1 /*
2  * Definitions for using the Apple Descriptor-Based DMA controller
3  * in Power Macintosh computers.
4  *
5  * Copyright (C) 1996 Paul Mackerras.
6  */
7 
8 #ifdef __KERNEL__
9 #ifndef _ASM_DBDMA_H_
10 #define _ASM_DBDMA_H_
11 /*
12  * DBDMA control/status registers.  All little-endian.
13  */
14 struct dbdma_regs {
15     unsigned int control;	/* lets you change bits in status */
16     unsigned int status;	/* DMA and device status bits (see below) */
17     unsigned int cmdptr_hi;	/* upper 32 bits of command address */
18     unsigned int cmdptr;	/* (lower 32 bits of) command address (phys) */
19     unsigned int intr_sel;	/* select interrupt condition bit */
20     unsigned int br_sel;	/* select branch condition bit */
21     unsigned int wait_sel;	/* select wait condition bit */
22     unsigned int xfer_mode;
23     unsigned int data2ptr_hi;
24     unsigned int data2ptr;
25     unsigned int res1;
26     unsigned int address_hi;
27     unsigned int br_addr_hi;
28     unsigned int res2[3];
29 };
30 
31 /* Bits in control and status registers */
32 #define RUN	0x8000
33 #define PAUSE	0x4000
34 #define FLUSH	0x2000
35 #define WAKE	0x1000
36 #define DEAD	0x0800
37 #define ACTIVE	0x0400
38 #define BT	0x0100
39 #define DEVSTAT	0x00ff
40 
41 /*
42  * DBDMA command structure.  These fields are all little-endian!
43  */
44 struct dbdma_cmd {
45     unsigned short req_count;	/* requested byte transfer count */
46     unsigned short command;	/* command word (has bit-fields) */
47     unsigned int   phy_addr;	/* physical data address */
48     unsigned int   cmd_dep;	/* command-dependent field */
49     unsigned short res_count;	/* residual count after completion */
50     unsigned short xfer_status;	/* transfer status */
51 };
52 
53 /* DBDMA command values in command field */
54 #define OUTPUT_MORE	0	/* transfer memory data to stream */
55 #define OUTPUT_LAST	0x1000	/* ditto followed by end marker */
56 #define INPUT_MORE	0x2000	/* transfer stream data to memory */
57 #define INPUT_LAST	0x3000	/* ditto, expect end marker */
58 #define STORE_WORD	0x4000	/* write word (4 bytes) to device reg */
59 #define LOAD_WORD	0x5000	/* read word (4 bytes) from device reg */
60 #define DBDMA_NOP	0x6000	/* do nothing */
61 #define DBDMA_STOP	0x7000	/* suspend processing */
62 
63 /* Key values in command field */
64 #define KEY_STREAM0	0	/* usual data stream */
65 #define KEY_STREAM1	0x100	/* control/status stream */
66 #define KEY_STREAM2	0x200	/* device-dependent stream */
67 #define KEY_STREAM3	0x300	/* device-dependent stream */
68 #define KEY_REGS	0x500	/* device register space */
69 #define KEY_SYSTEM	0x600	/* system memory-mapped space */
70 #define KEY_DEVICE	0x700	/* device memory-mapped space */
71 
72 /* Interrupt control values in command field */
73 #define INTR_NEVER	0	/* don't interrupt */
74 #define INTR_IFSET	0x10	/* intr if condition bit is 1 */
75 #define INTR_IFCLR	0x20	/* intr if condition bit is 0 */
76 #define INTR_ALWAYS	0x30	/* always interrupt */
77 
78 /* Branch control values in command field */
79 #define BR_NEVER	0	/* don't branch */
80 #define BR_IFSET	0x4	/* branch if condition bit is 1 */
81 #define BR_IFCLR	0x8	/* branch if condition bit is 0 */
82 #define BR_ALWAYS	0xc	/* always branch */
83 
84 /* Wait control values in command field */
85 #define WAIT_NEVER	0	/* don't wait */
86 #define WAIT_IFSET	1	/* wait if condition bit is 1 */
87 #define WAIT_IFCLR	2	/* wait if condition bit is 0 */
88 #define WAIT_ALWAYS	3	/* always wait */
89 
90 /* Align an address for a DBDMA command structure */
91 #define DBDMA_ALIGN(x)	(((unsigned long)(x) + sizeof(struct dbdma_cmd) - 1) \
92 			 & -sizeof(struct dbdma_cmd))
93 
94 /* Useful macros */
95 #define DBDMA_DO_STOP(regs) do {				\
96 	out_le32(&((regs)->control), (RUN|FLUSH)<<16);		\
97 	while(in_le32(&((regs)->status)) & (ACTIVE|FLUSH))	\
98 		; \
99 } while(0)
100 
101 #define DBDMA_DO_RESET(regs) do {				\
102 	out_le32(&((regs)->control), (ACTIVE|DEAD|WAKE|FLUSH|PAUSE|RUN)<<16);\
103 	while(in_le32(&((regs)->status)) & (RUN)) \
104 		; \
105 } while(0)
106 
107 #endif /* _ASM_DBDMA_H_ */
108 #endif /* __KERNEL__ */
109