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 = bd->props.brightness; 91 92 if (bd->props.power != FB_BLANK_UNBLANK) 93 intensity = 0; 94 if (bd->props.fb_blank != FB_BLANK_UNBLANK) 95 intensity = 0; 96 if (kb3886bl_flags & KB3886BL_SUSPENDED) 97 intensity = 0; 98 99 bl_machinfo->set_bl_intensity(intensity); 100 101 kb3886bl_intensity = intensity; 102 return 0; 103 } 104 105 #ifdef CONFIG_PM_SLEEP 106 static int kb3886bl_suspend(struct device *dev) 107 { 108 struct backlight_device *bd = dev_get_drvdata(dev); 109 110 kb3886bl_flags |= KB3886BL_SUSPENDED; 111 backlight_update_status(bd); 112 return 0; 113 } 114 115 static int kb3886bl_resume(struct device *dev) 116 { 117 struct backlight_device *bd = dev_get_drvdata(dev); 118 119 kb3886bl_flags &= ~KB3886BL_SUSPENDED; 120 backlight_update_status(bd); 121 return 0; 122 } 123 #endif 124 125 static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume); 126 127 static int kb3886bl_get_intensity(struct backlight_device *bd) 128 { 129 return kb3886bl_intensity; 130 } 131 132 static const struct backlight_ops kb3886bl_ops = { 133 .get_brightness = kb3886bl_get_intensity, 134 .update_status = kb3886bl_send_intensity, 135 }; 136 137 static int kb3886bl_probe(struct platform_device *pdev) 138 { 139 struct backlight_properties props; 140 struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev); 141 142 bl_machinfo = machinfo; 143 if (!machinfo->limit_mask) 144 machinfo->limit_mask = -1; 145 146 memset(&props, 0, sizeof(struct backlight_properties)); 147 props.type = BACKLIGHT_RAW; 148 props.max_brightness = machinfo->max_intensity; 149 kb3886_backlight_device = devm_backlight_device_register(&pdev->dev, 150 "kb3886-bl", &pdev->dev, 151 NULL, &kb3886bl_ops, 152 &props); 153 if (IS_ERR(kb3886_backlight_device)) 154 return PTR_ERR(kb3886_backlight_device); 155 156 platform_set_drvdata(pdev, kb3886_backlight_device); 157 158 kb3886_backlight_device->props.power = FB_BLANK_UNBLANK; 159 kb3886_backlight_device->props.brightness = machinfo->default_intensity; 160 backlight_update_status(kb3886_backlight_device); 161 162 return 0; 163 } 164 165 static struct platform_driver kb3886bl_driver = { 166 .probe = kb3886bl_probe, 167 .driver = { 168 .name = "kb3886-bl", 169 .pm = &kb3886bl_pm_ops, 170 }, 171 }; 172 173 static int __init kb3886_init(void) 174 { 175 if (!dmi_check_system(kb3886bl_device_table)) 176 return -ENODEV; 177 178 platform_add_devices(devices, ARRAY_SIZE(devices)); 179 return platform_driver_register(&kb3886bl_driver); 180 } 181 182 static void __exit kb3886_exit(void) 183 { 184 platform_driver_unregister(&kb3886bl_driver); 185 } 186 187 module_init(kb3886_init); 188 module_exit(kb3886_exit); 189 190 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>"); 191 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver"); 192 MODULE_LICENSE("GPL"); 193 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*"); 194