/*
* 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_128B132B_RATES }};
/*
* 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 = kcalloc(*out_size, sizeof(**out_data), GFP_KERNEL);
ASSERT(*out_data);
}
}
/*
* 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 = DC_ERROR_UNEXPECTED;
/* 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 = DC_ERROR_UNEXPECTED;
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;
}
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