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u-boot/drivers/video/logicore_dp_tx.c
Mario Six 25a9f9747a video_display: Add Xilinx LogiCore DP TX 
Add a driver for the Xilinx LogiCORE DisplayPort IP core, which is a
pure DP transmitter core for Xiling FPGA (no display capabilities).

Signed-off-by: Mario Six <mario.six@gdsys.cc>
2018-08-11 09:18:44 +02:00

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// SPDX-License-Identifier: GPL-2.0+
/*
* logicore_dp_tx.c
*
* Driver for XILINX LogiCore DisplayPort v6.1 TX (Source)
* based on Xilinx dp_v3_1 driver sources, updated to dp_v4_0
*
* (C) Copyright 2016
* Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
*/
#include <common.h>
#include <clk.h>
#include <display.h>
#include <dm.h>
#include <errno.h>
#include "axi.h"
#include "logicore_dp_dpcd.h"
#include "logicore_dp_tx.h"
#include "logicore_dp_tx_regif.h"
/* Default AXI clock frequency value */
#define S_AXI_CLK_DEFAULT 100000000
/* Default DP phy clock value */
#define PHY_CLOCK_SELECT_DEFAULT PHY_CLOCK_SELECT_540GBPS
/* The maximum voltage swing level is 3 */
#define MAXIMUM_VS_LEVEL 3
/* The maximum pre-emphasis level is 3 */
#define MAXIMUM_PE_LEVEL 3
/* Error out if an AUX request yields a defer reply more than 50 times */
#define AUX_MAX_DEFER_COUNT 50
/* Error out if an AUX request times out more than 50 times awaiting a reply */
#define AUX_MAX_TIMEOUT_COUNT 50
/* Error out if checking for a connected device times out more than 50 times */
#define IS_CONNECTED_MAX_TIMEOUT_COUNT 50
/**
* enum link_training_states - States for link training state machine
* @TS_CLOCK_RECOVERY: State for clock recovery
* @TS_CHANNEL_EQUALIZATION: State for channel equalization
* @TS_ADJUST_LINK_RATE: State where link rate is reduced in reaction to
* failed link training
* @TS_ADJUST_LANE_COUNT: State where lane count is reduced in reaction to
* failed link training
* @TS_FAILURE: State of link training failure
* @TS_SUCCESS:: State for successfully completed link training
*/
enum link_training_states {
TS_CLOCK_RECOVERY,
TS_CHANNEL_EQUALIZATION,
TS_ADJUST_LINK_RATE,
TS_ADJUST_LANE_COUNT,
TS_FAILURE,
TS_SUCCESS
};
/**
* struct aux_transaction - Description of an AUX channel transaction
* @cmd_code: Command code of the transaction
* @num_bytes: The number of bytes in the transaction's payload data
* @address: The DPCD address of the transaction
* @data: Payload data of the AUX channel transaction
*/
struct aux_transaction {
u16 cmd_code;
u8 num_bytes;
u32 address;
u8 *data;
};
/**
* struct main_stream_attributes - Main stream attributes
* @pixel_clock_hz: Pixel clock of the stream (in Hz)
* @misc_0: Miscellaneous stream attributes 0 as specified
* by the DisplayPort 1.2 specification
* @misc_1: Miscellaneous stream attributes 1 as specified
* by the DisplayPort 1.2 specification
* @n_vid: N value for the video stream
* @m_vid: M value used to recover the video clock from the
* link clock
* @user_pixel_width: Width of the user data input port
* @data_per_lane: Used to translate the number of pixels per line
* to the native internal 16-bit datapath
* @avg_bytes_per_tu: Average number of bytes per transfer unit,
* scaled up by a factor of 1000
* @transfer_unit_size: Size of the transfer unit in the framing logic
* In MST mode, this is also the number of time
* slots that are alloted in the payload ID table
* @init_wait: Number of initial wait cycles at the start of a
* new line by the framing logic
* @bits_per_color: Bits per color component
* @component_format: The component format currently in use by the
* video stream
* @dynamic_range: The dynamic range currently in use by the video
* stream
* @y_cb_cr_colorimetry: The YCbCr colorimetry currently in use by the
* video stream
* @synchronous_clock_mode: Synchronous clock mode is currently in use by
* the video stream
* @override_user_pixel_width: If set to 1, the value stored for
* user_pixel_width will be used as the pixel width
* @h_start: Horizontal blank start (pixels)
* @h_active: Horizontal active resolution (pixels)
* @h_sync_width: Horizontal sync width (pixels)
* @h_total: Horizontal total (pixels)
