cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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rave-sp-backlight.c (2368B)

      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
     18static 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
     35static const struct backlight_ops rave_sp_backlight_ops = {
     36	.options	= BL_CORE_SUSPENDRESUME,
     37	.update_status	= rave_sp_backlight_update_status,
     38};
     39
     40static struct backlight_properties rave_sp_backlight_props = {
     41	.type		= BACKLIGHT_PLATFORM,
     42	.max_brightness = 100,
     43	.brightness	= 50,
     44};
     45
     46static 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,
     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	/*
     59	 * If there is a phandle pointing to the device node we can
     60	 * assume that another device will manage the status changes.
     61	 * If not we make sure the backlight is in a consistent state.
     62	 */
     63	if (!dev->of_node->phandle)
     64		backlight_update_status(bd);
     65
     66	return 0;
     67}
     68
     69static const struct of_device_id rave_sp_backlight_of_match[] = {
     70	{ .compatible = "zii,rave-sp-backlight" },
     71	{}
     72};
     73
     74static struct platform_driver rave_sp_backlight_driver = {
     75	.probe = rave_sp_backlight_probe,
     76	.driver	= {
     77		.name = KBUILD_MODNAME,
     78		.of_match_table = rave_sp_backlight_of_match,
     79	},
     80};
     81module_platform_driver(rave_sp_backlight_driver);
     82
     83MODULE_DEVICE_TABLE(of, rave_sp_backlight_of_match);
     84MODULE_LICENSE("GPL");
     85MODULE_AUTHOR("Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>");
     86MODULE_AUTHOR("Nikita Yushchenko <nikita.yoush@cogentembedded.com>");
     87MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>");
     88MODULE_DESCRIPTION("RAVE SP Backlight driver");