drivers/watchdog/riowd.c

1 // SPDX-License-Identifier: GPL-2.0-only
2 /* riowd.c - driver for hw watchdog inside Super I/O of RIO
23 /* RIO uses the NatSemi Super I/O power management logical device
28  * trigger a power-on reset when the signal is asserted.  The BBC
31  * The only Super I/O device register we care about is at index
32  * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
33  * If set to zero, this disables the watchdog.  When set, the system
34  * must periodically (before watchdog expires) clear (set to zero) and
35  * re-set the watchdog else it will trigger.
37  * There are two other indexed watchdog registers inside this Super I/O
39  * the watchdog control and can be used to make the watchdog timer re-set
71 	spin_lock_irqsave(&p->lock, flags);  in riowd_writereg()
72 	writeb(index, p->regs + 0);  in riowd_writereg()
73 	writeb(val, p->regs + 1);  in riowd_writereg()
74 	spin_unlock_irqrestore(&p->lock, flags);  in riowd_writereg()
103 			return -EFAULT;  in riowd_ioctl()
109 			return -EFAULT;  in riowd_ioctl()
118 			return -EFAULT;  in riowd_ioctl()
125 			return -EINVAL;  in riowd_ioctl()
131 			return -EFAULT;  in riowd_ioctl()
133 			return -EINVAL;  in riowd_ioctl()
142 		return -EINVAL;  in riowd_ioctl()
179 	int err = -EINVAL;  in riowd_probe()
184 	err = -ENOMEM;  in riowd_probe()
185 	p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);  in riowd_probe()
189 	spin_lock_init(&p->lock);  in riowd_probe()
191 	p->regs = of_ioremap(&op->resource[0], 0, 2, DRIVER_NAME);  in riowd_probe()
192 	if (!p->regs) {  in riowd_probe()
206 		riowd_timeout, p->regs);  in riowd_probe()
213 	of_iounmap(&op->resource[0], p->regs, 2);  in riowd_probe()
224 	of_iounmap(&op->resource[0], p->regs, 2);  in riowd_remove()