drivers/video/backlight/omap1_bl.c

   1 /*
   2  * Backlight driver for OMAP based boards.
   3  *
   4  * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
   5  *
   6  * This package is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This package is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this package; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/fb.h>
  26 #include <linux/backlight.h>
  27 #include <linux/slab.h>
  28
  29 #include <mach/hardware.h>
  30 #include <plat/board.h>
  31 #include <plat/mux.h>
  32
  33 #define OMAPBL_MAX_INTENSITY            0xff
  34
  35 struct omap_backlight {
  36         int powermode;
  37         int current_intensity;
  38
  39         struct device *dev;
  40         struct omap_backlight_config *pdata;
  41 };
  42
  43 static void inline omapbl_send_intensity(int intensity)
  44 {
  45         omap_writeb(intensity, OMAP_PWL_ENABLE);
  46 }
  47
  48 static void inline omapbl_send_enable(int enable)
  49 {
  50         omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  51 }
  52
  53 static void omapbl_blank(struct omap_backlight *bl, int mode)
  54 {
  55         if (bl->pdata->set_power)
  56                 bl->pdata->set_power(bl->dev, mode);
  57
  58         switch (mode) {
  59         case FB_BLANK_NORMAL:
  60         case FB_BLANK_VSYNC_SUSPEND:
  61         case FB_BLANK_HSYNC_SUSPEND:
  62         case FB_BLANK_POWERDOWN:
  63                 omapbl_send_intensity(0);
  64                 omapbl_send_enable(0);
  65                 break;
  66
  67         case FB_BLANK_UNBLANK:
  68                 omapbl_send_intensity(bl->current_intensity);
  69                 omapbl_send_enable(1);
  70                 break;
  71         }
  72 }
  73
  74 #ifdef CONFIG_PM
  75 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state)
  76 {
  77         struct backlight_device *dev = platform_get_drvdata(pdev);
  78         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  79
  80         omapbl_blank(bl, FB_BLANK_POWERDOWN);
  81         return 0;
  82 }
  83
  84 static int omapbl_resume(struct platform_device *pdev)
  85 {
  86         struct backlight_device *dev = platform_get_drvdata(pdev);
  87         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  88
  89         omapbl_blank(bl, bl->powermode);
  90         return 0;
  91 }
  92 #else
  93 #define omapbl_suspend  NULL
  94 #define omapbl_resume   NULL
  95 #endif
  96
  97 static int omapbl_set_power(struct backlight_device *dev, int state)
  98 {
  99         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 100
 101         omapbl_blank(bl, state);
 102         bl->powermode = state;
 103
 104         return 0;
 105 }
 106
 107 static int omapbl_update_status(struct backlight_device *dev)
 108 {
 109         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 110
 111         if (bl->current_intensity != dev->props.brightness) {
 112                 if (bl->powermode == FB_BLANK_UNBLANK)
 113                         omapbl_send_intensity(dev->props.brightness);
 114                 bl->current_intensity = dev->props.brightness;
 115         }
 116
 117         if (dev->props.fb_blank != bl->powermode)
 118                 omapbl_set_power(dev, dev->props.fb_blank);
 119
 120         return 0;
 121 }
 122
 123 static int omapbl_get_intensity(struct backlight_device *dev)
 124 {
 125         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 126         return bl->current_intensity;
 127 }
 128
 129 static const struct backlight_ops omapbl_ops = {
 130         .get_brightness = omapbl_get_intensity,
 131         .update_status  = omapbl_update_status,
 132 };
 133
 134 static int omapbl_probe(struct platform_device *pdev)
 135 {
 136         struct backlight_properties props;
 137         struct backlight_device *dev;
 138         struct omap_backlight *bl;
 139         struct omap_backlight_config *pdata = pdev->dev.platform_data;
 140
 141         if (!pdata)
 142                 return -ENXIO;
 143
 144         bl = kzalloc(sizeof(struct omap_backlight), GFP_KERNEL);
 145         if (unlikely(!bl))
 146                 return -ENOMEM;
 147
 148         memset(&props, 0, sizeof(struct backlight_properties));
 149         props.max_brightness = OMAPBL_MAX_INTENSITY;
 150         dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops,
 151                                         &props);
 152         if (IS_ERR(dev)) {
 153                 kfree(bl);
 154                 return PTR_ERR(dev);
 155         }
 156
 157         bl->powermode = FB_BLANK_POWERDOWN;
 158         bl->current_intensity = 0;
 159
 160         bl->pdata = pdata;
 161         bl->dev = &pdev->dev;
 162
 163         platform_set_drvdata(pdev, dev);
 164
 165         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 166
 167         dev->props.fb_blank = FB_BLANK_UNBLANK;
 168         dev->props.brightness = pdata->default_intensity;
 169         omapbl_update_status(dev);
 170
 171         printk(KERN_INFO "OMAP LCD backlight initialised\n");
 172
 173         return 0;
 174 }
 175
 176 static int omapbl_remove(struct platform_device *pdev)
 177 {
 178         struct backlight_device *dev = platform_get_drvdata(pdev);
 179         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 180
 181         backlight_device_unregister(dev);
 182         kfree(bl);
 183
 184         return 0;
 185 }
 186
 187 static struct platform_driver omapbl_driver = {
 188         .probe          = omapbl_probe,
 189         .remove         = omapbl_remove,
 190         .suspend        = omapbl_suspend,
 191         .resume         = omapbl_resume,
 192         .driver         = {
 193                 .name   = "omap-bl",
 194         },
 195 };
 196
 197 static int __init omapbl_init(void)
 198 {
 199         return platform_driver_register(&omapbl_driver);
 200 }
 201
 202 static void __exit omapbl_exit(void)
 203 {
 204         platform_driver_unregister(&omapbl_driver);
 205 }
 206
 207 module_init(omapbl_init);
 208 module_exit(omapbl_exit);
 209
 210 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 211 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 212 MODULE_LICENSE("GPL");