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/backlight.h> 24 25 #include "hid-picolcd.h" 26 27 static int picolcd_get_brightness(struct backlight_device *bdev) 28 { 29 struct picolcd_data *data = bl_get_data(bdev); 30 return data->lcd_brightness; 31 } 32 33 static int picolcd_set_brightness(struct backlight_device *bdev) 34 { 35 struct picolcd_data *data = bl_get_data(bdev); 36 struct hid_report *report = picolcd_out_report(REPORT_BRIGHTNESS, data->hdev); 37 unsigned long flags; 38 39 if (!report || report->maxfield != 1 || report->field[0]->report_count != 1) 40 return -ENODEV; 41 42 data->lcd_brightness = bdev->props.brightness & 0x0ff; 43 data->lcd_power = bdev->props.power; 44 spin_lock_irqsave(&data->lock, flags); 45 hid_set_field(report->field[0], 0, data->lcd_power == FB_BLANK_UNBLANK ? data->lcd_brightness : 0); 46 if (!(data->status & PICOLCD_FAILED)) 47 hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT); 48 spin_unlock_irqrestore(&data->lock, flags); 49 return 0; 50 } 51 52 static int picolcd_check_bl_fb(struct backlight_device *bdev, struct fb_info *fb) 53 { 54 return fb && fb == picolcd_fbinfo((struct picolcd_data *)bl_get_data(bdev)); 55 } 56 57 static const struct backlight_ops picolcd_blops = { 58 .update_status = picolcd_set_brightness, 59 .get_brightness = picolcd_get_brightness, 60 .check_fb = picolcd_check_bl_fb, 61 }; 62 63 int picolcd_init_backlight(struct picolcd_data *data, struct hid_report *report) 64 { 65 struct device *dev = &data->hdev->dev; 66 struct backlight_device *bdev; 67 struct backlight_properties props; 68 if (!report) 69 return -ENODEV; 70 if (report->maxfield != 1 || report->field[0]->report_count != 1 || 71 report->field[0]->report_size != 8) { 72 dev_err(dev, "unsupported BRIGHTNESS report"); 73 return -EINVAL; 74 } 75 76 memset(&props, 0, sizeof(props)); 77 props.type = BACKLIGHT_RAW; 78 props.max_brightness = 0xff; 79 bdev = backlight_device_register(dev_name(dev), dev, data, 80 &picolcd_blops, &props); 81 if (IS_ERR(bdev)) { 82 dev_err(dev, "failed to register backlight\n"); 83 return PTR_ERR(bdev); 84 } 85 bdev->props.brightness = 0xff; 86 data->lcd_brightness = 0xff; 87 data->backlight = bdev; 88 picolcd_set_brightness(bdev); 89 return 0; 90 } 91 92 void picolcd_exit_backlight(struct picolcd_data *data) 93 { 94 struct backlight_device *bdev = data->backlight; 95 96 data->backlight = NULL; 97 if (bdev) 98 backlight_device_unregister(bdev); 99 } 100 101 int picolcd_resume_backlight(struct picolcd_data *data) 102 { 103 if (!data->backlight) 104 return 0; 105 return picolcd_set_brightness(data->backlight); 106 } 107 108 #ifdef CONFIG_PM 109 void picolcd_suspend_backlight(struct picolcd_data *data) 110 { 111 int bl_power = data->lcd_power; 112 if (!data->backlight) 113 return; 114 115 data->backlight->props.power = FB_BLANK_POWERDOWN; 116 picolcd_set_brightness(data->backlight); 117 data->lcd_power = data->backlight->props.power = bl_power; 118 } 119 #endif /* CONFIG_PM */ 120 121