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linux/include/drm/drm_dp_helper.h
Rob Clark d816f07736 drm/dp: add drm_dp_link_power_down() helper 
We had _power_up(), but drivers also need to be able to power down.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
2015-02-01 15:06:42 -05:00

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/*
* Copyright © 2008 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.
*/
#ifndef _DRM_DP_HELPER_H_
#define _DRM_DP_HELPER_H_
#include <linux/types.h>
#include <linux/i2c.h>
#include <linux/delay.h>
/*
* Unless otherwise noted, all values are from the DP 1.1a spec. Note that
* DP and DPCD versions are independent. Differences from 1.0 are not noted,
* 1.0 devices basically don't exist in the wild.
*
* Abbreviations, in chronological order:
*
* eDP: Embedded DisplayPort version 1
* DPI: DisplayPort Interoperability Guideline v1.1a
* 1.2: DisplayPort 1.2
* MST: Multistream Transport - part of DP 1.2a
*
* 1.2 formally includes both eDP and DPI definitions.
*/
#define DP_AUX_I2C_WRITE 0x0
#define DP_AUX_I2C_READ 0x1
#define DP_AUX_I2C_STATUS 0x2
#define DP_AUX_I2C_MOT 0x4
#define DP_AUX_NATIVE_WRITE 0x8
#define DP_AUX_NATIVE_READ 0x9
#define DP_AUX_NATIVE_REPLY_ACK (0x0 << 0)
#define DP_AUX_NATIVE_REPLY_NACK (0x1 << 0)
#define DP_AUX_NATIVE_REPLY_DEFER (0x2 << 0)
#define DP_AUX_NATIVE_REPLY_MASK (0x3 << 0)
#define DP_AUX_I2C_REPLY_ACK (0x0 << 2)
#define DP_AUX_I2C_REPLY_NACK (0x1 << 2)
#define DP_AUX_I2C_REPLY_DEFER (0x2 << 2)
#define DP_AUX_I2C_REPLY_MASK (0x3 << 2)
/* AUX CH addresses */
/* DPCD */
#define DP_DPCD_REV 0x000
#define DP_MAX_LINK_RATE 0x001
#define DP_MAX_LANE_COUNT 0x002
# define DP_MAX_LANE_COUNT_MASK 0x1f
# define DP_TPS3_SUPPORTED (1 << 6) /* 1.2 */
# define DP_ENHANCED_FRAME_CAP (1 << 7)
#define DP_MAX_DOWNSPREAD 0x003
# define DP_NO_AUX_HANDSHAKE_LINK_TRAINING (1 << 6)
#define DP_NORP 0x004
#define DP_DOWNSTREAMPORT_PRESENT 0x005
# define DP_DWN_STRM_PORT_PRESENT (1 << 0)
# define DP_DWN_STRM_PORT_TYPE_MASK 0x06
# define DP_DWN_STRM_PORT_TYPE_DP (0 << 1)
# define DP_DWN_STRM_PORT_TYPE_ANALOG (1 << 1)
# define DP_DWN_STRM_PORT_TYPE_TMDS (2 << 1)
# define DP_DWN_STRM_PORT_TYPE_OTHER (3 << 1)
# define DP_FORMAT_CONVERSION (1 << 3)
# define DP_DETAILED_CAP_INFO_AVAILABLE (1 << 4) /* DPI */
#define DP_MAIN_LINK_CHANNEL_CODING 0x006
#define DP_DOWN_STREAM_PORT_COUNT 0x007
# define DP_PORT_COUNT_MASK 0x0f
# define DP_MSA_TIMING_PAR_IGNORED (1 << 6) /* eDP */
# define DP_OUI_SUPPORT (1 << 7)
#define DP_I2C_SPEED_CAP 0x00c /* DPI */
# define DP_I2C_SPEED_1K 0x01
# define DP_I2C_SPEED_5K 0x02
# define DP_I2C_SPEED_10K 0x04
# define DP_I2C_SPEED_100K 0x08
# define DP_I2C_SPEED_400K 0x10
# define DP_I2C_SPEED_1M 0x20
#define DP_EDP_CONFIGURATION_CAP 0x00d /* XXX 1.2? */
#define DP_TRAINING_AUX_RD_INTERVAL 0x00e /* XXX 1.2? */
/* Multiple stream transport */
#define DP_FAUX_CAP 0x020 /* 1.2 */
# define DP_FAUX_CAP_1 (1 << 0)
#define DP_MSTM_CAP 0x021 /* 1.2 */
# define DP_MST_CAP (1 << 0)
#define DP_GUID 0x030 /* 1.2 */
#define DP_PSR_SUPPORT 0x070 /* XXX 1.2? */
