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 #include <inc/core_status.h>
27 #include <dc_link.h>
28 #include <inc/link_hwss.h>
29 #include <inc/link_dpcd.h>
30 #include "drm/drm_dp_helper.h"
31 #include <dc_dp_types.h>
32 #include "dm_helpers.h"
33 
34 #define END_ADDRESS(start, size) (start + size - 1)
35 #define ADDRESS_RANGE_SIZE(start, end) (end - start + 1)
36 struct dpcd_address_range {
37 	uint32_t start;
38 	uint32_t end;
39 };
40 
internal_link_read_dpcd(struct dc_link * link,uint32_t address,uint8_t * data,uint32_t size)41 static enum dc_status internal_link_read_dpcd(
42 	struct dc_link *link,
43 	uint32_t address,
44 	uint8_t *data,
45 	uint32_t size)
46 {
47 	if (!link->aux_access_disabled &&
48 			!dm_helpers_dp_read_dpcd(link->ctx,
49 			link, address, data, size)) {
50 		return DC_ERROR_UNEXPECTED;
51 	}
52 
53 	return DC_OK;
54 }
55 
internal_link_write_dpcd(struct dc_link * link,uint32_t address,const uint8_t * data,uint32_t size)56 static enum dc_status internal_link_write_dpcd(
57 	struct dc_link *link,
58 	uint32_t address,
59 	const uint8_t *data,
60 	uint32_t size)
61 {
62 	if (!link->aux_access_disabled &&
63 			!dm_helpers_dp_write_dpcd(link->ctx,
64 			link, address, data, size)) {
65 		return DC_ERROR_UNEXPECTED;
66 	}
67 
68 	return DC_OK;
69 }
70 
71 /*
72  * Partition the entire DPCD address space
73  * XXX: This partitioning must cover the entire DPCD address space,
74  * and must contain no gaps or overlapping address ranges.
75  */
76 static const struct dpcd_address_range mandatory_dpcd_partitions[] = {
77 	{ 0, DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1) - 1},
78 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2) - 1 },
79 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3) - 1 },
80 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4) - 1 },
81 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5) - 1 },
82 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6) - 1 },
83 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7) - 1 },
84 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8) - 1 },
85 	{ DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 },
86 	/*
87 	 * The FEC registers are contiguous
88 	 */
89 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 },
90 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2) - 1 },
91 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3) - 1 },
92 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4) - 1 },
93 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5) - 1 },
94 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6) - 1 },
95 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7) - 1 },
96 	{ DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR8), DP_LTTPR_MAX_ADD },
97 	/* all remaining DPCD addresses */
98 	{ DP_LTTPR_MAX_ADD + 1, DP_DPCD_MAX_ADD } };
99 
do_addresses_intersect_with_range(const struct dpcd_address_range * range,const uint32_t start_address,const uint32_t end_address)100 static inline bool do_addresses_intersect_with_range(
101 		const struct dpcd_address_range *range,
102 		const uint32_t start_address,
103 		const uint32_t end_address)
104 {
105 	return start_address <= range->end && end_address >= range->start;
106 }
107 
dpcd_get_next_partition_size(const uint32_t address,const uint32_t size)108 static uint32_t dpcd_get_next_partition_size(const uint32_t address, const uint32_t size)
109 {
110 	const uint32_t end_address = END_ADDRESS(address, size);
111 	uint32_t partition_iterator = 0;
112 
113 	/*
114 	 * find current partition
115 	 * this loop spins forever if partition map above is not surjective
116 	 */
117 	while (!do_addresses_intersect_with_range(&mandatory_dpcd_partitions[partition_iterator],
118 				address, end_address))
119 		partition_iterator++;
120 	if (end_address < mandatory_dpcd_partitions[partition_iterator].end)
121 		return size;
122 	return ADDRESS_RANGE_SIZE(address, mandatory_dpcd_partitions[partition_iterator].end);
123 }
124 
125 /*
126  * Ranges of DPCD addresses that must be read in a single transaction
127  * XXX: Do not allow any two address ranges in this array to overlap
128  */
129 static const struct dpcd_address_range mandatory_dpcd_blocks[] = {
130 	{ DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT }};
131 
132 /*
133  * extend addresses to read all mandatory blocks together
