xref: /freebsd/sys/powerpc/include/dbdma.h (revision 7431dfd4580e850375fe5478d92ec770344db098)
1 /*-
2  * Copyright (c) 2008 Nathan Whitehorn
3  * All rights reserved
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #ifndef _MACHINE_DBDMA_H_
30 #define _MACHINE_DBDMA_H_
31 
32 #include <sys/param.h>
33 #include <machine/bus.h>
34 
35 /*
36  * Apple's DBDMA (Descriptor-based DMA) interface is a common DMA engine
37  * used by a variety of custom Apple ASICs. It is described in the CHRP
38  * specification and in the book Macintosh Technology in the Common
39  * Hardware Reference Platform, copyright 1995 Apple Computer.
40  */
41 
42 /* DBDMA Command Values */
43 
44 enum {
45 	DBDMA_OUTPUT_MORE	= 0,
46 	DBDMA_OUTPUT_LAST	= 1,
47 	DBDMA_INPUT_MORE	= 2,
48 	DBDMA_INPUT_LAST	= 3,
49 
50 	DBDMA_STORE_QUAD	= 4,
51 	DBDMA_LOAD_QUAD		= 5,
52 	DBDMA_NOP		= 6,
53 	DBDMA_STOP		= 7
54 };
55 
56 /* These codes are for the interrupt, branch, and wait flags */
57 
58 enum {
59 	DBDMA_NEVER		= 0,
60 	DBDMA_COND_TRUE		= 1,
61 	DBDMA_COND_FALSE	= 2,
62 	DBDMA_ALWAYS		= 3
63 };
64 
65 /* Channel status bits */
66 #define DBDMA_STATUS_RUN    (0x01 << 15)
67 #define DBDMA_STATUS_PAUSE  (0x01 << 14)
68 #define DBDMA_STATUS_FLUSH  (0x01 << 13)
69 #define DBDMA_STATUS_WAKE   (0x01 << 12)
70 #define DBDMA_STATUS_DEAD   (0x01 << 11)
71 #define DBDMA_STATUS_ACTIVE (0x01 << 10)
72 
73 /* Set by hardware if a branch was taken */
74 #define DBDMA_STATUS_BRANCH 8
75 
76 struct dbdma_command;
77 typedef struct dbdma_command dbdma_command_t;
78 struct dbdma_channel;
79 typedef struct dbdma_channel dbdma_channel_t;
80 
81 int dbdma_allocate_channel(struct resource *dbdma_regs, u_int offset,
82     bus_dma_tag_t parent_dma, int slots, dbdma_channel_t **chan);
83 
84 int dbdma_resize_channel(dbdma_channel_t *chan, int newslots);
85 int dbdma_free_channel(dbdma_channel_t *chan);
86 
87 void dbdma_run(dbdma_channel_t *chan);
88 void dbdma_stop(dbdma_channel_t *chan);
89 void dbdma_reset(dbdma_channel_t *chan);
90 void dbdma_set_current_cmd(dbdma_channel_t *chan, int slot);
91 
92 void dbdma_pause(dbdma_channel_t *chan);
93 void dbdma_wake(dbdma_channel_t *chan);
94 
95 /*
96  * DBDMA uses a 16 bit channel control register to describe the current
97  * state of DMA on the channel. The high-order bits (8-15) contain information
98  * on the run state and are listed in the DBDMA_STATUS_* constants above. These
99  * are manipulated with the dbdma_run/stop/reset() routines above.
100  *
101  * The low order bits (0-7) are device dependent status bits. These can be set
102  * and read by both hardware and software. The mask is the set of bits to
103  * modify; if mask is 0x03 and value is 0, the lowest order 2 bits will be
104  * zeroed.
105  */
106 
107 uint16_t dbdma_get_chan_status(dbdma_channel_t *chan);
108 
109 uint8_t dbdma_get_device_status(dbdma_channel_t *chan);
110 void dbdma_set_device_status(dbdma_channel_t *chan, uint8_t mask,
111     uint8_t value);
112 
113 /*
114  * Each DBDMA command word has the current channel status register and the
115  * number of residual bytes (requested - actually transferred) written to it
116  * at time of command completion.
117  */
118 
119 uint16_t dbdma_get_cmd_status(dbdma_channel_t *chan, int slot);
120 uint16_t dbdma_get_residuals(dbdma_channel_t *chan, int slot);
121 
122 void dbdma_clear_cmd_status(dbdma_channel_t *chan, int slot);
123 
124 /*
125  * The interrupt/branch/wait selector let you specify a set of values
126  * of the device dependent status bits that will cause intterupt/branch/wait
127  * conditions to be taken if the flags for these are set to one of the
128  * DBDMA_COND_* values.
129  *
130  * The condition is considered true if (status & mask) == value.
131  */
132 
133 void dbdma_set_interrupt_selector(dbdma_channel_t *chan, uint8_t mask,
134     uint8_t value);
135 void dbdma_set_branch_selector(dbdma_channel_t *chan, uint8_t mask,
136     uint8_t value);
137 void dbdma_set_wait_selector(dbdma_channel_t *chan, uint8_t mask,
138     uint8_t value);
139 
140 void dbdma_insert_command(dbdma_channel_t *chan, int slot, int command,
141     int stream, bus_addr_t data, size_t count, uint8_t interrupt,
142     uint8_t branch, uint8_t wait, uint32_t branch_slot);
143 
144 void dbdma_insert_stop(dbdma_channel_t *chan, int slot);
145 void dbdma_insert_nop(dbdma_channel_t *chan, int slot);
146 void dbdma_insert_branch(dbdma_channel_t *chan, int slot, int to_slot);
147 
148 void dbdma_sync_commands(dbdma_channel_t *chan, bus_dmasync_op_t op);
149 
150 void dbdma_save_state(dbdma_channel_t *chan);
151 void dbdma_restore_state(dbdma_channel_t *chan);
152 
153 #endif /* _MACHINE_DBDMA_H_ */
154