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-asic3.c (4487B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 *  Copyright (C) 2011 Paul Parsons <lost.distance@yahoo.com>
      4 */
      5
      6#include <linux/kernel.h>
      7#include <linux/platform_device.h>
      8#include <linux/leds.h>
      9#include <linux/slab.h>
     10
     11#include <linux/mfd/asic3.h>
     12#include <linux/mfd/core.h>
     13#include <linux/module.h>
     14
     15/*
     16 *	The HTC ASIC3 LED GPIOs are inputs, not outputs.
     17 *	Hence we turn the LEDs on/off via the TimeBase register.
     18 */
     19
     20/*
     21 *	When TimeBase is 4 the clock resolution is about 32Hz.
     22 *	This driver supports hardware blinking with an on+off
     23 *	period from 62ms (2 clocks) to 125s (4000 clocks).
     24 */
     25#define MS_TO_CLK(ms)	DIV_ROUND_CLOSEST(((ms)*1024), 32000)
     26#define CLK_TO_MS(clk)	(((clk)*32000)/1024)
     27#define MAX_CLK		4000            /* Fits into 12-bit Time registers */
     28#define MAX_MS		CLK_TO_MS(MAX_CLK)
     29
     30static const unsigned int led_n_base[ASIC3_NUM_LEDS] = {
     31	[0] = ASIC3_LED_0_Base,
     32	[1] = ASIC3_LED_1_Base,
     33	[2] = ASIC3_LED_2_Base,
     34};
     35
     36static void brightness_set(struct led_classdev *cdev,
     37	enum led_brightness value)
     38{
     39	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
     40	const struct mfd_cell *cell = mfd_get_cell(pdev);
     41	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
     42	u32 timebase;
     43	unsigned int base;
     44
     45	timebase = (value == LED_OFF) ? 0 : (LED_EN|0x4);
     46
     47	base = led_n_base[cell->id];
     48	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), 32);
     49	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), 32);
     50	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
     51	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), timebase);
     52}
     53
     54static int blink_set(struct led_classdev *cdev,
     55	unsigned long *delay_on,
     56	unsigned long *delay_off)
     57{
     58	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
     59	const struct mfd_cell *cell = mfd_get_cell(pdev);
     60	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
     61	u32 on;
     62	u32 off;
     63	unsigned int base;
     64
     65	if (*delay_on > MAX_MS || *delay_off > MAX_MS)
     66		return -EINVAL;
     67
     68	if (*delay_on == 0 && *delay_off == 0) {
     69		/* If both are zero then a sensible default should be chosen */
     70		on = MS_TO_CLK(500);
     71		off = MS_TO_CLK(500);
     72	} else {
     73		on = MS_TO_CLK(*delay_on);
     74		off = MS_TO_CLK(*delay_off);
     75		if ((on + off) > MAX_CLK)
     76			return -EINVAL;
     77	}
     78
     79	base = led_n_base[cell->id];
     80	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), (on + off));
     81	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), on);
     82	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
     83	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), (LED_EN|0x4));
     84
     85	*delay_on = CLK_TO_MS(on);
     86	*delay_off = CLK_TO_MS(off);
     87
     88	return 0;
     89}
     90
     91static int asic3_led_probe(struct platform_device *pdev)
     92{
     93	struct asic3_led *led = dev_get_platdata(&pdev->dev);
     94	int ret;
     95
     96	ret = mfd_cell_enable(pdev);
     97	if (ret < 0)
     98		return ret;
     99
    100	led->cdev = devm_kzalloc(&pdev->dev, sizeof(struct led_classdev),
    101				GFP_KERNEL);
    102	if (!led->cdev) {
    103		ret = -ENOMEM;
    104		goto out;
    105	}
    106
    107	led->cdev->name = led->name;
    108	led->cdev->flags = LED_CORE_SUSPENDRESUME;
    109	led->cdev->brightness_set = brightness_set;
    110	led->cdev->blink_set = blink_set;
    111	led->cdev->default_trigger = led->default_trigger;
    112
    113	ret = led_classdev_register(&pdev->dev, led->cdev);
    114	if (ret < 0)
    115		goto out;
    116
    117	return 0;
    118
    119out:
    120	(void) mfd_cell_disable(pdev);
    121	return ret;
    122}
    123
    124static int asic3_led_remove(struct platform_device *pdev)
    125{
    126	struct asic3_led *led = dev_get_platdata(&pdev->dev);
    127
    128	led_classdev_unregister(led->cdev);
    129
    130	return mfd_cell_disable(pdev);
    131}
    132
    133#ifdef CONFIG_PM_SLEEP
    134static int asic3_led_suspend(struct device *dev)
    135{
    136	struct platform_device *pdev = to_platform_device(dev);
    137	const struct mfd_cell *cell = mfd_get_cell(pdev);
    138	int ret;
    139
    140	ret = 0;
    141	if (cell->suspend)
    142		ret = (*cell->suspend)(pdev);
    143
    144	return ret;
    145}
    146
    147static int asic3_led_resume(struct device *dev)
    148{
    149	struct platform_device *pdev = to_platform_device(dev);
    150	const struct mfd_cell *cell = mfd_get_cell(pdev);
    151	int ret;
    152
    153	ret = 0;
    154	if (cell->resume)
    155		ret = (*cell->resume)(pdev);
    156
    157	return ret;
    158}
    159#endif
    160
    161static SIMPLE_DEV_PM_OPS(asic3_led_pm_ops, asic3_led_suspend, asic3_led_resume);
    162
    163static struct platform_driver asic3_led_driver = {
    164	.probe		= asic3_led_probe,
    165	.remove		= asic3_led_remove,
    166	.driver		= {
    167		.name	= "leds-asic3",
    168		.pm	= &asic3_led_pm_ops,
    169	},
    170};
    171
    172module_platform_driver(asic3_led_driver);
    173
    174MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
    175MODULE_DESCRIPTION("HTC ASIC3 LED driver");
    176MODULE_LICENSE("GPL");
    177MODULE_ALIAS("platform:leds-asic3");