snvs_lpgpr.c 3.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * Copyright (c) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
  4. * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
  5. */
  6. #include <linux/mfd/syscon.h>
  7. #include <linux/module.h>
  8. #include <linux/nvmem-provider.h>
  9. #include <linux/of_device.h>
  10. #include <linux/regmap.h>
  11. #define IMX6Q_SNVS_HPLR 0x00
  12. #define IMX6Q_SNVS_LPLR 0x34
  13. #define IMX6Q_SNVS_LPGPR 0x68
  14. #define IMX7D_SNVS_HPLR 0x00
  15. #define IMX7D_SNVS_LPLR 0x34
  16. #define IMX7D_SNVS_LPGPR 0x90
  17. #define IMX_GPR_SL BIT(5)
  18. #define IMX_GPR_HL BIT(5)
  19. struct snvs_lpgpr_cfg {
  20. int offset;
  21. int offset_hplr;
  22. int offset_lplr;
  23. int size;
  24. };
  25. struct snvs_lpgpr_priv {
  26. struct device_d *dev;
  27. struct regmap *regmap;
  28. struct nvmem_config cfg;
  29. const struct snvs_lpgpr_cfg *dcfg;
  30. };
  31. static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx6q = {
  32. .offset = IMX6Q_SNVS_LPGPR,
  33. .offset_hplr = IMX6Q_SNVS_HPLR,
  34. .offset_lplr = IMX6Q_SNVS_LPLR,
  35. .size = 4,
  36. };
  37. static const struct snvs_lpgpr_cfg snvs_lpgpr_cfg_imx7d = {
  38. .offset = IMX7D_SNVS_LPGPR,
  39. .offset_hplr = IMX7D_SNVS_HPLR,
  40. .offset_lplr = IMX7D_SNVS_LPLR,
  41. .size = 16,
  42. };
  43. static int snvs_lpgpr_write(void *context, unsigned int offset, void *val,
  44. size_t bytes)
  45. {
  46. struct snvs_lpgpr_priv *priv = context;
  47. const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;
  48. unsigned int lock_reg;
  49. int ret;
  50. ret = regmap_read(priv->regmap, dcfg->offset_hplr, &lock_reg);
  51. if (ret < 0)
  52. return ret;
  53. if (lock_reg & IMX_GPR_SL)
  54. return -EPERM;
  55. ret = regmap_read(priv->regmap, dcfg->offset_lplr, &lock_reg);
  56. if (ret < 0)
  57. return ret;
  58. if (lock_reg & IMX_GPR_HL)
  59. return -EPERM;
  60. return regmap_bulk_write(priv->regmap, dcfg->offset + offset, val,
  61. bytes / 4);
  62. }
  63. static int snvs_lpgpr_read(void *context, unsigned int offset, void *val,
  64. size_t bytes)
  65. {
  66. struct snvs_lpgpr_priv *priv = context;
  67. const struct snvs_lpgpr_cfg *dcfg = priv->dcfg;
  68. return regmap_bulk_read(priv->regmap, dcfg->offset + offset,
  69. val, bytes / 4);
  70. }
  71. static int snvs_lpgpr_probe(struct platform_device *pdev)
  72. {
  73. struct device *dev = &pdev->dev;
  74. struct device_node *node = dev->of_node;
  75. struct device_node *syscon_node;
  76. struct snvs_lpgpr_priv *priv;
  77. struct nvmem_config *cfg;
  78. struct nvmem_device *nvmem;
  79. const struct snvs_lpgpr_cfg *dcfg;
  80. if (!node)
  81. return -ENOENT;
  82. priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
  83. if (!priv)
  84. return -ENOMEM;
  85. dcfg = of_device_get_match_data(dev);
  86. if (!dcfg)
  87. return -EINVAL;
  88. syscon_node = of_get_parent(node);
  89. if (!syscon_node)
  90. return -ENODEV;
  91. priv->regmap = syscon_node_to_regmap(syscon_node);
  92. of_node_put(syscon_node);
  93. if (IS_ERR(priv->regmap))
  94. return PTR_ERR(priv->regmap);
  95. priv->dcfg = dcfg;
  96. cfg = &priv->cfg;
  97. cfg->priv = priv;
  98. cfg->name = dev_name(dev);
  99. cfg->dev = dev;
  100. cfg->stride = 4;
  101. cfg->word_size = 4;
  102. cfg->size = dcfg->size,
  103. cfg->owner = THIS_MODULE;
  104. cfg->reg_read = snvs_lpgpr_read;
  105. cfg->reg_write = snvs_lpgpr_write;
  106. nvmem = devm_nvmem_register(dev, cfg);
  107. return PTR_ERR_OR_ZERO(nvmem);
  108. }
  109. static const struct of_device_id snvs_lpgpr_dt_ids[] = {
  110. { .compatible = "fsl,imx6q-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx6q },
  111. { .compatible = "fsl,imx6ul-snvs-lpgpr",
  112. .data = &snvs_lpgpr_cfg_imx6q },
  113. { .compatible = "fsl,imx7d-snvs-lpgpr", .data = &snvs_lpgpr_cfg_imx7d },
  114. { },
  115. };
  116. MODULE_DEVICE_TABLE(of, snvs_lpgpr_dt_ids);
  117. static struct platform_driver snvs_lpgpr_driver = {
  118. .probe = snvs_lpgpr_probe,
  119. .driver = {
  120. .name = "snvs_lpgpr",
  121. .of_match_table = snvs_lpgpr_dt_ids,
  122. },
  123. };
  124. module_platform_driver(snvs_lpgpr_driver);
  125. MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
  126. MODULE_DESCRIPTION("Low Power General Purpose Register in i.MX6 and i.MX7 Secure Non-Volatile Storage");
  127. MODULE_LICENSE("GPL v2");