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linux-sg2042/drivers/gpu/drm/drm_dp_mst_topology.c

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/*
* Copyright © 2014 Red Hat
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/i2c.h>
#include <drm/drm_dp_mst_helper.h>
#include <drm/drmP.h>
#include <drm/drm_fixed.h>
/**
* DOC: dp mst helper
*
* These functions contain parts of the DisplayPort 1.2a MultiStream Transport
* protocol. The helpers contain a topology manager and bandwidth manager.
* The helpers encapsulate the sending and received of sideband msgs.
*/
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf);
static int test_calc_pbn_mode(void);
static void drm_dp_put_port(struct drm_dp_mst_port *port);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload);
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes);
static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb);
static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port);
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid);
static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
/* sideband msg handling */
static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = num_nibbles * 4;
u8 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x10) == 0x10)
remainder ^= 0x13;
}
number_of_bits = 4;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x10) != 0)
remainder ^= 0x13;
}
return remainder;
}
static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
{
u8 bitmask = 0x80;
u8 bitshift = 7;
u8 array_index = 0;
int number_of_bits = number_of_bytes * 8;
u16 remainder = 0;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
remainder |= (data[array_index] & bitmask) >> bitshift;
bitmask >>= 1;
bitshift--;
if (bitmask == 0) {
bitmask = 0x80;
bitshift = 7;
array_index++;
}
if ((remainder & 0x100) == 0x100)
remainder ^= 0xd5;
}
number_of_bits = 8;
while (number_of_bits != 0) {
number_of_bits--;
remainder <<= 1;
if ((remainder & 0x100) != 0)
remainder ^= 0xd5;
}
return remainder & 0xff;
}
static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
{
u8 size = 3;
size += (hdr->lct / 2);
return size;
}
static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int *len)
{
int idx = 0;
int i;
u8 crc4;
buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
for (i = 0; i < (hdr->lct / 2); i++)
buf[idx++] = hdr->rad[i];
buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
(hdr->msg_len & 0x3f);
buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
buf[idx - 1] |= (crc4 & 0xf);
*len = idx;
}
static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
u8 *buf, int buflen, u8 *hdrlen)
{
u8 crc4;
u8 len;
int i;
u8 idx;
if (buf[0] == 0)
return false;
len = 3;
len += ((buf[0] & 0xf0) >> 4) / 2;
if (len > buflen)
return false;
crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
return false;
}
hdr->lct = (buf[0] & 0xf0) >> 4;
hdr->lcr = (buf[0] & 0xf);
idx = 1;
for (i = 0; i < (hdr->lct / 2); i++)
hdr->rad[i] = buf[idx++];
hdr->broadcast = (buf[idx] >> 7) & 0x1;
hdr->path_msg = (buf[idx] >> 6) & 0x1;
hdr->msg_len = buf[idx] & 0x3f;
idx++;
hdr->somt = (buf[idx] >> 7) & 0x1;
hdr->eomt = (buf[idx] >> 6) & 0x1;
hdr->seqno = (buf[idx] >> 4) & 0x1;
idx++;
*hdrlen = idx;
return true;
}
static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
int i;
u8 *buf = raw->msg;
buf[idx++] = req->req_type & 0x7f;
switch (req->req_type) {
case DP_ENUM_PATH_RESOURCES:
buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
idx++;
break;
case DP_ALLOCATE_PAYLOAD:
buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
(req->u.allocate_payload.number_sdp_streams & 0xf);
idx++;
buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
idx++;
buf[idx] = (req->u.allocate_payload.pbn >> 8);
idx++;
buf[idx] = (req->u.allocate_payload.pbn & 0xff);
idx++;
for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
idx++;
}
if (req->u.allocate_payload.number_sdp_streams & 1) {
i = req->u.allocate_payload.number_sdp_streams - 1;
buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
idx++;
}
break;
case DP_QUERY_PAYLOAD:
buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.query_payload.vcpi & 0x7f);
idx++;
break;
case DP_REMOTE_DPCD_READ:
buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_read.num_bytes);
idx++;
break;
case DP_REMOTE_DPCD_WRITE:
buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
idx++;
buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
idx++;
buf[idx] = (req->u.dpcd_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
idx += req->u.dpcd_write.num_bytes;
break;
case DP_REMOTE_I2C_READ:
buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
idx++;
for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
idx++;
buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
idx++;
memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
idx += req->u.i2c_read.transactions[i].num_bytes;
buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
idx++;
}
buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_read.num_bytes_read);
idx++;
break;
case DP_REMOTE_I2C_WRITE:
buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
idx++;
buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
idx++;
buf[idx] = (req->u.i2c_write.num_bytes);
idx++;
memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
idx += req->u.i2c_write.num_bytes;
break;
}
raw->cur_len = idx;
}
static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
{
u8 crc4;
crc4 = drm_dp_msg_data_crc4(msg, len);
msg[len] = crc4;
}
static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
struct drm_dp_sideband_msg_tx *raw)
{
int idx = 0;
u8 *buf = raw->msg;
buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
raw->cur_len = idx;
}
/* this adds a chunk of msg to the builder to get the final msg */
static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
u8 *replybuf, u8 replybuflen, bool hdr)
{
int ret;
u8 crc4;
if (hdr) {
u8 hdrlen;
struct drm_dp_sideband_msg_hdr recv_hdr;
ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
if (ret == false) {
print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
return false;
}
/* get length contained in this portion */
msg->curchunk_len = recv_hdr.msg_len;
msg->curchunk_hdrlen = hdrlen;
/* we have already gotten an somt - don't bother parsing */
if (recv_hdr.somt && msg->have_somt)
return false;
if (recv_hdr.somt) {
memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
msg->have_somt = true;
}
if (recv_hdr.eomt)
msg->have_eomt = true;
/* copy the bytes for the remainder of this header chunk */
msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
} else {
memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
msg->curchunk_idx += replybuflen;
}
if (msg->curchunk_idx >= msg->curchunk_len) {
/* do CRC */
crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
/* copy chunk into bigger msg */
memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
msg->curlen += msg->curchunk_len - 1;
}
return true;
}
static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
int i;
memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
idx += 16;
repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
for (i = 0; i < repmsg->u.link_addr.nports; i++) {
if (raw->msg[idx] & 0x80)
repmsg->u.link_addr.ports[i].input_port = 1;
repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
if (repmsg->u.link_addr.ports[i].input_port == 0)
repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
idx++;
if (idx > raw->curlen)
goto fail_len;
if (repmsg->u.link_addr.ports[i].input_port == 0) {
repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
idx++;
}
if (idx > raw->curlen)
goto fail_len;
}
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
if (idx > raw->curlen)
goto fail_len;
memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
idx++;
/* TODO check */
memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
return true;
fail_len:
DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.vcpi = raw->msg[idx];
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *repmsg)
{
int idx = 1;
repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
idx++;
if (idx > raw->curlen)
goto fail_len;
repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx += 2;
if (idx > raw->curlen)
goto fail_len;
return true;
fail_len:
DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_reply_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->reply_type = (raw->msg[0] & 0x80) >> 7;
msg->req_type = (raw->msg[0] & 0x7f);
if (msg->reply_type) {
memcpy(msg->u.nak.guid, &raw->msg[1], 16);
msg->u.nak.reason = raw->msg[17];
msg->u.nak.nak_data = raw->msg[18];
return false;
}
switch (msg->req_type) {
case DP_LINK_ADDRESS:
return drm_dp_sideband_parse_link_address(raw, msg);
case DP_QUERY_PAYLOAD:
return drm_dp_sideband_parse_query_payload_ack(raw, msg);
case DP_REMOTE_DPCD_READ:
return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
case DP_REMOTE_DPCD_WRITE:
return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
case DP_REMOTE_I2C_READ:
return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
case DP_ENUM_PATH_RESOURCES:
return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
case DP_ALLOCATE_PAYLOAD:
return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
default:
DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
return false;
}
}
static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
int idx = 1;
msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
idx++;
if (idx > raw->curlen)
goto fail_len;
memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
idx += 16;
if (idx > raw->curlen)
goto fail_len;
msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
idx++;
return true;
fail_len:
DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
return false;
}
static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
{
memset(msg, 0, sizeof(*msg));
msg->req_type = (raw->msg[0] & 0x7f);
switch (msg->req_type) {
case DP_CONNECTION_STATUS_NOTIFY:
return drm_dp_sideband_parse_connection_status_notify(raw, msg);
case DP_RESOURCE_STATUS_NOTIFY:
return drm_dp_sideband_parse_resource_status_notify(raw, msg);
default:
DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
return false;
}
}
static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_WRITE;
req.u.dpcd_write.port_number = port_num;
req.u.dpcd_write.dpcd_address = offset;
req.u.dpcd_write.num_bytes = num_bytes;
req.u.dpcd_write.bytes = bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_LINK_ADDRESS;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_ENUM_PATH_RESOURCES;
req.u.port_num.port_number = port_num;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
u8 vcpi, uint16_t pbn)
{
struct drm_dp_sideband_msg_req_body req;
memset(&req, 0, sizeof(req));
req.req_type = DP_ALLOCATE_PAYLOAD;
req.u.allocate_payload.port_number = port_num;
req.u.allocate_payload.vcpi = vcpi;
req.u.allocate_payload.pbn = pbn;
drm_dp_encode_sideband_req(&req, msg);
msg->path_msg = true;
return 0;
}
static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi)
{
int ret, vcpi_ret;
mutex_lock(&mgr->payload_lock);
ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
if (ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of payload ids %d\n", ret);
goto out_unlock;
}
vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
if (vcpi_ret > mgr->max_payloads) {
ret = -EINVAL;
DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
goto out_unlock;
}
set_bit(ret, &mgr->payload_mask);
set_bit(vcpi_ret, &mgr->vcpi_mask);
vcpi->vcpi = vcpi_ret + 1;
mgr->proposed_vcpis[ret - 1] = vcpi;
out_unlock:
mutex_unlock(&mgr->payload_lock);
return ret;
}
static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
int vcpi)
{
int i;
if (vcpi == 0)
return;
mutex_lock(&mgr->payload_lock);
DRM_DEBUG_KMS("putting payload %d\n", vcpi);
clear_bit(vcpi - 1, &mgr->vcpi_mask);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i])
if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
mgr->proposed_vcpis[i] = NULL;
clear_bit(i + 1, &mgr->payload_mask);
}
}
mutex_unlock(&mgr->payload_lock);
}
static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
bool ret;
/*
* All updates to txmsg->state are protected by mgr->qlock, and the two
* cases we check here are terminal states. For those the barriers
* provided by the wake_up/wait_event pair are enough.
*/
ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
return ret;
}
static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
int ret;
ret = wait_event_timeout(mgr->tx_waitq,
check_txmsg_state(mgr, txmsg),
(4 * HZ));
mutex_lock(&mstb->mgr->qlock);
if (ret > 0) {
if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
ret = -EIO;
goto out;
}
} else {
DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
/* dump some state */
ret = -EIO;
/* remove from q */
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
list_del(&txmsg->next);
}
if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
mstb->tx_slots[txmsg->seqno] = NULL;
}
}
out:
mutex_unlock(&mgr->qlock);
return ret;
}
static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
if (!mstb)
return NULL;
mstb->lct = lct;
if (lct > 1)
memcpy(mstb->rad, rad, lct / 2);
INIT_LIST_HEAD(&mstb->ports);
kref_init(&mstb->kref);
return mstb;
}
static void drm_dp_destroy_mst_branch_device(struct kref *kref)
{
struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
struct drm_dp_mst_port *port, *tmp;
bool wake_tx = false;
cancel_work_sync(&mstb->mgr->work);
/*
* destroy all ports - don't need lock
* as there are no more references to the mst branch
* device at this point.
