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/backlight.h> 26 27 #include "hid-picolcd.h" 28 29 static int picolcd_get_brightness(struct backlight_device *bdev) 30 { 31 struct picolcd_data *data = bl_get_data(bdev); 32 return data->lcd_brightness; 33 } 34 35 static int picolcd_set_brightness(struct backlight_device *bdev) 36 { 37 struct picolcd_data *data = bl_get_data(bdev); 38 struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev); 39 unsigned long flags; 40 41 if (!report || report->maxfield != 1 || report->field[0]->report_count != 1) 42 return -ENODEV; 43 44 data->lcd_brightness = bdev->props.brightness & 0x0ff; 45 data->lcd_power = bdev->props.power; 46 spin_lock_irqsave(&data->lock, flags); 47 hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0); 48 if (!(data->status & PICOLCD_FAILED)) 49 usbhid_submit_report(data->hdev, report, USB_DIR_OUT); 50 spin_unlock_irqrestore(&data->lock, flags); 51 return 0; 52 } 53 54 static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb) 55 { 56 return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev)); 57 } 58 59 static const struct backlight_ops picolcd_blops = { 60 .update_status = picolcd_set_brightness, 61 .get_brightness = picolcd_get_brightness, 62 .check_fb = picolcd_check_bl_fb, 63 }; 64 65 int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report) 66 { 67 struct device *dev = &data->hdev->dev; 68 struct backlight_device *bdev; 69 struct backlight_properties props; 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 BRIGHTNESS report"); 75 return -EINVAL; 76 } 77 78 memset(&props, 0, sizeof(props)); 79 props.type = BACKLIGHT_RAW; 80 props.max_brightness = 0xff; 81 bdev = backlight_device_register(dev_name(dev), dev, data, 82 &picolcd_blops, &props); 83 if (IS_ERR(bdev)) { 84 dev_err(dev, "failed to register backlight\n"); 85 return PTR_ERR(bdev); 86 } 87 bdev->props.brightness = 0xff; 88 data->lcd_brightness = 0xff; 89 data->backlight = bdev; 90 picolcd_set_brightness(bdev); 91 return 0; 92 } 93 94 void picolcd_exit_backlight(struct picolcd_data *data) 95 { 96 struct backlight_device *bdev = data->backlight; 97 98 data->backlight = NULL; 99 if (bdev) 100 backlight_device_unregister(bdev); 101 } 102 103 int picolcd_resume_backlight(struct picolcd_data *data) 104 { 105 if (!data->backlight) 106 return 0; 107 return picolcd_set_brightness(data->backlight); 108 } 109 110 #ifdef CONFIG_PM 111 void picolcd_suspend_backlight(struct picolcd_data *data) 112 { 113 int bl_power = data->lcd_power; 114 if (!data->backlight) 115 return; 116 117 data->backlight->props.power = FB_BLANK_POWERDOWN; 118 picolcd_set_brightness(data->backlight); 119 data->lcd_power = data->backlight->props.power = bl_power; 120 } 121 #endif /* CONFIG_PM */ 122 123