platform_lcd.c 3.5 KB

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  1. /* drivers/video/backlight/platform_lcd.c
  2. *
  3. * Copyright 2008 Simtec Electronics
  4. * Ben Dooks <ben@simtec.co.uk>
  5. *
  6. * Generic platform-device LCD power control interface.
  7. *
  8. * This program is free software; you can redistribute it and/or modify
  9. * it under the terms of the GNU General Public License version 2 as
  10. * published by the Free Software Foundation.
  11. *
  12. */
  13. #include <linux/module.h>
  14. #include <linux/platform_device.h>
  15. #include <linux/fb.h>
  16. #include <linux/backlight.h>
  17. #include <linux/lcd.h>
  18. #include <linux/slab.h>
  19. #include <video/platform_lcd.h>
  20. struct platform_lcd {
  21. struct device *us;
  22. struct lcd_device *lcd;
  23. struct plat_lcd_data *pdata;
  24. unsigned int power;
  25. unsigned int suspended : 1;
  26. };
  27. static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
  28. {
  29. return lcd_get_data(lcd);
  30. }
  31. static int platform_lcd_get_power(struct lcd_device *lcd)
  32. {
  33. struct platform_lcd *plcd = to_our_lcd(lcd);
  34. return plcd->power;
  35. }
  36. static int platform_lcd_set_power(struct lcd_device *lcd, int power)
  37. {
  38. struct platform_lcd *plcd = to_our_lcd(lcd);
  39. int lcd_power = 1;
  40. if (power == FB_BLANK_POWERDOWN || plcd->suspended)
  41. lcd_power = 0;
  42. plcd->pdata->set_power(plcd->pdata, lcd_power);
  43. plcd->power = power;
  44. return 0;
  45. }
  46. static int platform_lcd_match(struct lcd_device *lcd, struct fb_info *info)
  47. {
  48. struct platform_lcd *plcd = to_our_lcd(lcd);
  49. struct plat_lcd_data *pdata = plcd->pdata;
  50. if (pdata->match_fb)
  51. return pdata->match_fb(pdata, info);
  52. return plcd->us->parent == info->device;
  53. }
  54. static struct lcd_ops platform_lcd_ops = {
  55. .get_power = platform_lcd_get_power,
  56. .set_power = platform_lcd_set_power,
  57. .check_fb = platform_lcd_match,
  58. };
  59. static int __devinit platform_lcd_probe(struct platform_device *pdev)
  60. {
  61. struct plat_lcd_data *pdata;
  62. struct platform_lcd *plcd;
  63. struct device *dev = &pdev->dev;
  64. int err;
  65. pdata = pdev->dev.platform_data;
  66. if (!pdata) {
  67. dev_err(dev, "no platform data supplied\n");
  68. return -EINVAL;
  69. }
  70. plcd = devm_kzalloc(&pdev->dev, sizeof(struct platform_lcd),
  71. GFP_KERNEL);
  72. if (!plcd) {
  73. dev_err(dev, "no memory for state\n");
  74. return -ENOMEM;
  75. }
  76. plcd->us = dev;
  77. plcd->pdata = pdata;
  78. plcd->lcd = lcd_device_register(dev_name(dev), dev,
  79. plcd, &platform_lcd_ops);
  80. if (IS_ERR(plcd->lcd)) {
  81. dev_err(dev, "cannot register lcd device\n");
  82. err = PTR_ERR(plcd->lcd);
  83. goto err;
  84. }
  85. platform_set_drvdata(pdev, plcd);
  86. platform_lcd_set_power(plcd->lcd, FB_BLANK_NORMAL);
  87. return 0;
  88. err:
  89. return err;
  90. }
  91. static int __devexit platform_lcd_remove(struct platform_device *pdev)
  92. {
  93. struct platform_lcd *plcd = platform_get_drvdata(pdev);
  94. lcd_device_unregister(plcd->lcd);
  95. return 0;
  96. }
  97. #ifdef CONFIG_PM
  98. static int platform_lcd_suspend(struct device *dev)
  99. {
  100. struct platform_lcd *plcd = dev_get_drvdata(dev);
  101. plcd->suspended = 1;
  102. platform_lcd_set_power(plcd->lcd, plcd->power);
  103. return 0;
  104. }
  105. static int platform_lcd_resume(struct device *dev)
  106. {
  107. struct platform_lcd *plcd = dev_get_drvdata(dev);
  108. plcd->suspended = 0;
  109. platform_lcd_set_power(plcd->lcd, plcd->power);
  110. return 0;
  111. }
  112. static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
  113. platform_lcd_resume);
  114. #endif
  115. static struct platform_driver platform_lcd_driver = {
  116. .driver = {
  117. .name = "platform-lcd",
  118. .owner = THIS_MODULE,
  119. #ifdef CONFIG_PM
  120. .pm = &platform_lcd_pm_ops,
  121. #endif
  122. },
  123. .probe = platform_lcd_probe,
  124. .remove = __devexit_p(platform_lcd_remove),
  125. };
  126. module_platform_driver(platform_lcd_driver);
  127. MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
  128. MODULE_LICENSE("GPL v2");
  129. MODULE_ALIAS("platform:platform-lcd");