LXR linux/drivers/hid/hid-picolcd

   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
  22#include <linux/fb.h>
  23#include <linux/lcd.h>
  24
  25#include "hid-picolcd.h"
  26
  27/*
  28 * lcd class device
  29 */
  30static int picolcd_get_contrast(struct lcd_device *ldev)
  31{
  32        struct picolcd_data *data = lcd_get_data(ldev);
  33        return data->lcd_contrast;
  34}
  35
  36static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
  37{
  38        struct picolcd_data *data = lcd_get_data(ldev);
  39        struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
  40        unsigned long flags;
  41
  42        if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
  43                return -ENODEV;
  44
  45        data->lcd_contrast = contrast & 0x0ff;
  46        spin_lock_irqsave(&data->lock, flags);
  47        hid_set_field(report->field[0], 0, data->lcd_contrast);
  48        if (!(data->status & PICOLCD_FAILED))
  49                hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
  50        spin_unlock_irqrestore(&data->lock, flags);
  51        return 0;
  52}
  53
  54static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
  55{
  56        return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
  57}
  58
  59static struct lcd_ops picolcd_lcdops = {
  60        .get_contrast   = picolcd_get_contrast,
  61        .set_contrast   = picolcd_set_contrast,
  62        .check_fb       = picolcd_check_lcd_fb,
  63};
  64
  65int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
  66{
  67        struct device *dev = &data->hdev->dev;
  68        struct lcd_device *ldev;
  69
  70        if (!report)
  71                return -ENODEV;
  72        if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
  73                        report->field[0]->report_size != 8) {
  74                dev_err(dev, "unsupported CONTRAST report");
  75                return -EINVAL;
  76        }
  77
  78        ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
  79        if (IS_ERR(ldev)) {
  80                dev_err(dev, "failed to register LCD\n");
  81                return PTR_ERR(ldev);
  82        }
  83        ldev->props.max_contrast = 0x0ff;
  84        data->lcd_contrast = 0xe5;
  85        data->lcd = ldev;
  86        picolcd_set_contrast(ldev, 0xe5);
  87        return 0;
  88}
  89
  90void picolcd_exit_lcd(struct picolcd_data *data)
  91{
  92        struct lcd_device *ldev = data->lcd;
  93
  94        data->lcd = NULL;
  95        if (ldev)
  96                lcd_device_unregister(ldev);
  97}
  98
  99int picolcd_resume_lcd(struct picolcd_data *data)
 100{
 101        if (!data->lcd)
 102                return 0;
 103        return picolcd_set_contrast(data->lcd, data->lcd_contrast);
 104}
 105
 106