# define DP_PSR_IS_SUPPORTED 1
#define DP_PSR_CAPS 0x071 /* XXX 1.2? */
# define DP_PSR_NO_TRAIN_ON_EXIT 1
# define DP_PSR_SETUP_TIME_330 (0 << 1)
# define DP_PSR_SETUP_TIME_275 (1 << 1)
# define DP_PSR_SETUP_TIME_220 (2 << 1)
# define DP_PSR_SETUP_TIME_165 (3 << 1)
# define DP_PSR_SETUP_TIME_110 (4 << 1)
# define DP_PSR_SETUP_TIME_55 (5 << 1)
# define DP_PSR_SETUP_TIME_0 (6 << 1)
# define DP_PSR_SETUP_TIME_MASK (7 << 1)
# define DP_PSR_SETUP_TIME_SHIFT 1
/*
* 0x80-0x8f describe downstream port capabilities, but there are two layouts
* based on whether DP_DETAILED_CAP_INFO_AVAILABLE was set. If it was not,
* each port's descriptor is one byte wide. If it was set, each port's is
* four bytes wide, starting with the one byte from the base info. As of
* DP interop v1.1a only VGA defines additional detail.
*/
/* offset 0 */
#define DP_DOWNSTREAM_PORT_0 0x80
# define DP_DS_PORT_TYPE_MASK (7 << 0)
# define DP_DS_PORT_TYPE_DP 0
# define DP_DS_PORT_TYPE_VGA 1
# define DP_DS_PORT_TYPE_DVI 2
# define DP_DS_PORT_TYPE_HDMI 3
# define DP_DS_PORT_TYPE_NON_EDID 4
# define DP_DS_PORT_HPD (1 << 3)
/* offset 1 for VGA is maximum megapixels per second / 8 */
/* offset 2 */
# define DP_DS_VGA_MAX_BPC_MASK (3 << 0)
# define DP_DS_VGA_8BPC 0
# define DP_DS_VGA_10BPC 1
# define DP_DS_VGA_12BPC 2
# define DP_DS_VGA_16BPC 3
/* link configuration */
#define DP_LINK_BW_SET 0x100
# define DP_LINK_BW_1_62 0x06
# define DP_LINK_BW_2_7 0x0a
# define DP_LINK_BW_5_4 0x14 /* 1.2 */
#define DP_LANE_COUNT_SET 0x101
# define DP_LANE_COUNT_MASK 0x0f
# define DP_LANE_COUNT_ENHANCED_FRAME_EN (1 << 7)
#define DP_TRAINING_PATTERN_SET 0x102
# define DP_TRAINING_PATTERN_DISABLE 0
# define DP_TRAINING_PATTERN_1 1
# define DP_TRAINING_PATTERN_2 2
# define DP_TRAINING_PATTERN_3 3 /* 1.2 */
# define DP_TRAINING_PATTERN_MASK 0x3
# define DP_LINK_QUAL_PATTERN_DISABLE (0 << 2)
# define DP_LINK_QUAL_PATTERN_D10_2 (1 << 2)
# define DP_LINK_QUAL_PATTERN_ERROR_RATE (2 << 2)
# define DP_LINK_QUAL_PATTERN_PRBS7 (3 << 2)
# define DP_LINK_QUAL_PATTERN_MASK (3 << 2)
# define DP_RECOVERED_CLOCK_OUT_EN (1 << 4)
# define DP_LINK_SCRAMBLING_DISABLE (1 << 5)
# define DP_SYMBOL_ERROR_COUNT_BOTH (0 << 6)
# define DP_SYMBOL_ERROR_COUNT_DISPARITY (1 << 6)
# define DP_SYMBOL_ERROR_COUNT_SYMBOL (2 << 6)
# define DP_SYMBOL_ERROR_COUNT_MASK (3 << 6)
#define DP_TRAINING_LANE0_SET 0x103
#define DP_TRAINING_LANE1_SET 0x104
#define DP_TRAINING_LANE2_SET 0x105
#define DP_TRAINING_LANE3_SET 0x106
# define DP_TRAIN_VOLTAGE_SWING_MASK 0x3
# define DP_TRAIN_VOLTAGE_SWING_SHIFT 0
# define DP_TRAIN_MAX_SWING_REACHED (1 << 2)
# define DP_TRAIN_VOLTAGE_SWING_LEVEL_0 (0 << 0)
# define DP_TRAIN_VOLTAGE_SWING_LEVEL_1 (1 << 0)
# define DP_TRAIN_VOLTAGE_SWING_LEVEL_2 (2 << 0)
# define DP_TRAIN_VOLTAGE_SWING_LEVEL_3 (3 << 0)
# define DP_TRAIN_PRE_EMPHASIS_MASK (3 << 3)
# define DP_TRAIN_PRE_EMPH_LEVEL_0 (0 << 3)
# define DP_TRAIN_PRE_EMPH_LEVEL_1 (1 << 3)
# define DP_TRAIN_PRE_EMPH_LEVEL_2 (2 << 3)
# define DP_TRAIN_PRE_EMPH_LEVEL_3 (3 << 3)
# define DP_TRAIN_PRE_EMPHASIS_SHIFT 3
# define DP_TRAIN_MAX_PRE_EMPHASIS_REACHED (1 << 5)
#define DP_DOWNSPREAD_CTRL 0x107
