xref: /linux/drivers/thunderbolt/nhi_regs.h (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * Thunderbolt Cactus Ridge driver - NHI registers
3  *
4  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
5  */
6 
7 #ifndef DSL3510_REGS_H_
8 #define DSL3510_REGS_H_
9 
10 #include <linux/types.h>
11 
12 enum ring_flags {
13 	RING_FLAG_ISOCH_ENABLE = 1 << 27, /* TX only? */
14 	RING_FLAG_E2E_FLOW_CONTROL = 1 << 28,
15 	RING_FLAG_PCI_NO_SNOOP = 1 << 29,
16 	RING_FLAG_RAW = 1 << 30, /* ignore EOF/SOF mask, include checksum */
17 	RING_FLAG_ENABLE = 1 << 31,
18 };
19 
20 enum ring_desc_flags {
21 	RING_DESC_ISOCH = 0x1, /* TX only? */
22 	RING_DESC_COMPLETED = 0x2, /* set by NHI */
23 	RING_DESC_POSTED = 0x4, /* always set this */
24 	RING_DESC_INTERRUPT = 0x8, /* request an interrupt on completion */
25 };
26 
27 /**
28  * struct ring_desc - TX/RX ring entry
29  *
30  * For TX set length/eof/sof.
31  * For RX length/eof/sof are set by the NHI.
32  */
33 struct ring_desc {
34 	u64 phys;
35 	u32 length:12;
36 	u32 eof:4;
37 	u32 sof:4;
38 	enum ring_desc_flags flags:12;
39 	u32 time; /* write zero */
40 } __packed;
41 
42 /* NHI registers in bar 0 */
43 
44 /*
45  * 16 bytes per entry, one entry for every hop (REG_HOP_COUNT)
46  * 00: physical pointer to an array of struct ring_desc
47  * 08: ring tail (set by NHI)
48  * 10: ring head (index of first non posted descriptor)
49  * 12: descriptor count
50  */
51 #define REG_TX_RING_BASE	0x00000
52 
53 /*
54  * 16 bytes per entry, one entry for every hop (REG_HOP_COUNT)
55  * 00: physical pointer to an array of struct ring_desc
56  * 08: ring head (index of first not posted descriptor)
57  * 10: ring tail (set by NHI)
58  * 12: descriptor count
59  * 14: max frame sizes (anything larger than 0x100 has no effect)
60  */
61 #define REG_RX_RING_BASE	0x08000
62 
63 /*
64  * 32 bytes per entry, one entry for every hop (REG_HOP_COUNT)
65  * 00: enum_ring_flags
66  * 04: isoch time stamp ?? (write 0)
67  * ..: unknown
68  */
69 #define REG_TX_OPTIONS_BASE	0x19800
70 
71 /*
72  * 32 bytes per entry, one entry for every hop (REG_HOP_COUNT)
73  * 00: enum ring_flags
74  *     If RING_FLAG_E2E_FLOW_CONTROL is set then bits 13-23 must be set to
75  *     the corresponding TX hop id.
76  * 04: EOF/SOF mask (ignored for RING_FLAG_RAW rings)
77  * ..: unknown
78  */
79 #define REG_RX_OPTIONS_BASE	0x29800
80 
81 /*
82  * three bitfields: tx, rx, rx overflow
83  * Every bitfield contains one bit for every hop (REG_HOP_COUNT). Registers are
84  * cleared on read. New interrupts are fired only after ALL registers have been
85  * read (even those containing only disabled rings).
86  */
87 #define REG_RING_NOTIFY_BASE	0x37800
88 #define RING_NOTIFY_REG_COUNT(nhi) ((31 + 3 * nhi->hop_count) / 32)
89 
90 /*
91  * two bitfields: rx, tx
92  * Both bitfields contains one bit for every hop (REG_HOP_COUNT). To
93  * enable/disable interrupts set/clear the corresponding bits.
94  */
95 #define REG_RING_INTERRUPT_BASE	0x38200
96 #define RING_INTERRUPT_REG_COUNT(nhi) ((31 + 2 * nhi->hop_count) / 32)
97 
98 /* The last 11 bits contain the number of hops supported by the NHI port. */
99 #define REG_HOP_COUNT		0x39640
100 
101 #endif
102