*/
list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
list_del(&port->next);
drm_dp_put_port(port);
}
/* drop any tx slots msg */
mutex_lock(&mstb->mgr->qlock);
if (mstb->tx_slots[0]) {
mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
mstb->tx_slots[0] = NULL;
wake_tx = true;
}
if (mstb->tx_slots[1]) {
mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
mstb->tx_slots[1] = NULL;
wake_tx = true;
}
mutex_unlock(&mstb->mgr->qlock);
if (wake_tx)
wake_up(&mstb->mgr->tx_waitq);
kfree(mstb);
}
static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
{
kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
}
static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
{
struct drm_dp_mst_branch *mstb;
switch (old_pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
/* remove i2c over sideband */
drm_dp_mst_unregister_i2c_bus(&port->aux);
break;
case DP_PEER_DEVICE_MST_BRANCHING:
mstb = port->mstb;
port->mstb = NULL;
drm_dp_put_mst_branch_device(mstb);
break;
}
}
static void drm_dp_destroy_port(struct kref *kref)
{
struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
if (!port->input) {
port->vcpi.num_slots = 0;
kfree(port->cached_edid);
/* we can't destroy the connector here, as
we might be holding the mode_config.mutex
from an EDID retrieval */
if (port->connector) {
mutex_lock(&mgr->destroy_connector_lock);
list_add(&port->next, &mgr->destroy_connector_list);
mutex_unlock(&mgr->destroy_connector_lock);
schedule_work(&mgr->destroy_connector_work);
return;
}
drm_dp_port_teardown_pdt(port, port->pdt);
if (!port->input && port->vcpi.vcpi > 0)
drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
}
kfree(port);
(*mgr->cbs->hotplug)(mgr);
}
static void drm_dp_put_port(struct drm_dp_mst_port *port)
{
kref_put(&port->kref, drm_dp_destroy_port);
}
static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *rmstb;
if (to_find == mstb) {
kref_get(&mstb->kref);
return mstb;
}
list_for_each_entry(port, &mstb->ports, next) {
if (port->mstb) {
rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
if (rmstb)
return rmstb;
}
}
return NULL;
}
static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_branch *rmstb = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary)
rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
mutex_unlock(&mgr->lock);
return rmstb;
}
static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
{
struct drm_dp_mst_port *port, *mport;
list_for_each_entry(port, &mstb->ports, next) {
if (port == to_find) {
kref_get(&port->kref);
return port;
}
if (port->mstb) {
mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
if (mport)
return mport;
}
}
return NULL;
}
static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
struct drm_dp_mst_port *rport = NULL;
mutex_lock(&mgr->lock);
if (mgr->mst_primary)
rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
mutex_unlock(&mgr->lock);
return rport;
}
static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
{
struct drm_dp_mst_port *port;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
kref_get(&port->kref);
return port;
}
}
return NULL;
}
/*
* calculate a new RAD for this MST branch device
* if parent has an LCT of 2 then it has 1 nibble of RAD,
* if parent has an LCT of 3 then it has 2 nibbles of RAD,
*/
static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
u8 *rad)
{
int lct = port->parent->lct;
int shift = 4;
int idx = lct / 2;
if (lct > 1) {
memcpy(rad, port->parent->rad, idx);
shift = (lct % 2) ? 4 : 0;
} else
rad[0] = 0;
rad[idx] |= port->port_num << shift;
return lct + 1;
}
/*
* return sends link address for new mstb
*/
static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
{
int ret;
u8 rad[6], lct;
bool send_link = false;
switch (port->pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
case DP_PEER_DEVICE_SST_SINK:
/* add i2c over sideband */
ret = drm_dp_mst_register_i2c_bus(&port->aux);
break;
case DP_PEER_DEVICE_MST_BRANCHING:
lct = drm_dp_calculate_rad(port, rad);
port->mstb = drm_dp_add_mst_branch_device(lct, rad);
port->mstb->mgr = port->mgr;
port->mstb->port_parent = port;
send_link = true;
break;
}
return send_link;
}
static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
int ret;
if (port->dpcd_rev >= 0x12) {
port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
if (!port->guid_valid) {
ret = drm_dp_send_dpcd_write(mstb->mgr,
port,
DP_GUID,
16, port->guid);
port->guid_valid = true;
}
}
}
static void build_mst_prop_path(struct drm_dp_mst_port *port,
struct drm_dp_mst_branch *mstb,
char *proppath,
size_t proppath_size)
{
int i;
char temp[8];
snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
for (i = 0; i < (mstb->lct - 1); i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = mstb->rad[i / 2] >> shift;
snprintf(temp, sizeof(temp), "-%d", port_num);
strlcat(proppath, temp, proppath_size);
}
snprintf(temp, sizeof(temp), "-%d", port->port_num);
strlcat(proppath, temp, proppath_size);
}
static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
struct device *dev,
struct drm_dp_link_addr_reply_port *port_msg)
{
struct drm_dp_mst_port *port;
bool ret;
bool created = false;
int old_pdt = 0;
int old_ddps = 0;
port = drm_dp_get_port(mstb, port_msg->port_number);
if (!port) {
port = kzalloc(sizeof(*port), GFP_KERNEL);
if (!port)
return;
kref_init(&port->kref);
port->parent = mstb;
port->port_num = port_msg->port_number;
port->mgr = mstb->mgr;
port->aux.name = "DPMST";
port->aux.dev = dev;
created = true;
} else {
old_pdt = port->pdt;
old_ddps = port->ddps;
}
port->pdt = port_msg->peer_device_type;
port->input = port_msg->input_port;
port->mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
port->num_sdp_streams = port_msg->num_sdp_streams;
port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
memcpy(port->guid, port_msg->peer_guid, 16);
/* manage mstb port lists with mgr lock - take a reference
for this list */
if (created) {
mutex_lock(&mstb->mgr->lock);
kref_get(&port->kref);
list_add(&port->next, &mstb->ports);
mutex_unlock(&mstb->mgr->lock);
}
if (old_ddps != port->ddps) {
if (port->ddps) {
drm_dp_check_port_guid(mstb, port);
if (!port->input)
drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
} else {
port->guid_valid = false;
port->available_pbn = 0;
}
}
if (old_pdt != port->pdt && !port->input) {
drm_dp_port_teardown_pdt(port, old_pdt);
ret = drm_dp_port_setup_pdt(port);
if (ret == true) {
drm_dp_send_link_address(mstb->mgr, port->mstb);
port->mstb->link_address_sent = true;
}
}
if (created && !port->input) {
char proppath[255];
build_mst_prop_path(port, mstb, proppath, sizeof(proppath));
port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
if (port->port_num >= 8) {
port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
}
}
/* put reference to this port */
drm_dp_put_port(port);
}
static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
struct drm_dp_connection_status_notify *conn_stat)
{
struct drm_dp_mst_port *port;
int old_pdt;
int old_ddps;
bool dowork = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
if (!port)
return;
old_ddps = port->ddps;
old_pdt = port->pdt;
port->pdt = conn_stat->peer_device_type;
port->mcs = conn_stat->message_capability_status;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
if (old_ddps != port->ddps) {
if (port->ddps) {
drm_dp_check_port_guid(mstb, port);
dowork = true;
} else {
port->guid_valid = false;
port->available_pbn = 0;
}
}
if (old_pdt != port->pdt && !port->input) {
drm_dp_port_teardown_pdt(port, old_pdt);
if (drm_dp_port_setup_pdt(port))
dowork = true;
}
drm_dp_put_port(port);
if (dowork)
queue_work(system_long_wq, &mstb->mgr->work);
}
static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
u8 lct, u8 *rad)
{
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_port *port;
int i;
/* find the port by iterating down */
mutex_lock(&mgr->lock);
mstb = mgr->mst_primary;
for (i = 0; i < lct - 1; i++) {
int shift = (i % 2) ? 0 : 4;
int port_num = rad[i / 2] >> shift;
list_for_each_entry(port, &mstb->ports, next) {
if (port->port_num == port_num) {
if (!port->mstb) {
DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
return NULL;
}
mstb = port->mstb;
break;
}
}
}
kref_get(&mstb->kref);
mutex_unlock(&mgr->lock);
return mstb;
}
static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
struct drm_dp_mst_branch *mstb_child;
if (!mstb->link_address_sent) {
drm_dp_send_link_address(mgr, mstb);
mstb->link_address_sent = true;