* @h_sync_polarity: Horizontal sync polarity (0=neg|1=pos)
* @v_start: Vertical blank start (in lines)
* @v_active: Vertical active resolution (lines)
* @v_sync_width: Vertical sync width (lines)
* @v_total: Vertical total (lines)
* @v_sync_polarity: Vertical sync polarity (0=neg|1=pos)
*
* All porch parameters have been removed, because our videodata is
* hstart/vstart based, and there is no benefit in keeping the porches
*/
struct main_stream_attributes {
u32 pixel_clock_hz;
u32 misc_0;
u32 misc_1;
u32 n_vid;
//u32 m_vid;
u32 user_pixel_width;
u32 data_per_lane;
u32 avg_bytes_per_tu;
u32 transfer_unit_size;
u32 init_wait;
u32 bits_per_color;
u8 component_format;
u8 dynamic_range;
u8 y_cb_cr_colorimetry;
u8 synchronous_clock_mode;
u8 override_user_pixel_width;
u32 h_start;
u16 h_active;
u16 h_sync_width;
u16 h_total;
bool h_sync_polarity;
u32 v_start;
u16 v_active;
u16 v_sync_width;
u16 v_total;
bool v_sync_polarity;
};
/**
* struct link_config - Description of link configuration
* @lane_count: Currently selected lane count for this link
* @link_rate: Currently selected link rate for this link
* @scrambler_en: Flag to determine whether the scrambler is
* enabled for this link
* @enhanced_framing_mode: Flag to determine whether enhanced framing
* mode is active for this link
* @max_lane_count: Maximum lane count for this link
* @max_link_rate: Maximum link rate for this link
* @support_enhanced_framing_mode: Flag to indicate whether the link supports
* enhanced framing mode
* @vs_level: Voltage swing for each lane
* @pe_level: Pre-emphasis/cursor level for each lane
*/
struct link_config {
u8 lane_count;
u8 link_rate;
bool scrambler_en;
bool enhanced_framing_mode;
u8 max_lane_count;
u8 max_link_rate;
bool support_enhanced_framing_mode;
u8 vs_level;
u8 pe_level;
};
/**
* struct dp_tx - Private data structure of LogiCore DP TX devices
*
* @base: Address of register base of device
* @s_axi_clk: The AXI clock frequency in Hz
* @train_adaptive: Use adaptive link trainig (i.e. successively reduce
* link rate and/or lane count) for this device
* @max_link_rate: Maximum link rate for this device
* @max_lane_count: Maximum lane count for this device
* @dpcd_rx_caps: RX device's status registers, see below
* @lane_status_ajd_reqs: Lane status and adjustment requests information for
* this device
* @link_config: The link configuration for this device
* @main_stream_attributes: MSA set for this device
*
* dpcd_rx_caps is a raw read of the RX device's status registers. The first 4
* bytes correspond to the lane status associated with clock recovery, channel
* equalization, symbol lock, and interlane alignment. The remaining 2 bytes
* represent the pre-emphasis and voltage swing level adjustments requested by
* the RX device.
*/
struct dp_tx {
u32 base;
u32 s_axi_clk;
bool train_adaptive;
u8 max_link_rate;
u8 max_lane_count;
u8 dpcd_rx_caps[16];
u8 lane_status_ajd_reqs[6];
struct link_config link_config;
struct main_stream_attributes main_stream_attributes;
};
/*
* Internal API
*/
/**
* get_reg() - Read a register of a LogiCore DP TX device
* @dev: The LogiCore DP TX device in question
* @reg: The offset of the register to read
*
* Return: The read register value
*/
static u32 get_reg(struct udevice *dev, u32 reg)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u32 value = 0;
int res;
/* TODO(mario.six@gdsys.cc): error handling */
res = axi_read(dev->parent, dp_tx->base + reg, &value, AXI_SIZE_32);
if (res < 0)
printf("%s() failed; res = %d\n", __func__, res);
return value;
}
/**
* set_reg() - Write a register of a LogiCore DP TX device
* @dev: The LogiCore DP TX device in question
* @reg: The offset of the register to write
* @value: The value to write to the register
*/
static void set_reg(struct udevice *dev, u32 reg, u32 value)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
axi_write(dev->parent, dp_tx->base + reg, &value, AXI_SIZE_32);
}
/**
* is_connected() - Check if there is a connected RX device
* @dev: The LogiCore DP TX device in question
*
* The Xilinx original calls msleep_interruptible at least once, ignoring
* status.
