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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Backlight Driver for the KB3886 Backlight4 *5 * Copyright (c) 2007-2008 Claudio Nieder6 *7 * Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle8 */9 10#include <linux/module.h>11#include <linux/kernel.h>12#include <linux/init.h>13#include <linux/io.h>14#include <linux/platform_device.h>15#include <linux/mutex.h>16#include <linux/backlight.h>17#include <linux/delay.h>18#include <linux/dmi.h>19 20#define KB3886_PARENT 0x6421#define KB3886_IO 0x6022#define KB3886_ADC_DAC_PWM 0xC423#define KB3886_PWM0_WRITE 0x8124#define KB3886_PWM0_READ 0x4125 26static DEFINE_MUTEX(bl_mutex);27 28static 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 40struct kb3886bl_machinfo {41 int max_intensity;42 int default_intensity;43 int limit_mask;44 void (*set_bl_intensity)(int intensity);45};46 47static 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 54static struct platform_device kb3886bl_device = {55 .name = "kb3886-bl",56 .dev = {57 .platform_data = &kb3886_bl_machinfo,58 },59 .id = -1,60};61 62static struct platform_device *devices[] __initdata = {63 &kb3886bl_device,64};65 66/*67 * Back to driver68 */69 70static int kb3886bl_intensity;71static struct backlight_device *kb3886_backlight_device;72static struct kb3886bl_machinfo *bl_machinfo;73 74static unsigned long kb3886bl_flags;75#define KB3886BL_SUSPENDED 0x0176 77static 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 88static 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_SLEEP102static 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 111static 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#endif120 121static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);122 123static int kb3886bl_get_intensity(struct backlight_device *bd)124{125 return kb3886bl_intensity;126}127 128static const struct backlight_ops kb3886bl_ops = {129 .get_brightness = kb3886bl_get_intensity,130 .update_status = kb3886bl_send_intensity,131};132 133static 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 = BACKLIGHT_POWER_ON;155 kb3886_backlight_device->props.brightness = machinfo->default_intensity;156 backlight_update_status(kb3886_backlight_device);157 158 return 0;159}160 161static struct platform_driver kb3886bl_driver = {162 .probe = kb3886bl_probe,163 .driver = {164 .name = "kb3886-bl",165 .pm = &kb3886bl_pm_ops,166 },167};168 169static 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 178static void __exit kb3886_exit(void)179{180 platform_driver_unregister(&kb3886bl_driver);181}182 183module_init(kb3886_init);184module_exit(kb3886_exit);185 186MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");187MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");188MODULE_LICENSE("GPL");189MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");190