47 lines
1.1 KiB
C
47 lines
1.1 KiB
C
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/*
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* Useful info describing the parallel port device.
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*
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* Copyright (C) 2001 Alessandro Rubini and Jonathan Corbet
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* Copyright (C) 2001 O'Reilly & Associates
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*
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* The source code in this file can be freely used, adapted,
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* and redistributed in source or binary form, so long as an
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* acknowledgment appears in derived source files. The citation
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* should list that the code comes from the book "Linux Device
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* Drivers" by Alessandro Rubini and Jonathan Corbet, published
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* by O'Reilly & Associates. No warranty is attached;
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* we cannot take responsibility for errors or fitness for use.
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*
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*/
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/*
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* Register offsets
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*/
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#define SP_DATA 0x00
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#define SP_STATUS 0x01
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#define SP_CONTROL 0x02
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#define SP_NPORTS 3
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/*
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* Status register bits.
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*/
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#define SP_SR_BUSY 0x80
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#define SP_SR_ACK 0x40
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#define SP_SR_PAPER 0x20
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#define SP_SR_ONLINE 0x10
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#define SP_SR_ERR 0x08
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/*
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* Control register.
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*/
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#define SP_CR_IRQ 0x10
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#define SP_CR_SELECT 0x08
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#define SP_CR_INIT 0x04
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#define SP_CR_AUTOLF 0x02
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#define SP_CR_STROBE 0x01
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/*
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* Minimum space before waking up a writer.
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*/
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#define SP_MIN_SPACE PAGE_SIZE/2
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