*
* Return: true if a connected RX device was detected, false otherwise
*/
static bool is_connected(struct udevice *dev)
{
u8 retries = 0;
do {
int status = get_reg(dev, REG_INTERRUPT_SIG_STATE) &
INTERRUPT_SIG_STATE_HPD_STATE_MASK;
if (status)
return true;
udelay(1000);
} while (retries++ < IS_CONNECTED_MAX_TIMEOUT_COUNT);
return false;
}
/**
* wait_phy_ready() - Wait for the DisplayPort PHY to come out of reset
* @dev: The LogiCore DP TX device in question
* @mask: Bit mask specifying which bit in the status register should be waited
* for
*
* Return: 0 if wait succeeded, -ve if error occurred
*/
static int wait_phy_ready(struct udevice *dev, u32 mask)
{
u16 timeout = 20000;
u32 phy_status;
/* Wait until the PHY is ready. */
do {
phy_status = get_reg(dev, REG_PHY_STATUS) & mask;
/* Protect against an infinite loop. */
if (!timeout--)
return -ETIMEDOUT;
udelay(20);
} while (phy_status != mask);
return 0;
}
/* AUX channel access */
/**
* aux_wait_ready() - Wait until another request is no longer in progress
* @dev: The LogiCore DP TX device in question
*
* Return: 0 if wait succeeded, -ve if error occurred
*/
static int aux_wait_ready(struct udevice *dev)
{
int status;
u32 timeout = 100;
/* Wait until the DisplayPort TX core is ready. */
do {
status = get_reg(dev, REG_INTERRUPT_SIG_STATE);
/* Protect against an infinite loop. */
if (!timeout--)
return -ETIMEDOUT;
udelay(20);
} while (status & REPLY_STATUS_REPLY_IN_PROGRESS_MASK);
return 0;
}
/**
* aux_wait_reply() - Wait for reply on AUX channel
* @dev: The LogiCore DP TX device in question
*
* Wait for a reply indicating that the most recent AUX request
* has been received by the RX device.
*
* Return: 0 if wait succeeded, -ve if error occurred
*/
static int aux_wait_reply(struct udevice *dev)
{
u32 timeout = 100;
while (timeout > 0) {
int status = get_reg(dev, REG_REPLY_STATUS);
/* Check for error. */
if (status & REPLY_STATUS_REPLY_ERROR_MASK)
return -ETIMEDOUT;
/* Check for a reply. */
if ((status & REPLY_STATUS_REPLY_RECEIVED_MASK) &&
!(status &
REPLY_STATUS_REQUEST_IN_PROGRESS_MASK) &&
!(status &
REPLY_STATUS_REPLY_IN_PROGRESS_MASK)) {
return 0;
}
timeout--;
udelay(20);
}
return -ETIMEDOUT;
}
/**
* aux_request_send() - Send request on the AUX channel
* @dev: The LogiCore DP TX device in question
* @request: The request to send
*
* Submit the supplied AUX request to the RX device over the AUX
* channel by writing the command, the destination address, (the write buffer
* for write commands), and the data size to the DisplayPort TX core.
*
* This is the lower-level sending routine, which is called by aux_request().
*
* Return: 0 if request was sent successfully, -ve on error
*/
static int aux_request_send(struct udevice *dev,
struct aux_transaction *request)
{
u32 timeout_count;
int status;
u8 index;
/* Ensure that any pending AUX transactions have completed. */
timeout_count = 0;
do {
status = get_reg(dev, REG_REPLY_STATUS);
udelay(20);
timeout_count++;
if (timeout_count >= AUX_MAX_TIMEOUT_COUNT)
return -ETIMEDOUT;
} while ((status & REPLY_STATUS_REQUEST_IN_PROGRESS_MASK) ||
(status & REPLY_STATUS_REPLY_IN_PROGRESS_MASK));
set_reg(dev, REG_AUX_ADDRESS, request->address);
if (request->cmd_code == AUX_CMD_WRITE ||
request->cmd_code == AUX_CMD_I2C_WRITE ||
request->cmd_code == AUX_CMD_I2C_WRITE_MOT) {
/* Feed write data into the DisplayPort TX core's write FIFO. */
for (index = 0; index < request->num_bytes; index++) {
set_reg(dev,
REG_AUX_WRITE_FIFO, request->data[index]);
}
}
/* Submit the command and the data size. */
set_reg(dev, REG_AUX_CMD,
((request->cmd_code << AUX_CMD_SHIFT) |
((request->num_bytes - 1) &
AUX_CMD_NBYTES_TRANSFER_MASK)));
/* Check for a reply from the RX device to the submitted request. */
status = aux_wait_reply(dev);
if (status)
/* Waiting for a reply timed out. */
return -ETIMEDOUT;
/* Analyze the reply. */
status = get_reg(dev, REG_AUX_REPLY_CODE);
if (status == AUX_REPLY_CODE_DEFER ||
status == AUX_REPLY_CODE_I2C_DEFER) {
/* The request was deferred. */
return -EAGAIN;
} else if ((status == AUX_REPLY_CODE_NACK) ||
(status == AUX_REPLY_CODE_I2C_NACK)) {
/* The request was not acknowledged. */
return -EIO;
}
/* The request was acknowledged. */
if (request->cmd_code == AUX_CMD_READ ||
request->cmd_code == AUX_CMD_I2C_READ ||
request->cmd_code == AUX_CMD_I2C_READ_MOT) {
/* Wait until all data has been received. */
timeout_count = 0;
do {
status = get_reg(dev, REG_REPLY_DATA_COUNT);
udelay(100);
timeout_count++;
if (timeout_count >= AUX_MAX_TIMEOUT_COUNT)
return -ETIMEDOUT;
} while (status != request->num_bytes);
/* Obtain the read data from the reply FIFO. */
for (index = 0; index < request->num_bytes; index++)
request->data[index] = get_reg(dev, REG_AUX_REPLY_DATA);
}
return 0;
}
/**
* aux_request() - Submit request on the AUX channel
* @dev: The LogiCore DP TX device in question
* @request: The request to submit
*
* Submit the supplied AUX request to the RX device over the AUX
* channel. If waiting for a reply times out, or if the DisplayPort TX core
* indicates that the request was deferred, the request is sent again (up to a
* maximum specified by AUX_MAX_DEFER_COUNT|AUX_MAX_TIMEOUT_COUNT).