}
list_for_each_entry(port, &mstb->ports, next) {
if (port->input)
continue;
if (!port->ddps)
continue;
if (!port->available_pbn)
drm_dp_send_enum_path_resources(mgr, mstb, port);
if (port->mstb) {
mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
if (mstb_child) {
drm_dp_check_and_send_link_address(mgr, mstb_child);
drm_dp_put_mst_branch_device(mstb_child);
}
}
}
}
static void drm_dp_mst_link_probe_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
struct drm_dp_mst_branch *mstb;
mutex_lock(&mgr->lock);
mstb = mgr->mst_primary;
if (mstb) {
kref_get(&mstb->kref);
}
mutex_unlock(&mgr->lock);
if (mstb) {
drm_dp_check_and_send_link_address(mgr, mstb);
drm_dp_put_mst_branch_device(mstb);
}
}
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
u8 *guid)
{
static u8 zero_guid[16];
if (!memcmp(guid, zero_guid, 16)) {
u64 salt = get_jiffies_64();
memcpy(&guid[0], &salt, sizeof(u64));
memcpy(&guid[8], &salt, sizeof(u64));
return false;
}
return true;
}
#if 0
static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
{
struct drm_dp_sideband_msg_req_body req;
req.req_type = DP_REMOTE_DPCD_READ;
req.u.dpcd_read.port_number = port_num;
req.u.dpcd_read.dpcd_address = offset;
req.u.dpcd_read.num_bytes = num_bytes;
drm_dp_encode_sideband_req(&req, msg);
return 0;
}
#endif
static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
bool up, u8 *msg, int len)
{
int ret;
int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
int tosend, total, offset;
int retries = 0;
retry:
total = len;
offset = 0;
do {
tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
&msg[offset],
tosend);
if (ret != tosend) {
if (ret == -EIO && retries < 5) {
retries++;
goto retry;
}
DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
return -EIO;
}
offset += tosend;
total -= tosend;
} while (total > 0);
return 0;
}
static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
struct drm_dp_sideband_msg_tx *txmsg)
{
struct drm_dp_mst_branch *mstb = txmsg->dst;
/* both msg slots are full */
if (txmsg->seqno == -1) {
if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
return -EAGAIN;
}
if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
txmsg->seqno = mstb->last_seqno;
mstb->last_seqno ^= 1;
} else if (mstb->tx_slots[0] == NULL)
txmsg->seqno = 0;
else
txmsg->seqno = 1;
mstb->tx_slots[txmsg->seqno] = txmsg;
}
hdr->broadcast = 0;
hdr->path_msg = txmsg->path_msg;
hdr->lct = mstb->lct;
hdr->lcr = mstb->lct - 1;
if (mstb->lct > 1)
memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
hdr->seqno = txmsg->seqno;
return 0;
}
/*
* process a single block of the next message in the sideband queue
*/
static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg,
bool up)
{
u8 chunk[48];
struct drm_dp_sideband_msg_hdr hdr;
int len, space, idx, tosend;
int ret;
memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
txmsg->seqno = -1;
txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
}
/* make hdr from dst mst - for replies use seqno
otherwise assign one */
ret = set_hdr_from_dst_qlock(&hdr, txmsg);
if (ret < 0)
return ret;
/* amount left to send in this message */
len = txmsg->cur_len - txmsg->cur_offset;
/* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
tosend = min(len, space);
if (len == txmsg->cur_len)
hdr.somt = 1;
if (space >= len)
hdr.eomt = 1;
hdr.msg_len = tosend + 1;
drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
/* add crc at end */
drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
idx += tosend + 1;
ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
if (ret) {
DRM_DEBUG_KMS("sideband msg failed to send\n");
return ret;
}
txmsg->cur_offset += tosend;
if (txmsg->cur_offset == txmsg->cur_len) {
txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
return 1;
}
return 0;
}
static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
WARN_ON(!mutex_is_locked(&mgr->qlock));
/* construct a chunk from the first msg in the tx_msg queue */
if (list_empty(&mgr->tx_msg_downq)) {
mgr->tx_down_in_progress = false;
return;
}
mgr->tx_down_in_progress = true;
txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
ret = process_single_tx_qlock(mgr, txmsg, false);
if (ret == 1) {
/* txmsg is sent it should be in the slots now */
list_del(&txmsg->next);
} else if (ret) {
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
list_del(&txmsg->next);
if (txmsg->seqno != -1)
txmsg->dst->tx_slots[txmsg->seqno] = NULL;
txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
wake_up(&mgr->tx_waitq);
}
if (list_empty(&mgr->tx_msg_downq)) {
mgr->tx_down_in_progress = false;
return;
}
}
/* called holding qlock */
static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
/* construct a chunk from the first msg in the tx_msg queue */
if (list_empty(&mgr->tx_msg_upq)) {
mgr->tx_up_in_progress = false;
return;
}
txmsg = list_first_entry(&mgr->tx_msg_upq, struct drm_dp_sideband_msg_tx, next);
ret = process_single_tx_qlock(mgr, txmsg, true);
if (ret == 1) {
/* up txmsgs aren't put in slots - so free after we send it */
list_del(&txmsg->next);
kfree(txmsg);
} else if (ret)
DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
mgr->tx_up_in_progress = true;
}
static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_tx *txmsg)
{
mutex_lock(&mgr->qlock);
list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
if (!mgr->tx_down_in_progress)
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb)
{
int len;
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
len = build_link_address(txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
int i;
if (txmsg->reply.reply_type == 1)
DRM_DEBUG_KMS("link address nak received\n");
else {
DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
txmsg->reply.u.link_addr.ports[i].input_port,
txmsg->reply.u.link_addr.ports[i].peer_device_type,
txmsg->reply.u.link_addr.ports[i].port_number,
txmsg->reply.u.link_addr.ports[i].dpcd_revision,
txmsg->reply.u.link_addr.ports[i].mcs,
txmsg->reply.u.link_addr.ports[i].ddps,
txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
}
for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
}
(*mgr->cbs->hotplug)(mgr);
}
} else
DRM_DEBUG_KMS("link address failed %d\n", ret);
kfree(txmsg);
return 0;
}
static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
{
int len;
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
len = build_enum_path_resources(txmsg, port->port_num);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == 1)
DRM_DEBUG_KMS("enum path resources nak received\n");
else {
if (port->port_num != txmsg->reply.u.path_resources.port_number)
DRM_ERROR("got incorrect port in response\n");
DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
txmsg->reply.u.path_resources.avail_payload_bw_number);
port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
}
}
kfree(txmsg);
return 0;
}
static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
int pbn)
{
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
int len, ret;
mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
txmsg->dst = mstb;
len = build_allocate_payload(txmsg, port->port_num,
id,
pbn);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == 1) {
ret = -EINVAL;
} else
ret = 0;
}
kfree(txmsg);
fail_put:
drm_dp_put_mst_branch_device(mstb);
return ret;
}
static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_dpcd_write_payload(mgr, id, payload);
if (ret < 0) {
payload->payload_state = 0;
return ret;
}
payload->payload_state = DP_PAYLOAD_LOCAL;
return 0;
}
static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
int ret;
ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
if (ret < 0)
return ret;
payload->payload_state = DP_PAYLOAD_REMOTE;
return ret;
}
static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int id,
struct drm_dp_payload *payload)
{
DRM_DEBUG_KMS("\n");
/* its okay for these to fail */
if (port) {
drm_dp_payload_send_msg(mgr, port, id, 0);
}
drm_dp_dpcd_write_payload(mgr, id, payload);
payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
return 0;
}
static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
int id,
struct drm_dp_payload *payload)
{
payload->payload_state = 0;
return 0;
}
/**
* drm_dp_update_payload_part1() - Execute payload update part 1
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step just writes the VCPI to the MST device. For slots->0
* transitions, this writes the updated VCPIs and removes the
* remote VC payloads.
