kernel/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 #include <linux/platform_data/omap1_bl.h>
  29
  30 #include <mach/hardware.h>
  31 #include <mach/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 inline void omapbl_send_intensity(int intensity)
  44 {
  45         omap_writeb(intensity, OMAP_PWL_ENABLE);
  46 }
  47
  48 static inline void 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_SLEEP
  75 static int omapbl_suspend(struct device *dev)
  76 {
  77         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  78         struct omap_backlight *bl = bl_get_data(bl_dev);
  79
  80         omapbl_blank(bl, FB_BLANK_POWERDOWN);
  81         return 0;
  82 }
  83
  84 static int omapbl_resume(struct device *dev)
  85 {
  86         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  87         struct omap_backlight *bl = bl_get_data(bl_dev);
  88
  89         omapbl_blank(bl, bl->powermode);
  90         return 0;
  91 }
  92 #endif
  93
  94 static int omapbl_set_power(struct backlight_device *dev, int state)
  95 {
  96         struct omap_backlight *bl = bl_get_data(dev);
  97
  98         omapbl_blank(bl, state);
  99         bl->powermode = state;
 100
 101         return 0;
 102 }
 103
 104 static int omapbl_update_status(struct backlight_device *dev)
 105 {
 106         struct omap_backlight *bl = bl_get_data(dev);
 107
 108         if (bl->current_intensity != dev->props.brightness) {
 109                 if (bl->powermode == FB_BLANK_UNBLANK)
 110                         omapbl_send_intensity(dev->props.brightness);
 111                 bl->current_intensity = dev->props.brightness;
 112         }
 113
 114         if (dev->props.fb_blank != bl->powermode)
 115                 omapbl_set_power(dev, dev->props.fb_blank);
 116
 117         return 0;
 118 }
 119
 120 static int omapbl_get_intensity(struct backlight_device *dev)
 121 {
 122         struct omap_backlight *bl = bl_get_data(dev);
 123
 124         return bl->current_intensity;
 125 }
 126
 127 static const struct backlight_ops omapbl_ops = {
 128         .get_brightness = omapbl_get_intensity,
 129         .update_status  = omapbl_update_status,
 130 };
 131
 132 static int omapbl_probe(struct platform_device *pdev)
 133 {
 134         struct backlight_properties props;
 135         struct backlight_device *dev;
 136         struct omap_backlight *bl;
 137         struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
 138
 139         if (!pdata)
 140                 return -ENXIO;
 141
 142         bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
 143                           GFP_KERNEL);
 144         if (unlikely(!bl))
 145                 return -ENOMEM;
 146
 147         memset(&props, 0, sizeof(struct backlight_properties));
 148         props.type = BACKLIGHT_RAW;
 149         props.max_brightness = OMAPBL_MAX_INTENSITY;
 150         dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
 151                                         bl, &omapbl_ops, &props);
 152         if (IS_ERR(dev))
 153                 return PTR_ERR(dev);
 154
 155         bl->powermode = FB_BLANK_POWERDOWN;
 156         bl->current_intensity = 0;
 157
 158         bl->pdata = pdata;
 159         bl->dev = &pdev->dev;
 160
 161         platform_set_drvdata(pdev, dev);
 162
 163         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 164
 165         dev->props.fb_blank = FB_BLANK_UNBLANK;
 166         dev->props.brightness = pdata->default_intensity;
 167         omapbl_update_status(dev);
 168
 169         dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
 170
 171         return 0;
 172 }
 173
 174 static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
 175
 176 static struct platform_driver omapbl_driver = {
 177         .probe          = omapbl_probe,
 178         .driver         = {
 179                 .name   = "omap-bl",
 180                 .pm     = &omapbl_pm_ops,
 181         },
 182 };
 183
 184 module_platform_driver(omapbl_driver);
 185
 186 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 187 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 188 MODULE_LICENSE("GPL");