drivers/video/backlight/kb3886_bl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  Backlight Driver for the KB3886 Backlight
   4  *
   5  *  Copyright (c) 2007-2008 Claudio Nieder
   6  *
   7  *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/mutex.h>
  15 #include <linux/fb.h>
  16 #include <linux/backlight.h>
  17 #include <linux/delay.h>
  18 #include <linux/dmi.h>
  19
  20 #define KB3886_PARENT 0x64
  21 #define KB3886_IO 0x60
  22 #define KB3886_ADC_DAC_PWM 0xC4
  23 #define KB3886_PWM0_WRITE 0x81
  24 #define KB3886_PWM0_READ 0x41
  25
  26 static DEFINE_MUTEX(bl_mutex);
  27
  28 static void kb3886_bl_set_intensity(int intensity)
  29 {
  30         mutex_lock(&bl_mutex);
  31         intensity = intensity&0xff;
  32         outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
  33         usleep_range(10000, 11000);
  34         outb(KB3886_PWM0_WRITE, KB3886_IO);
  35         usleep_range(10000, 11000);
  36         outb(intensity, KB3886_IO);
  37         mutex_unlock(&bl_mutex);
  38 }
  39
  40 struct kb3886bl_machinfo {
  41         int max_intensity;
  42         int default_intensity;
  43         int limit_mask;
  44         void (*set_bl_intensity)(int intensity);
  45 };
  46
  47 static struct kb3886bl_machinfo kb3886_bl_machinfo = {
  48         .max_intensity = 0xff,
  49         .default_intensity = 0xa0,
  50         .limit_mask = 0x7f,
  51         .set_bl_intensity = kb3886_bl_set_intensity,
  52 };
  53
  54 static struct platform_device kb3886bl_device = {
  55         .name           = "kb3886-bl",
  56         .dev            = {
  57                 .platform_data  = &kb3886_bl_machinfo,
  58         },
  59         .id             = -1,
  60 };
  61
  62 static struct platform_device *devices[] __initdata = {
  63         &kb3886bl_device,
  64 };
  65
  66 /*
  67  * Back to driver
  68  */
  69
  70 static int kb3886bl_intensity;
  71 static struct backlight_device *kb3886_backlight_device;
  72 static struct kb3886bl_machinfo *bl_machinfo;
  73
  74 static unsigned long kb3886bl_flags;
  75 #define KB3886BL_SUSPENDED     0x01
  76
  77 static const struct dmi_system_id kb3886bl_device_table[] __initconst = {
  78         {
  79                 .ident = "Sahara Touch-iT",
  80                 .matches = {
  81                         DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
  82                         DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
  83                 },
  84         },
  85         { }
  86 };
  87
  88 static int kb3886bl_send_intensity(struct backlight_device *bd)
  89 {
  90         int intensity = backlight_get_brightness(bd);
  91
  92         if (kb3886bl_flags & KB3886BL_SUSPENDED)
  93                 intensity = 0;
  94
  95         bl_machinfo->set_bl_intensity(intensity);
  96
  97         kb3886bl_intensity = intensity;
  98         return 0;
  99 }
 100
 101 #ifdef CONFIG_PM_SLEEP
 102 static int kb3886bl_suspend(struct device *dev)
 103 {
 104         struct backlight_device *bd = dev_get_drvdata(dev);
 105
 106         kb3886bl_flags |= KB3886BL_SUSPENDED;
 107         backlight_update_status(bd);
 108         return 0;
 109 }
 110
 111 static int kb3886bl_resume(struct device *dev)
 112 {
 113         struct backlight_device *bd = dev_get_drvdata(dev);
 114
 115         kb3886bl_flags &= ~KB3886BL_SUSPENDED;
 116         backlight_update_status(bd);
 117         return 0;
 118 }
 119 #endif
 120
 121 static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
 122
 123 static int kb3886bl_get_intensity(struct backlight_device *bd)
 124 {
 125         return kb3886bl_intensity;
 126 }
 127
 128 static const struct backlight_ops kb3886bl_ops = {
 129         .get_brightness = kb3886bl_get_intensity,
 130         .update_status  = kb3886bl_send_intensity,
 131 };
 132
 133 static int kb3886bl_probe(struct platform_device *pdev)
 134 {
 135         struct backlight_properties props;
 136         struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev);
 137
 138         bl_machinfo = machinfo;
 139         if (!machinfo->limit_mask)
 140                 machinfo->limit_mask = -1;
 141
 142         memset(&props, 0, sizeof(struct backlight_properties));
 143         props.type = BACKLIGHT_RAW;
 144         props.max_brightness = machinfo->max_intensity;
 145         kb3886_backlight_device = devm_backlight_device_register(&pdev->dev,
 146                                                         "kb3886-bl", &pdev->dev,
 147                                                         NULL, &kb3886bl_ops,
 148                                                         &props);
 149         if (IS_ERR(kb3886_backlight_device))
 150                 return PTR_ERR(kb3886_backlight_device);
 151
 152         platform_set_drvdata(pdev, kb3886_backlight_device);
 153
 154         kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
 155         kb3886_backlight_device->props.brightness = machinfo->default_intensity;
 156         backlight_update_status(kb3886_backlight_device);
 157
 158         return 0;
 159 }
 160
 161 static struct platform_driver kb3886bl_driver = {
 162         .probe          = kb3886bl_probe,
 163         .driver         = {
 164                 .name   = "kb3886-bl",
 165                 .pm     = &kb3886bl_pm_ops,
 166         },
 167 };
 168
 169 static int __init kb3886_init(void)
 170 {
 171         if (!dmi_check_system(kb3886bl_device_table))
 172                 return -ENODEV;
 173
 174         platform_add_devices(devices, ARRAY_SIZE(devices));
 175         return platform_driver_register(&kb3886bl_driver);
 176 }
 177
 178 static void __exit kb3886_exit(void)
 179 {
 180         platform_driver_unregister(&kb3886bl_driver);
 181 }
 182
 183 module_init(kb3886_init);
 184 module_exit(kb3886_exit);
 185
 186 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
 187 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
 188 MODULE_LICENSE("GPL");
 189 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");