// SPDX-License-Identifier: GPL-2.0-only
/***************************************************************************
 *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
 *                                                                         *
 *   Based on Logitech G13 driver (v0.4)                                   *
 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
 *                                                                         *
 ***************************************************************************/

#include <linux/hid.h>

#include <linux/fb.h>
#include <linux/lcd.h>

#include "hid-picolcd.h"

/*
 * lcd class device
 */
static int picolcd_get_contrast(struct lcd_device *ldev)
{
        struct picolcd_data *data = lcd_get_data(ldev);
        return data->lcd_contrast;
}

static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
{
        struct picolcd_data *data = lcd_get_data(ldev);
        struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
        unsigned long flags;

        if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
                return -ENODEV;

        data->lcd_contrast = contrast & 0x0ff;
        spin_lock_irqsave(&data->lock, flags);
        hid_set_field(report->field[0], 0, data->lcd_contrast);
        if (!(data->status & PICOLCD_FAILED))
                hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
        spin_unlock_irqrestore(&data->lock, flags);
        return 0;
}

static const struct lcd_ops picolcd_lcdops = {
        .get_contrast   = picolcd_get_contrast,
        .set_contrast   = picolcd_set_contrast,
};

int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
{
        struct device *dev = &data->hdev->dev;
        struct lcd_device *ldev;

        if (!report)
                return -ENODEV;
        if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
                        report->field[0]->report_size != 8) {
                dev_err(dev, "unsupported CONTRAST report");
                return -EINVAL;
        }

        ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
        if (IS_ERR(ldev)) {
                dev_err(dev, "failed to register LCD\n");
                return PTR_ERR(ldev);
        }
        ldev->props.max_contrast = 0x0ff;
        data->lcd_contrast = 0xe5;
        data->lcd = ldev;
        picolcd_set_contrast(ldev, 0xe5);
        return 0;
}

void picolcd_exit_lcd(struct picolcd_data *data)
{
        struct lcd_device *ldev = data->lcd;

        data->lcd = NULL;
        lcd_device_unregister(ldev);
}

int picolcd_resume_lcd(struct picolcd_data *data)
{
        if (!data->lcd)
                return 0;
        return picolcd_set_contrast(data->lcd, data->lcd_contrast);
}