*
* after calling this the driver should generate ACT and payload
* packets.
*/
int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
{
int i, j;
int cur_slots = 1;
struct drm_dp_payload req_payload;
struct drm_dp_mst_port *port;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
/* solve the current payloads - compare to the hw ones
- update the hw view */
req_payload.start_slot = cur_slots;
if (mgr->proposed_vcpis[i]) {
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
} else {
port = NULL;
req_payload.num_slots = 0;
}
if (mgr->payloads[i].start_slot != req_payload.start_slot) {
mgr->payloads[i].start_slot = req_payload.start_slot;
}
/* work out what is required to happen with this payload */
if (mgr->payloads[i].num_slots != req_payload.num_slots) {
/* need to push an update for this payload */
if (req_payload.num_slots) {
drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
mgr->payloads[i].num_slots = req_payload.num_slots;
} else if (mgr->payloads[i].num_slots) {
mgr->payloads[i].num_slots = 0;
drm_dp_destroy_payload_step1(mgr, port, port->vcpi.vcpi, &mgr->payloads[i]);
req_payload.payload_state = mgr->payloads[i].payload_state;
mgr->payloads[i].start_slot = 0;
}
mgr->payloads[i].payload_state = req_payload.payload_state;
}
cur_slots += req_payload.num_slots;
}
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
DRM_DEBUG_KMS("removing payload %d\n", i);
for (j = i; j < mgr->max_payloads - 1; j++) {
memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
set_bit(j + 1, &mgr->payload_mask);
} else {
clear_bit(j + 1, &mgr->payload_mask);
}
}
memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
clear_bit(mgr->max_payloads, &mgr->payload_mask);
}
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part1);
/**
* drm_dp_update_payload_part2() - Execute payload update part 2
* @mgr: manager to use.
*
* This iterates over all proposed virtual channels, and tries to
* allocate space in the link for them. For 0->slots transitions,
* this step writes the remote VC payload commands. For slots->0
* this just resets some internal state.
*/
int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
{
struct drm_dp_mst_port *port;
int i;
int ret = 0;
mutex_lock(&mgr->payload_lock);
for (i = 0; i < mgr->max_payloads; i++) {
if (!mgr->proposed_vcpis[i])
continue;
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
} else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
}
if (ret) {
mutex_unlock(&mgr->payload_lock);
return ret;
}
}
mutex_unlock(&mgr->payload_lock);
return 0;
}
EXPORT_SYMBOL(drm_dp_update_payload_part2);
#if 0 /* unused as of yet */
static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size)
{
int len;
struct drm_dp_sideband_msg_tx *txmsg;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
len = build_dpcd_read(txmsg, port->port_num, 0, 8);
txmsg->dst = port->parent;
drm_dp_queue_down_tx(mgr, txmsg);
return 0;
}
#endif
static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_port *port,
int offset, int size, u8 *bytes)
{
int len;
int ret;
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
if (!mstb)
return -EINVAL;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto fail_put;
}
len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
txmsg->dst = mstb;
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == 1) {
ret = -EINVAL;
} else
ret = 0;
}
kfree(txmsg);
fail_put:
drm_dp_put_mst_branch_device(mstb);
return ret;
}
static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
{
struct drm_dp_sideband_msg_reply_body reply;
reply.reply_type = 1;
reply.req_type = req_type;
drm_dp_encode_sideband_reply(&reply, msg);
return 0;
}
static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_mst_branch *mstb,
int req_type, int seqno, bool broadcast)
{
struct drm_dp_sideband_msg_tx *txmsg;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return -ENOMEM;
txmsg->dst = mstb;
txmsg->seqno = seqno;
drm_dp_encode_up_ack_reply(txmsg, req_type);
mutex_lock(&mgr->qlock);
list_add_tail(&txmsg->next, &mgr->tx_msg_upq);
if (!mgr->tx_up_in_progress) {
process_single_up_tx_qlock(mgr);
}
mutex_unlock(&mgr->qlock);
return 0;
}
static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
int dp_link_count,
int *out)
{
switch (dp_link_bw) {
default:
DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
dp_link_bw, dp_link_count);
return false;
case DP_LINK_BW_1_62:
*out = 3 * dp_link_count;
break;
case DP_LINK_BW_2_7:
*out = 5 * dp_link_count;
break;
case DP_LINK_BW_5_4:
*out = 10 * dp_link_count;
break;
}
return true;
}
/**
* drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
* @mgr: manager to set state for
* @mst_state: true to enable MST on this connector - false to disable.
*
* This is called by the driver when it detects an MST capable device plugged
* into a DP MST capable port, or when a DP MST capable device is unplugged.
*/
int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
{
int ret = 0;
struct drm_dp_mst_branch *mstb = NULL;
mutex_lock(&mgr->lock);
if (mst_state == mgr->mst_state)
goto out_unlock;
mgr->mst_state = mst_state;
/* set the device into MST mode */
if (mst_state) {
WARN_ON(mgr->mst_primary);
/* get dpcd info */
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (ret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("failed to read DPCD\n");
goto out_unlock;
}
if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
&mgr->pbn_div)) {
ret = -EINVAL;
goto out_unlock;
}
mgr->total_pbn = 2560;
mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
mgr->avail_slots = mgr->total_slots;
/* add initial branch device at LCT 1 */
mstb = drm_dp_add_mst_branch_device(1, NULL);
if (mstb == NULL) {
ret = -ENOMEM;
goto out_unlock;
}
mstb->mgr = mgr;
/* give this the main reference */
mgr->mst_primary = mstb;
kref_get(&mgr->mst_primary->kref);
{
struct drm_dp_payload reset_pay;
reset_pay.start_slot = 0;
reset_pay.num_slots = 0x3f;
drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
}
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
if (ret < 0) {
goto out_unlock;
}
/* sort out guid */
ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
if (ret != 16) {
DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
goto out_unlock;
}
mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
if (!mgr->guid_valid) {
ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
mgr->guid_valid = true;
}
queue_work(system_long_wq, &mgr->work);
ret = 0;
} else {
/* disable MST on the device */
mstb = mgr->mst_primary;
mgr->mst_primary = NULL;
/* this can fail if the device is gone */
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
ret = 0;
memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
mgr->payload_mask = 0;
set_bit(0, &mgr->payload_mask);
mgr->vcpi_mask = 0;
}
out_unlock:
mutex_unlock(&mgr->lock);
if (mstb)
drm_dp_put_mst_branch_device(mstb);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
/**
* drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
* @mgr: manager to suspend
*
* This function tells the MST device that we can't handle UP messages
* anymore. This should stop it from sending any since we are suspended.
