1 | /* |
2 | * Copyright 2021 Advanced Micro Devices, Inc. |
3 | * |
4 | * Permission is hereby granted, free of charge, to any person obtaining a |
5 | * copy of this software and associated documentation files (the "Software"), |
6 | * to deal in the Software without restriction, including without limitation |
7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
8 | * and/or sell copies of the Software, and to permit persons to whom the |
9 | * Software is furnished to do so, subject to the following conditions: |
10 | * |
11 | * The above copyright notice and this permission notice shall be included in |
12 | * all copies or substantial portions of the Software. |
13 | * |
14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
20 | * OTHER DEALINGS IN THE SOFTWARE. |
21 | * |
22 | * Authors: AMD |
23 | * |
24 | */ |
25 | |
26 | /* FILE POLICY AND INTENDED USAGE: |
27 | * |
28 | * This file implements basic dpcd read/write functionality. It also does basic |
29 | * dpcd range check to ensure that every dpcd request is compliant with specs |
30 | * range requirements. |
31 | */ |
32 | |
33 | #include "link_dpcd.h" |
34 | #include <drm/display/drm_dp_helper.h> |
35 | #include "dm_helpers.h" |
36 | |
37 | #define END_ADDRESS(start, size) (start + size - 1) |
38 | #define ADDRESS_RANGE_SIZE(start, end) (end - start + 1) |
39 | struct dpcd_address_range { |
40 | uint32_t start; |
41 | uint32_t end; |
42 | }; |
43 | |
44 | static enum dc_status internal_link_read_dpcd( |
45 | struct dc_link *link, |
46 | uint32_t address, |
47 | uint8_t *data, |
48 | uint32_t size) |
49 | { |
50 | if (!link->aux_access_disabled && |
51 | !dm_helpers_dp_read_dpcd(ctx: link->ctx, |
52 | link, address, data, size)) { |
53 | return DC_ERROR_UNEXPECTED; |
54 | } |
55 | |
56 | return DC_OK; |
57 | } |
58 | |
59 | static enum dc_status internal_link_write_dpcd( |
60 | struct dc_link *link, |
61 | uint32_t address, |
62 | const uint8_t *data, |
63 | uint32_t size) |
64 | { |
65 | if (!link->aux_access_disabled && |
66 | !dm_helpers_dp_write_dpcd(ctx: link->ctx, |
67 | link, address, data, size)) { |
68 | return DC_ERROR_UNEXPECTED; |
69 | } |
70 | |
71 | return DC_OK; |
72 | } |
73 | |
74 | /* |
75 | * Partition the entire DPCD address space |
76 | * XXX: This partitioning must cover the entire DPCD address space, |
77 | * and must contain no gaps or overlapping address ranges. |
78 | */ |
79 | static const struct dpcd_address_range mandatory_dpcd_partitions[] = { |
80 | { 0, DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1) - 1}, |
81 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, |
82 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, |
83 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, |
84 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, |
85 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, |
86 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, |
87 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8) - 1 }, |
88 | { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, |
89 | /* |
90 | * The FEC registers are contiguous |
91 | */ |
92 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, |
93 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, |
94 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, |
95 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, |
96 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, |
97 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, |
98 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, |
99 | { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR8), DP_LTTPR_MAX_ADD }, |
100 | /* all remaining DPCD addresses */ |
101 | { DP_LTTPR_MAX_ADD + 1, DP_DPCD_MAX_ADD } }; |
102 | |
103 | static inline bool do_addresses_intersect_with_range( |
104 | const struct dpcd_address_range *range, |
105 | const uint32_t start_address, |
106 | const uint32_t end_address) |
107 | { |
108 | return start_address <= range->end && end_address >= range->start; |
109 | } |
110 | |
111 | static uint32_t dpcd_get_next_partition_size(const uint32_t address, const uint32_t size) |
112 | { |
113 | const uint32_t end_address = END_ADDRESS(address, size); |
114 | uint32_t partition_iterator = 0; |
115 | |
116 | /* |
117 | * find current partition |
118 | * this loop spins forever if partition map above is not surjective |
119 | */ |
120 | while (!do_addresses_intersect_with_range(range: &mandatory_dpcd_partitions[partition_iterator], |
121 | start_address: address, end_address)) |
122 | partition_iterator++; |
123 | if (end_address < mandatory_dpcd_partitions[partition_iterator].end) |
124 | return size; |
125 | return ADDRESS_RANGE_SIZE(address, mandatory_dpcd_partitions[partition_iterator].end); |
126 | } |
127 | |
