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