# define DP_SPREAD_AMP_0_5 (1 << 4)
# define DP_MSA_TIMING_PAR_IGNORE_EN (1 << 7) /* eDP */
#define DP_MAIN_LINK_CHANNEL_CODING_SET 0x108
# define DP_SET_ANSI_8B10B (1 << 0)
#define DP_I2C_SPEED_CONTROL_STATUS 0x109 /* DPI */
/* bitmask as for DP_I2C_SPEED_CAP */
#define DP_EDP_CONFIGURATION_SET 0x10a /* XXX 1.2? */
#define DP_MSTM_CTRL 0x111 /* 1.2 */
# define DP_MST_EN (1 << 0)
# define DP_UP_REQ_EN (1 << 1)
# define DP_UPSTREAM_IS_SRC (1 << 2)
#define DP_PSR_EN_CFG 0x170 /* XXX 1.2? */
# define DP_PSR_ENABLE (1 << 0)
# define DP_PSR_MAIN_LINK_ACTIVE (1 << 1)
# define DP_PSR_CRC_VERIFICATION (1 << 2)
# define DP_PSR_FRAME_CAPTURE (1 << 3)
#define DP_ADAPTER_CTRL 0x1a0
# define DP_ADAPTER_CTRL_FORCE_LOAD_SENSE (1 << 0)
#define DP_BRANCH_DEVICE_CTRL 0x1a1
# define DP_BRANCH_DEVICE_IRQ_HPD (1 << 0)
#define DP_PAYLOAD_ALLOCATE_SET 0x1c0
#define DP_PAYLOAD_ALLOCATE_START_TIME_SLOT 0x1c1
#define DP_PAYLOAD_ALLOCATE_TIME_SLOT_COUNT 0x1c2
#define DP_SINK_COUNT 0x200
/* prior to 1.2 bit 7 was reserved mbz */
# define DP_GET_SINK_COUNT(x) ((((x) & 0x80) >> 1) | ((x) & 0x3f))
# define DP_SINK_CP_READY (1 << 6)
#define DP_DEVICE_SERVICE_IRQ_VECTOR 0x201
# define DP_REMOTE_CONTROL_COMMAND_PENDING (1 << 0)
# define DP_AUTOMATED_TEST_REQUEST (1 << 1)
# define DP_CP_IRQ (1 << 2)
# define DP_MCCS_IRQ (1 << 3)
# define DP_DOWN_REP_MSG_RDY (1 << 4) /* 1.2 MST */
# define DP_UP_REQ_MSG_RDY (1 << 5) /* 1.2 MST */
# define DP_SINK_SPECIFIC_IRQ (1 << 6)
#define DP_LANE0_1_STATUS 0x202
#define DP_LANE2_3_STATUS 0x203
# define DP_LANE_CR_DONE (1 << 0)
# define DP_LANE_CHANNEL_EQ_DONE (1 << 1)
# define DP_LANE_SYMBOL_LOCKED (1 << 2)
#define DP_CHANNEL_EQ_BITS (DP_LANE_CR_DONE | \
DP_LANE_CHANNEL_EQ_DONE | \
DP_LANE_SYMBOL_LOCKED)
#define DP_LANE_ALIGN_STATUS_UPDATED 0x204
#define DP_INTERLANE_ALIGN_DONE (1 << 0)
#define DP_DOWNSTREAM_PORT_STATUS_CHANGED (1 << 6)
#define DP_LINK_STATUS_UPDATED (1 << 7)
#define DP_SINK_STATUS 0x205
#define DP_RECEIVE_PORT_0_STATUS (1 << 0)
#define DP_RECEIVE_PORT_1_STATUS (1 << 1)
#define DP_ADJUST_REQUEST_LANE0_1 0x206
#define DP_ADJUST_REQUEST_LANE2_3 0x207
# define DP_ADJUST_VOLTAGE_SWING_LANE0_MASK 0x03
# define DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT 0
# define DP_ADJUST_PRE_EMPHASIS_LANE0_MASK 0x0c
# define DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT 2
# define DP_ADJUST_VOLTAGE_SWING_LANE1_MASK 0x30
# define DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT 4
# define DP_ADJUST_PRE_EMPHASIS_LANE1_MASK 0xc0
# define DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT 6
#define DP_TEST_REQUEST 0x218
# define DP_TEST_LINK_TRAINING (1 << 0)
# define DP_TEST_LINK_VIDEO_PATTERN (1 << 1)
# define DP_TEST_LINK_EDID_READ (1 << 2)
# define DP_TEST_LINK_PHY_TEST_PATTERN (1 << 3) /* DPCD >= 1.1 */
# define DP_TEST_LINK_FAUX_PATTERN (1 << 4) /* DPCD >= 1.2 */
#define DP_TEST_LINK_RATE 0x219
# define DP_LINK_RATE_162 (0x6)
# define DP_LINK_RATE_27 (0xa)
#define DP_TEST_LANE_COUNT 0x220
#define DP_TEST_PATTERN 0x221
#define DP_TEST_CRC_R_CR 0x240
