i2c-multi-instantiate.c 3.3 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * I2C multi-instantiate driver, pseudo driver to instantiate multiple
  4. * i2c-clients from a single fwnode.
  5. *
  6. * Copyright 2018 Hans de Goede <hdegoede@redhat.com>
  7. */
  8. #include <linux/acpi.h>
  9. #include <linux/i2c.h>
  10. #include <linux/interrupt.h>
  11. #include <linux/kernel.h>
  12. #include <linux/module.h>
  13. #include <linux/platform_device.h>
  14. struct i2c_inst_data {
  15. const char *type;
  16. int gpio_irq_idx;
  17. };
  18. struct i2c_multi_inst_data {
  19. int num_clients;
  20. struct i2c_client *clients[0];
  21. };
  22. static int i2c_multi_inst_probe(struct platform_device *pdev)
  23. {
  24. struct i2c_multi_inst_data *multi;
  25. const struct acpi_device_id *match;
  26. const struct i2c_inst_data *inst_data;
  27. struct i2c_board_info board_info = {};
  28. struct device *dev = &pdev->dev;
  29. struct acpi_device *adev;
  30. char name[32];
  31. int i, ret;
  32. match = acpi_match_device(dev->driver->acpi_match_table, dev);
  33. if (!match) {
  34. dev_err(dev, "Error ACPI match data is missing\n");
  35. return -ENODEV;
  36. }
  37. inst_data = (const struct i2c_inst_data *)match->driver_data;
  38. adev = ACPI_COMPANION(dev);
  39. /* Count number of clients to instantiate */
  40. for (i = 0; inst_data[i].type; i++) {}
  41. multi = devm_kmalloc(dev,
  42. offsetof(struct i2c_multi_inst_data, clients[i]),
  43. GFP_KERNEL);
  44. if (!multi)
  45. return -ENOMEM;
  46. multi->num_clients = i;
  47. for (i = 0; i < multi->num_clients; i++) {
  48. memset(&board_info, 0, sizeof(board_info));
  49. strlcpy(board_info.type, inst_data[i].type, I2C_NAME_SIZE);
  50. snprintf(name, sizeof(name), "%s-%s", match->id,
  51. inst_data[i].type);
  52. board_info.dev_name = name;
  53. board_info.irq = 0;
  54. if (inst_data[i].gpio_irq_idx != -1) {
  55. ret = acpi_dev_gpio_irq_get(adev,
  56. inst_data[i].gpio_irq_idx);
  57. if (ret < 0) {
  58. dev_err(dev, "Error requesting irq at index %d: %d\n",
  59. inst_data[i].gpio_irq_idx, ret);
  60. goto error;
  61. }
  62. board_info.irq = ret;
  63. }
  64. multi->clients[i] = i2c_acpi_new_device(dev, i, &board_info);
  65. if (!multi->clients[i]) {
  66. dev_err(dev, "Error creating i2c-client, idx %d\n", i);
  67. ret = -ENODEV;
  68. goto error;
  69. }
  70. }
  71. platform_set_drvdata(pdev, multi);
  72. return 0;
  73. error:
  74. while (--i >= 0)
  75. i2c_unregister_device(multi->clients[i]);
  76. return ret;
  77. }
  78. static int i2c_multi_inst_remove(struct platform_device *pdev)
  79. {
  80. struct i2c_multi_inst_data *multi = platform_get_drvdata(pdev);
  81. int i;
  82. for (i = 0; i < multi->num_clients; i++)
  83. i2c_unregister_device(multi->clients[i]);
  84. return 0;
  85. }
  86. static const struct i2c_inst_data bsg1160_data[] = {
  87. { "bmc150_accel", 0 },
  88. { "bmc150_magn", -1 },
  89. { "bmg160", -1 },
  90. {}
  91. };
  92. /*
  93. * Note new device-ids must also be added to i2c_multi_instantiate_ids in
  94. * drivers/acpi/scan.c: acpi_device_enumeration_by_parent().
  95. */
  96. static const struct acpi_device_id i2c_multi_inst_acpi_ids[] = {
  97. { "BSG1160", (unsigned long)bsg1160_data },
  98. { }
  99. };
  100. MODULE_DEVICE_TABLE(acpi, i2c_multi_inst_acpi_ids);
  101. static struct platform_driver i2c_multi_inst_driver = {
  102. .driver = {
  103. .name = "I2C multi instantiate pseudo device driver",
  104. .acpi_match_table = ACPI_PTR(i2c_multi_inst_acpi_ids),
  105. },
  106. .probe = i2c_multi_inst_probe,
  107. .remove = i2c_multi_inst_remove,
  108. };
  109. module_platform_driver(i2c_multi_inst_driver);
  110. MODULE_DESCRIPTION("I2C multi instantiate pseudo device driver");
  111. MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
  112. MODULE_LICENSE("GPL");