video/backlight/omap1_bl.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Backlight driver for OMAP based boards.
0004  *
0005  * Copyright (c) 2006 Andrzej Zaborowski  <balrog@zabor.org>
0006  */
0007
0008 #include <linux/module.h>
0009 #include <linux/kernel.h>
0010 #include <linux/init.h>
0011 #include <linux/platform_device.h>
0012 #include <linux/fb.h>
0013 #include <linux/backlight.h>
0014 #include <linux/slab.h>
0015 #include <linux/platform_data/omap1_bl.h>
0016
0017 #include <linux/soc/ti/omap1-io.h>
0018 #include <linux/soc/ti/omap1-mux.h>
0019
0020 #define OMAPBL_MAX_INTENSITY        0xff
0021
0022 struct omap_backlight {
0023     int powermode;
0024     int current_intensity;
0025
0026     struct device *dev;
0027     struct omap_backlight_config *pdata;
0028 };
0029
0030 static inline void omapbl_send_intensity(int intensity)
0031 {
0032     omap_writeb(intensity, OMAP_PWL_ENABLE);
0033 }
0034
0035 static inline void omapbl_send_enable(int enable)
0036 {
0037     omap_writeb(enable, OMAP_PWL_CLK_ENABLE);
0038 }
0039
0040 static void omapbl_blank(struct omap_backlight *bl, int mode)
0041 {
0042     if (bl->pdata->set_power)
0043         bl->pdata->set_power(bl->dev, mode);
0044
0045     switch (mode) {
0046     case FB_BLANK_NORMAL:
0047     case FB_BLANK_VSYNC_SUSPEND:
0048     case FB_BLANK_HSYNC_SUSPEND:
0049     case FB_BLANK_POWERDOWN:
0050         omapbl_send_intensity(0);
0051         omapbl_send_enable(0);
0052         break;
0053
0054     case FB_BLANK_UNBLANK:
0055         omapbl_send_intensity(bl->current_intensity);
0056         omapbl_send_enable(1);
0057         break;
0058     }
0059 }
0060
0061 #ifdef CONFIG_PM_SLEEP
0062 static int omapbl_suspend(struct device *dev)
0063 {
0064     struct backlight_device *bl_dev = dev_get_drvdata(dev);
0065     struct omap_backlight *bl = bl_get_data(bl_dev);
0066
0067     omapbl_blank(bl, FB_BLANK_POWERDOWN);
0068     return 0;
0069 }
0070
0071 static int omapbl_resume(struct device *dev)
0072 {
0073     struct backlight_device *bl_dev = dev_get_drvdata(dev);
0074     struct omap_backlight *bl = bl_get_data(bl_dev);
0075
0076     omapbl_blank(bl, bl->powermode);
0077     return 0;
0078 }
0079 #endif
0080
0081 static int omapbl_set_power(struct backlight_device *dev, int state)
0082 {
0083     struct omap_backlight *bl = bl_get_data(dev);
0084
0085     omapbl_blank(bl, state);
0086     bl->powermode = state;
0087
0088     return 0;
0089 }
0090
0091 static int omapbl_update_status(struct backlight_device *dev)
0092 {
0093     struct omap_backlight *bl = bl_get_data(dev);
0094
0095     if (bl->current_intensity != dev->props.brightness) {
0096         if (bl->powermode == FB_BLANK_UNBLANK)
0097             omapbl_send_intensity(dev->props.brightness);
0098         bl->current_intensity = dev->props.brightness;
0099     }
0100
0101     if (dev->props.fb_blank != bl->powermode)
0102         omapbl_set_power(dev, dev->props.fb_blank);
0103
0104     return 0;
0105 }
0106
0107 static int omapbl_get_intensity(struct backlight_device *dev)
0108 {
0109     struct omap_backlight *bl = bl_get_data(dev);
0110
0111     return bl->current_intensity;
0112 }
0113
0114 static const struct backlight_ops omapbl_ops = {
0115     .get_brightness = omapbl_get_intensity,
0116     .update_status  = omapbl_update_status,
0117 };
0118
0119 static int omapbl_probe(struct platform_device *pdev)
0120 {
0121     struct backlight_properties props;
0122     struct backlight_device *dev;
0123     struct omap_backlight *bl;
0124     struct omap_backlight_config *pdata = dev_get_platdata(&pdev->dev);
0125
0126     if (!pdata)
0127         return -ENXIO;
0128
0129     bl = devm_kzalloc(&pdev->dev, sizeof(struct omap_backlight),
0130               GFP_KERNEL);
0131     if (unlikely(!bl))
0132         return -ENOMEM;
0133
0134     memset(&props, 0, sizeof(struct backlight_properties));
0135     props.type = BACKLIGHT_RAW;
0136     props.max_brightness = OMAPBL_MAX_INTENSITY;
0137     dev = devm_backlight_device_register(&pdev->dev, "omap-bl", &pdev->dev,
0138                     bl, &omapbl_ops, &props);
0139     if (IS_ERR(dev))
0140         return PTR_ERR(dev);
0141
0142     bl->powermode = FB_BLANK_POWERDOWN;
0143     bl->current_intensity = 0;
0144
0145     bl->pdata = pdata;
0146     bl->dev = &pdev->dev;
0147
0148     platform_set_drvdata(pdev, dev);
0149
0150     omap_cfg_reg(PWL);  /* Conflicts with UART3 */
0151
0152     dev->props.fb_blank = FB_BLANK_UNBLANK;
0153     dev->props.brightness = pdata->default_intensity;
0154     omapbl_update_status(dev);
0155
0156     dev_info(&pdev->dev, "OMAP LCD backlight initialised\n");
0157
0158     return 0;
0159 }
0160
0161 static SIMPLE_DEV_PM_OPS(omapbl_pm_ops, omapbl_suspend, omapbl_resume);
0162
0163 static struct platform_driver omapbl_driver = {
0164     .probe      = omapbl_probe,
0165     .driver     = {
0166         .name   = "omap-bl",
0167         .pm = &omapbl_pm_ops,
0168     },
0169 };
0170
0171 module_platform_driver(omapbl_driver);
0172
0173 MODULE_AUTHOR("Andrzej Zaborowski <balrog@zabor.org>");
0174 MODULE_DESCRIPTION("OMAP LCD Backlight driver");
0175 MODULE_LICENSE("GPL");