1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * mpc8xxx_wdt.c - MPC8xx/MPC83xx/MPC86xx watchdog userspace interface
12  * Note: it appears that you can only actually ENABLE or DISABLE the thing
13  * once after POR. Once enabled, you cannot disable, and vice versa.
34 #define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
69 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
74 	/* Ping the WDT */  in mpc8xxx_wdt_keepalive()
75 	spin_lock(&ddata->lock);  in mpc8xxx_wdt_keepalive()
76 	out_be16(&ddata->base->swsrr, 0x556c);  in mpc8xxx_wdt_keepalive()
77 	out_be16(&ddata->base->swsrr, 0xaa39);  in mpc8xxx_wdt_keepalive()
78 	spin_unlock(&ddata->lock);  in mpc8xxx_wdt_keepalive()
85 	u32 tmp = in_be32(&ddata->base->swcrr);  in mpc8xxx_wdt_start()
89 	tmp |= SWCRR_SWEN | SWCRR_SWPR | (ddata->swtc << 16);  in mpc8xxx_wdt_start()
94 	out_be32(&ddata->base->swcrr, tmp);  in mpc8xxx_wdt_start()
96 	tmp = in_be32(&ddata->base->swcrr);  in mpc8xxx_wdt_start()
98 		return -EOPNOTSUPP;  in mpc8xxx_wdt_start()
100 	ddata->swtc = tmp >> 16;  in mpc8xxx_wdt_start()
101 	set_bit(WDOG_HW_RUNNING, &ddata->wdd.status);  in mpc8xxx_wdt_start()
135 	struct device *dev = &ofdev->dev;  in mpc8xxx_wdt_probe()
139 		return -EINVAL;  in mpc8xxx_wdt_probe()
141 	if (!freq || freq == -1)  in mpc8xxx_wdt_probe()
142 		return -EINVAL;  in mpc8xxx_wdt_probe()
146 		return -ENOMEM;  in mpc8xxx_wdt_probe()
148 	ddata->base = devm_platform_ioremap_resource(ofdev, 0);  in mpc8xxx_wdt_probe()
149 	if (IS_ERR(ddata->base))  in mpc8xxx_wdt_probe()
150 		return PTR_ERR(ddata->base);  in mpc8xxx_wdt_probe()
152 	enabled = in_be32(&ddata->base->swcrr) & SWCRR_SWEN;  in mpc8xxx_wdt_probe()
153 	if (!enabled && wdt_type->hw_enabled) {  in mpc8xxx_wdt_probe()
155 		return -ENODEV;  in mpc8xxx_wdt_probe()
161 		u32 __iomem *rsr = ioremap(res->start, resource_size(res));  in mpc8xxx_wdt_probe()
164 			return -ENOMEM;  in mpc8xxx_wdt_probe()
166 		status = in_be32(rsr) & wdt_type->rsr_mask;  in mpc8xxx_wdt_probe()
167 		ddata->wdd.bootstatus = status ? WDIOF_CARDRESET : 0;  in mpc8xxx_wdt_probe()
169 		out_be32(rsr, wdt_type->rsr_mask);  in mpc8xxx_wdt_probe()
176 	spin_lock_init(&ddata->lock);  in mpc8xxx_wdt_probe()
178 	ddata->wdd.info = &mpc8xxx_wdt_info;  in mpc8xxx_wdt_probe()
179 	ddata->wdd.ops = &mpc8xxx_wdt_ops;  in mpc8xxx_wdt_probe()
181 	ddata->wdd.timeout = WATCHDOG_TIMEOUT;  in mpc8xxx_wdt_probe()
182 	watchdog_init_timeout(&ddata->wdd, timeout, dev);  in mpc8xxx_wdt_probe()
184 	watchdog_set_nowayout(&ddata->wdd, nowayout);  in mpc8xxx_wdt_probe()
186 	ddata->swtc = min(ddata->wdd.timeout * freq / wdt_type->prescaler,  in mpc8xxx_wdt_probe()
191 	 * MPC8xxx, we should ping the wdt from the kernel until the  in mpc8xxx_wdt_probe()
195 		mpc8xxx_wdt_start(&ddata->wdd);  in mpc8xxx_wdt_probe()
197 	ddata->wdd.max_hw_heartbeat_ms = (ddata->swtc * wdt_type->prescaler) /  in mpc8xxx_wdt_probe()
199 	ddata->wdd.min_timeout = ddata->wdd.max_hw_heartbeat_ms / 1000;  in mpc8xxx_wdt_probe()
200 	if (ddata->wdd.timeout < ddata->wdd.min_timeout)  in mpc8xxx_wdt_probe()
201 		ddata->wdd.timeout = ddata->wdd.min_timeout;  in mpc8xxx_wdt_probe()
203 	ret = devm_watchdog_register_device(dev, &ddata->wdd);  in mpc8xxx_wdt_probe()
208 		 "WDT driver for MPC8xxx initialized. mode:%s timeout=%d sec\n",  in mpc8xxx_wdt_probe()
209 		 reset ? "reset" : "interrupt", ddata->wdd.timeout);  in mpc8xxx_wdt_probe()
224 		.compatible = "fsl,mpc8610-wdt",
232 		.compatible = "fsl,mpc823-wdt",