LXR linux/drivers/video/backlight/omap1

   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
  35struct omap_backlight {
  36        int powermode;
  37        int current_intensity;
  38
  39        struct device *dev;
  40        struct omap_backlight_config *pdata;
  41};
  42
  43static inline void omapbl_send_intensity(int intensity)
  44{
  45        omap_writeb(intensity, OMAP_PWL_ENABLE);
  46}
  47
  48static inline void omapbl_send_enable(int enable)
  49{
  50        omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  51}
  52
  53static 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
  75static 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
  84static 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
  94static 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
 104static 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
 120static 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
 127static const struct backlight_ops omapbl_ops = {
 128        .get_brightness = omapbl_get_intensity,
 129        .update_status  = omapbl_update_status,
 130};
 131
 132static 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
 174static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
 175
 176static struct platform_driver omapbl_driver = {
 177        .probe          = omapbl_probe,
 178        .driver         = {
 179                .name   = "omap-bl",
 180                .pm     = &omapbl_pm_ops,
 181        },
 182};
 183
 184module_platform_driver(omapbl_driver);
 185
 186MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 187MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 188MODULE_LICENSE("GPL");
 189