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  <[email protected]>
   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/backlight.h>
  13 #include <linux/slab.h>
  14 #include <linux/platform_data/omap1_bl.h>
  15
  16 #include <linux/soc/ti/omap1-io.h>
  17 #include <linux/soc/ti/omap1-mux.h>
  18
  19 #define OMAPBL_MAX_INTENSITY            0xff
  20
  21 struct omap_backlight {
  22         bool enabled;
  23         int current_intensity;
  24
  25         struct device *dev;
  26         struct omap_backlight_config *pdata;
  27 };
  28
  29 static inline void omapbl_send_intensity(int intensity)
  30 {
  31         omap_writeb(intensity, OMAP_PWL_ENABLE);
  32 }
  33
  34 static inline void omapbl_send_enable(int enable)
  35 {
  36         omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  37 }
  38
  39 static void omapbl_enable(struct omap_backlight *bl, bool enable)
  40 {
  41         if (enable) {
  42                 omapbl_send_intensity(bl->current_intensity);
  43                 omapbl_send_enable(1);
  44         } else {
  45                 omapbl_send_intensity(0);
  46                 omapbl_send_enable(0);
  47         }
  48 }
  49
  50 #ifdef CONFIG_PM_SLEEP
  51 static int omapbl_suspend(struct device *dev)
  52 {
  53         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  54         struct omap_backlight *bl = bl_get_data(bl_dev);
  55
  56         omapbl_enable(bl, false);
  57         return 0;
  58 }
  59
  60 static int omapbl_resume(struct device *dev)
  61 {
  62         struct backlight_device *bl_dev = dev_get_drvdata(dev);
  63         struct omap_backlight *bl = bl_get_data(bl_dev);
  64
  65         omapbl_enable(bl, bl->enabled);
  66         return 0;
  67 }
  68 #endif
  69
  70 static void omapbl_set_enabled(struct backlight_device *dev, bool enable)
  71 {
  72         struct omap_backlight *bl = bl_get_data(dev);
  73
  74         omapbl_enable(bl, enable);
  75         bl->enabled = enable;
  76 }
  77
  78 static int omapbl_update_status(struct backlight_device *dev)
  79 {
  80         struct omap_backlight *bl = bl_get_data(dev);
  81         bool enable;
  82
  83         if (bl->current_intensity != dev->props.brightness) {
  84                 if (bl->enabled)
  85                         omapbl_send_intensity(dev->props.brightness);
  86                 bl->current_intensity = dev->props.brightness;
  87         }
  88
  89         enable = !backlight_is_blank(dev);
  90
  91         if (enable != bl->enabled)
  92                 omapbl_set_enabled(dev, enable);
  93
  94         return 0;
  95 }
  96
  97 static int omapbl_get_intensity(struct backlight_device *dev)
  98 {
  99         struct omap_backlight *bl = bl_get_data(dev);
 100
 101         return bl->current_intensity;
 102 }
 103
 104 static const struct backlight_ops omapbl_ops = {
 105         .get_brightness = omapbl_get_intensity,
 106         .update_status  = omapbl_update_status,
 107 };
 108
 109 static int omapbl_probe(struct platform_device *pdev)
 110 {
 111         struct backlight_properties props;
 112         struct backlight_device *dev;
 113         struct omap_backlight *bl;
 114         struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
 115
 116         if (!pdata)
 117                 return -ENXIO;
 118
 119         bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
 120                           GFP_KERNEL);
 121         if (unlikely(!bl))
 122                 return -ENOMEM;
 123
 124         memset(&props, 0, sizeof(struct backlight_properties));
 125         props.type = BACKLIGHT_RAW;
 126         props.max_brightness = OMAPBL_MAX_INTENSITY;
 127         dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
 128                                         bl, &omapbl_ops, &props);
 129         if (IS_ERR(dev))
 130                 return PTR_ERR(dev);
 131
 132         bl->enabled = false;
 133         bl->current_intensity = 0;
 134
 135         bl->pdata = pdata;
 136         bl->dev = &pdev->dev;
 137
 138         platform_set_drvdata(pdev, dev);
 139
 140         omap_cfg_reg(PWL);      /* Conflicts with UART3 */
 141
 142         dev->props.brightness = pdata->default_intensity;
 143         omapbl_update_status(dev);
 144
 145         dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
 146
 147         return 0;
 148 }
 149
 150 static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
 151
 152 static struct platform_driver omapbl_driver = {
 153         .probe          = omapbl_probe,
 154         .driver         = {
 155                 .name   = "omap-bl",
 156                 .pm     = &omapbl_pm_ops,
 157         },
 158 };
 159
 160 module_platform_driver(omapbl_driver);
 161
 162 MODULE_AUTHOR("Andrzej Zaborowski <[email protected]>");
 163 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 164 MODULE_LICENSE("GPL");