134  */
dpcd_extend_address_range(const uint32_t in_address,uint8_t * const in_data,const uint32_t in_size,uint32_t * out_address,uint8_t ** out_data,uint32_t * out_size)135 static void dpcd_extend_address_range(
136 		const uint32_t in_address,
137 		uint8_t * const in_data,
138 		const uint32_t in_size,
139 		uint32_t *out_address,
140 		uint8_t **out_data,
141 		uint32_t *out_size)
142 {
143 	const uint32_t end_address = END_ADDRESS(in_address, in_size);
144 	const struct dpcd_address_range *addr_range;
145 	struct dpcd_address_range new_addr_range;
146 	uint32_t i;
147 
148 	new_addr_range.start = in_address;
149 	new_addr_range.end = end_address;
150 	for (i = 0; i < ARRAY_SIZE(mandatory_dpcd_blocks); i++) {
151 		addr_range = &mandatory_dpcd_blocks[i];
152 		if (addr_range->start <= in_address && addr_range->end >= in_address)
153 			new_addr_range.start = addr_range->start;
154 
155 		if (addr_range->start <= end_address && addr_range->end >= end_address)
156 			new_addr_range.end = addr_range->end;
157 	}
158 	*out_address = in_address;
159 	*out_size = in_size;
160 	*out_data = in_data;
161 	if (new_addr_range.start != in_address || new_addr_range.end != end_address) {
162 		*out_address = new_addr_range.start;
163 		*out_size = ADDRESS_RANGE_SIZE(new_addr_range.start, new_addr_range.end);
164 		*out_data = kzalloc(*out_size * sizeof(**out_data), GFP_KERNEL);
165 	}
166 }
167 
168 /*
169  * Reduce the AUX reply down to the values the caller requested
170  */
dpcd_reduce_address_range(const uint32_t extended_address,uint8_t * const extended_data,const uint32_t extended_size,const uint32_t reduced_address,uint8_t * const reduced_data,const uint32_t reduced_size)171 static void dpcd_reduce_address_range(
172 		const uint32_t extended_address,
173 		uint8_t * const extended_data,
174 		const uint32_t extended_size,
175 		const uint32_t reduced_address,
176 		uint8_t * const reduced_data,
177 		const uint32_t reduced_size)
178 {
179 	const uint32_t offset = reduced_address - extended_address;
180 
181 	/*
182 	 * If the address is same, address was not extended.
183 	 * So we do not need to free any memory.
184 	 * The data is in original buffer(reduced_data).
185 	 */
186 	if (extended_data == reduced_data)
187 		return;
188 
189 	memcpy(&extended_data[offset], reduced_data, reduced_size);
190 	kfree(extended_data);
191 }
192 
core_link_read_dpcd(struct dc_link * link,uint32_t address,uint8_t * data,uint32_t size)193 enum dc_status core_link_read_dpcd(
194 	struct dc_link *link,
195 	uint32_t address,
196 	uint8_t *data,
197 	uint32_t size)
198 {
199 	uint32_t extended_address;
200 	uint32_t partitioned_address;
201 	uint8_t *extended_data;
202 	uint32_t extended_size;
203 	/* size of the remaining partitioned address space */
204 	uint32_t size_left_to_read;
205 	enum dc_status status;
206 	/* size of the next partition to be read from */
207 	uint32_t partition_size;
208 	uint32_t data_index = 0;
209 
210 	dpcd_extend_address_range(address, data, size, &extended_address, &extended_data, &extended_size);
211 	partitioned_address = extended_address;
212 	size_left_to_read = extended_size;
213 	while (size_left_to_read) {
214 		partition_size = dpcd_get_next_partition_size(partitioned_address, size_left_to_read);
215 		status = internal_link_read_dpcd(link, partitioned_address, &extended_data[data_index], partition_size);
216 		if (status != DC_OK)
217 			break;
218 		partitioned_address += partition_size;
219 		data_index += partition_size;
220 		size_left_to_read -= partition_size;
221 	}
222 	dpcd_reduce_address_range(extended_address, extended_data, extended_size, address, data, size);
223 	return status;
224 }
225 
core_link_write_dpcd(struct dc_link * link,uint32_t address,const uint8_t * data,uint32_t size)226 enum dc_status core_link_write_dpcd(
227 	struct dc_link *link,
228 	uint32_t address,
229 	const uint8_t *data,
230 	uint32_t size)
231 {
232 	uint32_t partition_size;
233 	uint32_t data_index = 0;
234 	enum dc_status status;
235 
236 	while (size) {
237 		partition_size = dpcd_get_next_partition_size(address, size);
238 		status = internal_link_write_dpcd(link, address, &data[data_index], partition_size);
239 		if (status != DC_OK)
240 			break;
241 		address += partition_size;
242 		data_index += partition_size;
243 		size -= partition_size;
244 	}
245 	return status;
246 }
247