w1_ds2780.c 3.4 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /*
  3. * 1-Wire implementation for the ds2780 chip
  4. *
  5. * Copyright (C) 2010 Indesign, LLC
  6. *
  7. * Author: Clifton Barnes <[email protected]>
  8. *
  9. * Based on w1-ds2760 driver
  10. */
  11. #include <linux/kernel.h>
  12. #include <linux/module.h>
  13. #include <linux/device.h>
  14. #include <linux/types.h>
  15. #include <linux/platform_device.h>
  16. #include <linux/mutex.h>
  17. #include <linux/idr.h>
  18. #include <linux/w1.h>
  19. #include "w1_ds2780.h"
  20. #define W1_FAMILY_DS2780 0x32
  21. static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
  22. size_t count, int io)
  23. {
  24. struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  25. if (addr > DS2780_DATA_SIZE || addr < 0)
  26. return 0;
  27. count = min_t(int, count, DS2780_DATA_SIZE - addr);
  28. if (w1_reset_select_slave(sl) == 0) {
  29. if (io) {
  30. w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
  31. w1_write_8(sl->master, addr);
  32. w1_write_block(sl->master, buf, count);
  33. } else {
  34. w1_write_8(sl->master, W1_DS2780_READ_DATA);
  35. w1_write_8(sl->master, addr);
  36. count = w1_read_block(sl->master, buf, count);
  37. }
  38. }
  39. return count;
  40. }
  41. int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
  42. int io)
  43. {
  44. struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  45. int ret;
  46. if (!dev)
  47. return -ENODEV;
  48. mutex_lock(&sl->master->bus_mutex);
  49. ret = w1_ds2780_do_io(dev, buf, addr, count, io);
  50. mutex_unlock(&sl->master->bus_mutex);
  51. return ret;
  52. }
  53. EXPORT_SYMBOL(w1_ds2780_io);
  54. int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
  55. {
  56. struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  57. if (!dev)
  58. return -EINVAL;
  59. mutex_lock(&sl->master->bus_mutex);
  60. if (w1_reset_select_slave(sl) == 0) {
  61. w1_write_8(sl->master, cmd);
  62. w1_write_8(sl->master, addr);
  63. }
  64. mutex_unlock(&sl->master->bus_mutex);
  65. return 0;
  66. }
  67. EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
  68. static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
  69. struct bin_attribute *bin_attr, char *buf,
  70. loff_t off, size_t count)
  71. {
  72. struct device *dev = kobj_to_dev(kobj);
  73. return w1_ds2780_io(dev, buf, off, count, 0);
  74. }
  75. static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
  76. static struct bin_attribute *w1_ds2780_bin_attrs[] = {
  77. &bin_attr_w1_slave,
  78. NULL,
  79. };
  80. static const struct attribute_group w1_ds2780_group = {
  81. .bin_attrs = w1_ds2780_bin_attrs,
  82. };
  83. static const struct attribute_group *w1_ds2780_groups[] = {
  84. &w1_ds2780_group,
  85. NULL,
  86. };
  87. static int w1_ds2780_add_slave(struct w1_slave *sl)
  88. {
  89. int ret;
  90. struct platform_device *pdev;
  91. pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
  92. if (!pdev)
  93. return -ENOMEM;
  94. pdev->dev.parent = &sl->dev;
  95. ret = platform_device_add(pdev);
  96. if (ret)
  97. goto pdev_add_failed;
  98. dev_set_drvdata(&sl->dev, pdev);
  99. return 0;
  100. pdev_add_failed:
  101. platform_device_put(pdev);
  102. return ret;
  103. }
  104. static void w1_ds2780_remove_slave(struct w1_slave *sl)
  105. {
  106. struct platform_device *pdev = dev_get_drvdata(&sl->dev);
  107. platform_device_unregister(pdev);
  108. }
  109. static const struct w1_family_ops w1_ds2780_fops = {
  110. .add_slave = w1_ds2780_add_slave,
  111. .remove_slave = w1_ds2780_remove_slave,
  112. .groups = w1_ds2780_groups,
  113. };
  114. static struct w1_family w1_ds2780_family = {
  115. .fid = W1_FAMILY_DS2780,
  116. .fops = &w1_ds2780_fops,
  117. };
  118. module_w1_family(w1_ds2780_family);
  119. MODULE_AUTHOR("Clifton Barnes <[email protected]>");
  120. MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
  121. MODULE_LICENSE("GPL");
  122. MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));