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WSL2-Linux-Kernel/drivers/gpu/drm/drm_dp_helper.c

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/*
* Copyright © 2009 Keith Packard
*
* 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/delay.h>
#include <linux/errno.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <drm/drm_dp_helper.h>
#include <drm/drm_print.h>
#include <drm/drm_vblank.h>
#include <drm/drm_dp_mst_helper.h>
#include "drm_crtc_helper_internal.h"
/**
* DOC: dp helpers
*
* These functions contain some common logic and helpers at various abstraction
* levels to deal with Display Port sink devices and related things like DP aux
* channel transfers, EDID reading over DP aux channels, decoding certain DPCD
* blocks, ...
*/
/* Helpers for DP link training */
static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r)
{
return link_status[r - DP_LANE0_1_STATUS];
}
static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane)
{
int i = DP_LANE0_1_STATUS + (lane >> 1);
int s = (lane & 1) * 4;
u8 l = dp_link_status(link_status, i);
return (l >> s) & 0xf;
}
bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane_count)
{
u8 lane_align;
u8 lane_status;
int lane;
lane_align = dp_link_status(link_status,
DP_LANE_ALIGN_STATUS_UPDATED);
if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0)
return false;
for (lane = 0; lane < lane_count; lane++) {
lane_status = dp_get_lane_status(link_status, lane);
if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS)
return false;
}
return true;
}
EXPORT_SYMBOL(drm_dp_channel_eq_ok);
bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane_count)
{
int lane;
u8 lane_status;
for (lane = 0; lane < lane_count; lane++) {
lane_status = dp_get_lane_status(link_status, lane);
if ((lane_status & DP_LANE_CR_DONE) == 0)
return false;
}
return true;
}
EXPORT_SYMBOL(drm_dp_clock_recovery_ok);
u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane)
{
int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
int s = ((lane & 1) ?
DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT :
DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT);
u8 l = dp_link_status(link_status, i);
return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT;
}
EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage);
u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane)
{
int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1);
int s = ((lane & 1) ?
DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT :
DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT);
u8 l = dp_link_status(link_status, i);
return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT;
}
EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis);
u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
unsigned int lane)
{
unsigned int offset = DP_ADJUST_REQUEST_POST_CURSOR2;
u8 value = dp_link_status(link_status, offset);
return (value >> (lane << 1)) & 0x3;
}
EXPORT_SYMBOL(drm_dp_get_adjust_request_post_cursor);
void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
unsigned long rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
DP_TRAINING_AUX_RD_MASK;
if (rd_interval > 4)
DRM_DEBUG_KMS("AUX interval %lu, out of range (max 4)\n",
rd_interval);
if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
rd_interval = 100;
else
rd_interval *= 4 * USEC_PER_MSEC;
usleep_range(rd_interval, rd_interval * 2);
}
EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay);
static void __drm_dp_link_train_channel_eq_delay(unsigned long rd_interval)
{
if (rd_interval > 4)
DRM_DEBUG_KMS("AUX interval %lu, out of range (max 4)\n",
rd_interval);
if (rd_interval == 0)
rd_interval = 400;
else
rd_interval *= 4 * USEC_PER_MSEC;
usleep_range(rd_interval, rd_interval * 2);
}
void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
__drm_dp_link_train_channel_eq_delay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
DP_TRAINING_AUX_RD_MASK);
}
EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay);
void drm_dp_lttpr_link_train_clock_recovery_delay(void)
{
usleep_range(100, 200);
}
EXPORT_SYMBOL(drm_dp_lttpr_link_train_clock_recovery_delay);
static u8 dp_lttpr_phy_cap(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE], int r)
{
return phy_cap[r - DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1];
}
void drm_dp_lttpr_link_train_channel_eq_delay(const u8 phy_cap[DP_LTTPR_PHY_CAP_SIZE])
{
u8 interval = dp_lttpr_phy_cap(phy_cap,
DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER1) &
DP_TRAINING_AUX_RD_MASK;
__drm_dp_link_train_channel_eq_delay(interval);
}
EXPORT_SYMBOL(drm_dp_lttpr_link_train_channel_eq_delay);
u8 drm_dp_link_rate_to_bw_code(int link_rate)
{
/* Spec says link_bw = link_rate / 0.27Gbps */
return link_rate / 27000;
}
EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code);
int drm_dp_bw_code_to_link_rate(u8 link_bw)
{
/* Spec says link_rate = link_bw * 0.27Gbps */
return link_bw * 27000;
}
EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate);
#define AUX_RETRY_INTERVAL 500 /* us */
static inline void
drm_dp_dump_access(const struct drm_dp_aux *aux,
u8 request, uint offset, void *buffer, int ret)
{
const char *arrow = request == DP_AUX_NATIVE_READ ? "->" : "<-";
if (ret > 0)
DRM_DEBUG_DP("%s: 0x%05x AUX %s (ret=%3d) %*ph\n",
aux->name, offset, arrow, ret, min(ret, 20), buffer);
else
DRM_DEBUG_DP("%s: 0x%05x AUX %s (ret=%3d)\n",
aux->name, offset, arrow, ret);
}
/**
* DOC: dp helpers
*
* The DisplayPort AUX channel is an abstraction to allow generic, driver-
* independent access to AUX functionality. Drivers can take advantage of
* this by filling in the fields of the drm_dp_aux structure.
*
* Transactions are described using a hardware-independent drm_dp_aux_msg
* structure, which is passed into a driver's .transfer() implementation.
* Both native and I2C-over-AUX transactions are supported.
*/
static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
unsigned int offset, void *buffer, size_t size)
{
struct drm_dp_aux_msg msg;
unsigned int retry, native_reply;
int err = 0, ret = 0;
memset(&msg, 0, sizeof(msg));
msg.address = offset;
msg.request = request;
msg.buffer = buffer;
msg.size = size;
mutex_lock(&aux->hw_mutex);
/*
* The specification doesn't give any recommendation on how often to
* retry native transactions. We used to retry 7 times like for
* aux i2c transactions but real world devices this wasn't
* sufficient, bump to 32 which makes Dell 4k monitors happier.
*/
for (retry = 0; retry < 32; retry++) {
if (ret != 0 && ret != -ETIMEDOUT) {
usleep_range(AUX_RETRY_INTERVAL,
AUX_RETRY_INTERVAL + 100);
}
ret = aux->transfer(aux, &msg);
if (ret >= 0) {
native_reply = msg.reply & DP_AUX_NATIVE_REPLY_MASK;
if (native_reply == DP_AUX_NATIVE_REPLY_ACK) {
if (ret == size)
goto unlock;
ret = -EPROTO;
} else
ret = -EIO;
}
/*
* We want the error we return to be the error we received on
* the first transaction, since we may get a different error the
* next time we retry
*/
if (!err)
err = ret;
}
DRM_DEBUG_KMS("%s: Too many retries, giving up. First error: %d\n",
aux->name, err);
ret = err;
unlock:
mutex_unlock(&aux->hw_mutex);
return ret;
}
/**
* drm_dp_dpcd_read() - read a series of bytes from the DPCD
* @aux: DisplayPort AUX channel (SST or MST)
* @offset: address of the (first) register to read
* @buffer: buffer to store the register values
* @size: number of bytes in @buffer
*
* Returns the number of bytes transferred on success, or a negative error
* code on failure. -EIO is returned if the request was NAKed by the sink or
* if the retry count was exceeded. If not all bytes were transferred, this
* function returns -EPROTO. Errors from the underlying AUX channel transfer
* function, with the exception of -EBUSY (which causes the transaction to
* be retried), are propagated to the caller.
*/
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
int ret;
/*
* HP ZR24w corrupts the first DPCD access after entering power save
* mode. Eg. on a read, the entire buffer will be filled with the same
* byte. Do a throw away read to avoid corrupting anything we care
* about. Afterwards things will work correctly until the monitor
* gets woken up and subsequently re-enters power save mode.
*
* The user pressing any button on the monitor is enough to wake it
* up, so there is no particularly good place to do the workaround.
* We just have to do it before any DPCD access and hope that the
* monitor doesn't power down exactly after the throw away read.
*/
if (!aux->is_remote) {
ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, DP_DPCD_REV,
buffer, 1);
if (ret != 1)
goto out;
}
if (aux->is_remote)
ret = drm_dp_mst_dpcd_read(aux, offset, buffer, size);
else
ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset,
buffer, size);
out:
drm_dp_dump_access(aux, DP_AUX_NATIVE_READ, offset, buffer, ret);
return ret;
}
EXPORT_SYMBOL(drm_dp_dpcd_read);
/**
* drm_dp_dpcd_write() - write a series of bytes to the DPCD
* @aux: DisplayPort AUX channel (SST or MST)
* @offset: address of the (first) register to write
* @buffer: buffer containing the values to write
* @size: number of bytes in @buffer
*
* Returns the number of bytes transferred on success, or a negative error
* code on failure. -EIO is returned if the request was NAKed by the sink or
* if the retry count was exceeded. If not all bytes were transferred, this
* function returns -EPROTO. Errors from the underlying AUX channel transfer
* function, with the exception of -EBUSY (which causes the transaction to
* be retried), are propagated to the caller.