*/
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
{
mutex_lock(&mgr->lock);
drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UPSTREAM_IS_SRC);
mutex_unlock(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
/**
* drm_dp_mst_topology_mgr_resume() - resume the MST manager
* @mgr: manager to resume
*
* This will fetch DPCD and see if the device is still there,
* if it is, it will rewrite the MSTM control bits, and return.
*
* if the device fails this returns -1, and the driver should do
* a full MST reprobe, in case we were undocked.
*/
int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
{
int ret = 0;
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
int sret;
sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
if (sret != DP_RECEIVER_CAP_SIZE) {
DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
if (ret < 0) {
DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
ret = -1;
goto out_unlock;
}
ret = 0;
} else
ret = -1;
out_unlock:
mutex_unlock(&mgr->lock);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
static void drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
{
int len;
u8 replyblock[32];
int replylen, origlen, curreply;
int ret;
struct drm_dp_sideband_msg_rx *msg;
int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
len = min(mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg,
replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
return;
}
ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
if (!ret) {
DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
return;
}
replylen = msg->curchunk_len + msg->curchunk_hdrlen;
origlen = replylen;
replylen -= len;
curreply = len;
while (replylen > 0) {
len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
replyblock, len);
if (ret != len) {
DRM_DEBUG_KMS("failed to read a chunk\n");
}
ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
if (ret == false)
DRM_DEBUG_KMS("failed to build sideband msg\n");
curreply += len;
replylen -= len;
}
}
static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
{
int ret = 0;
drm_dp_get_one_sb_msg(mgr, false);
if (mgr->down_rep_recv.have_eomt) {
struct drm_dp_sideband_msg_tx *txmsg;
struct drm_dp_mst_branch *mstb;
int slot = -1;
mstb = drm_dp_get_mst_branch_device(mgr,
mgr->down_rep_recv.initial_hdr.lct,
mgr->down_rep_recv.initial_hdr.rad);
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
/* find the message */
slot = mgr->down_rep_recv.initial_hdr.seqno;
mutex_lock(&mgr->qlock);
txmsg = mstb->tx_slots[slot];
/* remove from slots */
mutex_unlock(&mgr->qlock);
if (!txmsg) {
DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
mstb,
mgr->down_rep_recv.initial_hdr.seqno,
mgr->down_rep_recv.initial_hdr.lct,
mgr->down_rep_recv.initial_hdr.rad[0],
mgr->down_rep_recv.msg[0]);
drm_dp_put_mst_branch_device(mstb);
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
if (txmsg->reply.reply_type == 1) {
DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
}
memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
drm_dp_put_mst_branch_device(mstb);
mutex_lock(&mgr->qlock);
txmsg->state = DRM_DP_SIDEBAND_TX_RX;
mstb->tx_slots[slot] = NULL;
mutex_unlock(&mgr->qlock);
wake_up(&mgr->tx_waitq);
}
return ret;
}
static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
{
int ret = 0;
drm_dp_get_one_sb_msg(mgr, true);
if (mgr->up_req_recv.have_eomt) {
struct drm_dp_sideband_msg_req_body msg;
struct drm_dp_mst_branch *mstb;
bool seqno;
mstb = drm_dp_get_mst_branch_device(mgr,
mgr->up_req_recv.initial_hdr.lct,
mgr->up_req_recv.initial_hdr.rad);
if (!mstb) {
DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
return 0;
}
seqno = mgr->up_req_recv.initial_hdr.seqno;
drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
drm_dp_update_port(mstb, &msg.u.conn_stat);
DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
(*mgr->cbs->hotplug)(mgr);
} else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
drm_dp_send_up_ack_reply(mgr, mstb, msg.req_type, seqno, false);
DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
}
drm_dp_put_mst_branch_device(mstb);
memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
}
return ret;
}
/**
* drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
* @mgr: manager to notify irq for.
* @esi: 4 bytes from SINK_COUNT_ESI
* @handled: whether the hpd interrupt was consumed or not
*
* This should be called from the driver when it detects a short IRQ,
* along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
* topology manager will process the sideband messages received as a result
* of this.
*/
int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
{
int ret = 0;
int sc;
*handled = false;
sc = esi[0] & 0x3f;
if (sc != mgr->sink_count) {
mgr->sink_count = sc;
*handled = true;
}
if (esi[1] & DP_DOWN_REP_MSG_RDY) {
ret = drm_dp_mst_handle_down_rep(mgr);
*handled = true;
}
if (esi[1] & DP_UP_REQ_MSG_RDY) {
ret |= drm_dp_mst_handle_up_req(mgr);
*handled = true;
}
drm_dp_mst_kick_tx(mgr);
return ret;
}
EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
/**
* drm_dp_mst_detect_port() - get connection status for an MST port
* @mgr: manager for this port
* @port: unverified pointer to a port
*
* This returns the current connection state for a port. It validates the
* port pointer still exists so the caller doesn't require a reference
*/
enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
enum drm_connector_status status = connector_status_disconnected;
/* we need to search for the port in the mgr in case its gone */
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return connector_status_disconnected;
if (!port->ddps)
goto out;
switch (port->pdt) {
case DP_PEER_DEVICE_NONE:
case DP_PEER_DEVICE_MST_BRANCHING:
break;
case DP_PEER_DEVICE_SST_SINK:
status = connector_status_connected;
/* for logical ports - cache the EDID */
if (port->port_num >= 8 && !port->cached_edid) {
port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
}
break;
case DP_PEER_DEVICE_DP_LEGACY_CONV:
if (port->ldps)
status = connector_status_connected;
break;
}
out:
drm_dp_put_port(port);
return status;
}
EXPORT_SYMBOL(drm_dp_mst_detect_port);
/**
* drm_dp_mst_get_edid() - get EDID for an MST port
* @connector: toplevel connector to get EDID for
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This returns an EDID for the port connected to a connector,
* It validates the pointer still exists so the caller doesn't require a
* reference.
