drivers/video/backlight/jornada720_lcd.c

   1 /*
   2  *
   3  * LCD driver for HP Jornada 700 series (710/720/728)
   4  * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License version
   8  * 2 or any later version as published by the Free Software Foundation.
   9  *
  10  */
  11
  12 #include <linux/device.h>
  13 #include <linux/fb.h>
  14 #include <linux/kernel.h>
  15 #include <linux/lcd.h>
  16 #include <linux/module.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/delay.h>
  19
  20 #include <mach/jornada720.h>
  21 #include <mach/hardware.h>
  22
  23 #include <video/s1d13xxxfb.h>
  24
  25 #define LCD_MAX_CONTRAST        0xff
  26 #define LCD_DEF_CONTRAST        0x80
  27
  28 static int jornada_lcd_get_power(struct lcd_device *dev)
  29 {
  30         /* LDD2 in PPC = LCD POWER */
  31         if (PPSR & PPC_LDD2)
  32                 return FB_BLANK_UNBLANK;        /* PW ON */
  33         else
  34                 return FB_BLANK_POWERDOWN;      /* PW OFF */
  35 }
  36
  37 static int jornada_lcd_get_contrast(struct lcd_device *dev)
  38 {
  39         int ret;
  40
  41         if (jornada_lcd_get_power(dev) != FB_BLANK_UNBLANK)
  42                 return 0;
  43
  44         jornada_ssp_start();
  45
  46         if (jornada_ssp_byte(GETCONTRAST) != TXDUMMY) {
  47                 printk(KERN_ERR "lcd: get contrast failed\n");
  48                 jornada_ssp_end();
  49                 return -ETIMEDOUT;
  50         } else {
  51                 ret = jornada_ssp_byte(TXDUMMY);
  52                 jornada_ssp_end();
  53                 return ret;
  54         }
  55 }
  56
  57 static int jornada_lcd_set_contrast(struct lcd_device *dev, int value)
  58 {
  59         int ret;
  60
  61         jornada_ssp_start();
  62
  63         /* start by sending our set contrast cmd to mcu */
  64         ret = jornada_ssp_byte(SETCONTRAST);
  65
  66         /* push the new value */
  67         if (jornada_ssp_byte(value) != TXDUMMY) {
  68                 printk(KERN_ERR "lcd : set contrast failed\n");
  69                 jornada_ssp_end();
  70                 return -ETIMEDOUT;
  71         }
  72
  73         /* if we get here we can assume everything went well */
  74         jornada_ssp_end();
  75
  76         return 0;
  77 }
  78
  79 static int jornada_lcd_set_power(struct lcd_device *dev, int power)
  80 {
  81         if (power != FB_BLANK_UNBLANK) {
  82                 PPSR &= ~PPC_LDD2;
  83                 PPDR |= PPC_LDD2;
  84         } else
  85                 PPSR |= PPC_LDD2;
  86
  87         return 0;
  88 }
  89
  90 static struct lcd_ops jornada_lcd_props = {
  91         .get_contrast = jornada_lcd_get_contrast,
  92         .set_contrast = jornada_lcd_set_contrast,
  93         .get_power = jornada_lcd_get_power,
  94         .set_power = jornada_lcd_set_power,
  95 };
  96
  97 static int jornada_lcd_probe(struct platform_device *pdev)
  98 {
  99         struct lcd_device *lcd_device;
 100         int ret;
 101
 102         lcd_device = lcd_device_register(S1D_DEVICENAME, &pdev->dev, NULL, &jornada_lcd_props);
 103
 104         if (IS_ERR(lcd_device)) {
 105                 ret = PTR_ERR(lcd_device);
 106                 printk(KERN_ERR "lcd : failed to register device\n");
 107                 return ret;
 108         }
 109
 110         platform_set_drvdata(pdev, lcd_device);
 111
 112         /* lets set our default values */
 113         jornada_lcd_set_contrast(lcd_device, LCD_DEF_CONTRAST);
 114         jornada_lcd_set_power(lcd_device, FB_BLANK_UNBLANK);
 115         /* give it some time to startup */
 116         msleep(100);
 117
 118         return 0;
 119 }
 120
 121 static int jornada_lcd_remove(struct platform_device *pdev)
 122 {
 123         struct lcd_device *lcd_device = platform_get_drvdata(pdev);
 124
 125         lcd_device_unregister(lcd_device);
 126
 127         return 0;
 128 }
 129
 130 static struct platform_driver jornada_lcd_driver = {
 131         .probe  = jornada_lcd_probe,
 132         .remove = jornada_lcd_remove,
 133         .driver = {
 134                 .name   = "jornada_lcd",
 135         },
 136 };
 137
 138 module_platform_driver(jornada_lcd_driver);
 139
 140 MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson@gmail.com>");
 141 MODULE_DESCRIPTION("HP Jornada 710/720/728 LCD driver");
 142 MODULE_LICENSE("GPL");