lcd.h 3.5 KB

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  1. /*
  2. * LCD Lowlevel Control Abstraction
  3. *
  4. * Copyright (C) 2003,2004 Hewlett-Packard Company
  5. *
  6. */
  7. #ifndef _LINUX_LCD_H
  8. #define _LINUX_LCD_H
  9. #include <linux/device.h>
  10. #include <linux/mutex.h>
  11. #include <linux/notifier.h>
  12. #include <linux/fb.h>
  13. /* Notes on locking:
  14. *
  15. * lcd_device->ops_lock is an internal backlight lock protecting the ops
  16. * field and no code outside the core should need to touch it.
  17. *
  18. * Access to set_power() is serialised by the update_lock mutex since
  19. * most drivers seem to need this and historically get it wrong.
  20. *
  21. * Most drivers don't need locking on their get_power() method.
  22. * If yours does, you need to implement it in the driver. You can use the
  23. * update_lock mutex if appropriate.
  24. *
  25. * Any other use of the locks below is probably wrong.
  26. */
  27. struct lcd_device;
  28. struct fb_info;
  29. struct lcd_properties {
  30. /* The maximum value for contrast (read-only) */
  31. int max_contrast;
  32. };
  33. struct lcd_ops {
  34. /* Get the LCD panel power status (0: full on, 1..3: controller
  35. power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
  36. int (*get_power)(struct lcd_device *);
  37. /* Enable or disable power to the LCD (0: on; 4: off, see FB_BLANK_XXX) */
  38. int (*set_power)(struct lcd_device *, int power);
  39. /* Get the current contrast setting (0-max_contrast) */
  40. int (*get_contrast)(struct lcd_device *);
  41. /* Set LCD panel contrast */
  42. int (*set_contrast)(struct lcd_device *, int contrast);
  43. /* Set LCD panel mode (resolutions ...) */
  44. int (*set_mode)(struct lcd_device *, struct fb_videomode *);
  45. /* Check if given framebuffer device is the one LCD is bound to;
  46. return 0 if not, !=0 if it is. If NULL, lcd always matches the fb. */
  47. int (*check_fb)(struct lcd_device *, struct fb_info *);
  48. };
  49. struct lcd_device {
  50. struct lcd_properties props;
  51. /* This protects the 'ops' field. If 'ops' is NULL, the driver that
  52. registered this device has been unloaded, and if class_get_devdata()
  53. points to something in the body of that driver, it is also invalid. */
  54. struct mutex ops_lock;
  55. /* If this is NULL, the backing module is unloaded */
  56. struct lcd_ops *ops;
  57. /* Serialise access to set_power method */
  58. struct mutex update_lock;
  59. /* The framebuffer notifier block */
  60. struct notifier_block fb_notif;
  61. struct device dev;
  62. };
  63. struct lcd_platform_data {
  64. /* reset lcd panel device. */
  65. int (*reset)(struct lcd_device *ld);
  66. /* on or off to lcd panel. if 'enable' is 0 then
  67. lcd power off and 1, lcd power on. */
  68. int (*power_on)(struct lcd_device *ld, int enable);
  69. /* it indicates whether lcd panel was enabled
  70. from bootloader or not. */
  71. int lcd_enabled;
  72. /* it means delay for stable time when it becomes low to high
  73. or high to low that is dependent on whether reset gpio is
  74. low active or high active. */
  75. unsigned int reset_delay;
  76. /* stable time needing to become lcd power on. */
  77. unsigned int power_on_delay;
  78. /* stable time needing to become lcd power off. */
  79. unsigned int power_off_delay;
  80. /* it could be used for any purpose. */
  81. void *pdata;
  82. };
  83. static inline void lcd_set_power(struct lcd_device *ld, int power)
  84. {
  85. mutex_lock(&ld->update_lock);
  86. if (ld->ops && ld->ops->set_power)
  87. ld->ops->set_power(ld, power);
  88. mutex_unlock(&ld->update_lock);
  89. }
  90. extern struct lcd_device *lcd_device_register(const char *name,
  91. struct device *parent, void *devdata, struct lcd_ops *ops);
  92. extern void lcd_device_unregister(struct lcd_device *ld);
  93. #define to_lcd_device(obj) container_of(obj, struct lcd_device, dev)
  94. static inline void * lcd_get_data(struct lcd_device *ld_dev)
  95. {
  96. return dev_get_drvdata(&ld_dev->dev);
  97. }
  98. #endif