*/
struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
struct edid *edid = NULL;
/* we need to search for the port in the mgr in case its gone */
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return NULL;
if (port->cached_edid)
edid = drm_edid_duplicate(port->cached_edid);
else
edid = drm_get_edid(connector, &port->aux.ddc);
drm_mode_connector_set_tile_property(connector);
drm_dp_put_port(port);
return edid;
}
EXPORT_SYMBOL(drm_dp_mst_get_edid);
/**
* drm_dp_find_vcpi_slots() - find slots for this PBN value
* @mgr: manager to use
* @pbn: payload bandwidth to convert into slots.
*/
int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
int pbn)
{
int num_slots;
num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
if (num_slots > mgr->avail_slots)
return -ENOSPC;
return num_slots;
}
EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_vcpi *vcpi, int pbn)
{
int num_slots;
int ret;
num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
if (num_slots > mgr->avail_slots)
return -ENOSPC;
vcpi->pbn = pbn;
vcpi->aligned_pbn = num_slots * mgr->pbn_div;
vcpi->num_slots = num_slots;
ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
if (ret < 0)
return ret;
return 0;
}
/**
* drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
* @mgr: manager for this port
* @port: port to allocate a virtual channel for.
* @pbn: payload bandwidth number to request
* @slots: returned number of slots for this PBN.
*/
bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
{
int ret;
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return false;
if (port->vcpi.vcpi > 0) {
DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
if (pbn == port->vcpi.pbn) {
*slots = port->vcpi.num_slots;
return true;
}
}
ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
if (ret) {
DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
goto out;
}
DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
*slots = port->vcpi.num_slots;
drm_dp_put_port(port);
return true;
out:
return false;
}
EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
int slots = 0;
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return slots;
slots = port->vcpi.num_slots;
drm_dp_put_port(port);
return slots;
}
EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
/**
* drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
* @mgr: manager for this port
* @port: unverified pointer to a port.
*
* This just resets the number of slots for the ports VCPI for later programming.
*/
void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return;
port->vcpi.num_slots = 0;
drm_dp_put_port(port);
}
EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
/**
* drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
* @mgr: manager for this port
* @port: unverified port to deallocate vcpi for
*/
void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
{
port = drm_dp_get_validated_port_ref(mgr, port);
if (!port)
return;
drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
port->vcpi.num_slots = 0;
port->vcpi.pbn = 0;
port->vcpi.aligned_pbn = 0;
port->vcpi.vcpi = 0;
drm_dp_put_port(port);
}
EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
int id, struct drm_dp_payload *payload)
{
u8 payload_alloc[3], status;
int ret;
int retries = 0;
drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
DP_PAYLOAD_TABLE_UPDATED);
payload_alloc[0] = id;
payload_alloc[1] = payload->start_slot;
payload_alloc[2] = payload->num_slots;
ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
if (ret != 3) {
DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
goto fail;
}
retry:
ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0) {
DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
goto fail;
}
if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
retries++;
if (retries < 20) {
usleep_range(10000, 20000);
goto retry;
}
DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
ret = -EINVAL;
goto fail;
}
ret = 0;
fail:
return ret;
}
/**
* drm_dp_check_act_status() - Check ACT handled status.
* @mgr: manager to use
*
* Check the payload status bits in the DPCD for ACT handled completion.
*/
int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
{
u8 status;
int ret;
int count = 0;
do {
ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
if (ret < 0) {
DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
goto fail;
}
if (status & DP_PAYLOAD_ACT_HANDLED)
break;
count++;
udelay(100);
} while (count < 30);
if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
ret = -EINVAL;
goto fail;
}
return 0;
fail:
return ret;
}
EXPORT_SYMBOL(drm_dp_check_act_status);
/**
* drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
* @clock: dot clock for the mode
* @bpp: bpp for the mode.
*
* This uses the formula in the spec to calculate the PBN value for a mode.
*/
int drm_dp_calc_pbn_mode(int clock, int bpp)
{
fixed20_12 pix_bw;
fixed20_12 fbpp;
fixed20_12 result;
fixed20_12 margin, tmp;
u32 res;
pix_bw.full = dfixed_const(clock);
fbpp.full = dfixed_const(bpp);
tmp.full = dfixed_const(8);
fbpp.full = dfixed_div(fbpp, tmp);
result.full = dfixed_mul(pix_bw, fbpp);
margin.full = dfixed_const(54);
tmp.full = dfixed_const(64);
margin.full = dfixed_div(margin, tmp);
result.full = dfixed_div(result, margin);
margin.full = dfixed_const(1006);
tmp.full = dfixed_const(1000);
margin.full = dfixed_div(margin, tmp);
result.full = dfixed_mul(result, margin);
result.full = dfixed_div(result, tmp);
result.full = dfixed_ceil(result);
res = dfixed_trunc(result);
return res;
}
EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
static int test_calc_pbn_mode(void)
{
int ret;
ret = drm_dp_calc_pbn_mode(154000, 30);
if (ret != 689)
return -EINVAL;
ret = drm_dp_calc_pbn_mode(234000, 30);
if (ret != 1047)
return -EINVAL;
return 0;
}
/* we want to kick the TX after we've ack the up/down IRQs. */
static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
{
queue_work(system_long_wq, &mgr->tx_work);
}
static void drm_dp_mst_dump_mstb(struct seq_file *m,
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
int tabs = mstb->lct;
char prefix[10];
int i;
for (i = 0; i < tabs; i++)
prefix[i] = '\t';
prefix[i] = '\0';
seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
list_for_each_entry(port, &mstb->ports, next) {
seq_printf(m, "%sport: %d: ddps: %d ldps: %d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port, port->connector);
if (port->mstb)
drm_dp_mst_dump_mstb(m, port->mstb);
}
}
static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
char *buf)
{
int ret;
int i;
for (i = 0; i < 4; i++) {
ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
if (ret != 16)
break;
}
if (i == 4)
return true;
return false;
}
/**
* drm_dp_mst_dump_topology(): dump topology to seq file.
* @m: seq_file to dump output to
* @mgr: manager to dump current topology for.
*
* helper to dump MST topology to a seq file for debugfs.