*/
ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size)
{
int ret;
if (aux->is_remote)
ret = drm_dp_mst_dpcd_write(aux, offset, buffer, size);
else
ret = drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset,
buffer, size);
drm_dp_dump_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, ret);
return ret;
}
EXPORT_SYMBOL(drm_dp_dpcd_write);
/**
* drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207)
* @aux: DisplayPort AUX channel
* @status: buffer to store the link status in (must be at least 6 bytes)
*
* Returns the number of bytes transferred on success or a negative error
* code on failure.
*/
int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
u8 status[DP_LINK_STATUS_SIZE])
{
return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status,
DP_LINK_STATUS_SIZE);
}
EXPORT_SYMBOL(drm_dp_dpcd_read_link_status);
/**
* drm_dp_dpcd_read_phy_link_status - get the link status information for a DP PHY
* @aux: DisplayPort AUX channel
* @dp_phy: the DP PHY to get the link status for
* @link_status: buffer to return the status in
*
* Fetch the AUX DPCD registers for the DPRX or an LTTPR PHY link status. The
* layout of the returned @link_status matches the DPCD register layout of the
* DPRX PHY link status.
*
* Returns 0 if the information was read successfully or a negative error code
* on failure.
*/
int drm_dp_dpcd_read_phy_link_status(struct drm_dp_aux *aux,
enum drm_dp_phy dp_phy,
u8 link_status[DP_LINK_STATUS_SIZE])
{
int ret;
if (dp_phy == DP_PHY_DPRX) {
ret = drm_dp_dpcd_read(aux,
DP_LANE0_1_STATUS,
link_status,
DP_LINK_STATUS_SIZE);
if (ret < 0)
return ret;
WARN_ON(ret != DP_LINK_STATUS_SIZE);
return 0;
}
ret = drm_dp_dpcd_read(aux,
DP_LANE0_1_STATUS_PHY_REPEATER(dp_phy),
link_status,
DP_LINK_STATUS_SIZE - 1);
if (ret < 0)
return ret;
WARN_ON(ret != DP_LINK_STATUS_SIZE - 1);
/* Convert the LTTPR to the sink PHY link status layout */
memmove(&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS + 1],
&link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS],
DP_LINK_STATUS_SIZE - (DP_SINK_STATUS - DP_LANE0_1_STATUS) - 1);
link_status[DP_SINK_STATUS - DP_LANE0_1_STATUS] = 0;
return 0;
}
EXPORT_SYMBOL(drm_dp_dpcd_read_phy_link_status);
static bool is_edid_digital_input_dp(const struct edid *edid)
{
return edid && edid->revision >= 4 &&
edid->input & DRM_EDID_INPUT_DIGITAL &&
(edid->input & DRM_EDID_DIGITAL_TYPE_MASK) == DRM_EDID_DIGITAL_TYPE_DP;
}
/**
* drm_dp_downstream_is_type() - is the downstream facing port of certain type?
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
* @type: port type to be checked. Can be:
* %DP_DS_PORT_TYPE_DP, %DP_DS_PORT_TYPE_VGA, %DP_DS_PORT_TYPE_DVI,
* %DP_DS_PORT_TYPE_HDMI, %DP_DS_PORT_TYPE_NON_EDID,
* %DP_DS_PORT_TYPE_DP_DUALMODE or %DP_DS_PORT_TYPE_WIRELESS.
*
* Caveat: Only works with DPCD 1.1+ port caps.
*
* Returns: whether the downstream facing port matches the type.
*/
bool drm_dp_downstream_is_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4], u8 type)
{
return drm_dp_is_branch(dpcd) &&
dpcd[DP_DPCD_REV] >= 0x11 &&
(port_cap[0] & DP_DS_PORT_TYPE_MASK) == type;
}
EXPORT_SYMBOL(drm_dp_downstream_is_type);
/**
* drm_dp_downstream_is_tmds() - is the downstream facing port TMDS?
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
* @edid: EDID
*
* Returns: whether the downstream facing port is TMDS (HDMI/DVI).
*/
bool drm_dp_downstream_is_tmds(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid)
{
if (dpcd[DP_DPCD_REV] < 0x11) {
switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
case DP_DWN_STRM_PORT_TYPE_TMDS:
return true;
default:
return false;
}
}
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_DP_DUALMODE:
if (is_edid_digital_input_dp(edid))
return false;
fallthrough;
case DP_DS_PORT_TYPE_DVI:
case DP_DS_PORT_TYPE_HDMI:
return true;
default:
return false;
}
}
EXPORT_SYMBOL(drm_dp_downstream_is_tmds);
/**
* drm_dp_send_real_edid_checksum() - send back real edid checksum value
* @aux: DisplayPort AUX channel
* @real_edid_checksum: real edid checksum for the last block
*
* Returns:
* True on success
*/
bool drm_dp_send_real_edid_checksum(struct drm_dp_aux *aux,
u8 real_edid_checksum)
{
u8 link_edid_read = 0, auto_test_req = 0, test_resp = 0;
if (drm_dp_dpcd_read(aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
&auto_test_req, 1) < 1) {
DRM_ERROR("%s: DPCD failed read at register 0x%x\n",
aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR);
return false;
}
auto_test_req &= DP_AUTOMATED_TEST_REQUEST;
if (drm_dp_dpcd_read(aux, DP_TEST_REQUEST, &link_edid_read, 1) < 1) {
DRM_ERROR("%s: DPCD failed read at register 0x%x\n",
aux->name, DP_TEST_REQUEST);
return false;
}
link_edid_read &= DP_TEST_LINK_EDID_READ;
if (!auto_test_req || !link_edid_read) {
DRM_DEBUG_KMS("%s: Source DUT does not support TEST_EDID_READ\n",
aux->name);
return false;
}
if (drm_dp_dpcd_write(aux, DP_DEVICE_SERVICE_IRQ_VECTOR,
&auto_test_req, 1) < 1) {
DRM_ERROR("%s: DPCD failed write at register 0x%x\n",
aux->name, DP_DEVICE_SERVICE_IRQ_VECTOR);
return false;
}
/* send back checksum for the last edid extension block data */
if (drm_dp_dpcd_write(aux, DP_TEST_EDID_CHECKSUM,
&real_edid_checksum, 1) < 1) {
DRM_ERROR("%s: DPCD failed write at register 0x%x\n",
aux->name, DP_TEST_EDID_CHECKSUM);
return false;
}
test_resp |= DP_TEST_EDID_CHECKSUM_WRITE;
if (drm_dp_dpcd_write(aux, DP_TEST_RESPONSE, &test_resp, 1) < 1) {
DRM_ERROR("%s: DPCD failed write at register 0x%x\n",
aux->name, DP_TEST_RESPONSE);
return false;
}
return true;
}
EXPORT_SYMBOL(drm_dp_send_real_edid_checksum);
static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
u8 port_count = dpcd[DP_DOWN_STREAM_PORT_COUNT] & DP_PORT_COUNT_MASK;
if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE && port_count > 4)
port_count = 4;
return port_count;
}
static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux,
u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
u8 dpcd_ext[6];
int ret;
/*
* Prior to DP1.3 the bit represented by
* DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved.
* If it is set DP_DPCD_REV at 0000h could be at a value less than
* the true capability of the panel. The only way to check is to
* then compare 0000h and 2200h.
*/
if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] &
DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT))
return 0;
ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext,
sizeof(dpcd_ext));
if (ret < 0)
return ret;
if (ret != sizeof(dpcd_ext))
return -EIO;
if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) {
DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n",
aux->name, dpcd[DP_DPCD_REV],
dpcd_ext[DP_DPCD_REV]);
return 0;
}
if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext)))
return 0;
DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n",
aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext));
return 0;
}
/**
* drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if
* available
* @aux: DisplayPort AUX channel
* @dpcd: Buffer to store the resulting DPCD in
*
* Attempts to read the base DPCD caps for @aux. Additionally, this function
* checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if
* present.
*
* Returns: %0 if the DPCD was read successfully, negative error code
* otherwise.
*/
int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux,
u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
int ret;
ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE);
if (ret < 0)
return ret;
if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0)
return -EIO;
ret = drm_dp_read_extended_dpcd_caps(aux, dpcd);
if (ret < 0)
return ret;
DRM_DEBUG_KMS("%s: DPCD: %*ph\n",
aux->name, DP_RECEIVER_CAP_SIZE, dpcd);
return ret;
}
EXPORT_SYMBOL(drm_dp_read_dpcd_caps);
/**
* drm_dp_read_downstream_info() - read DPCD downstream port info if available
* @aux: DisplayPort AUX channel
* @dpcd: A cached copy of the port's DPCD
* @downstream_ports: buffer to store the downstream port info in
*
* See also:
* drm_dp_downstream_max_clock()
* drm_dp_downstream_max_bpc()
*
* Returns: 0 if either the downstream port info was read successfully or
* there was no downstream info to read, or a negative error code otherwise.