*
* Return: 0 if request was submitted successfully, -ve on error
*/
static int aux_request(struct udevice *dev, struct aux_transaction *request)
{
u32 defer_count = 0;
u32 timeout_count = 0;
while ((defer_count < AUX_MAX_DEFER_COUNT) &&
(timeout_count < AUX_MAX_TIMEOUT_COUNT)) {
int status = aux_wait_ready(dev);
if (status) {
/* The RX device isn't ready yet. */
timeout_count++;
continue;
}
status = aux_request_send(dev, request);
if (status == -EAGAIN) {
/* The request was deferred. */
defer_count++;
} else if (status == -ETIMEDOUT) {
/* Waiting for a reply timed out. */
timeout_count++;
} else {
/*
* -EIO indicates that the request was NACK'ed,
* 0 indicates that the request was ACK'ed.
*/
return status;
}
udelay(100);
}
/* The request was not successfully received by the RX device. */
return -ETIMEDOUT;
}
/**
* aux_common() - Common (read/write) AUX communication transmission
* @dev: The LogiCore DP TX device in question
* @cmd_type: Command code of the transaction
* @address: The DPCD address of the transaction
* @num_bytes: Number of bytes in the payload data
* @data: The payload data of the AUX command
*
* Common sequence of submitting an AUX command for AUX read, AUX write,
* I2C-over-AUX read, and I2C-over-AUX write transactions. If required, the
* reads and writes are split into multiple requests, each acting on a maximum
* of 16 bytes.
*
* Return: 0 if OK, -ve on error
*/
static int aux_common(struct udevice *dev, u32 cmd_type, u32 address,
u32 num_bytes, u8 *data)
{
struct aux_transaction request;
u32 bytes_left;
/*
* Set the start address for AUX transactions. For I2C transactions,
* this is the address of the I2C bus.
*/
request.address = address;
bytes_left = num_bytes;
while (bytes_left) {
int status;
request.cmd_code = cmd_type;
if (cmd_type == AUX_CMD_READ ||
cmd_type == AUX_CMD_WRITE) {
/* Increment address for normal AUX transactions. */
request.address = address + (num_bytes - bytes_left);
}
/* Increment the pointer to the supplied data buffer. */
request.data = &data[num_bytes - bytes_left];
request.num_bytes = (bytes_left > 16) ? 16 : bytes_left;
bytes_left -= request.num_bytes;
if (cmd_type == AUX_CMD_I2C_READ && bytes_left) {
/*
* Middle of a transaction I2C read request. Override
* the command code that was set to cmd_type.
*/
request.cmd_code = AUX_CMD_I2C_READ_MOT;
} else if ((cmd_type == AUX_CMD_I2C_WRITE) && bytes_left) {
/*
* Middle of a transaction I2C write request. Override
* the command code that was set to cmd_type.
*/
request.cmd_code = AUX_CMD_I2C_WRITE_MOT;
}
status = aux_request(dev, &request);
if (status)
return status;
}
return 0;
}
/**
* aux_read() - Issue AUX read request
* @dev: The LogiCore DP TX device in question
* @dpcd_address: The DPCD address to read from
* @bytes_to_read: Number of bytes to read
* @read_data: Buffer to receive the read data
*
* Issue a read request over the AUX channel that will read from the RX
* device's DisplayPort Configuration data (DPCD) address space. The read
* message will be divided into multiple transactions which read a maximum of
* 16 bytes each.
