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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ipaq_micro_bl.c (2033B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *
      4 * iPAQ microcontroller backlight support
      5 * Author : Linus Walleij <linus.walleij@linaro.org>
      6 */
      7
      8#include <linux/backlight.h>
      9#include <linux/err.h>
     10#include <linux/fb.h>
     11#include <linux/init.h>
     12#include <linux/mfd/ipaq-micro.h>
     13#include <linux/module.h>
     14#include <linux/platform_device.h>
     15
     16static int micro_bl_update_status(struct backlight_device *bd)
     17{
     18	struct ipaq_micro *micro = dev_get_drvdata(&bd->dev);
     19	int intensity = bd->props.brightness;
     20	struct ipaq_micro_msg msg = {
     21		.id = MSG_BACKLIGHT,
     22		.tx_len = 3,
     23	};
     24
     25	if (bd->props.power != FB_BLANK_UNBLANK)
     26		intensity = 0;
     27	if (bd->props.state & (BL_CORE_FBBLANK | BL_CORE_SUSPENDED))
     28		intensity = 0;
     29
     30	/*
     31	 * Message format:
     32	 * Byte 0: backlight instance (usually 1)
     33	 * Byte 1: on/off
     34	 * Byte 2: intensity, 0-255
     35	 */
     36	msg.tx_data[0] = 0x01;
     37	msg.tx_data[1] = intensity > 0 ? 1 : 0;
     38	msg.tx_data[2] = intensity;
     39	return ipaq_micro_tx_msg_sync(micro, &msg);
     40}
     41
     42static const struct backlight_ops micro_bl_ops = {
     43	.options = BL_CORE_SUSPENDRESUME,
     44	.update_status  = micro_bl_update_status,
     45};
     46
     47static const struct backlight_properties micro_bl_props = {
     48	.type = BACKLIGHT_RAW,
     49	.max_brightness = 255,
     50	.power = FB_BLANK_UNBLANK,
     51	.brightness = 64,
     52};
     53
     54static int micro_backlight_probe(struct platform_device *pdev)
     55{
     56	struct backlight_device *bd;
     57	struct ipaq_micro *micro = dev_get_drvdata(pdev->dev.parent);
     58
     59	bd = devm_backlight_device_register(&pdev->dev, "ipaq-micro-backlight",
     60					    &pdev->dev, micro, &micro_bl_ops,
     61					    &micro_bl_props);
     62	if (IS_ERR(bd))
     63		return PTR_ERR(bd);
     64
     65	platform_set_drvdata(pdev, bd);
     66	backlight_update_status(bd);
     67
     68	return 0;
     69}
     70
     71static struct platform_driver micro_backlight_device_driver = {
     72	.driver = {
     73		.name    = "ipaq-micro-backlight",
     74	},
     75	.probe   = micro_backlight_probe,
     76};
     77module_platform_driver(micro_backlight_device_driver);
     78
     79MODULE_LICENSE("GPL v2");
     80MODULE_DESCRIPTION("driver for iPAQ Atmel micro backlight");
     81MODULE_ALIAS("platform:ipaq-micro-backlight");