*/
void drm_dp_mst_dump_topology(struct seq_file *m,
struct drm_dp_mst_topology_mgr *mgr)
{
int i;
struct drm_dp_mst_port *port;
mutex_lock(&mgr->lock);
if (mgr->mst_primary)
drm_dp_mst_dump_mstb(m, mgr->mst_primary);
/* dump VCPIs */
mutex_unlock(&mgr->lock);
mutex_lock(&mgr->payload_lock);
seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
for (i = 0; i < mgr->max_payloads; i++) {
if (mgr->proposed_vcpis[i]) {
port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
} else
seq_printf(m, "vcpi %d:unsed\n", i);
}
for (i = 0; i < mgr->max_payloads; i++) {
seq_printf(m, "payload %d: %d, %d, %d\n",
i,
mgr->payloads[i].payload_state,
mgr->payloads[i].start_slot,
mgr->payloads[i].num_slots);
}
mutex_unlock(&mgr->payload_lock);
mutex_lock(&mgr->lock);
if (mgr->mst_primary) {
u8 buf[64];
bool bret;
int ret;
ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
seq_printf(m, "dpcd: ");
for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
seq_printf(m, "%02x ", buf[i]);
seq_printf(m, "\n");
ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
seq_printf(m, "faux/mst: ");
for (i = 0; i < 2; i++)
seq_printf(m, "%02x ", buf[i]);
seq_printf(m, "\n");
ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
seq_printf(m, "mst ctrl: ");
for (i = 0; i < 1; i++)
seq_printf(m, "%02x ", buf[i]);
seq_printf(m, "\n");
/* dump the standard OUI branch header */
ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
seq_printf(m, "branch oui: ");
for (i = 0; i < 0x3; i++)
seq_printf(m, "%02x", buf[i]);
seq_printf(m, " devid: ");
for (i = 0x3; i < 0x8; i++)
seq_printf(m, "%c", buf[i]);
seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
seq_printf(m, "\n");
bret = dump_dp_payload_table(mgr, buf);
if (bret == true) {
seq_printf(m, "payload table: ");
for (i = 0; i < 63; i++)
seq_printf(m, "%02x ", buf[i]);
seq_printf(m, "\n");
}
}
mutex_unlock(&mgr->lock);
}
EXPORT_SYMBOL(drm_dp_mst_dump_topology);
static void drm_dp_tx_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
mutex_lock(&mgr->qlock);
if (mgr->tx_down_in_progress)
process_single_down_tx_qlock(mgr);
mutex_unlock(&mgr->qlock);
}
static void drm_dp_destroy_connector_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
struct drm_dp_mst_port *port;
/*
* Not a regular list traverse as we have to drop the destroy
* connector lock before destroying the connector, to avoid AB->BA
* ordering between this lock and the config mutex.
*/
for (;;) {
mutex_lock(&mgr->destroy_connector_lock);
port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
if (!port) {
mutex_unlock(&mgr->destroy_connector_lock);
break;
}
list_del(&port->next);
mutex_unlock(&mgr->destroy_connector_lock);
mgr->cbs->destroy_connector(mgr, port->connector);
drm_dp_port_teardown_pdt(port, port->pdt);
if (!port->input && port->vcpi.vcpi > 0)
drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
kfree(port);
}
}
/**
* drm_dp_mst_topology_mgr_init - initialise a topology manager
* @mgr: manager struct to initialise
* @dev: device providing this structure - for i2c addition.
* @aux: DP helper aux channel to talk to this device
* @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
* @max_payloads: maximum number of payloads this GPU can source
* @conn_base_id: the connector object ID the MST device is connected to.
*
* Return 0 for success, or negative error code on failure
*/
int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
struct device *dev, struct drm_dp_aux *aux,
int max_dpcd_transaction_bytes,
int max_payloads, int conn_base_id)
{
mutex_init(&mgr->lock);
mutex_init(&mgr->qlock);
mutex_init(&mgr->payload_lock);
mutex_init(&mgr->destroy_connector_lock);
INIT_LIST_HEAD(&mgr->tx_msg_upq);
INIT_LIST_HEAD(&mgr->tx_msg_downq);
INIT_LIST_HEAD(&mgr->destroy_connector_list);
INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
init_waitqueue_head(&mgr->tx_waitq);
mgr->dev = dev;
mgr->aux = aux;
mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
mgr->max_payloads = max_payloads;
mgr->conn_base_id = conn_base_id;
mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
if (!mgr->payloads)
return -ENOMEM;
mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
if (!mgr->proposed_vcpis)
return -ENOMEM;
set_bit(0, &mgr->payload_mask);
test_calc_pbn_mode();
return 0;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
/**
* drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
* @mgr: manager to destroy
*/
void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
{
flush_work(&mgr->destroy_connector_work);
mutex_lock(&mgr->payload_lock);
kfree(mgr->payloads);
mgr->payloads = NULL;
kfree(mgr->proposed_vcpis);
mgr->proposed_vcpis = NULL;
mutex_unlock(&mgr->payload_lock);
mgr->dev = NULL;
mgr->aux = NULL;
}
EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
/* I2C device */
static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
int num)
{
struct drm_dp_aux *aux = adapter->algo_data;
struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
struct drm_dp_mst_branch *mstb;
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
unsigned int i;
bool reading = false;
struct drm_dp_sideband_msg_req_body msg;
struct drm_dp_sideband_msg_tx *txmsg = NULL;
int ret;
mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
if (!mstb)
return -EREMOTEIO;
/* construct i2c msg */
/* see if last msg is a read */
if (msgs[num - 1].flags & I2C_M_RD)
reading = true;
if (!reading) {
DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
ret = -EIO;
goto out;
}
msg.req_type = DP_REMOTE_I2C_READ;
msg.u.i2c_read.num_transactions = num - 1;
msg.u.i2c_read.port_number = port->port_num;
for (i = 0; i < num - 1; i++) {
msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
}
msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg) {
ret = -ENOMEM;
goto out;
}
txmsg->dst = mstb;
drm_dp_encode_sideband_req(&msg, txmsg);
drm_dp_queue_down_tx(mgr, txmsg);
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
if (txmsg->reply.reply_type == 1) { /* got a NAK back */
ret = -EREMOTEIO;
goto out;
}
if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
ret = -EIO;
goto out;
}
memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
ret = num;
}
out:
kfree(txmsg);
drm_dp_put_mst_branch_device(mstb);
return ret;
}
static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR;
}
static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
.functionality = drm_dp_mst_i2c_functionality,
.master_xfer = drm_dp_mst_i2c_xfer,
};
/**
* drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
* @aux: DisplayPort AUX channel
*
* Returns 0 on success or a negative error code on failure.
*/
static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
{
aux->ddc.algo = &drm_dp_mst_i2c_algo;
aux->ddc.algo_data = aux;
aux->ddc.retries = 3;
aux->ddc.class = I2C_CLASS_DDC;
aux->ddc.owner = THIS_MODULE;
aux->ddc.dev.parent = aux->dev;
aux->ddc.dev.of_node = aux->dev->of_node;
strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
sizeof(aux->ddc.name));
return i2c_add_adapter(&aux->ddc);
}
/**
* drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
* @aux: DisplayPort AUX channel
*/
static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
{
i2c_del_adapter(&aux->ddc);
}
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