*
* Return: 0 if read operation was successful, -ve on error
*/
static int aux_read(struct udevice *dev, u32 dpcd_address, u32 bytes_to_read,
void *read_data)
{
int status;
if (!is_connected(dev))
return -ENODEV;
/* Send AUX read transaction. */
status = aux_common(dev, AUX_CMD_READ, dpcd_address,
bytes_to_read, (u8 *)read_data);
return status;
}
/**
* aux_write() - Issue AUX write request
* @dev: The LogiCore DP TX device in question
* @dpcd_address: The DPCD address to write to
* @bytes_to_write: Number of bytes to write
* @write_data: Buffer containig data to be written
*
* Issue a write request over the AUX channel that will write to
* the RX device's DisplayPort Configuration data (DPCD) address space. The
* write message will be divided into multiple transactions which write a
* maximum of 16 bytes each.
*
* Return: 0 if write operation was successful, -ve on error
*/
static int aux_write(struct udevice *dev, u32 dpcd_address, u32 bytes_to_write,
void *write_data)
{
int status;
if (!is_connected(dev))
return -ENODEV;
/* Send AUX write transaction. */
status = aux_common(dev, AUX_CMD_WRITE, dpcd_address,
bytes_to_write, (u8 *)write_data);
return status;
}
/* Core initialization */
/**
* initialize() - Initialize a LogiCore DP TX device
* @dev: The LogiCore DP TX device in question
*
* Return: Always 0
*/
static int initialize(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u32 val;
u32 phy_config;
unsigned int k;
/* place the PHY (and GTTXRESET) into reset. */
phy_config = get_reg(dev, REG_PHY_CONFIG);
set_reg(dev, REG_PHY_CONFIG, phy_config | PHY_CONFIG_GT_ALL_RESET_MASK);
/* reset the video streams and AUX logic. */
set_reg(dev, REG_SOFT_RESET,
SOFT_RESET_VIDEO_STREAM_ALL_MASK |
SOFT_RESET_AUX_MASK);
/* disable the DisplayPort TX core. */
set_reg(dev, REG_ENABLE, 0);
/* set the clock divider. */
val = get_reg(dev, REG_AUX_CLK_DIVIDER);
val &= ~AUX_CLK_DIVIDER_VAL_MASK;
val |= dp_tx->s_axi_clk / 1000000;
set_reg(dev, REG_AUX_CLK_DIVIDER, val);
/* set the DisplayPort TX core's clock speed. */
set_reg(dev, REG_PHY_CLOCK_SELECT, PHY_CLOCK_SELECT_DEFAULT);
/* bring the PHY (and GTTXRESET) out of reset. */
set_reg(dev, REG_PHY_CONFIG,
phy_config & ~PHY_CONFIG_GT_ALL_RESET_MASK);
/* enable the DisplayPort TX core. */
set_reg(dev, REG_ENABLE, 1);
/* Unmask Hot-Plug-Detect (HPD) interrupts. */
set_reg(dev, REG_INTERRUPT_MASK,
~INTERRUPT_MASK_HPD_PULSE_DETECTED_MASK &
~INTERRUPT_MASK_HPD_EVENT_MASK &
~INTERRUPT_MASK_HPD_IRQ_MASK);
for (k = 0; k < 4; k++) {
/* Disable pre-cursor levels. */
set_reg(dev, REG_PHY_PRECURSOR_LANE_0 + 4 * k, 0);
/* Write default voltage swing levels to the TX registers. */
set_reg(dev, REG_PHY_VOLTAGE_DIFF_LANE_0 + 4 * k, 0);
/* Write default pre-emphasis levels to the TX registers. */
set_reg(dev, REG_PHY_POSTCURSOR_LANE_0 + 4 * k, 0);
}
return 0;
}
/**
* is_link_rate_valid() - Check if given link rate is valif for device
* @dev: The LogiCore DP TX device in question
* @link_rate: The link rate to be checked for validity
*
* Return: true if he supplied link rate is valid, false otherwise
*/
static bool is_link_rate_valid(struct udevice *dev, u8 link_rate)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
bool valid = true;
if (link_rate != LINK_BW_SET_162GBPS &&
link_rate != LINK_BW_SET_270GBPS &&
link_rate != LINK_BW_SET_540GBPS)
valid = false;
else if (link_rate > dp_tx->link_config.max_link_rate)
valid = false;
return valid;
}
/**
* is_lane_count_valid() - Check if given lane count is valif for device
* @dev: The LogiCore DP TX device in question
* @lane_count: The lane count to be checked for validity
*
* Return: true if he supplied lane count is valid, false otherwise
*/
static bool is_lane_count_valid(struct udevice *dev, u8 lane_count)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
bool valid = true;
if (lane_count != LANE_COUNT_SET_1 &&
lane_count != LANE_COUNT_SET_2 &&
lane_count != LANE_COUNT_SET_4)
valid = false;
else if (lane_count > dp_tx->link_config.max_lane_count)
valid = false;
return valid;
}
/**
* get_rx_capabilities() - Check if capabilities of RX device are valid for TX
* device
* @dev: The LogiCore DP TX device in question
*
* Return: 0 if the capabilities of the RX device are valid for the TX device,
* -ve if not, of an error occurred during capability determination
*/
static int get_rx_capabilities(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u8 rx_max_link_rate;
u8 rx_max_lane_count;
if (!is_connected(dev))
return -ENODEV;
status = aux_read(dev, DPCD_RECEIVER_CAP_FIELD_START, 16,
dp_tx->dpcd_rx_caps);
if (status)
return -EIO;
rx_max_link_rate = dp_tx->dpcd_rx_caps[DPCD_MAX_LINK_RATE];
rx_max_lane_count = dp_tx->dpcd_rx_caps[DPCD_MAX_LANE_COUNT] &
DPCD_MAX_LANE_COUNT_MASK;
dp_tx->link_config.max_link_rate =
(rx_max_link_rate > dp_tx->max_link_rate) ?
