| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * console.c: Routines that deal with sending and receiving IO |
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| 4 | * to/from the current console device using the PROM. |
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| 5 | * |
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| 6 | * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) |
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| 7 | * Copyright (C) 1998 Pete Zaitcev <zaitcev@yahoo.com> |
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| 8 | */ |
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| 9 | |
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| 10 | #include <linux/types.h> |
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| 11 | #include <linux/kernel.h> |
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| 12 | #include <linux/sched.h> |
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| 13 | #include <asm/openprom.h> |
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| 14 | #include <asm/oplib.h> |
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| 15 | #include <linux/string.h> |
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| 16 | |
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| 17 | extern void restore_current(void); |
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| 18 | |
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| 19 | /* Non blocking put character to console device, returns -1 if |
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| 20 | * unsuccessful. |
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| 21 | */ |
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| 22 | static int prom_nbputchar(const char *buf) |
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| 23 | { |
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| 24 | unsigned long flags; |
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| 25 | int i = -1; |
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| 26 | |
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| 27 | spin_lock_irqsave(&prom_lock, flags); |
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| 28 | switch(prom_vers) { |
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| 29 | case PROM_V0: |
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| 30 | if ((*(romvec->pv_nbputchar))(*buf)) |
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| 31 | i = 1; |
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| 32 | break; |
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| 33 | case PROM_V2: |
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| 34 | case PROM_V3: |
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| 35 | if ((*(romvec->pv_v2devops).v2_dev_write)(*romvec->pv_v2bootargs.fd_stdout, |
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| 36 | buf, 0x1) == 1) |
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| 37 | i = 1; |
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| 38 | break; |
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| 39 | default: |
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| 40 | break; |
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| 41 | } |
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| 42 | restore_current(); |
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| 43 | spin_unlock_irqrestore(lock: &prom_lock, flags); |
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| 44 | return i; /* Ugh, we could spin forever on unsupported proms ;( */ |
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| 45 | } |
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| 46 | |
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| 47 | void prom_console_write_buf(const char *buf, int len) |
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| 48 | { |
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| 49 | while (len) { |
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| 50 | int n = prom_nbputchar(buf); |
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| 51 | if (n < 0) |
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| 52 | continue; |
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| 53 | len--; |
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| 54 | buf++; |
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| 55 | } |
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| 56 | } |
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| 57 | |
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| 58 | |
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