+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Watchdog driver for CSR Atlas7
- *
- * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
- */
-
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/watchdog.h>
-
-#define ATLAS7_TIMER_WDT_INDEX 5
-#define ATLAS7_WDT_DEFAULT_TIMEOUT 20
-
-#define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX)
-#define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX)
-#define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX)
-#define ATLAS7_WDT_CNT_EN (BIT(0) | BIT(1))
-#define ATLAS7_WDT_EN 0x64
-
-static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT;
-static bool nowayout = WATCHDOG_NOWAYOUT;
-
-module_param(timeout, uint, 0);
-module_param(nowayout, bool, 0);
-
-MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)");
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
- __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
-
-struct atlas7_wdog {
- struct device *dev;
- void __iomem *base;
- unsigned long tick_rate;
- struct clk *clk;
-};
-
-static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd)
-{
- struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
- u32 counter, match, delta;
-
- counter = readl(wdt->base + ATLAS7_WDT_CNT);
- match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH);
- delta = match - counter;
-
- return delta / wdt->tick_rate;
-}
-
-static int atlas7_wdt_ping(struct watchdog_device *wdd)
-{
- struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
- u32 counter, match, delta;
-
- counter = readl(wdt->base + ATLAS7_WDT_CNT);
- delta = wdd->timeout * wdt->tick_rate;
- match = counter + delta;
-
- writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH);
-
- return 0;
-}
-
-static int atlas7_wdt_enable(struct watchdog_device *wdd)
-{
- struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
-
- atlas7_wdt_ping(wdd);
-
- writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN,
- wdt->base + ATLAS7_WDT_CNT_CTRL);
- writel(1, wdt->base + ATLAS7_WDT_EN);
-
- return 0;
-}
-
-static int atlas7_wdt_disable(struct watchdog_device *wdd)
-{
- struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd);
-
- writel(0, wdt->base + ATLAS7_WDT_EN);
- writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN,
- wdt->base + ATLAS7_WDT_CNT_CTRL);
-
- return 0;
-}
-
-static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)
-{
- wdd->timeout = to;
-
- return 0;
-}
-
-#define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE)
-
-static const struct watchdog_info atlas7_wdt_ident = {
- .options = OPTIONS,
- .firmware_version = 0,
- .identity = "atlas7 Watchdog",
-};
-
-static const struct watchdog_ops atlas7_wdt_ops = {
- .owner = THIS_MODULE,
- .start = atlas7_wdt_enable,
- .stop = atlas7_wdt_disable,
- .get_timeleft = atlas7_wdt_gettimeleft,
- .ping = atlas7_wdt_ping,
- .set_timeout = atlas7_wdt_settimeout,
-};
-
-static struct watchdog_device atlas7_wdd = {
- .info = &atlas7_wdt_ident,
- .ops = &atlas7_wdt_ops,
- .timeout = ATLAS7_WDT_DEFAULT_TIMEOUT,
-};
-
-static const struct of_device_id atlas7_wdt_ids[] = {
- { .compatible = "sirf,atlas7-tick"},
- {}
-};
-
-static void atlas7_clk_disable_unprepare(void *data)
-{
- clk_disable_unprepare(data);
-}
-
-static int atlas7_wdt_probe(struct platform_device *pdev)
-{
- struct device *dev = &pdev->dev;
- struct atlas7_wdog *wdt;
- struct clk *clk;
- int ret;
-
- wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
- if (!wdt)
- return -ENOMEM;
- wdt->base = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(wdt->base))
- return PTR_ERR(wdt->base);
-
- clk = devm_clk_get(dev, NULL);
- if (IS_ERR(clk))
- return PTR_ERR(clk);
- ret = clk_prepare_enable(clk);
- if (ret) {
- dev_err(dev, "clk enable failed\n");
- return ret;
- }
- ret = devm_add_action_or_reset(dev, atlas7_clk_disable_unprepare, clk);
- if (ret)
- return ret;
-
- /* disable watchdog hardware */
- writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
-
- wdt->tick_rate = clk_get_rate(clk);
- if (!wdt->tick_rate)
- return -EINVAL;
-
- wdt->clk = clk;
- atlas7_wdd.min_timeout = 1;
- atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;
-
- watchdog_init_timeout(&atlas7_wdd, 0, dev);
- watchdog_set_nowayout(&atlas7_wdd, nowayout);
-
- watchdog_set_drvdata(&atlas7_wdd, wdt);
- platform_set_drvdata(pdev, &atlas7_wdd);
-
- watchdog_stop_on_reboot(&atlas7_wdd);
- watchdog_stop_on_unregister(&atlas7_wdd);
- return devm_watchdog_register_device(dev, &atlas7_wdd);
-}
-
-static int __maybe_unused atlas7_wdt_suspend(struct device *dev)
-{
- /*
- * NOTE:timer controller registers settings are saved
- * and restored back by the timer-atlas7.c
- */
- return 0;
-}
-
-static int __maybe_unused atlas7_wdt_resume(struct device *dev)
-{
- struct watchdog_device *wdd = dev_get_drvdata(dev);
-
- /*
- * NOTE: Since timer controller registers settings are saved
- * and restored back by the timer-atlas7.c, so we need not
- * update WD settings except refreshing timeout.
- */
- atlas7_wdt_ping(wdd);
-
- return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops,
- atlas7_wdt_suspend, atlas7_wdt_resume);
-
-MODULE_DEVICE_TABLE(of, atlas7_wdt_ids);
-
-static struct platform_driver atlas7_wdt_driver = {
- .driver = {
- .name = "atlas7-wdt",
- .pm = &atlas7_wdt_pm_ops,
- .of_match_table = atlas7_wdt_ids,
- },
- .probe = atlas7_wdt_probe,
-};
-module_platform_driver(atlas7_wdt_driver);
-
-MODULE_DESCRIPTION("CSRatlas7 watchdog driver");
-MODULE_AUTHOR("Guo Zeng <Guo.Zeng@csr.com>");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:atlas7-wdt");
projects / thirdparty / kernel / linux.git / commitdiff
