diff options
Diffstat (limited to 'drivers/gpu/drm/amd/display/dc/link/link_dpcd.c')
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/link/link_dpcd.c | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpcd.c b/drivers/gpu/drm/amd/display/dc/link/link_dpcd.c new file mode 100644 index 000000000000..5c9a30211c10 --- /dev/null +++ b/drivers/gpu/drm/amd/display/dc/link/link_dpcd.c @@ -0,0 +1,249 @@ +/* + * Copyright 2021 Advanced Micro Devices, Inc. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * Authors: AMD + * + */ + +/* FILE POLICY AND INTENDED USAGE: + * + * This file implements basic dpcd read/write functionality. It also does basic + * dpcd range check to ensure that every dpcd request is compliant with specs + * range requirements. + */ + +#include "link_dpcd.h" +#include <drm/display/drm_dp_helper.h> +#include "dm_helpers.h" + +#define END_ADDRESS(start, size) (start + size - 1) +#define ADDRESS_RANGE_SIZE(start, end) (end - start + 1) +struct dpcd_address_range { + uint32_t start; + uint32_t end; +}; + +static enum dc_status internal_link_read_dpcd( + struct dc_link *link, + uint32_t address, + uint8_t *data, + uint32_t size) +{ + if (!link->aux_access_disabled && + !dm_helpers_dp_read_dpcd(link->ctx, + link, address, data, size)) { + return DC_ERROR_UNEXPECTED; + } + + return DC_OK; +} + +static enum dc_status internal_link_write_dpcd( + struct dc_link *link, + uint32_t address, + const uint8_t *data, + uint32_t size) +{ + if (!link->aux_access_disabled && + !dm_helpers_dp_write_dpcd(link->ctx, + link, address, data, size)) { + return DC_ERROR_UNEXPECTED; + } + + return DC_OK; +} + +/* + * Partition the entire DPCD address space + * XXX: This partitioning must cover the entire DPCD address space, + * and must contain no gaps or overlapping address ranges. + */ +static const struct dpcd_address_range mandatory_dpcd_partitions[] = { + { 0, DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1) - 1}, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR1), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR2), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR3), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR4), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR5), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR6), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR7), DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8) - 1 }, + { DP_TRAINING_PATTERN_SET_PHY_REPEATER(DP_PHY_LTTPR8), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, + /* + * The FEC registers are contiguous + */ + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR1) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR2) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR3) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR4) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR5) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR6) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7), DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR7) - 1 }, + { DP_FEC_STATUS_PHY_REPEATER(DP_PHY_LTTPR8), DP_LTTPR_MAX_ADD }, + /* all remaining DPCD addresses */ + { DP_LTTPR_MAX_ADD + 1, DP_DPCD_MAX_ADD } }; + +static inline bool do_addresses_intersect_with_range( + const struct dpcd_address_range *range, + const uint32_t start_address, + const uint32_t end_address) +{ + return start_address <= range->end && end_address >= range->start; +} + +static uint32_t dpcd_get_next_partition_size(const uint32_t address, const uint32_t size) +{ + const uint32_t end_address = END_ADDRESS(address, size); + uint32_t partition_iterator = 0; + + /* + * find current partition + * this loop spins forever if partition map above is not surjective + */ + while (!do_addresses_intersect_with_range(&mandatory_dpcd_partitions[partition_iterator], + address, end_address)) + partition_iterator++; + if (end_address < mandatory_dpcd_partitions[partition_iterator].end) + return size; + return ADDRESS_RANGE_SIZE(address, mandatory_dpcd_partitions[partition_iterator].end); +} + +/* + * Ranges of DPCD addresses that must be read in a single transaction + * XXX: Do not allow any two address ranges in this array to overlap + */ +static const struct dpcd_address_range mandatory_dpcd_blocks[] = { + { DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV, DP_PHY_REPEATER_EXTENDED_WAIT_TIMEOUT }}; + +/* + * extend addresses to read all mandatory blocks together + */ +static void 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) +{ + const uint32_t end_address = END_ADDRESS(in_address, in_size); + const struct dpcd_address_range *addr_range; + struct dpcd_address_range new_addr_range; + uint32_t i; + + new_addr_range.start = in_address; + new_addr_range.end = end_address; + for (i = 0; i < ARRAY_SIZE(mandatory_dpcd_blocks); i++) { + addr_range = &mandatory_dpcd_blocks[i]; + if (addr_range->start <= in_address && addr_range->end >= in_address) + new_addr_range.start = addr_range->start; + + if (addr_range->start <= end_address && addr_range->end >= end_address) + new_addr_range.end = addr_range->end; + } + *out_address = in_address; + *out_size = in_size; + *out_data = in_data; + if (new_addr_range.start != in_address || new_addr_range.end != end_address) { + *out_address = new_addr_range.start; + *out_size = ADDRESS_RANGE_SIZE(new_addr_range.start, new_addr_range.end); + *out_data = kzalloc(*out_size * sizeof(**out_data), GFP_KERNEL); + } +} + +/* + * Reduce the AUX reply down to the values the caller requested + */ +static void 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) +{ + const uint32_t offset = reduced_address - extended_address; + + /* + * If the address is same, address was not extended. + * So we do not need to free any memory. + * The data is in original buffer(reduced_data). + */ + if (extended_data == reduced_data) + return; + + memcpy(&extended_data[offset], reduced_data, reduced_size); + kfree(extended_data); +} + +enum dc_status core_link_read_dpcd( + struct dc_link *link, + uint32_t address, + uint8_t *data, + uint32_t size) +{ + uint32_t extended_address; + uint32_t partitioned_address; + uint8_t *extended_data; + uint32_t extended_size; + /* size of the remaining partitioned address space */ + uint32_t size_left_to_read; + enum dc_status status; + /* size of the next partition to be read from */ + uint32_t partition_size; + uint32_t data_index = 0; + + dpcd_extend_address_range(address, data, size, &extended_address, &extended_data, &extended_size); + partitioned_address = extended_address; + size_left_to_read = extended_size; + while (size_left_to_read) { + partition_size = dpcd_get_next_partition_size(partitioned_address, size_left_to_read); + status = internal_link_read_dpcd(link, partitioned_address, &extended_data[data_index], partition_size); + if (status != DC_OK) + break; + partitioned_address += partition_size; + data_index += partition_size; + size_left_to_read -= partition_size; + } + dpcd_reduce_address_range(extended_address, extended_data, extended_size, address, data, size); + return status; +} + +enum dc_status core_link_write_dpcd( + struct dc_link *link, + uint32_t address, + const uint8_t *data, + uint32_t size) +{ + uint32_t partition_size; + uint32_t data_index = 0; + enum dc_status status; + + while (size) { + partition_size = dpcd_get_next_partition_size(address, size); + status = internal_link_write_dpcd(link, address, &data[data_index], partition_size); + if (status != DC_OK) + break; + address += partition_size; + data_index += partition_size; + size -= partition_size; + } + return status; +} |