| // SPDX-License-Identifier: GPL-2.0 | 
 | /* | 
 |  * console.c: Routines that deal with sending and receiving IO | 
 |  *            to/from the current console device using the PROM. | 
 |  * | 
 |  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) | 
 |  * Copyright (C) 1998 Pete Zaitcev <zaitcev@yahoo.com> | 
 |  */ | 
 |  | 
 | #include <linux/types.h> | 
 | #include <linux/kernel.h> | 
 | #include <linux/sched.h> | 
 | #include <asm/openprom.h> | 
 | #include <asm/oplib.h> | 
 | #include <linux/string.h> | 
 |  | 
 | extern void restore_current(void); | 
 |  | 
 | /* Non blocking put character to console device, returns -1 if | 
 |  * unsuccessful. | 
 |  */ | 
 | static int prom_nbputchar(const char *buf) | 
 | { | 
 | 	unsigned long flags; | 
 | 	int i = -1; | 
 |  | 
 | 	spin_lock_irqsave(&prom_lock, flags); | 
 | 	switch(prom_vers) { | 
 | 	case PROM_V0: | 
 | 		if ((*(romvec->pv_nbputchar))(*buf)) | 
 | 			i = 1; | 
 | 		break; | 
 | 	case PROM_V2: | 
 | 	case PROM_V3: | 
 | 		if ((*(romvec->pv_v2devops).v2_dev_write)(*romvec->pv_v2bootargs.fd_stdout, | 
 | 							  buf, 0x1) == 1) | 
 | 			i = 1; | 
 | 		break; | 
 | 	default: | 
 | 		break; | 
 | 	} | 
 | 	restore_current(); | 
 | 	spin_unlock_irqrestore(&prom_lock, flags); | 
 | 	return i; /* Ugh, we could spin forever on unsupported proms ;( */ | 
 | } | 
 |  | 
 | void prom_console_write_buf(const char *buf, int len) | 
 | { | 
 | 	while (len) { | 
 | 		int n = prom_nbputchar(buf); | 
 | 		if (n < 0) | 
 | 			continue; | 
 | 		len--; | 
 | 		buf++; | 
 | 	} | 
 | } | 
 |  |