/* * 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 #include #include /* * 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 /** * struct i2c_algo_dp_aux_data - driver interface structure for i2c over dp * aux algorithm * @running: set by the algo indicating whether an i2c is ongoing or whether * the i2c bus is quiescent * @address: i2c target address for the currently ongoing transfer * @aux_ch: driver callback to transfer a single byte of the i2c payload */ struct i2c_algo_dp_aux_data { bool running; u16 address; int (*aux_ch) (struct i2c_adapter *adapter, int mode, uint8_t write_byte, uint8_t *read_byte); }; int i2c_dp_aux_add_bus(struct i2c_adapter *adapter); #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); }; 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_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_ */