1 // SPDX-License-Identifier: GPL-2.0-only
5  *  Copyright (C) 2017 Hauke Mehrtens <hauke@hauke-m.de>
6  *  Based on EP93xx wdt driver
33  * The password sequence protects the WDT control register from unintended
34  * write actions, which might cause malfunction of the WDT.
37  * IO access to the WDT core
43 #define  LTQ_WDT_CR_GEN		BIT(31)		/* enable bit */
44 /* Pre-warning limit set to 1/16 of max WDT period */
49 #define  LTQ_WDT_CR_MAX_TIMEOUT	((1 << 16) - 1)	/* The reload field is 16 bit */
51 #define  LTQ_WDT_SR_EN		BIT(31)		/* Enable */
63 	struct watchdog_device wdt;  member
70 	return __raw_readl(priv->membase + offset);  in ltq_wdt_r32()
75 	__raw_writel(val, priv->membase + offset);  in ltq_wdt_w32()
88 static struct ltq_wdt_priv *ltq_wdt_get_priv(struct watchdog_device *wdt)  in ltq_wdt_get_priv()  argument
90 	return container_of(wdt, struct ltq_wdt_priv, wdt);  in ltq_wdt_get_priv()
99 static int ltq_wdt_start(struct watchdog_device *wdt)  in ltq_wdt_start()  argument
101 	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);  in ltq_wdt_start()
104 	timeout = wdt->timeout * priv->clk_rate;  in ltq_wdt_start()
116 static int ltq_wdt_stop(struct watchdog_device *wdt)  in ltq_wdt_stop()  argument
118 	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);  in ltq_wdt_stop()
127 static int ltq_wdt_ping(struct watchdog_device *wdt)  in ltq_wdt_ping()  argument
129 	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);  in ltq_wdt_ping()
132 	timeout = wdt->timeout * priv->clk_rate;  in ltq_wdt_ping()
142 static unsigned int ltq_wdt_get_timeleft(struct watchdog_device *wdt)  in ltq_wdt_get_timeleft()  argument
144 	struct ltq_wdt_priv *priv = ltq_wdt_get_priv(wdt);  in ltq_wdt_get_timeleft()
148 	return do_div(timeout, priv->clk_rate);  in ltq_wdt_get_timeleft()
165 	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap");  in ltq_wdt_xrx_bootstatus_get()
185 	rcu_regmap = syscon_regmap_lookup_by_phandle(dev->of_node,  in ltq_wdt_falcon_bootstatus_get()
202 	struct device *dev = &pdev->dev;  in ltq_wdt_probe()
204 	struct watchdog_device *wdt;  in ltq_wdt_probe()  local
212 		return -ENOMEM;  in ltq_wdt_probe()
214 	priv->membase = devm_platform_ioremap_resource(pdev, 0);  in ltq_wdt_probe()
215 	if (IS_ERR(priv->membase))  in ltq_wdt_probe()
216 		return PTR_ERR(priv->membase);  in ltq_wdt_probe()
218 	/* we do not need to enable the clock as it is always running */  in ltq_wdt_probe()
220 	priv->clk_rate = clk_get_rate(clk) / LTQ_WDT_DIVIDER;  in ltq_wdt_probe()
221 	if (!priv->clk_rate) {  in ltq_wdt_probe()
224 		return -EINVAL;  in ltq_wdt_probe()
227 	wdt = &priv->wdt;  in ltq_wdt_probe()
228 	wdt->info		= &ltq_wdt_info;  in ltq_wdt_probe()
229 	wdt->ops		= &ltq_wdt_ops;  in ltq_wdt_probe()
230 	wdt->min_timeout	= 1;  in ltq_wdt_probe()
231 	wdt->max_timeout	= LTQ_WDT_CR_MAX_TIMEOUT / priv->clk_rate;  in ltq_wdt_probe()
232 	wdt->timeout		= wdt->max_timeout;  in ltq_wdt_probe()
233 	wdt->parent		= dev;  in ltq_wdt_probe()
236 	if (ltq_wdt_hw && ltq_wdt_hw->bootstatus_get) {  in ltq_wdt_probe()
237 		ret = ltq_wdt_hw->bootstatus_get(dev);  in ltq_wdt_probe()
239 			wdt->bootstatus = ret;  in ltq_wdt_probe()
242 	watchdog_set_nowayout(wdt, nowayout);  in ltq_wdt_probe()
243 	watchdog_init_timeout(wdt, 0, dev);  in ltq_wdt_probe()
252 		ltq_wdt_start(wdt);  in ltq_wdt_probe()
253 		set_bit(WDOG_HW_RUNNING, &wdt->status);  in ltq_wdt_probe()
256 	return devm_watchdog_register_device(dev, wdt);  in ltq_wdt_probe()
268 	{ .compatible = "lantiq,wdt", .data = NULL },
269 	{ .compatible = "lantiq,xrx100-wdt", .data = &ltq_wdt_xrx100 },
270 	{ .compatible = "lantiq,falcon-wdt", .data = &ltq_wdt_falcon },
278 		.name = "wdt",
286 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");