#define DP_TEST_CRC_G_Y 0x242
#define DP_TEST_CRC_B_CB 0x244
#define DP_TEST_SINK_MISC 0x246
# define DP_TEST_CRC_SUPPORTED (1 << 5)
# define DP_TEST_COUNT_MASK 0x7
#define DP_TEST_RESPONSE 0x260
# define DP_TEST_ACK (1 << 0)
# define DP_TEST_NAK (1 << 1)
# define DP_TEST_EDID_CHECKSUM_WRITE (1 << 2)
#define DP_TEST_EDID_CHECKSUM 0x261
#define DP_TEST_SINK 0x270
# define DP_TEST_SINK_START (1 << 0)
#define DP_PAYLOAD_TABLE_UPDATE_STATUS 0x2c0 /* 1.2 MST */
# define DP_PAYLOAD_TABLE_UPDATED (1 << 0)
# define DP_PAYLOAD_ACT_HANDLED (1 << 1)
#define DP_VC_PAYLOAD_ID_SLOT_1 0x2c1 /* 1.2 MST */
/* up to ID_SLOT_63 at 0x2ff */
#define DP_SOURCE_OUI 0x300
#define DP_SINK_OUI 0x400
#define DP_BRANCH_OUI 0x500
#define DP_SET_POWER 0x600
# define DP_SET_POWER_D0 0x1
# define DP_SET_POWER_D3 0x2
# define DP_SET_POWER_MASK 0x3
#define DP_SIDEBAND_MSG_DOWN_REQ_BASE 0x1000 /* 1.2 MST */
#define DP_SIDEBAND_MSG_UP_REP_BASE 0x1200 /* 1.2 MST */
#define DP_SIDEBAND_MSG_DOWN_REP_BASE 0x1400 /* 1.2 MST */
#define DP_SIDEBAND_MSG_UP_REQ_BASE 0x1600 /* 1.2 MST */
#define DP_SINK_COUNT_ESI 0x2002 /* 1.2 */
/* 0-5 sink count */
# define DP_SINK_COUNT_CP_READY (1 << 6)
#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0 0x2003 /* 1.2 */
#define DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1 0x2004 /* 1.2 */
#define DP_LINK_SERVICE_IRQ_VECTOR_ESI0 0x2005 /* 1.2 */
#define DP_PSR_ERROR_STATUS 0x2006 /* XXX 1.2? */
# define DP_PSR_LINK_CRC_ERROR (1 << 0)
# define DP_PSR_RFB_STORAGE_ERROR (1 << 1)
#define DP_PSR_ESI 0x2007 /* XXX 1.2? */
# define DP_PSR_CAPS_CHANGE (1 << 0)
#define DP_PSR_STATUS 0x2008 /* XXX 1.2? */
# define DP_PSR_SINK_INACTIVE 0
# define DP_PSR_SINK_ACTIVE_SRC_SYNCED 1
# define DP_PSR_SINK_ACTIVE_RFB 2
# define DP_PSR_SINK_ACTIVE_SINK_SYNCED 3
# define DP_PSR_SINK_ACTIVE_RESYNC 4
# define DP_PSR_SINK_INTERNAL_ERROR 7
# define DP_PSR_SINK_STATE_MASK 0x07
/* DP 1.2 Sideband message defines */
/* peer device type - DP 1.2a Table 2-92 */
#define DP_PEER_DEVICE_NONE 0x0
#define DP_PEER_DEVICE_SOURCE_OR_SST 0x1
#define DP_PEER_DEVICE_MST_BRANCHING 0x2
#define DP_PEER_DEVICE_SST_SINK 0x3
#define DP_PEER_DEVICE_DP_LEGACY_CONV 0x4
/* DP 1.2 MST sideband request names DP 1.2a Table 2-80 */
#define DP_LINK_ADDRESS 0x01
#define DP_CONNECTION_STATUS_NOTIFY 0x02
#define DP_ENUM_PATH_RESOURCES 0x10
#define DP_ALLOCATE_PAYLOAD 0x11
#define DP_QUERY_PAYLOAD 0x12
#define DP_RESOURCE_STATUS_NOTIFY 0x13
#define DP_CLEAR_PAYLOAD_ID_TABLE 0x14
#define DP_REMOTE_DPCD_READ 0x20
#define DP_REMOTE_DPCD_WRITE 0x21
#define DP_REMOTE_I2C_READ 0x22
#define DP_REMOTE_I2C_WRITE 0x23
#define DP_POWER_UP_PHY 0x24
#define DP_POWER_DOWN_PHY 0x25
#define DP_SINK_EVENT_NOTIFY 0x30
#define DP_QUERY_STREAM_ENC_STATUS 0x38
/* DP 1.2 MST sideband nak reasons - table 2.84 */
#define DP_NAK_WRITE_FAILURE 0x01
#define DP_NAK_INVALID_READ 0x02
#define DP_NAK_CRC_FAILURE 0x03
#define DP_NAK_BAD_PARAM 0x04
#define DP_NAK_DEFER 0x05
#define DP_NAK_LINK_FAILURE 0x06
#define DP_NAK_NO_RESOURCES 0x07
#define DP_NAK_DPCD_FAIL 0x08
#define DP_NAK_I2C_NAK 0x09
#define DP_NAK_ALLOCATE_FAIL 0x0a
