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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leds-ariel.c (3100B)

      1// SPDX-License-Identifier: BSD-2-Clause OR GPL-2.0-or-later
      2/*
      3 * Dell Wyse 3020 a.k.a. "Ariel" Embedded Controller LED Driver
      4 *
      5 * Copyright (C) 2020 Lubomir Rintel
      6 */
      7
      8#include <linux/module.h>
      9#include <linux/leds.h>
     10#include <linux/regmap.h>
     11#include <linux/of_platform.h>
     12
     13enum ec_index {
     14	EC_BLUE_LED	= 0x01,
     15	EC_AMBER_LED	= 0x02,
     16	EC_GREEN_LED	= 0x03,
     17};
     18
     19enum {
     20	EC_LED_OFF	= 0x00,
     21	EC_LED_STILL	= 0x01,
     22	EC_LED_FADE	= 0x02,
     23	EC_LED_BLINK	= 0x03,
     24};
     25
     26struct ariel_led {
     27	struct regmap *ec_ram;
     28	enum ec_index ec_index;
     29	struct led_classdev led_cdev;
     30};
     31
     32#define led_cdev_to_ariel_led(c) container_of(c, struct ariel_led, led_cdev)
     33
     34static enum led_brightness ariel_led_get(struct led_classdev *led_cdev)
     35{
     36	struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
     37	unsigned int led_status = 0;
     38
     39	if (regmap_read(led->ec_ram, led->ec_index, &led_status))
     40		return LED_OFF;
     41
     42	if (led_status == EC_LED_STILL)
     43		return LED_FULL;
     44	else
     45		return LED_OFF;
     46}
     47
     48static void ariel_led_set(struct led_classdev *led_cdev,
     49			  enum led_brightness brightness)
     50{
     51	struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
     52
     53	if (brightness == LED_OFF)
     54		regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
     55	else
     56		regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
     57}
     58
     59static int ariel_blink_set(struct led_classdev *led_cdev,
     60			   unsigned long *delay_on, unsigned long *delay_off)
     61{
     62	struct ariel_led *led = led_cdev_to_ariel_led(led_cdev);
     63
     64	if (*delay_on == 0 && *delay_off == 0)
     65		return -EINVAL;
     66
     67	if (*delay_on == 0) {
     68		regmap_write(led->ec_ram, led->ec_index, EC_LED_OFF);
     69	} else if (*delay_off == 0) {
     70		regmap_write(led->ec_ram, led->ec_index, EC_LED_STILL);
     71	} else {
     72		*delay_on = 500;
     73		*delay_off = 500;
     74		regmap_write(led->ec_ram, led->ec_index, EC_LED_BLINK);
     75	}
     76
     77	return 0;
     78}
     79
     80#define NLEDS 3
     81
     82static int ariel_led_probe(struct platform_device *pdev)
     83{
     84	struct device *dev = &pdev->dev;
     85	struct ariel_led *leds;
     86	struct regmap *ec_ram;
     87	int ret;
     88	int i;
     89
     90	ec_ram = dev_get_regmap(dev->parent, "ec_ram");
     91	if (!ec_ram)
     92		return -ENODEV;
     93
     94	leds = devm_kcalloc(dev, NLEDS, sizeof(*leds), GFP_KERNEL);
     95	if (!leds)
     96		return -ENOMEM;
     97
     98	leds[0].ec_index = EC_BLUE_LED;
     99	leds[0].led_cdev.name = "blue:power";
    100	leds[0].led_cdev.default_trigger = "default-on";
    101
    102	leds[1].ec_index = EC_AMBER_LED;
    103	leds[1].led_cdev.name = "amber:status";
    104
    105	leds[2].ec_index = EC_GREEN_LED;
    106	leds[2].led_cdev.name = "green:status";
    107	leds[2].led_cdev.default_trigger = "default-on";
    108
    109	for (i = 0; i < NLEDS; i++) {
    110		leds[i].ec_ram = ec_ram;
    111		leds[i].led_cdev.brightness_get = ariel_led_get;
    112		leds[i].led_cdev.brightness_set = ariel_led_set;
    113		leds[i].led_cdev.blink_set = ariel_blink_set;
    114
    115		ret = devm_led_classdev_register(dev, &leds[i].led_cdev);
    116		if (ret)
    117			return ret;
    118	}
    119
    120	return 0;
    121}
    122
    123static struct platform_driver ariel_led_driver = {
    124	.probe = ariel_led_probe,
    125	.driver = {
    126		.name = "dell-wyse-ariel-led",
    127	},
    128};
    129module_platform_driver(ariel_led_driver);
    130
    131MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
    132MODULE_DESCRIPTION("Dell Wyse 3020 Status LEDs Driver");
    133MODULE_LICENSE("Dual BSD/GPL");