summaryrefslogtreecommitdiff
path: root/arch/parisc/include/asm/dma.h
blob: eea80ed34e6d66786759ff66e4291d260899bba2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/* SPDX-License-Identifier: GPL-2.0 */
/* asm/dma.h: Defines for using and allocating dma channels.
 * Written by Hennus Bergman, 1992.
 * High DMA channel support & info by Hannu Savolainen
 * and John Boyd, Nov. 1992.
 * (c) Copyright 2000, Grant Grundler
 */

#ifndef _ASM_DMA_H
#define _ASM_DMA_H

#include <asm/io.h>		/* need byte IO */

#define dma_outb	outb
#define dma_inb		inb

/*
** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up
** (or rather not merge) DMAs into manageable chunks.
** On parisc, this is more of the software/tuning constraint
** rather than the HW. I/O MMU allocation algorithms can be
** faster with smaller sizes (to some degree).
*/
#define DMA_CHUNK_SIZE	(BITS_PER_LONG*PAGE_SIZE)

/* The maximum address that we can perform a DMA transfer to on this platform
** New dynamic DMA interfaces should obsolete this....
*/
#define MAX_DMA_ADDRESS (~0UL)

/*
** We don't have DMA channels... well V-class does but the
** Dynamic DMA Mapping interface will support them... right? :^)
** Note: this is not relevant right now for PA-RISC, but we cannot 
** leave this as undefined because some things (e.g. sound)
** won't compile :-(
*/
#define MAX_DMA_CHANNELS 8
#define DMA_MODE_READ	0x44	/* I/O to memory, no autoinit, increment, single mode */
#define DMA_MODE_WRITE	0x48	/* memory to I/O, no autoinit, increment, single mode */
#define DMA_MODE_CASCADE 0xC0	/* pass thru DREQ->HRQ, DACK<-HLDA only */

#define DMA_AUTOINIT	0x10

/* 8237 DMA controllers */
#define IO_DMA1_BASE	0x00	/* 8 bit slave DMA, channels 0..3 */
#define IO_DMA2_BASE	0xC0	/* 16 bit master DMA, ch 4(=slave input)..7 */

/* DMA controller registers */
#define DMA1_CMD_REG		0x08	/* command register (w) */
#define DMA1_STAT_REG		0x08	/* status register (r) */
#define DMA1_REQ_REG            0x09    /* request register (w) */
#define DMA1_MASK_REG		0x0A	/* single-channel mask (w) */
#define DMA1_MODE_REG		0x0B	/* mode register (w) */
#define DMA1_CLEAR_FF_REG	0x0C	/* clear pointer flip-flop (w) */
#define DMA1_TEMP_REG           0x0D    /* Temporary Register (r) */
#define DMA1_RESET_REG		0x0D	/* Master Clear (w) */
#define DMA1_CLR_MASK_REG       0x0E    /* Clear Mask */
#define DMA1_MASK_ALL_REG       0x0F    /* all-channels mask (w) */
#define DMA1_EXT_MODE_REG	(0x400 | DMA1_MODE_REG)

#define DMA2_CMD_REG		0xD0	/* command register (w) */
#define DMA2_STAT_REG		0xD0	/* status register (r) */
#define DMA2_REQ_REG            0xD2    /* request register (w) */
#define DMA2_MASK_REG		0xD4	/* single-channel mask (w) */
#define DMA2_MODE_REG		0xD6	/* mode register (w) */
#define DMA2_CLEAR_FF_REG	0xD8	/* clear pointer flip-flop (w) */
#define DMA2_TEMP_REG           0xDA    /* Temporary Register (r) */
#define DMA2_RESET_REG		0xDA	/* Master Clear (w) */
#define DMA2_CLR_MASK_REG       0xDC    /* Clear Mask */
#define DMA2_MASK_ALL_REG       0xDE    /* all-channels mask (w) */
#define DMA2_EXT_MODE_REG	(0x400 | DMA2_MODE_REG)

static __inline__ unsigned long claim_dma_lock(void)
{
	return 0;
}

static __inline__ void release_dma_lock(unsigned long flags)
{
}


/* Get DMA residue count. After a DMA transfer, this
 * should return zero. Reading this while a DMA transfer is
 * still in progress will return unpredictable results.
 * If called before the channel has been used, it may return 1.
 * Otherwise, it returns the number of _bytes_ left to transfer.
 *
 * Assumes DMA flip-flop is clear.
 */
static __inline__ int get_dma_residue(unsigned int dmanr)
{
	unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE
					 : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE;

	/* using short to get 16-bit wrap around */
	unsigned short count;

	count = 1 + dma_inb(io_port);
	count += dma_inb(io_port) << 8;
	
	return (dmanr<=3)? count : (count<<1);
}

/* enable/disable a specific DMA channel */
static __inline__ void enable_dma(unsigned int dmanr)
{
#ifdef CONFIG_SUPERIO
	if (dmanr<=3)
		dma_outb(dmanr,  DMA1_MASK_REG);
	else
		dma_outb(dmanr & 3,  DMA2_MASK_REG);
#endif
}

static __inline__ void disable_dma(unsigned int dmanr)
{
#ifdef CONFIG_SUPERIO
	if (dmanr<=3)
		dma_outb(dmanr | 4,  DMA1_MASK_REG);
	else
		dma_outb((dmanr & 3) | 4,  DMA2_MASK_REG);
#endif
}

/* reserve a DMA channel */
#define request_dma(dmanr, device_id)	(0)

/* Clear the 'DMA Pointer Flip Flop'.
 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
 * Use this once to initialize the FF to a known state.
 * After that, keep track of it. :-)
 * --- In order to do that, the DMA routines below should ---
 * --- only be used while holding the DMA lock ! ---
 */
static __inline__ void clear_dma_ff(unsigned int dmanr)
{
}

/* set mode (above) for a specific DMA channel */
static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
{
}

/* Set only the page register bits of the transfer address.
 * This is used for successive transfers when we know the contents of
 * the lower 16 bits of the DMA current address register, but a 64k boundary
 * may have been crossed.
 */
static __inline__ void set_dma_page(unsigned int dmanr, char pagenr)
{
}


/* Set transfer address & page bits for specific DMA channel.
 * Assumes dma flipflop is clear.
 */
static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
{
}


/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
 * a specific DMA channel.
 * You must ensure the parameters are valid.
 * NOTE: from a manual: "the number of transfers is one more
 * than the initial word count"! This is taken into account.
 * Assumes dma flip-flop is clear.
 * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
 */
static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
{
}


#define free_dma(dmanr)

#ifdef CONFIG_PCI
extern int isa_dma_bridge_buggy;
#else
#define isa_dma_bridge_buggy 	(0)
#endif

#endif /* _ASM_DMA_H */