drivers/video/backlight/omap1_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Backlight driver for OMAP based boards.
   4  *
   5  * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/init.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/fb.h>
  13 #include <linux/backlight.h>
  14 #include <linux/slab.h>
  15 #include <linux/platform_data/omap1_bl.h>
  16
  17 #include <mach/hardware.h>
  18 #include <mach/mux.h>
  19
  20 #define OMAPBL_MAX_INTENSITY            0xff
  21
  22 struct omap_backlight {
  23         int powermode;
  24         int current_intensity;
  25
  26         struct device *dev;
  27         struct omap_backlight_config *pdata;
  28 };
  29
  30 static inline void omapbl_send_intensity(int intensity)
  31 {
  32         omap_writeb(intensity, OMAP_PWL_ENABLE);
  33 }
  34
  35 static inline void omapbl_send_enable(int enable)
  36 {
  37         omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  38 }
  39
  40 static void omapbl_blank(struct omap_backlight *bl, int mode)
  41 {
  42         if (bl->pdata->set_power)
  43                 bl->pdata->set_power(bl->dev, mode);
  44
  45         switch (mode) {
  46         case FB_BLANK_NORMAL:
  47         case FB_BLANK_VSYNC_SUSPEND:
  48         case FB_BLANK_HSYNC_SUSPEND:
  49         case FB_BLANK_POWERDOWN:
  50                 omapbl_send_intensity(0);
  51                 omapbl_send_enable(0);
  52                 break;
  53
  54         case FB_BLANK_UNBLANK:
  55                 omapbl_send_intensity(bl->current_intensity);
  56                 omapbl_send_enable(1);
  57                 break;
  58         }
  59 }
  60
  61 #ifdef CONFIG_PM_SLEEP
  62 static int omapbl_suspend(struct device *dev)
  63 {
  64         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  65         struct omap_backlight *bl = bl_get_data(bl_dev);
  66
  67         omapbl_blank(bl, FB_BLANK_POWERDOWN);
  68         return 0;
  69 }
  70
  71 static int omapbl_resume(struct device *dev)
  72 {
  73         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  74         struct omap_backlight *bl = bl_get_data(bl_dev);
  75
  76         omapbl_blank(bl, bl->powermode);
  77         return 0;
  78 }
  79 #endif
  80
  81 static int omapbl_set_power(struct backlight_device *dev, int state)
  82 {
  83         struct omap_backlight *bl = bl_get_data(dev);
  84
  85         omapbl_blank(bl, state);
  86         bl->powermode = state;
  87
  88         return 0;
  89 }
  90
  91 static int omapbl_update_status(struct backlight_device *dev)
  92 {
  93         struct omap_backlight *bl = bl_get_data(dev);
  94
  95         if (bl->current_intensity != dev->props.brightness) {
  96                 if (bl->powermode == FB_BLANK_UNBLANK)
  97                         omapbl_send_intensity(dev->props.brightness);
  98                 bl->current_intensity = dev->props.brightness;
  99         }
 100
 101         if (dev->props.fb_blank != bl->powermode)
 102                 omapbl_set_power(dev, dev->props.fb_blank);
 103
 104         return 0;
 105 }
 106
 107 static int omapbl_get_intensity(struct backlight_device *dev)
 108 {
 109         struct omap_backlight *bl = bl_get_data(dev);
 110
 111         return bl->current_intensity;
 112 }
 113
 114 static const struct backlight_ops omapbl_ops = {
 115         .get_brightness = omapbl_get_intensity,
 116         .update_status  = omapbl_update_status,
 117 };
 118
 119 static int omapbl_probe(struct platform_device *pdev)
 120 {
 121         struct backlight_properties props;
 122         struct backlight_device *dev;
 123         struct omap_backlight *bl;
 124         struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
 125
 126         if (!pdata)
 127                 return -ENXIO;
 128
 129         bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
 130                           GFP_KERNEL);
 131         if (unlikely(!bl))
 132                 return -ENOMEM;
 133
 134         memset(&props, 0, sizeof(struct backlight_properties));
 135         props.type = BACKLIGHT_RAW;
 136         props.max_brightness = OMAPBL_MAX_INTENSITY;
 137         dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
 138                                         bl, &omapbl_ops, &props);
 139         if (IS_ERR(dev))
 140                 return PTR_ERR(dev);
 141
 142         bl->powermode = FB_BLANK_POWERDOWN;
 143         bl->current_intensity = 0;
 144
 145         bl->pdata = pdata;
 146         bl->dev = &pdev->dev;
 147
 148         platform_set_drvdata(pdev, dev);
 149
 150         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 151
 152         dev->props.fb_blank = FB_BLANK_UNBLANK;
 153         dev->props.brightness = pdata->default_intensity;
 154         omapbl_update_status(dev);
 155
 156         dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
 157
 158         return 0;
 159 }
 160
 161 static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
 162
 163 static struct platform_driver omapbl_driver = {
 164         .probe          = omapbl_probe,
 165         .driver         = {
 166                 .name   = "omap-bl",
 167                 .pm     = &omapbl_pm_ops,
 168         },
 169 };
 170
 171 module_platform_driver(omapbl_driver);
 172
 173 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 174 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 175 MODULE_LICENSE("GPL");