drivers/hid/hid-picolcd_lcd.c

   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  */
  32 static 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
  38 static 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
  56 static 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
  61 static 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
  67 int 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
  92 void 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
 101 int 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