platform_lcd.c

  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
 17struct 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
 26static inline struct platform_lcd *to_our_lcd(struct lcd_device *lcd)
 27{
 28	return lcd_get_data(lcd);
 29}
 30
 31static 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
 38static 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
 52static 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
 59static 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
 65static 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(&pdev->dev, sizeof(struct platform_lcd),
 85			    GFP_KERNEL);
 86	if (!plcd)
 87		return -ENOMEM;
 88
 89	plcd->us = dev;
 90	plcd->pdata = pdata;
 91	plcd->lcd = devm_lcd_device_register(&pdev->dev, dev_name(dev), dev,
 92						plcd, &platform_lcd_ops);
 93	if (IS_ERR(plcd->lcd)) {
 94		dev_err(dev, "cannot register lcd device\n");
 95		return PTR_ERR(plcd->lcd);
 96	}
 97
 98	platform_set_drvdata(pdev, plcd);
 99	platform_lcd_set_power(plcd->lcd, LCD_POWER_REDUCED);
100
101	return 0;
102}
103
104#ifdef CONFIG_PM_SLEEP
105static int platform_lcd_suspend(struct device *dev)
106{
107	struct platform_lcd *plcd = dev_get_drvdata(dev);
108
109	plcd->suspended = 1;
110	platform_lcd_set_power(plcd->lcd, plcd->power);
111
112	return 0;
113}
114
115static int platform_lcd_resume(struct device *dev)
116{
117	struct platform_lcd *plcd = dev_get_drvdata(dev);
118
119	plcd->suspended = 0;
120	platform_lcd_set_power(plcd->lcd, plcd->power);
121
122	return 0;
123}
124#endif
125
126static SIMPLE_DEV_PM_OPS(platform_lcd_pm_ops, platform_lcd_suspend,
127			platform_lcd_resume);
128
129static struct platform_driver platform_lcd_driver = {
130	.driver		= {
131		.name	= "platform-lcd",
132		.pm	= &platform_lcd_pm_ops,
133	},
134	.probe		= platform_lcd_probe,
135};
136
137module_platform_driver(platform_lcd_driver);
138
139MODULE_AUTHOR("Ben Dooks <ben-linux@fluff.org>");
140MODULE_DESCRIPTION("Generic platform-device LCD power control interface");
141MODULE_LICENSE("GPL v2");
142MODULE_ALIAS("platform:platform-lcd");