1 // SPDX-License-Identifier: GPL-2.0-only 2 /*************************************************************************** 3 * Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org> * 4 * * 5 * Based on Logitech G13 driver (v0.4) * 6 * Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu> * 7 * * 8 ***************************************************************************/ 9 10 #include <linux/hid.h> 11 12 #include <linux/fb.h> 13 #include <linux/lcd.h> 14 15 #include "hid-picolcd.h" 16 17 /* 18 * lcd class device 19 */ 20 static int picolcd_get_contrast(struct lcd_device *ldev) 21 { 22 struct picolcd_data *data = lcd_get_data(ldev); 23 return data->lcd_contrast; 24 } 25 26 static int picolcd_set_contrast(struct lcd_device *ldev, int contrast) 27 { 28 struct picolcd_data *data = lcd_get_data(ldev); 29 struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev); 30 unsigned long flags; 31 32 if (!report || report->maxfield != 1 || report->field[0]->report_count != 1) 33 return -ENODEV; 34 35 data->lcd_contrast = contrast & 0x0ff; 36 spin_lock_irqsave(&data->lock, flags); 37 hid_set_field(report->field[0], 0, data->lcd_contrast); 38 if (!(data->status & PICOLCD_FAILED)) 39 hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT); 40 spin_unlock_irqrestore(&data->lock, flags); 41 return 0; 42 } 43 44 static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb) 45 { 46 return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev)); 47 } 48 49 static struct lcd_ops picolcd_lcdops = { 50 .get_contrast = picolcd_get_contrast, 51 .set_contrast = picolcd_set_contrast, 52 .check_fb = picolcd_check_lcd_fb, 53 }; 54 55 int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report) 56 { 57 struct device *dev = &data->hdev->dev; 58 struct lcd_device *ldev; 59 60 if (!report) 61 return -ENODEV; 62 if (report->maxfield != 1 || report->field[0]->report_count != 1 || 63 report->field[0]->report_size != 8) { 64 dev_err(dev, "unsupported CONTRAST report"); 65 return -EINVAL; 66 } 67 68 ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops); 69 if (IS_ERR(ldev)) { 70 dev_err(dev, "failed to register LCD\n"); 71 return PTR_ERR(ldev); 72 } 73 ldev->props.max_contrast = 0x0ff; 74 data->lcd_contrast = 0xe5; 75 data->lcd = ldev; 76 picolcd_set_contrast(ldev, 0xe5); 77 return 0; 78 } 79 80 void picolcd_exit_lcd(struct picolcd_data *data) 81 { 82 struct lcd_device *ldev = data->lcd; 83 84 data->lcd = NULL; 85 lcd_device_unregister(ldev); 86 } 87 88 int picolcd_resume_lcd(struct picolcd_data *data) 89 { 90 if (!data->lcd) 91 return 0; 92 return picolcd_set_contrast(data->lcd, data->lcd_contrast); 93 } 94 95