. static int imx_iim_probe(struct platform_device *pdev)
  82. {
  83. struct device *dev = &pdev->dev;
  84. struct iim_priv *iim;
  85. struct nvmem_device *nvmem;
  86. struct nvmem_config cfg = {};
  87. const struct imx_iim_drvdata *drvdata = NULL;
  88. iim = devm_kzalloc(dev, sizeof(*iim), GFP_KERNEL);
  89. if (!iim)
  90. return -ENOMEM;
  91. iim->base = devm_platform_ioremap_resource(pdev, 0);
  92. if (IS_ERR(iim->base))
  93. return PTR_ERR(iim->base);
  94. drvdata = of_device_get_match_data(&pdev->dev);
  95. iim->clk = devm_clk_get(dev, NULL);
  96. if (IS_ERR(iim->clk))
  97. return PTR_ERR(iim->clk);
  98. cfg.name = "imx-iim",
  99. cfg.read_only = true,
  100. cfg.word_size = 1,
  101. cfg.stride = 1,
  102. cfg.reg_read = imx_iim_read,
  103. cfg.dev = dev;
  104. cfg.size = drvdata->nregs;
  105. cfg.priv = iim;
  106. nvmem = devm_nvmem_register(dev, &cfg);
  107. return PTR_ERR_OR_ZERO(nvmem);
  108. }
  109. static struct platform_driver imx_iim_driver = {
  110. .probe = imx_iim_probe,
  111. .driver = {
  112. .name = "imx-iim",
  113. .of_match_table = imx_iim_dt_ids,
  114. },
  115. };
  116. module_platform_driver(imx_iim_driver);
  117. MODULE_AUTHOR("Michael Grzeschik <[email protected]>");
  118. MODULE_DESCRIPTION("i.MX IIM driver");
  119. MODULE_LICENSE("GPL v2");