1 // SPDX-License-Identifier: GPL-2.0+ 2 3 /* 4 * LCD Backlight driver for RAVE SP 5 * 6 * Copyright (C) 2018 Zodiac Inflight Innovations 7 * 8 */ 9 10 #include <linux/backlight.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/mfd/rave-sp.h> 14 #include <linux/platform_device.h> 15 16 #define RAVE_SP_BACKLIGHT_LCD_EN BIT(7) 17 18 static int rave_sp_backlight_update_status(struct backlight_device *bd) 19 { 20 const struct backlight_properties *p = &bd->props; 21 const u8 intensity = 22 (p->power == FB_BLANK_UNBLANK) ? p->brightness : 0; 23 struct rave_sp *sp = dev_get_drvdata(&bd->dev); 24 u8 cmd[] = { 25 [0] = RAVE_SP_CMD_SET_BACKLIGHT, 26 [1] = 0, 27 [2] = intensity ? RAVE_SP_BACKLIGHT_LCD_EN | intensity : 0, 28 [3] = 0, 29 [4] = 0, 30 }; 31 32 return rave_sp_exec(sp, cmd, sizeof(cmd), NULL, 0); 33 } 34 35 static const struct backlight_ops rave_sp_backlight_ops = { 36 .options = BL_CORE_SUSPENDRESUME, 37 .update_status = rave_sp_backlight_update_status, 38 }; 39 40 static struct backlight_properties rave_sp_backlight_props = { 41 .type = BACKLIGHT_PLATFORM, 42 .max_brightness = 100, 43 .brightness = 50, 44 }; 45 46 static int rave_sp_backlight_probe(struct platform_device *pdev) 47 { 48 struct device *dev = &pdev->dev; 49 struct backlight_device *bd; 50 51 bd = devm_backlight_device_register(dev, pdev->name, dev->parent, 52 dev_get_drvdata(dev->parent), 53 &rave_sp_backlight_ops, 54 &rave_sp_backlight_props); 55 if (IS_ERR(bd)) 56 return PTR_ERR(bd); 57 58 backlight_update_status(bd); 59 60 return 0; 61 } 62 63 static const struct of_device_id rave_sp_backlight_of_match[] = { 64 { .compatible = "zii,rave-sp-backlight" }, 65 {} 66 }; 67 68 static struct platform_driver rave_sp_backlight_driver = { 69 .probe = rave_sp_backlight_probe, 70 .driver = { 71 .name = KBUILD_MODNAME, 72 .of_match_table = rave_sp_backlight_of_match, 73 }, 74 }; 75 module_platform_driver(rave_sp_backlight_driver); 76 77 MODULE_DEVICE_TABLE(of, rave_sp_backlight_of_match); 78 MODULE_LICENSE("GPL"); 79 MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>"); 80 MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>"); 81 MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>"); 82 MODULE_DESCRIPTION("RAVE SP Backlight driver"); 83