*/
int drm_dp_read_downstream_info(struct drm_dp_aux *aux,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],
u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS])
{
int ret;
u8 len;
memset(downstream_ports, 0, DP_MAX_DOWNSTREAM_PORTS);
/* No downstream info to read */
if (!drm_dp_is_branch(dpcd) ||
dpcd[DP_DPCD_REV] < DP_DPCD_REV_10 ||
!(dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT))
return 0;
len = drm_dp_downstream_port_count(dpcd);
if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE)
len *= 4;
ret = drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, downstream_ports, len);
if (ret < 0)
return ret;
if (ret != len)
return -EIO;
DRM_DEBUG_KMS("%s: DPCD DFP: %*ph\n",
aux->name, len, downstream_ports);
return 0;
}
EXPORT_SYMBOL(drm_dp_read_downstream_info);
/**
* drm_dp_downstream_max_dotclock() - extract downstream facing port max dot clock
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
*
* Returns: Downstream facing port max dot clock in kHz on success,
* or 0 if max clock not defined
*/
int drm_dp_downstream_max_dotclock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4])
{
if (!drm_dp_is_branch(dpcd))
return 0;
if (dpcd[DP_DPCD_REV] < 0x11)
return 0;
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_VGA:
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return 0;
return port_cap[1] * 8000;
default:
return 0;
}
}
EXPORT_SYMBOL(drm_dp_downstream_max_dotclock);
/**
* drm_dp_downstream_max_tmds_clock() - extract downstream facing port max TMDS clock
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
* @edid: EDID
*
* Returns: HDMI/DVI downstream facing port max TMDS clock in kHz on success,
* or 0 if max TMDS clock not defined
*/
int drm_dp_downstream_max_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid)
{
if (!drm_dp_is_branch(dpcd))
return 0;
if (dpcd[DP_DPCD_REV] < 0x11) {
switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
case DP_DWN_STRM_PORT_TYPE_TMDS:
return 165000;
default:
return 0;
}
}
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_DP_DUALMODE:
if (is_edid_digital_input_dp(edid))
return 0;
/*
* It's left up to the driver to check the
* DP dual mode adapter's max TMDS clock.
*
* Unfortunatley it looks like branch devices
* may not fordward that the DP dual mode i2c
* access so we just usually get i2c nak :(
*/
fallthrough;
case DP_DS_PORT_TYPE_HDMI:
/*
* We should perhaps assume 165 MHz when detailed cap
* info is not available. But looks like many typical
* branch devices fall into that category and so we'd
* probably end up with users complaining that they can't
* get high resolution modes with their favorite dongle.
*
* So let's limit to 300 MHz instead since DPCD 1.4
* HDMI 2.0 DFPs are required to have the detailed cap
* info. So it's more likely we're dealing with a HDMI 1.4
* compatible* device here.
*/
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return 300000;
return port_cap[1] * 2500;
case DP_DS_PORT_TYPE_DVI:
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return 165000;
/* FIXME what to do about DVI dual link? */
return port_cap[1] * 2500;
default:
return 0;
}
}
EXPORT_SYMBOL(drm_dp_downstream_max_tmds_clock);
/**
* drm_dp_downstream_min_tmds_clock() - extract downstream facing port min TMDS clock
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
* @edid: EDID
*
* Returns: HDMI/DVI downstream facing port min TMDS clock in kHz on success,
* or 0 if max TMDS clock not defined
*/
int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid)
{
if (!drm_dp_is_branch(dpcd))
return 0;
if (dpcd[DP_DPCD_REV] < 0x11) {
switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
case DP_DWN_STRM_PORT_TYPE_TMDS:
return 25000;
default:
return 0;
}
}
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_DP_DUALMODE:
if (is_edid_digital_input_dp(edid))
return 0;
fallthrough;
case DP_DS_PORT_TYPE_DVI:
case DP_DS_PORT_TYPE_HDMI:
/*
* Unclear whether the protocol converter could
* utilize pixel replication. Assume it won't.
*/
return 25000;
default:
return 0;
}
}
EXPORT_SYMBOL(drm_dp_downstream_min_tmds_clock);
/**
* drm_dp_downstream_max_bpc() - extract downstream facing port max
* bits per component
* @dpcd: DisplayPort configuration data
* @port_cap: downstream facing port capabilities
* @edid: EDID
*
* Returns: Max bpc on success or 0 if max bpc not defined
*/
int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid)
{
if (!drm_dp_is_branch(dpcd))
return 0;
if (dpcd[DP_DPCD_REV] < 0x11) {
switch (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) {
case DP_DWN_STRM_PORT_TYPE_DP:
return 0;
default:
return 8;
}
}
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_DP:
return 0;
case DP_DS_PORT_TYPE_DP_DUALMODE:
if (is_edid_digital_input_dp(edid))
return 0;
fallthrough;
case DP_DS_PORT_TYPE_HDMI:
case DP_DS_PORT_TYPE_DVI:
case DP_DS_PORT_TYPE_VGA:
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return 8;
switch (port_cap[2] & DP_DS_MAX_BPC_MASK) {
case DP_DS_8BPC:
return 8;
case DP_DS_10BPC:
return 10;
case DP_DS_12BPC:
return 12;
case DP_DS_16BPC:
return 16;
default:
return 8;
}
break;
default:
return 8;
}
}
EXPORT_SYMBOL(drm_dp_downstream_max_bpc);
/**
* drm_dp_downstream_420_passthrough() - determine downstream facing port
* YCbCr 4:2:0 pass-through capability
* @dpcd: DisplayPort configuration data
* @port_cap: downstream facing port capabilities
*
* Returns: whether the downstream facing port can pass through YCbCr 4:2:0
*/
bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4])
{
if (!drm_dp_is_branch(dpcd))
return false;
if (dpcd[DP_DPCD_REV] < 0x13)
return false;
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_DP:
return true;
case DP_DS_PORT_TYPE_HDMI:
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return false;
return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH;
default:
return false;
}
}
EXPORT_SYMBOL(drm_dp_downstream_420_passthrough);
/**
* drm_dp_downstream_444_to_420_conversion() - determine downstream facing port
* YCbCr 4:4:4->4:2:0 conversion capability
* @dpcd: DisplayPort configuration data
* @port_cap: downstream facing port capabilities
*
* Returns: whether the downstream facing port can convert YCbCr 4:4:4 to 4:2:0
*/
bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4])
{
if (!drm_dp_is_branch(dpcd))
return false;
if (dpcd[DP_DPCD_REV] < 0x13)
return false;
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_HDMI:
if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
return false;
return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV;
default:
return false;
}
}
EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion);
/**
* drm_dp_downstream_mode() - return a mode for downstream facing port
* @dev: DRM device
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
*
* Provides a suitable mode for downstream facing ports without EDID.
*
* Returns: A new drm_display_mode on success or NULL on failure
*/
struct drm_display_mode *
drm_dp_downstream_mode(struct drm_device *dev,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4])
{
u8 vic;
if (!drm_dp_is_branch(dpcd))
return NULL;
if (dpcd[DP_DPCD_REV] < 0x11)
return NULL;
switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
case DP_DS_PORT_TYPE_NON_EDID:
switch (port_cap[0] & DP_DS_NON_EDID_MASK) {
case DP_DS_NON_EDID_720x480i_60:
vic = 6;
break;
case DP_DS_NON_EDID_720x480i_50:
vic = 21;
break;
case DP_DS_NON_EDID_1920x1080i_60:
vic = 5;
break;
case DP_DS_NON_EDID_1920x1080i_50:
vic = 20;
break;
case DP_DS_NON_EDID_1280x720_60:
vic = 4;
break;
case DP_DS_NON_EDID_1280x720_50:
vic = 19;
break;
default:
return NULL;
}
return drm_display_mode_from_cea_vic(dev, vic);
default:
return NULL;
}
}
EXPORT_SYMBOL(drm_dp_downstream_mode);
/**
* drm_dp_downstream_id() - identify branch device
* @aux: DisplayPort AUX channel
* @id: DisplayPort branch device id
*
* Returns branch device id on success or NULL on failure
*/
int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])
{
return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6);
}
EXPORT_SYMBOL(drm_dp_downstream_id);
/**
* drm_dp_downstream_debug() - debug DP branch devices
* @m: pointer for debugfs file
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
* @edid: EDID
* @aux: DisplayPort AUX channel
*
*/
void drm_dp_downstream_debug(struct seq_file *m,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid,
struct drm_dp_aux *aux)
{
bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
DP_DETAILED_CAP_INFO_AVAILABLE;
int clk;
int bpc;
char id[7];
int len;
uint8_t rev[2];
int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
bool branch_device = drm_dp_is_branch(dpcd);
seq_printf(m, "\tDP branch device present: %s\n",
