hid-picolcd_lcd.c 2.7 KB

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  1. // SPDX-License-Identifier: GPL-2.0-only
  2. /***************************************************************************
  3. * Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *
  4. * *
  5. * Based on Logitech G13 driver (v0.4) *
  6. * Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *
  7. * *
  8. ***************************************************************************/
  9. #include <linux/hid.h>
  10. #include <linux/fb.h>
  11. #include <linux/lcd.h>
  12. #include "hid-picolcd.h"
  13. /*
  14. * lcd class device
  15. */
  16. static int picolcd_get_contrast(struct lcd_device *ldev)
  17. {
  18. struct picolcd_data *data = lcd_get_data(ldev);
  19. return data->lcd_contrast;
  20. }
  21. static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
  22. {
  23. struct picolcd_data *data = lcd_get_data(ldev);
  24. struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
  25. unsigned long flags;
  26. if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
  27. return -ENODEV;
  28. data->lcd_contrast = contrast & 0x0ff;
  29. spin_lock_irqsave(&data->lock, flags);
  30. hid_set_field(report->field[0], 0, data->lcd_contrast);
  31. if (!(data->status & PICOLCD_FAILED))
  32. hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
  33. spin_unlock_irqrestore(&data->lock, flags);
  34. return 0;
  35. }
  36. static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
  37. {
  38. return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
  39. }
  40. static struct lcd_ops picolcd_lcdops = {
  41. .get_contrast = picolcd_get_contrast,
  42. .set_contrast = picolcd_set_contrast,
  43. .check_fb = picolcd_check_lcd_fb,
  44. };
  45. int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
  46. {
  47. struct device *dev = &data->hdev->dev;
  48. struct lcd_device *ldev;
  49. if (!report)
  50. return -ENODEV;
  51. if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
  52. report->field[0]->report_size != 8) {
  53. dev_err(dev, "unsupported CONTRAST report");
  54. return -EINVAL;
  55. }
  56. ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
  57. if (IS_ERR(ldev)) {
  58. dev_err(dev, "failed to register LCD\n");
  59. return PTR_ERR(ldev);
  60. }
  61. ldev->props.max_contrast = 0x0ff;
  62. data->lcd_contrast = 0xe5;
  63. data->lcd = ldev;
  64. picolcd_set_contrast(ldev, 0xe5);
  65. return 0;
  66. }
  67. void picolcd_exit_lcd(struct picolcd_data *data)
  68. {
  69. struct lcd_device *ldev = data->lcd;
  70. data->lcd = NULL;
  71. lcd_device_unregister(ldev);
  72. }
  73. int picolcd_resume_lcd(struct picolcd_data *data)
  74. {
  75. if (!data->lcd)
  76. return 0;
  77. return picolcd_set_contrast(data->lcd, data->lcd_contrast);
  78. }