LXR linux/drivers/video/backlight/omap1

   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
  22struct omap_backlight {
  23        int powermode;
  24        int current_intensity;
  25
  26        struct device *dev;
  27        struct omap_backlight_config *pdata;
  28};
  29
  30static inline void omapbl_send_intensity(int intensity)
  31{
  32        omap_writeb(intensity, OMAP_PWL_ENABLE);
  33}
  34
  35static inline void omapbl_send_enable(int enable)
  36{
  37        omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
  38}
  39
  40static 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
  62static 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
  71static 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
  81static 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
  91static 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
 107static 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
 114static const struct backlight_ops omapbl_ops = {
 115        .get_brightness = omapbl_get_intensity,
 116        .update_status  = omapbl_update_status,
 117};
 118
 119static 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
 161static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
 162
 163static struct platform_driver omapbl_driver = {
 164        .probe          = omapbl_probe,
 165        .driver         = {
 166                .name   = "omap-bl",
 167                .pm     = &omapbl_pm_ops,
 168        },
 169};
 170
 171module_platform_driver(omapbl_driver);
 172
 173MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
 174MODULE_DESCRIPTION("OMAP LCD Backlight driver");
 175MODULE_LICENSE("GPL");
 176