#define MODE_I2C_START 1
#define MODE_I2C_WRITE 2
#define MODE_I2C_READ 4
#define MODE_I2C_STOP 8
#define DP_LINK_STATUS_SIZE 6
bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane_count);
bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane_count);
u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane);
u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane);
#define DP_RECEIVER_CAP_SIZE 0xf
#define EDP_PSR_RECEIVER_CAP_SIZE 2
void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]);
u8 drm_dp_link_rate_to_bw_code(int link_rate);
int drm_dp_bw_code_to_link_rate(u8 link_bw);
struct edp_sdp_header {
u8 HB0; /* Secondary Data Packet ID */
u8 HB1; /* Secondary Data Packet Type */
u8 HB2; /* 7:5 reserved, 4:0 revision number */
u8 HB3; /* 7:5 reserved, 4:0 number of valid data bytes */
} __packed;
#define EDP_SDP_HEADER_REVISION_MASK 0x1F
#define EDP_SDP_HEADER_VALID_PAYLOAD_BYTES 0x1F
struct edp_vsc_psr {
struct edp_sdp_header sdp_header;
u8 DB0; /* Stereo Interface */
u8 DB1; /* 0 - PSR State; 1 - Update RFB; 2 - CRC Valid */
u8 DB2; /* CRC value bits 7:0 of the R or Cr component */
u8 DB3; /* CRC value bits 15:8 of the R or Cr component */
u8 DB4; /* CRC value bits 7:0 of the G or Y component */
u8 DB5; /* CRC value bits 15:8 of the G or Y component */
u8 DB6; /* CRC value bits 7:0 of the B or Cb component */
u8 DB7; /* CRC value bits 15:8 of the B or Cb component */
u8 DB8_31[24]; /* Reserved */
} __packed;
#define EDP_VSC_PSR_STATE_ACTIVE (1<<0)
#define EDP_VSC_PSR_UPDATE_RFB (1<<1)
#define EDP_VSC_PSR_CRC_VALUES_VALID (1<<2)
static inline int
drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
return drm_dp_bw_code_to_link_rate(dpcd[DP_MAX_LINK_RATE]);
}
static inline u8
drm_dp_max_lane_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
return dpcd[DP_MAX_LANE_COUNT] & DP_MAX_LANE_COUNT_MASK;
}
static inline bool
drm_dp_enhanced_frame_cap(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
{
return dpcd[DP_DPCD_REV] >= 0x11 &&
(dpcd[DP_MAX_LANE_COUNT] & DP_ENHANCED_FRAME_CAP);
}
/*
* DisplayPort AUX channel
*/
/**
* struct drm_dp_aux_msg - DisplayPort AUX channel transaction
* @address: address of the (first) register to access
* @request: contains the type of transaction (see DP_AUX_* macros)
* @reply: upon completion, contains the reply type of the transaction
* @buffer: pointer to a transmission or reception buffer
* @size: size of @buffer
*/
struct drm_dp_aux_msg {
unsigned int address;
u8 request;
u8 reply;
void *buffer;
size_t size;
};
/**
* struct drm_dp_aux - DisplayPort AUX channel
* @name: user-visible name of this AUX channel and the I2C-over-AUX adapter
* @ddc: I2C adapter that can be used for I2C-over-AUX communication
* @dev: pointer to struct device that is the parent for this AUX channel
* @hw_mutex: internal mutex used for locking transfers
* @transfer: transfers a message representing a single AUX transaction
*
* The .dev field should be set to a pointer to the device that implements
* the AUX channel.
*
* The .name field may be used to specify the name of the I2C adapter. If set to