branch_device ? "yes" : "no");
if (!branch_device)
return;
switch (type) {
case DP_DS_PORT_TYPE_DP:
seq_puts(m, "\t\tType: DisplayPort\n");
break;
case DP_DS_PORT_TYPE_VGA:
seq_puts(m, "\t\tType: VGA\n");
break;
case DP_DS_PORT_TYPE_DVI:
seq_puts(m, "\t\tType: DVI\n");
break;
case DP_DS_PORT_TYPE_HDMI:
seq_puts(m, "\t\tType: HDMI\n");
break;
case DP_DS_PORT_TYPE_NON_EDID:
seq_puts(m, "\t\tType: others without EDID support\n");
break;
case DP_DS_PORT_TYPE_DP_DUALMODE:
seq_puts(m, "\t\tType: DP++\n");
break;
case DP_DS_PORT_TYPE_WIRELESS:
seq_puts(m, "\t\tType: Wireless\n");
break;
default:
seq_puts(m, "\t\tType: N/A\n");
}
memset(id, 0, sizeof(id));
drm_dp_downstream_id(aux, id);
seq_printf(m, "\t\tID: %s\n", id);
len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1);
if (len > 0)
seq_printf(m, "\t\tHW: %d.%d\n",
(rev[0] & 0xf0) >> 4, rev[0] & 0xf);
len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, rev, 2);
if (len > 0)
seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]);
if (detailed_cap_info) {
clk = drm_dp_downstream_max_dotclock(dpcd, port_cap);
if (clk > 0)
seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk);
clk = drm_dp_downstream_max_tmds_clock(dpcd, port_cap, edid);
if (clk > 0)
seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk);
clk = drm_dp_downstream_min_tmds_clock(dpcd, port_cap, edid);
if (clk > 0)
seq_printf(m, "\t\tMin TMDS clock: %d kHz\n", clk);
bpc = drm_dp_downstream_max_bpc(dpcd, port_cap, edid);
if (bpc > 0)
seq_printf(m, "\t\tMax bpc: %d\n", bpc);
}
}
EXPORT_SYMBOL(drm_dp_downstream_debug);
/**
* drm_dp_subconnector_type() - get DP branch device type
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
*/
enum drm_mode_subconnector
drm_dp_subconnector_type(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4])
{
int type;
if (!drm_dp_is_branch(dpcd))
return DRM_MODE_SUBCONNECTOR_Native;
/* DP 1.0 approach */
if (dpcd[DP_DPCD_REV] == DP_DPCD_REV_10) {
type = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
DP_DWN_STRM_PORT_TYPE_MASK;
switch (type) {
case DP_DWN_STRM_PORT_TYPE_TMDS:
/* Can be HDMI or DVI-D, DVI-D is a safer option */
return DRM_MODE_SUBCONNECTOR_DVID;
case DP_DWN_STRM_PORT_TYPE_ANALOG:
/* Can be VGA or DVI-A, VGA is more popular */
return DRM_MODE_SUBCONNECTOR_VGA;
case DP_DWN_STRM_PORT_TYPE_DP:
return DRM_MODE_SUBCONNECTOR_DisplayPort;
case DP_DWN_STRM_PORT_TYPE_OTHER:
default:
return DRM_MODE_SUBCONNECTOR_Unknown;
}
}
type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
switch (type) {
case DP_DS_PORT_TYPE_DP:
case DP_DS_PORT_TYPE_DP_DUALMODE:
return DRM_MODE_SUBCONNECTOR_DisplayPort;
case DP_DS_PORT_TYPE_VGA:
return DRM_MODE_SUBCONNECTOR_VGA;
case DP_DS_PORT_TYPE_DVI:
return DRM_MODE_SUBCONNECTOR_DVID;
case DP_DS_PORT_TYPE_HDMI:
return DRM_MODE_SUBCONNECTOR_HDMIA;
case DP_DS_PORT_TYPE_WIRELESS:
return DRM_MODE_SUBCONNECTOR_Wireless;
case DP_DS_PORT_TYPE_NON_EDID:
default:
return DRM_MODE_SUBCONNECTOR_Unknown;
}
}
EXPORT_SYMBOL(drm_dp_subconnector_type);
/**
* drm_dp_set_subconnector_property - set subconnector for DP connector
* @connector: connector to set property on
* @status: connector status
* @dpcd: DisplayPort configuration data
* @port_cap: port capabilities
*
* Called by a driver on every detect event.
*/
void drm_dp_set_subconnector_property(struct drm_connector *connector,
enum drm_connector_status status,
const u8 *dpcd,
const u8 port_cap[4])
{
enum drm_mode_subconnector subconnector = DRM_MODE_SUBCONNECTOR_Unknown;
if (status == connector_status_connected)
subconnector = drm_dp_subconnector_type(dpcd, port_cap);
drm_object_property_set_value(&connector->base,
connector->dev->mode_config.dp_subconnector_property,
subconnector);
}
EXPORT_SYMBOL(drm_dp_set_subconnector_property);
/**
* drm_dp_read_sink_count_cap() - Check whether a given connector has a valid sink
* count
* @connector: The DRM connector to check
* @dpcd: A cached copy of the connector's DPCD RX capabilities
* @desc: A cached copy of the connector's DP descriptor
*
* See also: drm_dp_read_sink_count()
*
* Returns: %True if the (e)DP connector has a valid sink count that should
* be probed, %false otherwise.
*/
bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const struct drm_dp_desc *desc)
{
/* Some eDP panels don't set a valid value for the sink count */
return connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 &&
dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT &&
!drm_dp_has_quirk(desc, 0, DP_DPCD_QUIRK_NO_SINK_COUNT);
}
EXPORT_SYMBOL(drm_dp_read_sink_count_cap);
/**
* drm_dp_read_sink_count() - Retrieve the sink count for a given sink
* @aux: The DP AUX channel to use
*
* See also: drm_dp_read_sink_count_cap()
*
* Returns: The current sink count reported by @aux, or a negative error code
* otherwise.
*/
int drm_dp_read_sink_count(struct drm_dp_aux *aux)
{
u8 count;
int ret;
ret = drm_dp_dpcd_readb(aux, DP_SINK_COUNT, &count);
if (ret < 0)
return ret;
if (ret != 1)
return -EIO;
return DP_GET_SINK_COUNT(count);
}
EXPORT_SYMBOL(drm_dp_read_sink_count);
/*
* I2C-over-AUX implementation
*/
static u32 drm_dp_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 void drm_dp_i2c_msg_write_status_update(struct drm_dp_aux_msg *msg)
{
/*
* In case of i2c defer or short i2c ack reply to a write,
* we need to switch to WRITE_STATUS_UPDATE to drain the
* rest of the message
*/
if ((msg->request & ~DP_AUX_I2C_MOT) == DP_AUX_I2C_WRITE) {
msg->request &= DP_AUX_I2C_MOT;
msg->request |= DP_AUX_I2C_WRITE_STATUS_UPDATE;
}
}
#define AUX_PRECHARGE_LEN 10 /* 10 to 16 */
#define AUX_SYNC_LEN (16 + 4) /* preamble + AUX_SYNC_END */
#define AUX_STOP_LEN 4
#define AUX_CMD_LEN 4
#define AUX_ADDRESS_LEN 20
#define AUX_REPLY_PAD_LEN 4
#define AUX_LENGTH_LEN 8
/*
* Calculate the duration of the AUX request/reply in usec. Gives the
* "best" case estimate, ie. successful while as short as possible.
*/
static int drm_dp_aux_req_duration(const struct drm_dp_aux_msg *msg)
{
int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN +
AUX_CMD_LEN + AUX_ADDRESS_LEN + AUX_LENGTH_LEN;
if ((msg->request & DP_AUX_I2C_READ) == 0)
len += msg->size * 8;
return len;
}
static int drm_dp_aux_reply_duration(const struct drm_dp_aux_msg *msg)
{
int len = AUX_PRECHARGE_LEN + AUX_SYNC_LEN + AUX_STOP_LEN +
AUX_CMD_LEN + AUX_REPLY_PAD_LEN;
/*
* For read we expect what was asked. For writes there will
* be 0 or 1 data bytes. Assume 0 for the "best" case.
*/
if (msg->request & DP_AUX_I2C_READ)
len += msg->size * 8;
return len;
}
#define I2C_START_LEN 1
#define I2C_STOP_LEN 1
#define I2C_ADDR_LEN 9 /* ADDRESS + R/W + ACK/NACK */
#define I2C_DATA_LEN 9 /* DATA + ACK/NACK */
/*
* Calculate the length of the i2c transfer in usec, assuming
* the i2c bus speed is as specified. Gives the the "worst"
* case estimate, ie. successful while as long as possible.
* Doesn't account the the "MOT" bit, and instead assumes each
* message includes a START, ADDRESS and STOP. Neither does it
* account for additional random variables such as clock stretching.
*/
static int drm_dp_i2c_msg_duration(const struct drm_dp_aux_msg *msg,
int i2c_speed_khz)
{
/* AUX bitrate is 1MHz, i2c bitrate as specified */
return DIV_ROUND_UP((I2C_START_LEN + I2C_ADDR_LEN +
msg->size * I2C_DATA_LEN +
I2C_STOP_LEN) * 1000, i2c_speed_khz);
}
/*
* Deterine how many retries should be attempted to successfully transfer
* the specified message, based on the estimated durations of the
* i2c and AUX transfers.
*/
static int drm_dp_i2c_retry_count(const struct drm_dp_aux_msg *msg,
int i2c_speed_khz)
{
int aux_time_us = drm_dp_aux_req_duration(msg) +
drm_dp_aux_reply_duration(msg);
int i2c_time_us = drm_dp_i2c_msg_duration(msg, i2c_speed_khz);
return DIV_ROUND_UP(i2c_time_us, aux_time_us + AUX_RETRY_INTERVAL);
}
/*
* FIXME currently assumes 10 kHz as some real world devices seem
* to require it. We should query/set the speed via DPCD if supported.
*/
static int dp_aux_i2c_speed_khz __read_mostly = 10;
module_param_unsafe(dp_aux_i2c_speed_khz, int, 0644);
MODULE_PARM_DESC(dp_aux_i2c_speed_khz,
"Assumed speed of the i2c bus in kHz, (1-400, default 10)");
/*
* Transfer a single I2C-over-AUX message and handle various error conditions,
* retrying the transaction as appropriate. It is assumed that the
* &drm_dp_aux.transfer function does not modify anything in the msg other than the
* reply field.
*
* Returns bytes transferred on success, or a negative error code on failure.
*/
static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
{
unsigned int retry, defer_i2c;
int ret;
/*
* DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device
* is required to retry at least seven times upon receiving AUX_DEFER
* before giving up the AUX transaction.