128 | /* |
129 | * Ranges of DPCD addresses that must be read in a single transaction |
130 | * XXX: Do not allow any two address ranges in this array to overlap |
131 | */ |
132 | static const struct dpcd_address_range mandatory_dpcd_blocks[] = { |
133 | { DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT }}; |
134 | |
135 | /* |
136 | * extend addresses to read all mandatory blocks together |
137 | */ |
138 | static void dpcd_extend_address_range( |
139 | const uint32_t in_address, |
140 | uint8_t * const in_data, |
141 | const uint32_t in_size, |
142 | uint32_t *out_address, |
143 | uint8_t **out_data, |
144 | uint32_t *out_size) |
145 | { |
146 | const uint32_t end_address = END_ADDRESS(in_address, in_size); |
147 | const struct dpcd_address_range *addr_range; |
148 | struct dpcd_address_range new_addr_range; |
149 | uint32_t i; |
150 | |
151 | new_addr_range.start = in_address; |
152 | new_addr_range.end = end_address; |
153 | for (i = 0; i < ARRAY_SIZE(mandatory_dpcd_blocks); i++) { |
154 | addr_range = &mandatory_dpcd_blocks[i]; |
155 | if (addr_range->start <= in_address && addr_range->end >= in_address) |
156 | new_addr_range.start = addr_range->start; |
157 | |
158 | if (addr_range->start <= end_address && addr_range->end >= end_address) |
159 | new_addr_range.end = addr_range->end; |
160 | } |
161 | *out_address = in_address; |
162 | *out_size = in_size; |
163 | *out_data = in_data; |
164 | if (new_addr_range.start != in_address || new_addr_range.end != end_address) { |
165 | *out_address = new_addr_range.start; |
166 | *out_size = ADDRESS_RANGE_SIZE(new_addr_range.start, new_addr_range.end); |
167 | *out_data = kcalloc(n: *out_size, size: sizeof(**out_data), GFP_KERNEL); |
168 | } |
169 | } |
170 | |
171 | /* |
172 | * Reduce the AUX reply down to the values the caller requested |
173 | */ |
174 | static void dpcd_reduce_address_range( |
175 | const uint32_t extended_address, |
176 | uint8_t * const extended_data, |
177 | const uint32_t extended_size, |
178 | const uint32_t reduced_address, |
179 | uint8_t * const reduced_data, |
180 | const uint32_t reduced_size) |
181 | { |
182 | const uint32_t offset = reduced_address - extended_address; |
183 | |
184 | /* |
185 | * If the address is same, address was not extended. |
186 | * So we do not need to free any memory. |
187 | * The data is in original buffer(reduced_data). |
188 | */ |
189 | if (extended_data == reduced_data) |
190 | return; |
191 | |
192 | memcpy(&extended_data[offset], reduced_data, reduced_size); |
193 | kfree(objp: extended_data); |
194 | } |
195 | |
196 | enum dc_status core_link_read_dpcd( |
197 | struct dc_link *link, |
198 | uint32_t address, |
199 | uint8_t *data, |
200 | uint32_t size) |
201 | { |
202 | uint32_t extended_address; |
203 | uint32_t partitioned_address; |
204 | uint8_t *extended_data; |
205 | uint32_t extended_size; |
206 | /* size of the remaining partitioned address space */ |
207 | uint32_t size_left_to_read; |
208 | enum dc_status status = DC_ERROR_UNEXPECTED; |
209 | /* size of the next partition to be read from */ |
210 | uint32_t partition_size; |
211 | uint32_t data_index = 0; |
212 | |
213 | dpcd_extend_address_range(in_address: address, in_data: data, in_size: size, out_address: &extended_address, out_data: &extended_data, out_size: &extended_size); |
214 | partitioned_address = extended_address; |
215 | size_left_to_read = extended_size; |
216 | while (size_left_to_read) { |
217 | partition_size = dpcd_get_next_partition_size(address: partitioned_address, size: size_left_to_read); |
218 | status = internal_link_read_dpcd(link, address: partitioned_address, data: &extended_data[data_index], size: partition_size); |
219 | if (status != DC_OK) |
220 | break; |
221 | partitioned_address += partition_size; |
222 | data_index += partition_size; |
223 | size_left_to_read -= partition_size; |
224 | } |
225 | dpcd_reduce_address_range(extended_address, extended_data, extended_size, reduced_address: address, reduced_data: data, reduced_size: size); |
226 | return status; |
227 | } |
228 | |
229 | enum dc_status core_link_write_dpcd( |
230 | struct dc_link *link, |
231 | uint32_t address, |
232 | const uint8_t *data, |
233 | uint32_t size) |
234 | { |
235 | uint32_t partition_size; |
236 | uint32_t data_index = 0; |
237 | enum dc_status status = DC_ERROR_UNEXPECTED; |
238 | |
239 | while (size) { |
240 | partition_size = dpcd_get_next_partition_size(address, size); |
241 | status = internal_link_write_dpcd(link, address, data: &data[data_index], size: partition_size); |
242 | if (status != DC_OK) |
243 | break; |
244 | address += partition_size; |
245 | data_index += partition_size; |
246 | size -= partition_size; |
247 | } |
248 | return status; |
249 | } |
250 | |