cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

loongson1_wdt.c (3640B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
      4 */
      5
      6#include <linux/clk.h>
      7#include <linux/module.h>
      8#include <linux/platform_device.h>
      9#include <linux/watchdog.h>
     10#include <loongson1.h>
     11
     12#define DEFAULT_HEARTBEAT	30
     13
     14static bool nowayout = WATCHDOG_NOWAYOUT;
     15module_param(nowayout, bool, 0444);
     16
     17static unsigned int heartbeat;
     18module_param(heartbeat, uint, 0444);
     19
     20struct ls1x_wdt_drvdata {
     21	void __iomem *base;
     22	struct clk *clk;
     23	unsigned long clk_rate;
     24	struct watchdog_device wdt;
     25};
     26
     27static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
     28{
     29	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
     30
     31	writel(0x1, drvdata->base + WDT_SET);
     32
     33	return 0;
     34}
     35
     36static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
     37				unsigned int timeout)
     38{
     39	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
     40	unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
     41	unsigned int counts;
     42
     43	wdt_dev->timeout = timeout;
     44
     45	counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
     46	writel(counts, drvdata->base + WDT_TIMER);
     47
     48	return 0;
     49}
     50
     51static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
     52{
     53	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
     54
     55	writel(0x1, drvdata->base + WDT_EN);
     56
     57	return 0;
     58}
     59
     60static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
     61{
     62	struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
     63
     64	writel(0x0, drvdata->base + WDT_EN);
     65
     66	return 0;
     67}
     68
     69static const struct watchdog_info ls1x_wdt_info = {
     70	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
     71	.identity = "Loongson1 Watchdog",
     72};
     73
     74static const struct watchdog_ops ls1x_wdt_ops = {
     75	.owner = THIS_MODULE,
     76	.start = ls1x_wdt_start,
     77	.stop = ls1x_wdt_stop,
     78	.ping = ls1x_wdt_ping,
     79	.set_timeout = ls1x_wdt_set_timeout,
     80};
     81
     82static void ls1x_clk_disable_unprepare(void *data)
     83{
     84	clk_disable_unprepare(data);
     85}
     86
     87static int ls1x_wdt_probe(struct platform_device *pdev)
     88{
     89	struct device *dev = &pdev->dev;
     90	struct ls1x_wdt_drvdata *drvdata;
     91	struct watchdog_device *ls1x_wdt;
     92	unsigned long clk_rate;
     93	int err;
     94
     95	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
     96	if (!drvdata)
     97		return -ENOMEM;
     98
     99	drvdata->base = devm_platform_ioremap_resource(pdev, 0);
    100	if (IS_ERR(drvdata->base))
    101		return PTR_ERR(drvdata->base);
    102
    103	drvdata->clk = devm_clk_get(dev, pdev->name);
    104	if (IS_ERR(drvdata->clk))
    105		return PTR_ERR(drvdata->clk);
    106
    107	err = clk_prepare_enable(drvdata->clk);
    108	if (err) {
    109		dev_err(dev, "clk enable failed\n");
    110		return err;
    111	}
    112	err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
    113				       drvdata->clk);
    114	if (err)
    115		return err;
    116
    117	clk_rate = clk_get_rate(drvdata->clk);
    118	if (!clk_rate)
    119		return -EINVAL;
    120	drvdata->clk_rate = clk_rate;
    121
    122	ls1x_wdt = &drvdata->wdt;
    123	ls1x_wdt->info = &ls1x_wdt_info;
    124	ls1x_wdt->ops = &ls1x_wdt_ops;
    125	ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
    126	ls1x_wdt->min_timeout = 1;
    127	ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
    128	ls1x_wdt->parent = dev;
    129
    130	watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
    131	watchdog_set_nowayout(ls1x_wdt, nowayout);
    132	watchdog_set_drvdata(ls1x_wdt, drvdata);
    133
    134	err = devm_watchdog_register_device(dev, &drvdata->wdt);
    135	if (err)
    136		return err;
    137
    138	platform_set_drvdata(pdev, drvdata);
    139
    140	dev_info(dev, "Loongson1 Watchdog driver registered\n");
    141
    142	return 0;
    143}
    144
    145static struct platform_driver ls1x_wdt_driver = {
    146	.probe = ls1x_wdt_probe,
    147	.driver = {
    148		.name = "ls1x-wdt",
    149	},
    150};
    151
    152module_platform_driver(ls1x_wdt_driver);
    153
    154MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
    155MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
    156MODULE_LICENSE("GPL");