*
* We also try to account for the i2c bus speed.
*/
int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
ret = aux->transfer(aux, msg);
if (ret < 0) {
if (ret == -EBUSY)
continue;
/*
* While timeouts can be errors, they're usually normal
* behavior (for instance, when a driver tries to
* communicate with a non-existant DisplayPort device).
* Avoid spamming the kernel log with timeout errors.
*/
if (ret == -ETIMEDOUT)
DRM_DEBUG_KMS_RATELIMITED("%s: transaction timed out\n",
aux->name);
else
DRM_DEBUG_KMS("%s: transaction failed: %d\n",
aux->name, ret);
return ret;
}
switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) {
case DP_AUX_NATIVE_REPLY_ACK:
/*
* For I2C-over-AUX transactions this isn't enough, we
* need to check for the I2C ACK reply.
*/
break;
case DP_AUX_NATIVE_REPLY_NACK:
DRM_DEBUG_KMS("%s: native nack (result=%d, size=%zu)\n",
aux->name, ret, msg->size);
return -EREMOTEIO;
case DP_AUX_NATIVE_REPLY_DEFER:
DRM_DEBUG_KMS("%s: native defer\n", aux->name);
/*
* We could check for I2C bit rate capabilities and if
* available adjust this interval. We could also be
* more careful with DP-to-legacy adapters where a
* long legacy cable may force very low I2C bit rates.
*
* For now just defer for long enough to hopefully be
* safe for all use-cases.
*/
usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
continue;
default:
DRM_ERROR("%s: invalid native reply %#04x\n",
aux->name, msg->reply);
return -EREMOTEIO;
}
switch (msg->reply & DP_AUX_I2C_REPLY_MASK) {
case DP_AUX_I2C_REPLY_ACK:
/*
* Both native ACK and I2C ACK replies received. We
* can assume the transfer was successful.
*/
if (ret != msg->size)
drm_dp_i2c_msg_write_status_update(msg);
return ret;
case DP_AUX_I2C_REPLY_NACK:
DRM_DEBUG_KMS("%s: I2C nack (result=%d, size=%zu)\n",
aux->name, ret, msg->size);
aux->i2c_nack_count++;
return -EREMOTEIO;
case DP_AUX_I2C_REPLY_DEFER:
DRM_DEBUG_KMS("%s: I2C defer\n", aux->name);
/* DP Compliance Test 4.2.2.5 Requirement:
* Must have at least 7 retries for I2C defers on the
* transaction to pass this test
*/
aux->i2c_defer_count++;
if (defer_i2c < 7)
defer_i2c++;
usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
drm_dp_i2c_msg_write_status_update(msg);
continue;
default:
DRM_ERROR("%s: invalid I2C reply %#04x\n",
aux->name, msg->reply);
return -EREMOTEIO;
}
}
DRM_DEBUG_KMS("%s: Too many retries, giving up\n", aux->name);
return -EREMOTEIO;
}
static void drm_dp_i2c_msg_set_request(struct drm_dp_aux_msg *msg,
const struct i2c_msg *i2c_msg)
{
msg->request = (i2c_msg->flags & I2C_M_RD) ?
DP_AUX_I2C_READ : DP_AUX_I2C_WRITE;
if (!(i2c_msg->flags & I2C_M_STOP))
msg->request |= DP_AUX_I2C_MOT;
}
/*
* Keep retrying drm_dp_i2c_do_msg until all data has been transferred.
*
* Returns an error code on failure, or a recommended transfer size on success.
*/
static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg)
{
int err, ret = orig_msg->size;
struct drm_dp_aux_msg msg = *orig_msg;
while (msg.size > 0) {
err = drm_dp_i2c_do_msg(aux, &msg);
if (err <= 0)
return err == 0 ? -EPROTO : err;
if (err < msg.size && err < ret) {
DRM_DEBUG_KMS("%s: Partial I2C reply: requested %zu bytes got %d bytes\n",
aux->name, msg.size, err);
ret = err;
}
msg.size -= err;
msg.buffer += err;
}
return ret;
}
/*
* Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX
* packets to be as large as possible. If not, the I2C transactions never
* succeed. Hence the default is maximum.
*/
static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES;
module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644);
MODULE_PARM_DESC(dp_aux_i2c_transfer_size,
"Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)");
static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
int num)
{
struct drm_dp_aux *aux = adapter->algo_data;
unsigned int i, j;
unsigned transfer_size;
struct drm_dp_aux_msg msg;
int err = 0;
dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES);
memset(&msg, 0, sizeof(msg));
for (i = 0; i < num; i++) {
msg.address = msgs[i].addr;
drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
/* Send a bare address packet to start the transaction.
* Zero sized messages specify an address only (bare
* address) transaction.
*/
msg.buffer = NULL;
msg.size = 0;
err = drm_dp_i2c_do_msg(aux, &msg);
/*
* Reset msg.request in case in case it got
* changed into a WRITE_STATUS_UPDATE.
*/
drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
if (err < 0)
break;
/* We want each transaction to be as large as possible, but
* we'll go to smaller sizes if the hardware gives us a
* short reply.
*/
transfer_size = dp_aux_i2c_transfer_size;
for (j = 0; j < msgs[i].len; j += msg.size) {
msg.buffer = msgs[i].buf + j;
msg.size = min(transfer_size, msgs[i].len - j);
err = drm_dp_i2c_drain_msg(aux, &msg);
/*
* Reset msg.request in case in case it got
* changed into a WRITE_STATUS_UPDATE.
*/
drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
if (err < 0)
break;
transfer_size = err;
}
if (err < 0)
break;
}
if (err >= 0)
err = num;
/* Send a bare address packet to close out the transaction.
* Zero sized messages specify an address only (bare
* address) transaction.
*/
msg.request &= ~DP_AUX_I2C_MOT;
msg.buffer = NULL;
msg.size = 0;
(void)drm_dp_i2c_do_msg(aux, &msg);
return err;
}
static const struct i2c_algorithm drm_dp_i2c_algo = {
.functionality = drm_dp_i2c_functionality,
.master_xfer = drm_dp_i2c_xfer,
};
static struct drm_dp_aux *i2c_to_aux(struct i2c_adapter *i2c)
{
return container_of(i2c, struct drm_dp_aux, ddc);
}
static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
mutex_lock(&i2c_to_aux(i2c)->hw_mutex);
}
static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
return mutex_trylock(&i2c_to_aux(i2c)->hw_mutex);
}
static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
mutex_unlock(&i2c_to_aux(i2c)->hw_mutex);
}
static const struct i2c_lock_operations drm_dp_i2c_lock_ops = {
.lock_bus = lock_bus,
.trylock_bus = trylock_bus,
.unlock_bus = unlock_bus,
};
static int drm_dp_aux_get_crc(struct drm_dp_aux *aux, u8 *crc)
{
u8 buf, count;
int ret;
ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
if (ret < 0)
return ret;
WARN_ON(!(buf & DP_TEST_SINK_START));
ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK_MISC, &buf);
if (ret < 0)
return ret;
count = buf & DP_TEST_COUNT_MASK;
if (count == aux->crc_count)
return -EAGAIN; /* No CRC yet */
aux->crc_count = count;
/*
* At DP_TEST_CRC_R_CR, there's 6 bytes containing CRC data, 2 bytes
* per component (RGB or CrYCb).
*/
ret = drm_dp_dpcd_read(aux, DP_TEST_CRC_R_CR, crc, 6);
if (ret < 0)
return ret;
return 0;
}
static void drm_dp_aux_crc_work(struct work_struct *work)
{
struct drm_dp_aux *aux = container_of(work, struct drm_dp_aux,
crc_work);
struct drm_crtc *crtc;
u8 crc_bytes[6];
uint32_t crcs[3];
int ret;
if (WARN_ON(!aux->crtc))
return;
crtc = aux->crtc;
while (crtc->crc.opened) {
drm_crtc_wait_one_vblank(crtc);
if (!crtc->crc.opened)
break;
ret = drm_dp_aux_get_crc(aux, crc_bytes);
if (ret == -EAGAIN) {
usleep_range(1000, 2000);
ret = drm_dp_aux_get_crc(aux, crc_bytes);
}
if (ret == -EAGAIN) {
DRM_DEBUG_KMS("%s: Get CRC failed after retrying: %d\n",
aux->name, ret);
continue;
} else if (ret) {
DRM_DEBUG_KMS("%s: Failed to get a CRC: %d\n",
aux->name, ret);
continue;
}
crcs[0] = crc_bytes[0] | crc_bytes[1] << 8;
crcs[1] = crc_bytes[2] | crc_bytes[3] << 8;
crcs[2] = crc_bytes[4] | crc_bytes[5] << 8;
drm_crtc_add_crc_entry(crtc, false, 0, crcs);
}
}
/**
* drm_dp_remote_aux_init() - minimally initialise a remote aux channel
* @aux: DisplayPort AUX channel
*
* Used for remote aux channel in general. Merely initialize the crc work
* struct.
*/
void drm_dp_remote_aux_init(struct drm_dp_aux *aux)
{
INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
}
EXPORT_SYMBOL(drm_dp_remote_aux_init);
/**
* drm_dp_aux_init() - minimally initialise an aux channel
* @aux: DisplayPort AUX channel
*
* If you need to use the drm_dp_aux's i2c adapter prior to registering it
* with the outside world, call drm_dp_aux_init() first. You must still
* call drm_dp_aux_register() once the connector has been registered to
* allow userspace access to the auxiliary DP channel.