dp_tx->max_link_rate : rx_max_link_rate;
if (!is_link_rate_valid(dev, rx_max_link_rate))
return -EINVAL;
dp_tx->link_config.max_lane_count =
(rx_max_lane_count > dp_tx->max_lane_count) ?
dp_tx->max_lane_count : rx_max_lane_count;
if (!is_lane_count_valid(dev, rx_max_lane_count))
return -EINVAL;
dp_tx->link_config.support_enhanced_framing_mode =
dp_tx->dpcd_rx_caps[DPCD_MAX_LANE_COUNT] &
DPCD_ENHANCED_FRAME_SUPPORT_MASK;
return 0;
}
/**
* enable_main_link() - Switch on main link for a device
* @dev: The LogiCore DP TX device in question
*/
static void enable_main_link(struct udevice *dev)
{
/* reset the scrambler. */
set_reg(dev, REG_FORCE_SCRAMBLER_RESET, 0x1);
/* enable the main stream. */
set_reg(dev, REG_ENABLE_MAIN_STREAM, 0x1);
}
/**
* disable_main_link() - Switch off main link for a device
* @dev: The LogiCore DP TX device in question
*/
static void disable_main_link(struct udevice *dev)
{
/* reset the scrambler. */
set_reg(dev, REG_FORCE_SCRAMBLER_RESET, 0x1);
/* Disable the main stream. */
set_reg(dev, REG_ENABLE_MAIN_STREAM, 0x0);
}
/**
* reset_dp_phy() - Reset a device
* @dev: The LogiCore DP TX device in question
* @reset: Bit mask determining which bits in the device's config register
* should be set for the reset
*/
static void reset_dp_phy(struct udevice *dev, u32 reset)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u32 val;
set_reg(dev, REG_ENABLE, 0x0);
val = get_reg(dev, REG_PHY_CONFIG);
/* Apply reset. */
set_reg(dev, REG_PHY_CONFIG, val | reset);
/* Remove reset. */
set_reg(dev, REG_PHY_CONFIG, val);
/* Wait for the PHY to be ready. */
wait_phy_ready(dev, phy_status_lanes_ready_mask(dp_tx->max_lane_count));
set_reg(dev, REG_ENABLE, 0x1);
}
/**
* set_enhanced_frame_mode() - Enable/Disable enhanced frame mode
* @dev: The LogiCore DP TX device in question
* @enable: Flag to determine whether to enable (1) or disable (0) the enhanced
* frame mode
*
* Enable or disable the enhanced framing symbol sequence for
* both the DisplayPort TX core and the RX device.
*
* Return: 0 if enabling/disabling the enhanced frame mode was successful, -ve
* on error
*/
static int set_enhanced_frame_mode(struct udevice *dev, u8 enable)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u8 val;
if (!is_connected(dev))
return -ENODEV;
if (dp_tx->link_config.support_enhanced_framing_mode)
dp_tx->link_config.enhanced_framing_mode = enable;
else
dp_tx->link_config.enhanced_framing_mode = false;
/* Write enhanced frame mode enable to the DisplayPort TX core. */
set_reg(dev, REG_ENHANCED_FRAME_EN,
dp_tx->link_config.enhanced_framing_mode);
/* Write enhanced frame mode enable to the RX device. */
status = aux_read(dev, DPCD_LANE_COUNT_SET, 0x1, &val);
if (status)
return -EIO;
if (dp_tx->link_config.enhanced_framing_mode)
val |= DPCD_ENHANCED_FRAME_EN_MASK;
else
val &= ~DPCD_ENHANCED_FRAME_EN_MASK;
status = aux_write(dev, DPCD_LANE_COUNT_SET, 0x1, &val);
if (status)
return -EIO;
return 0;
}
/**
* set_lane_count() - Set the lane count
* @dev: The LogiCore DP TX device in question
* @lane_count: Lane count to set
*
* Set the number of lanes to be used by the main link for both
* the DisplayPort TX core and the RX device.
