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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/module.h>
  24 #include <linux/kernel.h>
  25 #include <linux/init.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/fb.h>
  28 #include <linux/backlight.h>
  29 #include <linux/slab.h>
  30
  31 #include <mach/hardware.h>
  32 #include <plat/board.h>
  33 #include <plat/mux.h>
  34
  35 #define OMAPBL_MAX_INTENSITY            0xff
  36
  37 struct omap_backlight {
  38         int powermode;
  39         int current_intensity;
  40
  41         struct device *dev;
  42         struct omap_backlight_config *pdata;
  43 };
  44
  45 static void inline omapbl_send_intensity(int intensity)
  46 {
  47         omap_writeb(intensity, OMAP_PWL_ENABLE);
  48 }
  49
  50 static void inline omapbl_send_enable(int enable)
  51 {
  52         omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  53 }
  54
  55 static void omapbl_blank(struct omap_backlight *bl, int mode)
  56 {
  57         if (bl->pdata->set_power)
  58                 bl->pdata->set_power(bl->dev, mode);
  59
  60         switch (mode) {
  61         case FB_BLANK_NORMAL:
  62         case FB_BLANK_VSYNC_SUSPEND:
  63         case FB_BLANK_HSYNC_SUSPEND:
  64         case FB_BLANK_POWERDOWN:
  65                 omapbl_send_intensity(0);
  66                 omapbl_send_enable(0);
  67                 break;
  68
  69         case FB_BLANK_UNBLANK:
  70                 omapbl_send_intensity(bl->current_intensity);
  71                 omapbl_send_enable(1);
  72                 break;
  73         }
  74 }
  75
  76 #ifdef CONFIG_PM
  77 static int omapbl_suspend(struct platform_device *pdev, pm_message_t state)
  78 {
  79         struct backlight_device *dev = platform_get_drvdata(pdev);
  80         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  81
  82         omapbl_blank(bl, FB_BLANK_POWERDOWN);
  83         return 0;
  84 }
  85
  86 static int omapbl_resume(struct platform_device *pdev)
  87 {
  88         struct backlight_device *dev = platform_get_drvdata(pdev);
  89         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
  90
  91         omapbl_blank(bl, bl->powermode);
  92         return 0;
  93 }
  94 #else
  95 #define omapbl_suspend  NULL
  96 #define omapbl_resume   NULL
  97 #endif
  98
  99 static int omapbl_set_power(struct backlight_device *dev, int state)
 100 {
 101         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 102
 103         omapbl_blank(bl, state);
 104         bl->powermode = state;
 105
 106         return 0;
 107 }
 108
 109 static int omapbl_update_status(struct backlight_device *dev)
 110 {
 111         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 112
 113         if (bl->current_intensity != dev->props.brightness) {
 114                 if (bl->powermode == FB_BLANK_UNBLANK)
 115                         omapbl_send_intensity(dev->props.brightness);
 116                 bl->current_intensity = dev->props.brightness;
 117         }
 118
 119         if (dev->props.fb_blank != bl->powermode)
 120                 omapbl_set_power(dev, dev->props.fb_blank);
 121
 122         return 0;
 123 }
 124
 125 static int omapbl_get_intensity(struct backlight_device *dev)
 126 {
 127         struct omap_backlight *bl = dev_get_drvdata(&dev->dev);
 128         return bl->current_intensity;
 129 }
 130
 131 static const struct backlight_ops omapbl_ops = {
 132         .get_brightness = omapbl_get_intensity,
 133         .update_status  = omapbl_update_status,
 134 };
 135
 136 static int omapbl_probe(struct platform_device *pdev)
 137 {
 138         struct backlight_properties props;
 139         struct backlight_device *dev;
 140         struct omap_backlight *bl;
 141         struct omap_backlight_config *pdata = pdev->dev.platform_data;
 142
 143         if (!pdata)
 144                 return -ENXIO;
 145
 146         bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
 147                           GFP_KERNEL);
 148         if (unlikely(!bl))
 149                 return -ENOMEM;
 150
 151         memset(&props, 0, sizeof(struct backlight_properties));
 152         props.type = BACKLIGHT_RAW;
 153         props.max_brightness = OMAPBL_MAX_INTENSITY;
 154         dev = backlight_device_register("omap-bl", &pdev->dev, bl, &omapbl_ops,
 155                                         &props);
 156         if (IS_ERR(dev))
 157                 return PTR_ERR(dev);
 158
 159         bl->powermode = FB_BLANK_POWERDOWN;
 160         bl->current_intensity = 0;
 161
 162         bl->pdata = pdata;
 163         bl->dev = &pdev->dev;
 164
 165         platform_set_drvdata(pdev, dev);
 166
 167         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 168
 169         dev->props.fb_blank = FB_BLANK_UNBLANK;
 170         dev->props.brightness = pdata->default_intensity;
 171         omapbl_update_status(dev);
 172
 173         pr_info("OMAP LCD backlight initialised\n");
 174
 175         return 0;
 176 }
 177
 178 static int omapbl_remove(struct platform_device *pdev)
 179 {
 180         struct backlight_device *dev = platform_get_drvdata(pdev);
 181
 182         backlight_device_unregister(dev);
 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 module_platform_driver(omapbl_driver);
 198
 199 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 200 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 201 MODULE_LICENSE("GPL");