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1// SPDX-License-Identifier: GPL-2.0-only2/***************************************************************************3 * Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> *4 * *5 * Based on Logitech G13 driver (v0.4) *6 * Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> *7 * *8 ***************************************************************************/9 10#include <linux/hid.h>11 12#include <linux/backlight.h>13 14#include "hid-picolcd.h"15 16static int picolcd_get_brightness(struct backlight_device *bdev)17{18 struct picolcd_data *data = bl_get_data(bdev);19 return data->lcd_brightness;20}21 22static int picolcd_set_brightness(struct backlight_device *bdev)23{24 struct picolcd_data *data = bl_get_data(bdev);25 struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev);26 unsigned long flags;27 28 if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)29 return -ENODEV;30 31 data->lcd_brightness = bdev->props.brightness & 0x0ff;32 data->lcd_power = bdev->props.power;33 spin_lock_irqsave(&data->lock, flags);34 hid_set_field(report->field[0], 0,35 data->lcd_power == BACKLIGHT_POWER_ON ? data->lcd_brightness : 0);36 if (!(data->status & PICOLCD_FAILED))37 hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);38 spin_unlock_irqrestore(&data->lock, flags);39 return 0;40}41 42static const struct backlight_ops picolcd_blops = {43 .update_status = picolcd_set_brightness,44 .get_brightness = picolcd_get_brightness,45};46 47int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report)48{49 struct device *dev = &data->hdev->dev;50 struct backlight_device *bdev;51 struct backlight_properties props;52 if (!report)53 return -ENODEV;54 if (report->maxfield != 1 || report->field[0]->report_count != 1 ||55 report->field[0]->report_size != 8) {56 dev_err(dev, "unsupported BRIGHTNESS report");57 return -EINVAL;58 }59 60 memset(&props, 0, sizeof(props));61 props.type = BACKLIGHT_RAW;62 props.max_brightness = 0xff;63 bdev = backlight_device_register(dev_name(dev), dev, data,64 &picolcd_blops, &props);65 if (IS_ERR(bdev)) {66 dev_err(dev, "failed to register backlight\n");67 return PTR_ERR(bdev);68 }69 bdev->props.brightness = 0xff;70 data->lcd_brightness = 0xff;71 data->backlight = bdev;72 picolcd_set_brightness(bdev);73 return 0;74}75 76void picolcd_exit_backlight(struct picolcd_data *data)77{78 struct backlight_device *bdev = data->backlight;79 80 data->backlight = NULL;81 backlight_device_unregister(bdev);82}83 84int picolcd_resume_backlight(struct picolcd_data *data)85{86 if (!data->backlight)87 return 0;88 return picolcd_set_brightness(data->backlight);89}90 91#ifdef CONFIG_PM92void picolcd_suspend_backlight(struct picolcd_data *data)93{94 int bl_power = data->lcd_power;95 if (!data->backlight)96 return;97 98 data->backlight->props.power = BACKLIGHT_POWER_OFF;99 picolcd_set_brightness(data->backlight);100 data->lcd_power = data->backlight->props.power = bl_power;101}102#endif /* CONFIG_PM */103 104