*
* Return: 0 if setting the lane count was successful, -ve on error
*/
static int set_lane_count(struct udevice *dev, u8 lane_count)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u8 val;
if (!is_connected(dev))
return -ENODEV;
printf(" set lane count to %u\n", lane_count);
dp_tx->link_config.lane_count = lane_count;
/* Write the new lane count to the DisplayPort TX core. */
set_reg(dev, REG_LANE_COUNT_SET, dp_tx->link_config.lane_count);
/* Write the new lane count to the RX device. */
status = aux_read(dev, DPCD_LANE_COUNT_SET, 0x1, &val);
if (status)
return -EIO;
val &= ~DPCD_LANE_COUNT_SET_MASK;
val |= dp_tx->link_config.lane_count;
status = aux_write(dev, DPCD_LANE_COUNT_SET, 0x1, &val);
if (status)
return -EIO;
return 0;
}
/**
* set_clk_speed() - Set DP phy clock speed
* @dev: The LogiCore DP TX device in question
* @speed: The clock frquency to set (one of PHY_CLOCK_SELECT_*)
*
* Set the clock frequency for the DisplayPort PHY corresponding to a desired
* data rate.
*
* Return: 0 if setting the DP phy clock speed was successful, -ve on error
*/
static int set_clk_speed(struct udevice *dev, u32 speed)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u32 val;
u32 mask;
/* Disable the DisplayPort TX core first. */
val = get_reg(dev, REG_ENABLE);
set_reg(dev, REG_ENABLE, 0x0);
/* Change speed of the feedback clock. */
set_reg(dev, REG_PHY_CLOCK_SELECT, speed);
/* Re-enable the DisplayPort TX core if it was previously enabled. */
if (val)
set_reg(dev, REG_ENABLE, 0x1);
/* Wait until the PHY is ready. */
mask = phy_status_lanes_ready_mask(dp_tx->max_lane_count);
status = wait_phy_ready(dev, mask);
if (status)
return -EIO;
return 0;
}
/**
* set_link_rate() - Set the link rate
* @dev: The LogiCore DP TX device in question
* @link_rate: The link rate to set (one of LINK_BW_SET_*)
*
* Set the data rate to be used by the main link for both the DisplayPort TX
* core and the RX device.
*
* Return: 0 if setting the link rate was successful, -ve on error
*/
static int set_link_rate(struct udevice *dev, u8 link_rate)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
/* Write a corresponding clock frequency to the DisplayPort TX core. */
switch (link_rate) {
case LINK_BW_SET_162GBPS:
printf(" set link rate to 1.62 Gb/s\n");
status = set_clk_speed(dev, PHY_CLOCK_SELECT_162GBPS);
break;
case LINK_BW_SET_270GBPS:
printf(" set link rate to 2.70 Gb/s\n");
status = set_clk_speed(dev, PHY_CLOCK_SELECT_270GBPS);
break;
case LINK_BW_SET_540GBPS:
printf(" set link rate to 5.40 Gb/s\n");
status = set_clk_speed(dev, PHY_CLOCK_SELECT_540GBPS);
break;
default:
return -EINVAL;
}
if (status)
return -EIO;
dp_tx->link_config.link_rate = link_rate;
/* Write new link rate to the DisplayPort TX core. */
set_reg(dev, REG_LINK_BW_SET, dp_tx->link_config.link_rate);
/* Write new link rate to the RX device. */
status = aux_write(dev, DPCD_LINK_BW_SET, 1,
&dp_tx->link_config.link_rate);
if (status)
return -EIO;
return 0;
}
/* Link training */
/**
* get_training_delay() - Get training delay
* @dev: The LogiCore DP TX device in question
* @training_state: The training state for which the required training delay
* should be queried
*
* Determine what the RX device's required training delay is for
* link training.