*/
void drm_dp_aux_init(struct drm_dp_aux *aux)
{
mutex_init(&aux->hw_mutex);
mutex_init(&aux->cec.lock);
INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work);
aux->ddc.algo = &drm_dp_i2c_algo;
aux->ddc.algo_data = aux;
aux->ddc.retries = 3;
aux->ddc.lock_ops = &drm_dp_i2c_lock_ops;
}
EXPORT_SYMBOL(drm_dp_aux_init);
/**
* drm_dp_aux_register() - initialise and register aux channel
* @aux: DisplayPort AUX channel
*
* Automatically calls drm_dp_aux_init() if this hasn't been done yet.
* This should only be called when the underlying &struct drm_connector is
* initialiazed already. Therefore the best place to call this is from
* &drm_connector_funcs.late_register. Not that drivers which don't follow this
* will Oops when CONFIG_DRM_DP_AUX_CHARDEV is enabled.
*
* Drivers which need to use the aux channel before that point (e.g. at driver
* load time, before drm_dev_register() has been called) need to call
* drm_dp_aux_init().
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_aux_register(struct drm_dp_aux *aux)
{
int ret;
if (!aux->ddc.algo)
drm_dp_aux_init(aux);
aux->ddc.class = I2C_CLASS_DDC;
aux->ddc.owner = THIS_MODULE;
aux->ddc.dev.parent = aux->dev;
strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
sizeof(aux->ddc.name));
ret = drm_dp_aux_register_devnode(aux);
if (ret)
return ret;
ret = i2c_add_adapter(&aux->ddc);
if (ret) {
drm_dp_aux_unregister_devnode(aux);
return ret;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_aux_register);
/**
* drm_dp_aux_unregister() - unregister an AUX adapter
* @aux: DisplayPort AUX channel
*/
void drm_dp_aux_unregister(struct drm_dp_aux *aux)
{
drm_dp_aux_unregister_devnode(aux);
i2c_del_adapter(&aux->ddc);
}
EXPORT_SYMBOL(drm_dp_aux_unregister);
#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)
/**
* drm_dp_psr_setup_time() - PSR setup in time usec
* @psr_cap: PSR capabilities from DPCD
*
* Returns:
* PSR setup time for the panel in microseconds, negative
* error code on failure.
*/
int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
{
static const u16 psr_setup_time_us[] = {
PSR_SETUP_TIME(330),
PSR_SETUP_TIME(275),
PSR_SETUP_TIME(220),
PSR_SETUP_TIME(165),
PSR_SETUP_TIME(110),
PSR_SETUP_TIME(55),
PSR_SETUP_TIME(0),
};
int i;
i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT;
if (i >= ARRAY_SIZE(psr_setup_time_us))
return -EINVAL;
return psr_setup_time_us[i];
}
EXPORT_SYMBOL(drm_dp_psr_setup_time);
#undef PSR_SETUP_TIME
/**
* drm_dp_start_crc() - start capture of frame CRCs
* @aux: DisplayPort AUX channel
* @crtc: CRTC displaying the frames whose CRCs are to be captured
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_start_crc(struct drm_dp_aux *aux, struct drm_crtc *crtc)
{
u8 buf;
int ret;
ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
if (ret < 0)
return ret;
ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf | DP_TEST_SINK_START);
if (ret < 0)
return ret;
aux->crc_count = 0;
aux->crtc = crtc;
schedule_work(&aux->crc_work);
return 0;
}
EXPORT_SYMBOL(drm_dp_start_crc);
/**
* drm_dp_stop_crc() - stop capture of frame CRCs
* @aux: DisplayPort AUX channel
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_stop_crc(struct drm_dp_aux *aux)
{
u8 buf;
int ret;
ret = drm_dp_dpcd_readb(aux, DP_TEST_SINK, &buf);
if (ret < 0)
return ret;
ret = drm_dp_dpcd_writeb(aux, DP_TEST_SINK, buf & ~DP_TEST_SINK_START);
if (ret < 0)
return ret;
flush_work(&aux->crc_work);
aux->crtc = NULL;
return 0;
}
EXPORT_SYMBOL(drm_dp_stop_crc);
struct dpcd_quirk {
u8 oui[3];
u8 device_id[6];
bool is_branch;
u32 quirks;
};
#define OUI(first, second, third) { (first), (second), (third) }
#define DEVICE_ID(first, second, third, fourth, fifth, sixth) \
{ (first), (second), (third), (fourth), (fifth), (sixth) }
#define DEVICE_ID_ANY DEVICE_ID(0, 0, 0, 0, 0, 0)
static const struct dpcd_quirk dpcd_quirk_list[] = {
/* Analogix 7737 needs reduced M and N at HBR2 link rates */
{ OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
/* LG LP140WF6-SPM1 eDP panel */
{ OUI(0x00, 0x22, 0xb9), DEVICE_ID('s', 'i', 'v', 'a', 'r', 'T'), false, BIT(DP_DPCD_QUIRK_CONSTANT_N) },
/* Apple panels need some additional handling to support PSR */
{ OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) },
/* CH7511 seems to leave SINK_COUNT zeroed */
{ OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) },
/* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */
{ OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) },
/* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */
{ OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) },
};
#undef OUI
/*
* Get a bit mask of DPCD quirks for the sink/branch device identified by
* ident. The quirk data is shared but it's up to the drivers to act on the
* data.
*
* For now, only the OUI (first three bytes) is used, but this may be extended
* to device identification string and hardware/firmware revisions later.
*/
static u32
drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
{
const struct dpcd_quirk *quirk;
u32 quirks = 0;
int i;
u8 any_device[] = DEVICE_ID_ANY;
for (i = 0; i < ARRAY_SIZE(dpcd_quirk_list); i++) {
quirk = &dpcd_quirk_list[i];
if (quirk->is_branch != is_branch)
continue;
if (memcmp(quirk->oui, ident->oui, sizeof(ident->oui)) != 0)
continue;
if (memcmp(quirk->device_id, any_device, sizeof(any_device)) != 0 &&
memcmp(quirk->device_id, ident->device_id, sizeof(ident->device_id)) != 0)
continue;
quirks |= quirk->quirks;
}
return quirks;
}
#undef DEVICE_ID_ANY
#undef DEVICE_ID
struct edid_quirk {
u8 mfg_id[2];
u8 prod_id[2];
u32 quirks;
};
#define MFG(first, second) { (first), (second) }
#define PROD_ID(first, second) { (first), (second) }
/*
* Some devices have unreliable OUIDs where they don't set the device ID
* correctly, and as a result we need to use the EDID for finding additional
* DP quirks in such cases.
*/
static const struct edid_quirk edid_quirk_list[] = {
/* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation
* only supports DPCD backlight controls
*/
{ MFG(0x4c, 0x83), PROD_ID(0x41, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
/*
* Some Dell CML 2020 systems have panels support both AUX and PWM
* backlight control, and some only support AUX backlight control. All
* said panels start up in AUX mode by default, and we don't have any
* support for disabling HDR mode on these panels which would be
* required to switch to PWM backlight control mode (plus, I'm not
* even sure we want PWM backlight controls over DPCD backlight
* controls anyway...). Until we have a better way of detecting these,
* force DPCD backlight mode on all of them.
*/
{ MFG(0x06, 0xaf), PROD_ID(0x9b, 0x32), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x06, 0xaf), PROD_ID(0xeb, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x4d, 0x10), PROD_ID(0xc7, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x4c, 0x83), PROD_ID(0x47, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
{ MFG(0x09, 0xe5), PROD_ID(0xde, 0x08), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
};
#undef MFG
#undef PROD_ID
/**
* drm_dp_get_edid_quirks() - Check the EDID of a DP device to find additional
* DP-specific quirks
* @edid: The EDID to check
*
* While OUIDs are meant to be used to recognize a DisplayPort device, a lot
* of manufacturers don't seem to like following standards and neglect to fill
* the dev-ID in, making it impossible to only use OUIDs for determining
* quirks in some cases. This function can be used to check the EDID and look
* up any additional DP quirks. The bits returned by this function correspond
* to the quirk bits in &drm_dp_quirk.
*
* Returns: a bitmask of quirks, if any. The driver can check this using
* drm_dp_has_quirk().
*/
u32 drm_dp_get_edid_quirks(const struct edid *edid)
{
const struct edid_quirk *quirk;
u32 quirks = 0;
int i;
if (!edid)
return 0;
for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
quirk = &edid_quirk_list[i];
if (memcmp(quirk->mfg_id, edid->mfg_id,
sizeof(edid->mfg_id)) == 0 &&
memcmp(quirk->prod_id, edid->prod_code,
sizeof(edid->prod_code)) == 0)
quirks |= quirk->quirks;
}
DRM_DEBUG_KMS("DP sink: EDID mfg %*phD prod-ID %*phD quirks: 0x%04x\n",
(int)sizeof(edid->mfg_id), edid->mfg_id,
(int)sizeof(edid->prod_code), edid->prod_code, quirks);
return quirks;
}
EXPORT_SYMBOL(drm_dp_get_edid_quirks);
/**
* drm_dp_read_desc - read sink/branch descriptor from DPCD
* @aux: DisplayPort AUX channel
* @desc: Device descriptor to fill from DPCD
* @is_branch: true for branch devices, false for sink devices
*
* Read DPCD 0x400 (sink) or 0x500 (branch) into @desc. Also debug log the
* identification.
