1 // SPDX-License-Identifier: GPL-2.0-only 2 /* drivers/video/backlight/platform_lcd.c 3 * 4 * Copyright 2008 Simtec Electronics 5 * Ben Dooks <ben@simtec.co.uk> 6 * 7 * Generic platform-device LCD power control interface. 8 */ 9 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/lcd.h> 13 #include <linux/slab.h> 14 15 #include <video/platform_lcd.h> 16 17 struct platform_lcd { 18 struct device *us; 19 struct lcd_device *lcd; 20 struct plat_lcd_data *pdata; 21 22 unsigned int power; 23 unsigned int suspended:1; 24 }; 25 26 static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd) 27 { 28 return lcd_get_data(lcd); 29 } 30 31 static int platform_lcd_get_power(struct lcd_device *lcd) 32 { 33 struct platform_lcd *plcd = to_our_lcd(lcd); 34 35 return plcd->power; 36 } 37 38 static int platform_lcd_set_power(struct lcd_device *lcd, int power) 39 { 40 struct platform_lcd *plcd = to_our_lcd(lcd); 41 int lcd_power = 1; 42 43 if (power == LCD_POWER_OFF || plcd->suspended) 44 lcd_power = 0; 45 46 plcd->pdata->set_power(plcd->pdata, lcd_power); 47 plcd->power = power; 48 49 return 0; 50 } 51 52 static bool platform_lcd_controls_device(struct lcd_device *lcd, struct device *display_device) 53 { 54 struct platform_lcd *plcd = to_our_lcd(lcd); 55 56 return plcd->us->parent == display_device; 57 } 58 59 static const struct lcd_ops platform_lcd_ops = { 60 .get_power = platform_lcd_get_power, 61 .set_power = platform_lcd_set_power, 62 .controls_device = platform_lcd_controls_device, 63 }; 64 65 static int platform_lcd_probe(struct platform_device *pdev) 66 { 67 struct plat_lcd_data *pdata; 68 struct platform_lcd *plcd; 69 struct device *dev = &pdev->dev; 70 int err; 71 72 pdata = dev_get_platdata(&pdev->dev); 73 if (!pdata) { 74 dev_err(dev, "no platform data supplied\n"); 75 return -EINVAL; 76 } 77 78 if (pdata->probe) { 79 err = pdata->probe(pdata); 80 if (err) 81 return err; 82 } 83 84 plcd = devm_kzalloc_obj(&pdev->dev, struct platform_lcd); 85 if (!plcd) 86 return -ENOMEM; 87 88 plcd->us = dev; 89 plcd->pdata = pdata; 90 plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev, 91 plcd, &platform_lcd_ops); 92 if (IS_ERR(plcd->lcd)) { 93 dev_err(dev, "cannot register lcd device\n"); 94 return PTR_ERR(plcd->lcd); 95 } 96 97 platform_set_drvdata(pdev, plcd); 98 platform_lcd_set_power(plcd->lcd, LCD_POWER_REDUCED); 99 100 return 0; 101 } 102 103 #ifdef CONFIG_PM_SLEEP 104 static int platform_lcd_suspend(struct device *dev) 105 { 106 struct platform_lcd *plcd = dev_get_drvdata(dev); 107 108 plcd->suspended = 1; 109 platform_lcd_set_power(plcd->lcd, plcd->power); 110 111 return 0; 112 } 113 114 static int platform_lcd_resume(struct device *dev) 115 { 116 struct platform_lcd *plcd = dev_get_drvdata(dev); 117 118 plcd->suspended = 0; 119 platform_lcd_set_power(plcd->lcd, plcd->power); 120 121 return 0; 122 } 123 #endif 124 125 static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend, 126 platform_lcd_resume); 127 128 static struct platform_driver platform_lcd_driver = { 129 .driver = { 130 .name = "platform-lcd", 131 .pm = &platform_lcd_pm_ops, 132 }, 133 .probe = platform_lcd_probe, 134 }; 135 136 module_platform_driver(platform_lcd_driver); 137 138 MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>"); 139 MODULE_DESCRIPTION("Generic platform-device LCD power control interface"); 140 MODULE_LICENSE("GPL v2"); 141 MODULE_ALIAS("platform:platform-lcd"); 142