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 const struct lcd_ops picolcd_lcdops = { 45 .get_contrast = picolcd_get_contrast, 46 .set_contrast = picolcd_set_contrast, 47 }; 48 49 int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report) 50 { 51 struct device *dev = &data->hdev->dev; 52 struct lcd_device *ldev; 53 54 if (!report) 55 return -ENODEV; 56 if (report->maxfield != 1 || report->field[0]->report_count != 1 || 57 report->field[0]->report_size != 8) { 58 dev_err(dev, "unsupported CONTRAST report"); 59 return -EINVAL; 60 } 61 62 ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops); 63 if (IS_ERR(ldev)) { 64 dev_err(dev, "failed to register LCD\n"); 65 return PTR_ERR(ldev); 66 } 67 ldev->props.max_contrast = 0x0ff; 68 data->lcd_contrast = 0xe5; 69 data->lcd = ldev; 70 picolcd_set_contrast(ldev, 0xe5); 71 return 0; 72 } 73 74 void picolcd_exit_lcd(struct picolcd_data *data) 75 { 76 struct lcd_device *ldev = data->lcd; 77 78 data->lcd = NULL; 79 lcd_device_unregister(ldev); 80 } 81 82 int picolcd_resume_lcd(struct picolcd_data *data) 83 { 84 if (!data->lcd) 85 return 0; 86 return picolcd_set_contrast(data->lcd, data->lcd_contrast); 87 } 88 89