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc,
bool is_branch)
{
struct drm_dp_dpcd_ident *ident = &desc->ident;
unsigned int offset = is_branch ? DP_BRANCH_OUI : DP_SINK_OUI;
int ret, dev_id_len;
ret = drm_dp_dpcd_read(aux, offset, ident, sizeof(*ident));
if (ret < 0)
return ret;
desc->quirks = drm_dp_get_quirks(ident, is_branch);
dev_id_len = strnlen(ident->device_id, sizeof(ident->device_id));
DRM_DEBUG_KMS("%s: DP %s: OUI %*phD dev-ID %*pE HW-rev %d.%d SW-rev %d.%d quirks 0x%04x\n",
aux->name, is_branch ? "branch" : "sink",
(int)sizeof(ident->oui), ident->oui,
dev_id_len, ident->device_id,
ident->hw_rev >> 4, ident->hw_rev & 0xf,
ident->sw_major_rev, ident->sw_minor_rev,
desc->quirks);
return 0;
}
EXPORT_SYMBOL(drm_dp_read_desc);
/**
* drm_dp_dsc_sink_max_slice_count() - Get the max slice count
* supported by the DSC sink.
* @dsc_dpcd: DSC capabilities from DPCD
* @is_edp: true if its eDP, false for DP
*
* Read the slice capabilities DPCD register from DSC sink to get
* the maximum slice count supported. This is used to populate
* the DSC parameters in the &struct drm_dsc_config by the driver.
* Driver creates an infoframe using these parameters to populate
* &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
* infoframe using the helper function drm_dsc_pps_infoframe_pack()
*
* Returns:
* Maximum slice count supported by DSC sink or 0 its invalid
*/
u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
bool is_edp)
{
u8 slice_cap1 = dsc_dpcd[DP_DSC_SLICE_CAP_1 - DP_DSC_SUPPORT];
if (is_edp) {
/* For eDP, register DSC_SLICE_CAPABILITIES_1 gives slice count */
if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK)
return 4;
if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK)
return 2;
if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK)
return 1;
} else {
/* For DP, use values from DSC_SLICE_CAP_1 and DSC_SLICE_CAP2 */
u8 slice_cap2 = dsc_dpcd[DP_DSC_SLICE_CAP_2 - DP_DSC_SUPPORT];
if (slice_cap2 & DP_DSC_24_PER_DP_DSC_SINK)
return 24;
if (slice_cap2 & DP_DSC_20_PER_DP_DSC_SINK)
return 20;
if (slice_cap2 & DP_DSC_16_PER_DP_DSC_SINK)
return 16;
if (slice_cap1 & DP_DSC_12_PER_DP_DSC_SINK)
return 12;
if (slice_cap1 & DP_DSC_10_PER_DP_DSC_SINK)
return 10;
if (slice_cap1 & DP_DSC_8_PER_DP_DSC_SINK)
return 8;
if (slice_cap1 & DP_DSC_6_PER_DP_DSC_SINK)
return 6;
if (slice_cap1 & DP_DSC_4_PER_DP_DSC_SINK)
return 4;
if (slice_cap1 & DP_DSC_2_PER_DP_DSC_SINK)
return 2;
if (slice_cap1 & DP_DSC_1_PER_DP_DSC_SINK)
return 1;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_dsc_sink_max_slice_count);
/**
* drm_dp_dsc_sink_line_buf_depth() - Get the line buffer depth in bits
* @dsc_dpcd: DSC capabilities from DPCD
*
* Read the DSC DPCD register to parse the line buffer depth in bits which is
* number of bits of precision within the decoder line buffer supported by
* the DSC sink. This is used to populate the DSC parameters in the
* &struct drm_dsc_config by the driver.
* Driver creates an infoframe using these parameters to populate
* &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
* infoframe using the helper function drm_dsc_pps_infoframe_pack()
*
* Returns:
* Line buffer depth supported by DSC panel or 0 its invalid
*/
u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
{
u8 line_buf_depth = dsc_dpcd[DP_DSC_LINE_BUF_BIT_DEPTH - DP_DSC_SUPPORT];
switch (line_buf_depth & DP_DSC_LINE_BUF_BIT_DEPTH_MASK) {
case DP_DSC_LINE_BUF_BIT_DEPTH_9:
return 9;
case DP_DSC_LINE_BUF_BIT_DEPTH_10:
return 10;
case DP_DSC_LINE_BUF_BIT_DEPTH_11:
return 11;
case DP_DSC_LINE_BUF_BIT_DEPTH_12:
return 12;
case DP_DSC_LINE_BUF_BIT_DEPTH_13:
return 13;
case DP_DSC_LINE_BUF_BIT_DEPTH_14:
return 14;
case DP_DSC_LINE_BUF_BIT_DEPTH_15:
return 15;
case DP_DSC_LINE_BUF_BIT_DEPTH_16:
return 16;
case DP_DSC_LINE_BUF_BIT_DEPTH_8:
return 8;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth);
/**
* drm_dp_dsc_sink_supported_input_bpcs() - Get all the input bits per component
* values supported by the DSC sink.
* @dsc_dpcd: DSC capabilities from DPCD
* @dsc_bpc: An array to be filled by this helper with supported
* input bpcs.
*
* Read the DSC DPCD from the sink device to parse the supported bits per
* component values. This is used to populate the DSC parameters
* in the &struct drm_dsc_config by the driver.
* Driver creates an infoframe using these parameters to populate
* &struct drm_dsc_pps_infoframe. These are sent to the sink using DSC
* infoframe using the helper function drm_dsc_pps_infoframe_pack()
*
* Returns:
* Number of input BPC values parsed from the DPCD
*/
int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
u8 dsc_bpc[3])
{
int num_bpc = 0;
u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
if (color_depth & DP_DSC_12_BPC)
dsc_bpc[num_bpc++] = 12;
if (color_depth & DP_DSC_10_BPC)
dsc_bpc[num_bpc++] = 10;
if (color_depth & DP_DSC_8_BPC)
dsc_bpc[num_bpc++] = 8;
return num_bpc;
}
EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs);
/**
* drm_dp_read_lttpr_common_caps - read the LTTPR common capabilities
* @aux: DisplayPort AUX channel
* @caps: buffer to return the capability info in
*
* Read capabilities common to all LTTPRs.
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_read_lttpr_common_caps(struct drm_dp_aux *aux,
u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
{
int ret;
ret = drm_dp_dpcd_read(aux,
DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV,
caps, DP_LTTPR_COMMON_CAP_SIZE);
if (ret < 0)
return ret;
WARN_ON(ret != DP_LTTPR_COMMON_CAP_SIZE);
return 0;
}
EXPORT_SYMBOL(drm_dp_read_lttpr_common_caps);
/**
* drm_dp_read_lttpr_phy_caps - read the capabilities for a given LTTPR PHY
* @aux: DisplayPort AUX channel
* @dp_phy: LTTPR PHY to read the capabilities for
* @caps: buffer to return the capability info in
*
* Read the capabilities for the given LTTPR PHY.
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_read_lttpr_phy_caps(struct drm_dp_aux *aux,
enum drm_dp_phy dp_phy,
u8 caps[DP_LTTPR_PHY_CAP_SIZE])
{
int ret;
ret = drm_dp_dpcd_read(aux,
DP_TRAINING_AUX_RD_INTERVAL_PHY_REPEATER(dp_phy),
caps, DP_LTTPR_PHY_CAP_SIZE);
if (ret < 0)
return ret;
WARN_ON(ret != DP_LTTPR_PHY_CAP_SIZE);
return 0;
}
EXPORT_SYMBOL(drm_dp_read_lttpr_phy_caps);
static u8 dp_lttpr_common_cap(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE], int r)
{
return caps[r - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV];
}
/**
* drm_dp_lttpr_count - get the number of detected LTTPRs
* @caps: LTTPR common capabilities
*
* Get the number of detected LTTPRs from the LTTPR common capabilities info.
*
* Returns:
* -ERANGE if more than supported number (8) of LTTPRs are detected
* -EINVAL if the DP_PHY_REPEATER_CNT register contains an invalid value
* otherwise the number of detected LTTPRs
*/
int drm_dp_lttpr_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
{
u8 count = dp_lttpr_common_cap(caps, DP_PHY_REPEATER_CNT);
switch (hweight8(count)) {
case 0:
return 0;
case 1:
return 8 - ilog2(count);
case 8:
return -ERANGE;
default:
return -EINVAL;
}
}
EXPORT_SYMBOL(drm_dp_lttpr_count);
/**
* drm_dp_lttpr_max_link_rate - get the maximum link rate supported by all LTTPRs
* @caps: LTTPR common capabilities
*
* Returns the maximum link rate supported by all detected LTTPRs.
*/
int drm_dp_lttpr_max_link_rate(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
{
u8 rate = dp_lttpr_common_cap(caps, DP_MAX_LINK_RATE_PHY_REPEATER);
return drm_dp_bw_code_to_link_rate(rate);
}
EXPORT_SYMBOL(drm_dp_lttpr_max_link_rate);
/**
* drm_dp_lttpr_max_lane_count - get the maximum lane count supported by all LTTPRs
* @caps: LTTPR common capabilities
*
* Returns the maximum lane count supported by all detected LTTPRs.
