linux/drivers/hid/hid-picolcd_lcd.c
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   1/***************************************************************************
   2 *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
   3 *                                                                         *
   4 *   Based on Logitech G13 driver (v0.4)                                   *
   5 *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
   6 *                                                                         *
   7 *   This program is free software: you can redistribute it and/or modify  *
   8 *   it under the terms of the GNU General Public License as published by  *
   9 *   the Free Software Foundation, version 2 of the License.               *
  10 *                                                                         *
  11 *   This driver is distributed in the hope that it will be useful, but    *
  12 *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
  13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
  14 *   General Public License for more details.                              *
  15 *                                                                         *
  16 *   You should have received a copy of the GNU General Public License     *
  17 *   along with this software. If not see <http://www.gnu.org/licenses/>.  *
  18 ***************************************************************************/
  19
  20#include <linux/hid.h>
  21#include "usbhid/usbhid.h"
  22#include <linux/usb.h>
  23
  24#include <linux/fb.h>
  25#include <linux/lcd.h>
  26
  27#include "hid-picolcd.h"
  28
  29/*
  30 * lcd class device
  31 */
  32static int picolcd_get_contrast(struct lcd_device *ldev)
  33{
  34        struct picolcd_data *data = lcd_get_data(ldev);
  35        return data->lcd_contrast;
  36}
  37
  38static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
  39{
  40        struct picolcd_data *data = lcd_get_data(ldev);
  41        struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
  42        unsigned long flags;
  43
  44        if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
  45                return -ENODEV;
  46
  47        data->lcd_contrast = contrast & 0x0ff;
  48        spin_lock_irqsave(&data->lock, flags);
  49        hid_set_field(report->field[0], 0, data->lcd_contrast);
  50        if (!(data->status & PICOLCD_FAILED))
  51                usbhid_submit_report(data->hdev, report, USB_DIR_OUT);
  52        spin_unlock_irqrestore(&data->lock, flags);
  53        return 0;
  54}
  55
  56static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
  57{
  58        return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
  59}
  60
  61static struct lcd_ops picolcd_lcdops = {
  62        .get_contrast   = picolcd_get_contrast,
  63        .set_contrast   = picolcd_set_contrast,
  64        .check_fb       = picolcd_check_lcd_fb,
  65};
  66
  67int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
  68{
  69        struct device *dev = &data->hdev->dev;
  70        struct lcd_device *ldev;
  71
  72        if (!report)
  73                return -ENODEV;
  74        if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
  75                        report->field[0]->report_size != 8) {
  76                dev_err(dev, "unsupported CONTRAST report");
  77                return -EINVAL;
  78        }
  79
  80        ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
  81        if (IS_ERR(ldev)) {
  82                dev_err(dev, "failed to register LCD\n");
  83                return PTR_ERR(ldev);
  84        }
  85        ldev->props.max_contrast = 0x0ff;
  86        data->lcd_contrast = 0xe5;
  87        data->lcd = ldev;
  88        picolcd_set_contrast(ldev, 0xe5);
  89        return 0;
  90}
  91
  92void picolcd_exit_lcd(struct picolcd_data *data)
  93{
  94        struct lcd_device *ldev = data->lcd;
  95
  96        data->lcd = NULL;
  97        if (ldev)
  98                lcd_device_unregister(ldev);
  99}
 100
 101int picolcd_resume_lcd(struct picolcd_data *data)
 102{
 103        if (!data->lcd)
 104                return 0;
 105        return picolcd_set_contrast(data->lcd, data->lcd_contrast);
 106}
 107
 108
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