* NULL, dev_name() of .dev will be used.
*
* Drivers provide a hardware-specific implementation of how transactions
* are executed via the .transfer() function. A pointer to a drm_dp_aux_msg
* structure describing the transaction is passed into this function. Upon
* success, the implementation should return the number of payload bytes
* that were transferred, or a negative error-code on failure. Helpers
* propagate errors from the .transfer() function, with the exception of
* the -EBUSY error, which causes a transaction to be retried. On a short,
* helpers will return -EPROTO to make it simpler to check for failure.
*
* An AUX channel can also be used to transport I2C messages to a sink. A
* typical application of that is to access an EDID that's present in the
* sink device. The .transfer() function can also be used to execute such
* transactions. The drm_dp_aux_register_i2c_bus() function registers an
* I2C adapter that can be passed to drm_probe_ddc(). Upon removal, drivers
* should call drm_dp_aux_unregister_i2c_bus() to remove the I2C adapter.
*
* Note that the aux helper code assumes that the .transfer() function
* only modifies the reply field of the drm_dp_aux_msg structure. The
* retry logic and i2c helpers assume this is the case.
*/
struct drm_dp_aux {
const char *name;
struct i2c_adapter ddc;
struct device *dev;
struct mutex hw_mutex;
ssize_t (*transfer)(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg);
unsigned i2c_nack_count, i2c_defer_count;
};
ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size);
ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset,
void *buffer, size_t size);
/**
* drm_dp_dpcd_readb() - read a single byte from the DPCD
* @aux: DisplayPort AUX channel
* @offset: address of the register to read
* @valuep: location where the value of the register will be stored
*
* Returns the number of bytes transferred (1) on success, or a negative
* error code on failure.
*/
static inline ssize_t drm_dp_dpcd_readb(struct drm_dp_aux *aux,
unsigned int offset, u8 *valuep)
{
return drm_dp_dpcd_read(aux, offset, valuep, 1);
}
/**
* drm_dp_dpcd_writeb() - write a single byte to the DPCD
* @aux: DisplayPort AUX channel
* @offset: address of the register to write
* @value: value to write to the register
*
* Returns the number of bytes transferred (1) on success, or a negative
* error code on failure.
*/
static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux,
unsigned int offset, u8 value)
{
return drm_dp_dpcd_write(aux, offset, &value, 1);
}
int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,
u8 status[DP_LINK_STATUS_SIZE]);
/*
* DisplayPort link
*/
#define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0)
struct drm_dp_link {
unsigned char revision;
unsigned int rate;
unsigned int num_lanes;
unsigned long capabilities;
};
int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link);
int drm_dp_aux_register(struct drm_dp_aux *aux);
void drm_dp_aux_unregister(struct drm_dp_aux *aux);
#endif /* _DRM_DP_HELPER_H_ */
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