diff options
Diffstat (limited to 'drivers/watchdog/airoha_wdt.c')
| -rw-r--r-- | drivers/watchdog/airoha_wdt.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/watchdog/airoha_wdt.c b/drivers/watchdog/airoha_wdt.c new file mode 100644 index 000000000000..dc8ca11c14d8 --- /dev/null +++ b/drivers/watchdog/airoha_wdt.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Airoha Watchdog Driver + * + * Copyright (c) 2024, AIROHA All rights reserved. + * + * Mayur Kumar <mayur.kumar@airoha.com> + * Christian Marangi <ansuelsmth@gmail.com> + * + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/math.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/watchdog.h> + +/* Base address of timer and watchdog registers */ +#define TIMER_CTRL 0x0 +#define WDT_ENABLE BIT(25) +#define WDT_TIMER_INTERRUPT BIT(21) +/* Timer3 is used as Watchdog Timer */ +#define WDT_TIMER_ENABLE BIT(5) +#define WDT_TIMER_LOAD_VALUE 0x2c +#define WDT_TIMER_CUR_VALUE 0x30 +#define WDT_TIMER_VAL GENMASK(31, 0) +#define WDT_RELOAD 0x38 +#define WDT_RLD BIT(0) + +/* Airoha watchdog structure description */ +struct airoha_wdt_desc { + struct watchdog_device wdog_dev; + unsigned int wdt_freq; + void __iomem *base; +}; + +#define WDT_HEARTBEAT 24 +static int heartbeat = WDT_HEARTBEAT; +module_param(heartbeat, int, 0); +MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. (default=" + __MODULE_STRING(WDT_HEARTBEAT) ")"); + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +static int airoha_wdt_start(struct watchdog_device *wdog_dev) +{ + struct airoha_wdt_desc *airoha_wdt = watchdog_get_drvdata(wdog_dev); + u32 val; + + val = readl(airoha_wdt->base + TIMER_CTRL); + val |= (WDT_TIMER_ENABLE | WDT_ENABLE | WDT_TIMER_INTERRUPT); + writel(val, airoha_wdt->base + TIMER_CTRL); + val = wdog_dev->timeout * airoha_wdt->wdt_freq; + writel(val, airoha_wdt->base + WDT_TIMER_LOAD_VALUE); + + return 0; +} + +static int airoha_wdt_stop(struct watchdog_device *wdog_dev) +{ + struct airoha_wdt_desc *airoha_wdt = watchdog_get_drvdata(wdog_dev); + u32 val; + + val = readl(airoha_wdt->base + TIMER_CTRL); + val &= (~WDT_ENABLE & ~WDT_TIMER_ENABLE); + writel(val, airoha_wdt->base + TIMER_CTRL); + + return 0; +} + +static int airoha_wdt_ping(struct watchdog_device *wdog_dev) +{ + struct airoha_wdt_desc *airoha_wdt = watchdog_get_drvdata(wdog_dev); + u32 val; + + val = readl(airoha_wdt->base + WDT_RELOAD); + val |= WDT_RLD; + writel(val, airoha_wdt->base + WDT_RELOAD); + + return 0; +} + +static int airoha_wdt_set_timeout(struct watchdog_device *wdog_dev, unsigned int timeout) +{ + wdog_dev->timeout = timeout; + + if (watchdog_active(wdog_dev)) { + airoha_wdt_stop(wdog_dev); + return airoha_wdt_start(wdog_dev); + } + + return 0; +} + +static unsigned int airoha_wdt_get_timeleft(struct watchdog_device *wdog_dev) +{ + struct airoha_wdt_desc *airoha_wdt = watchdog_get_drvdata(wdog_dev); + u32 val; + + val = readl(airoha_wdt->base + WDT_TIMER_CUR_VALUE); + return DIV_ROUND_UP(val, airoha_wdt->wdt_freq); +} + +static const struct watchdog_info airoha_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, + .identity = "Airoha Watchdog", +}; + +static const struct watchdog_ops airoha_wdt_ops = { + .owner = THIS_MODULE, + .start = airoha_wdt_start, + .stop = airoha_wdt_stop, + .ping = airoha_wdt_ping, + .set_timeout = airoha_wdt_set_timeout, + .get_timeleft = airoha_wdt_get_timeleft, +}; + +static int airoha_wdt_probe(struct platform_device *pdev) +{ + struct airoha_wdt_desc *airoha_wdt; + struct watchdog_device *wdog_dev; + struct device *dev = &pdev->dev; + struct clk *bus_clk; + int ret; + + airoha_wdt = devm_kzalloc(dev, sizeof(*airoha_wdt), GFP_KERNEL); + if (!airoha_wdt) + return -ENOMEM; + + airoha_wdt->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(airoha_wdt->base)) + return PTR_ERR(airoha_wdt->base); + + bus_clk = devm_clk_get_enabled(dev, "bus"); + if (IS_ERR(bus_clk)) + return dev_err_probe(dev, PTR_ERR(bus_clk), + "failed to enable bus clock\n"); + + /* Watchdog ticks at half the bus rate */ + airoha_wdt->wdt_freq = clk_get_rate(bus_clk) / 2; + + /* Initialize struct watchdog device */ + wdog_dev = &airoha_wdt->wdog_dev; + wdog_dev->timeout = heartbeat; + wdog_dev->info = &airoha_wdt_info; + wdog_dev->ops = &airoha_wdt_ops; + /* Bus 300MHz, watchdog 150MHz, 28 seconds */ + wdog_dev->max_timeout = FIELD_MAX(WDT_TIMER_VAL) / airoha_wdt->wdt_freq; + wdog_dev->parent = dev; + + watchdog_set_drvdata(wdog_dev, airoha_wdt); + watchdog_set_nowayout(wdog_dev, nowayout); + watchdog_stop_on_unregister(wdog_dev); + + ret = devm_watchdog_register_device(dev, wdog_dev); + if (ret) + return ret; + + platform_set_drvdata(pdev, airoha_wdt); + return 0; +} + +static int airoha_wdt_suspend(struct device *dev) +{ + struct airoha_wdt_desc *airoha_wdt = dev_get_drvdata(dev); + + if (watchdog_active(&airoha_wdt->wdog_dev)) + airoha_wdt_stop(&airoha_wdt->wdog_dev); + + return 0; +} + +static int airoha_wdt_resume(struct device *dev) +{ + struct airoha_wdt_desc *airoha_wdt = dev_get_drvdata(dev); + + if (watchdog_active(&airoha_wdt->wdog_dev)) { + airoha_wdt_start(&airoha_wdt->wdog_dev); + airoha_wdt_ping(&airoha_wdt->wdog_dev); + } + return 0; +} + +static const struct of_device_id airoha_wdt_of_match[] = { + { .compatible = "airoha,en7581-wdt", }, + { }, +}; + +MODULE_DEVICE_TABLE(of, airoha_wdt_of_match); + +static DEFINE_SIMPLE_DEV_PM_OPS(airoha_wdt_pm_ops, airoha_wdt_suspend, airoha_wdt_resume); + +static struct platform_driver airoha_wdt_driver = { + .probe = airoha_wdt_probe, + .driver = { + .name = "airoha-wdt", + .pm = pm_sleep_ptr(&airoha_wdt_pm_ops), + .of_match_table = airoha_wdt_of_match, + }, +}; + +module_platform_driver(airoha_wdt_driver); + +MODULE_AUTHOR("Mayur Kumar <mayur.kumar@airoha.com>"); +MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>"); +MODULE_DESCRIPTION("Airoha EN7581 Watchdog Driver"); +MODULE_LICENSE("GPL"); |