| 1 | // SPDX-License-Identifier: GPL-2.0 |
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| 2 | /* |
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| 3 | * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) |
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| 4 | */ |
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| 5 | |
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| 6 | #include <stddef.h> |
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| 7 | #include <errno.h> |
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| 8 | #include <fcntl.h> |
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| 9 | #include "chan_user.h" |
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| 10 | #include <os.h> |
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| 11 | |
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| 12 | /* This address is used only as a unique identifier */ |
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| 13 | static int null_chan; |
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| 14 | |
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| 15 | static void *null_init(char *str, int device, const struct chan_opts *opts) |
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| 16 | { |
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| 17 | return &null_chan; |
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| 18 | } |
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| 19 | |
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| 20 | static int null_open(int input, int output, int primary, void *d, |
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| 21 | char **dev_out) |
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| 22 | { |
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| 23 | int fd; |
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| 24 | |
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| 25 | *dev_out = NULL; |
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| 26 | |
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| 27 | fd = open(DEV_NULL, O_RDWR); |
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| 28 | return (fd < 0) ? -errno : fd; |
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| 29 | } |
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| 30 | |
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| 31 | static int null_read(int fd, __u8 *c_out, void *unused) |
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| 32 | { |
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| 33 | return -ENODEV; |
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| 34 | } |
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| 35 | |
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| 36 | static void null_free(void *data) |
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| 37 | { |
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| 38 | } |
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| 39 | |
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| 40 | const struct chan_ops null_ops = { |
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| 41 | .type = "null" , |
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| 42 | .init = null_init, |
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| 43 | .open = null_open, |
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| 44 | .close = generic_close, |
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| 45 | .read = null_read, |
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| 46 | .write = generic_write, |
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| 47 | .console_write = generic_console_write, |
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| 48 | .window_size = generic_window_size, |
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| 49 | .free = null_free, |
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| 50 | .winch = 0, |
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| 51 | }; |
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| 52 | |
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