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
  28 #include <mach/hardware.h>
  29 #include <plat/board.h>
  30 #include <plat/mux.h>
  31
  32 #define OMAPBL_MAX_INTENSITY            0xff
  33
  34 struct omap_backlight {
  35         int powermode;
  36         int current_intensity;
  37
  38         struct device *dev;
  39         struct omap_backlight_config *pdata;
  40 };
  41
  42 static void inline omapbl_send_intensity(int intensity)
  43 {
  44         omap_writeb(intensity, OMAP_PWL_ENABLE);
  45 }
  46
  47 static void inline omapbl_send_enable(int enable)
  48 {
  49         omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  50 }
  51
  52 static void omapbl_blank(struct omap_backlight *bl, int mode)
  53 {
  54         if (bl->pdata->set_power)
  55                 bl->pdata->set_power(bl->dev, mode);
  56
  57         switch (mode) {
  58         case FB_BLANK_NORMAL:
  59         case FB_BLANK_VSYNC_SUSPEND:
  60         case FB_BLANK_HSYNC_SUSPEND:
  61         case FB_BLANK_POWERDOWN:
  62                 omapbl_send_intensity(0);
  63                 omapbl_send_enable(0);
  64                 break;
  65
  66         case FB_BLANK_UNBLANK:
  67                 omapbl_send_intensity(bl->current_intensity);
  68                 omapbl_send_enable(1);
  69                 break;
  70         }
  71 }
  72
  73 #ifdef CONFIG_PM
  74 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state)
  75 {
  76         struct backlight_device *dev = platform_get_drvdata(pdev);
  77         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  78
  79         omapbl_blank(bl, FB_BLANK_POWERDOWN);
  80         return 0;
  81 }
  82
  83 static int omapbl_resume(struct platform_device *pdev)
  84 {
  85         struct backlight_device *dev = platform_get_drvdata(pdev);
  86         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  87
  88         omapbl_blank(bl, bl->powermode);
  89         return 0;
  90 }
  91 #else
  92 #define omapbl_suspend  NULL
  93 #define omapbl_resume   NULL
  94 #endif
  95
  96 static int omapbl_set_power(struct backlight_device *dev, int state)
  97 {
  98         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  99
 100         omapbl_blank(bl, state);
 101         bl->powermode = state;
 102
 103         return 0;
 104 }
 105
 106 static int omapbl_update_status(struct backlight_device *dev)
 107 {
 108         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 109
 110         if (bl->current_intensity != dev->props.brightness) {
 111                 if (bl->powermode == FB_BLANK_UNBLANK)
 112                         omapbl_send_intensity(dev->props.brightness);
 113                 bl->current_intensity = dev->props.brightness;
 114         }
 115
 116         if (dev->props.fb_blank != bl->powermode)
 117                 omapbl_set_power(dev, dev->props.fb_blank);
 118
 119         return 0;
 120 }
 121
 122 static int omapbl_get_intensity(struct backlight_device *dev)
 123 {
 124         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 125         return bl->current_intensity;
 126 }
 127
 128 static const struct backlight_ops omapbl_ops = {
 129         .get_brightness = omapbl_get_intensity,
 130         .update_status  = omapbl_update_status,
 131 };
 132
 133 static int omapbl_probe(struct platform_device *pdev)
 134 {
 135         struct backlight_device *dev;
 136         struct omap_backlight *bl;
 137         struct omap_backlight_config *pdata = pdev->dev.platform_data;
 138
 139         if (!pdata)
 140                 return -ENXIO;
 141
 142         bl = kzalloc(sizeof(struct omap_backlight), GFP_KERNEL);
 143         if (unlikely(!bl))
 144                 return -ENOMEM;
 145
 146         dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops);
 147         if (IS_ERR(dev)) {
 148                 kfree(bl);
 149                 return PTR_ERR(dev);
 150         }
 151
 152         bl->powermode = FB_BLANK_POWERDOWN;
 153         bl->current_intensity = 0;
 154
 155         bl->pdata = pdata;
 156         bl->dev = &pdev->dev;
 157
 158         platform_set_drvdata(pdev, dev);
 159
 160         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 161
 162         dev->props.fb_blank = FB_BLANK_UNBLANK;
 163         dev->props.max_brightness = OMAPBL_MAX_INTENSITY;
 164         dev->props.brightness = pdata->default_intensity;
 165         omapbl_update_status(dev);
 166
 167         printk(KERN_INFO "OMAP LCD backlight initialised\n");
 168
 169         return 0;
 170 }
 171
 172 static int omapbl_remove(struct platform_device *pdev)
 173 {
 174         struct backlight_device *dev = platform_get_drvdata(pdev);
 175         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 176
 177         backlight_device_unregister(dev);
 178         kfree(bl);
 179
 180         return 0;
 181 }
 182
 183 static struct platform_driver omapbl_driver = {
 184         .probe          = omapbl_probe,
 185         .remove         = omapbl_remove,
 186         .suspend        = omapbl_suspend,
 187         .resume         = omapbl_resume,
 188         .driver         = {
 189                 .name   = "omap-bl",
 190         },
 191 };
 192
 193 static int __init omapbl_init(void)
 194 {
 195         return platform_driver_register(&omapbl_driver);
 196 }
 197
 198 static void __exit omapbl_exit(void)
 199 {
 200         platform_driver_unregister(&omapbl_driver);
 201 }
 202
 203 module_init(omapbl_init);
 204 module_exit(omapbl_exit);
 205
 206 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 207 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 208 MODULE_LICENSE("GPL");