*/
int drm_dp_lttpr_max_lane_count(const u8 caps[DP_LTTPR_COMMON_CAP_SIZE])
{
u8 max_lanes = dp_lttpr_common_cap(caps, DP_MAX_LANE_COUNT_PHY_REPEATER);
return max_lanes & DP_MAX_LANE_COUNT_MASK;
}
EXPORT_SYMBOL(drm_dp_lttpr_max_lane_count);
/**
* drm_dp_lttpr_voltage_swing_level_3_supported - check for LTTPR vswing3 support
* @caps: LTTPR PHY capabilities
*
* Returns true if the @caps for an LTTPR TX PHY indicate support for
* voltage swing level 3.
*/
bool
drm_dp_lttpr_voltage_swing_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE])
{
u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1);
return txcap & DP_VOLTAGE_SWING_LEVEL_3_SUPPORTED;
}
EXPORT_SYMBOL(drm_dp_lttpr_voltage_swing_level_3_supported);
/**
* drm_dp_lttpr_pre_emphasis_level_3_supported - check for LTTPR preemph3 support
* @caps: LTTPR PHY capabilities
*
* Returns true if the @caps for an LTTPR TX PHY indicate support for
* pre-emphasis level 3.
*/
bool
drm_dp_lttpr_pre_emphasis_level_3_supported(const u8 caps[DP_LTTPR_PHY_CAP_SIZE])
{
u8 txcap = dp_lttpr_phy_cap(caps, DP_TRANSMITTER_CAPABILITY_PHY_REPEATER1);
return txcap & DP_PRE_EMPHASIS_LEVEL_3_SUPPORTED;
}
EXPORT_SYMBOL(drm_dp_lttpr_pre_emphasis_level_3_supported);
/**
* drm_dp_get_phy_test_pattern() - get the requested pattern from the sink.
* @aux: DisplayPort AUX channel
* @data: DP phy compliance test parameters.
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_get_phy_test_pattern(struct drm_dp_aux *aux,
struct drm_dp_phy_test_params *data)
{
int err;
u8 rate, lanes;
err = drm_dp_dpcd_readb(aux, DP_TEST_LINK_RATE, &rate);
if (err < 0)
return err;
data->link_rate = drm_dp_bw_code_to_link_rate(rate);
err = drm_dp_dpcd_readb(aux, DP_TEST_LANE_COUNT, &lanes);
if (err < 0)
return err;
data->num_lanes = lanes & DP_MAX_LANE_COUNT_MASK;
if (lanes & DP_ENHANCED_FRAME_CAP)
data->enhanced_frame_cap = true;
err = drm_dp_dpcd_readb(aux, DP_PHY_TEST_PATTERN, &data->phy_pattern);
if (err < 0)
return err;
switch (data->phy_pattern) {
case DP_PHY_TEST_PATTERN_80BIT_CUSTOM:
err = drm_dp_dpcd_read(aux, DP_TEST_80BIT_CUSTOM_PATTERN_7_0,
&data->custom80, sizeof(data->custom80));
if (err < 0)
return err;
break;
case DP_PHY_TEST_PATTERN_CP2520:
err = drm_dp_dpcd_read(aux, DP_TEST_HBR2_SCRAMBLER_RESET,
&data->hbr2_reset,
sizeof(data->hbr2_reset));
if (err < 0)
return err;
}
return 0;
}
EXPORT_SYMBOL(drm_dp_get_phy_test_pattern);
/**
* drm_dp_set_phy_test_pattern() - set the pattern to the sink.
* @aux: DisplayPort AUX channel
* @data: DP phy compliance test parameters.
* @dp_rev: DP revision to use for compliance testing
*
* Returns 0 on success or a negative error code on failure.
*/
int drm_dp_set_phy_test_pattern(struct drm_dp_aux *aux,
struct drm_dp_phy_test_params *data, u8 dp_rev)
{
int err, i;
u8 link_config[2];
u8 test_pattern;
link_config[0] = drm_dp_link_rate_to_bw_code(data->link_rate);
link_config[1] = data->num_lanes;
if (data->enhanced_frame_cap)
link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, link_config, 2);
if (err < 0)
return err;
test_pattern = data->phy_pattern;
if (dp_rev < 0x12) {
test_pattern = (test_pattern << 2) &
DP_LINK_QUAL_PATTERN_11_MASK;
err = drm_dp_dpcd_writeb(aux, DP_TRAINING_PATTERN_SET,
test_pattern);
if (err < 0)
return err;
} else {
for (i = 0; i < data->num_lanes; i++) {
err = drm_dp_dpcd_writeb(aux,
DP_LINK_QUAL_LANE0_SET + i,
test_pattern);
if (err < 0)
return err;
}
}
return 0;
}
EXPORT_SYMBOL(drm_dp_set_phy_test_pattern);
static const char *dp_pixelformat_get_name(enum dp_pixelformat pixelformat)
{
if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED)
return "Invalid";
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "RGB";
case DP_PIXELFORMAT_YUV444:
return "YUV444";
case DP_PIXELFORMAT_YUV422:
return "YUV422";
case DP_PIXELFORMAT_YUV420:
return "YUV420";
case DP_PIXELFORMAT_Y_ONLY:
return "Y_ONLY";
case DP_PIXELFORMAT_RAW:
return "RAW";
default:
return "Reserved";
}
}
static const char *dp_colorimetry_get_name(enum dp_pixelformat pixelformat,
enum dp_colorimetry colorimetry)
{
if (pixelformat < 0 || pixelformat > DP_PIXELFORMAT_RESERVED)
return "Invalid";
switch (colorimetry) {
case DP_COLORIMETRY_DEFAULT:
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "sRGB";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "BT.601";
case DP_PIXELFORMAT_Y_ONLY:
return "DICOM PS3.14";
case DP_PIXELFORMAT_RAW:
return "Custom Color Profile";
default:
return "Reserved";
}
case DP_COLORIMETRY_RGB_WIDE_FIXED: /* and DP_COLORIMETRY_BT709_YCC */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "Wide Fixed";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "BT.709";
default:
return "Reserved";
}
case DP_COLORIMETRY_RGB_WIDE_FLOAT: /* and DP_COLORIMETRY_XVYCC_601 */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "Wide Float";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "xvYCC 601";
default:
return "Reserved";
}
case DP_COLORIMETRY_OPRGB: /* and DP_COLORIMETRY_XVYCC_709 */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "OpRGB";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "xvYCC 709";
default:
return "Reserved";
}
case DP_COLORIMETRY_DCI_P3_RGB: /* and DP_COLORIMETRY_SYCC_601 */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "DCI-P3";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "sYCC 601";
default:
return "Reserved";
}
case DP_COLORIMETRY_RGB_CUSTOM: /* and DP_COLORIMETRY_OPYCC_601 */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "Custom Profile";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "OpYCC 601";
default:
return "Reserved";
}
case DP_COLORIMETRY_BT2020_RGB: /* and DP_COLORIMETRY_BT2020_CYCC */
switch (pixelformat) {
case DP_PIXELFORMAT_RGB:
return "BT.2020 RGB";
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "BT.2020 CYCC";
default:
return "Reserved";
}
case DP_COLORIMETRY_BT2020_YCC:
switch (pixelformat) {
case DP_PIXELFORMAT_YUV444:
case DP_PIXELFORMAT_YUV422:
case DP_PIXELFORMAT_YUV420:
return "BT.2020 YCC";
default:
return "Reserved";
}
default:
return "Invalid";
}
}
static const char *dp_dynamic_range_get_name(enum dp_dynamic_range dynamic_range)
{
switch (dynamic_range) {
case DP_DYNAMIC_RANGE_VESA:
return "VESA range";
case DP_DYNAMIC_RANGE_CTA:
return "CTA range";
default:
return "Invalid";
}
}
static const char *dp_content_type_get_name(enum dp_content_type content_type)
{
switch (content_type) {
case DP_CONTENT_TYPE_NOT_DEFINED:
return "Not defined";
case DP_CONTENT_TYPE_GRAPHICS:
return "Graphics";
case DP_CONTENT_TYPE_PHOTO:
return "Photo";
case DP_CONTENT_TYPE_VIDEO:
return "Video";
case DP_CONTENT_TYPE_GAME:
return "Game";
default:
return "Reserved";
}
}
void drm_dp_vsc_sdp_log(const char *level, struct device *dev,
const struct drm_dp_vsc_sdp *vsc)
{
#define DP_SDP_LOG(fmt, ...) dev_printk(level, dev, fmt, ##__VA_ARGS__)
DP_SDP_LOG("DP SDP: %s, revision %u, length %u\n", "VSC",
vsc->revision, vsc->length);
DP_SDP_LOG(" pixelformat: %s\n",
dp_pixelformat_get_name(vsc->pixelformat));
DP_SDP_LOG(" colorimetry: %s\n",
dp_colorimetry_get_name(vsc->pixelformat, vsc->colorimetry));
DP_SDP_LOG(" bpc: %u\n", vsc->bpc);
DP_SDP_LOG(" dynamic range: %s\n",
dp_dynamic_range_get_name(vsc->dynamic_range));
DP_SDP_LOG(" content type: %s\n",
dp_content_type_get_name(vsc->content_type));
#undef DP_SDP_LOG
}
EXPORT_SYMBOL(drm_dp_vsc_sdp_log);
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