*
* Return: The training delay in us
*/
static int get_training_delay(struct udevice *dev, int training_state)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u16 delay;
switch (dp_tx->dpcd_rx_caps[DPCD_TRAIN_AUX_RD_INTERVAL]) {
case DPCD_TRAIN_AUX_RD_INT_100_400US:
if (training_state == TS_CLOCK_RECOVERY)
/* delay for the clock recovery phase. */
delay = 100;
else
/* delay for the channel equalization phase. */
delay = 400;
break;
case DPCD_TRAIN_AUX_RD_INT_4MS:
delay = 4000;
break;
case DPCD_TRAIN_AUX_RD_INT_8MS:
delay = 8000;
break;
case DPCD_TRAIN_AUX_RD_INT_12MS:
delay = 12000;
break;
case DPCD_TRAIN_AUX_RD_INT_16MS:
delay = 16000;
break;
default:
/* Default to 20 ms. */
delay = 20000;
break;
}
return delay;
}
/**
* set_vswing_preemp() - Build AUX data to set voltage swing and pre-emphasis
* @dev: The LogiCore DP TX device in question
* @aux_data: Buffer to receive the built AUX data
*
* Build AUX data to set current voltage swing and pre-emphasis level settings;
* the necessary data is taken from the link_config structure.
*/
static void set_vswing_preemp(struct udevice *dev, u8 *aux_data)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u8 data;
u8 vs_level_rx = dp_tx->link_config.vs_level;
u8 pe_level_rx = dp_tx->link_config.pe_level;
/* Set up the data buffer for writing to the RX device. */
data = (pe_level_rx << DPCD_TRAINING_LANEX_SET_PE_SHIFT) | vs_level_rx;
/* The maximum voltage swing has been reached. */
if (vs_level_rx == MAXIMUM_VS_LEVEL)
data |= DPCD_TRAINING_LANEX_SET_MAX_VS_MASK;
/* The maximum pre-emphasis level has been reached. */
if (pe_level_rx == MAXIMUM_PE_LEVEL)
data |= DPCD_TRAINING_LANEX_SET_MAX_PE_MASK;
memset(aux_data, data, 4);
}
/**
* adj_vswing_preemp() - Adjust voltage swing and pre-emphasis
* @dev: The LogiCore DP TX device in question
*
* Set new voltage swing and pre-emphasis levels using the
* adjustment requests obtained from the RX device.
*
* Return: 0 if voltage swing and pre-emphasis could be adjusted successfully,
* -ve on error
*/
static int adj_vswing_preemp(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u8 index;
u8 vs_level_adj_req[4];
u8 pe_level_adj_req[4];
u8 aux_data[4];
u8 *ajd_reqs = &dp_tx->lane_status_ajd_reqs[4];
/*
* Analyze the adjustment requests for changes in voltage swing and
* pre-emphasis levels.
*/
vs_level_adj_req[0] = ajd_reqs[0] & DPCD_ADJ_REQ_LANE_0_2_VS_MASK;
vs_level_adj_req[1] = (ajd_reqs[0] & DPCD_ADJ_REQ_LANE_1_3_VS_MASK) >>
DPCD_ADJ_REQ_LANE_1_3_VS_SHIFT;
vs_level_adj_req[2] = ajd_reqs[1] & DPCD_ADJ_REQ_LANE_0_2_VS_MASK;
vs_level_adj_req[3] = (ajd_reqs[1] & DPCD_ADJ_REQ_LANE_1_3_VS_MASK) >>
DPCD_ADJ_REQ_LANE_1_3_VS_SHIFT;
pe_level_adj_req[0] = (ajd_reqs[0] & DPCD_ADJ_REQ_LANE_0_2_PE_MASK) >>
DPCD_ADJ_REQ_LANE_0_2_PE_SHIFT;
pe_level_adj_req[1] = (ajd_reqs[0] & DPCD_ADJ_REQ_LANE_1_3_PE_MASK) >>
DPCD_ADJ_REQ_LANE_1_3_PE_SHIFT;
pe_level_adj_req[2] = (ajd_reqs[1] & DPCD_ADJ_REQ_LANE_0_2_PE_MASK) >>
DPCD_ADJ_REQ_LANE_0_2_PE_SHIFT;
pe_level_adj_req[3] = (ajd_reqs[1] & DPCD_ADJ_REQ_LANE_1_3_PE_MASK) >>
DPCD_ADJ_REQ_LANE_1_3_PE_SHIFT;
/*
* Change the drive settings to match the adjustment requests. Use the
* greatest level requested.
*/
dp_tx->link_config.vs_level = 0;
dp_tx->link_config.pe_level = 0;
for (index = 0; index < dp_tx->link_config.lane_count; index++) {
if (vs_level_adj_req[index] > dp_tx->link_config.vs_level)
dp_tx->link_config.vs_level = vs_level_adj_req[index];
if (pe_level_adj_req[index] > dp_tx->link_config.pe_level)
dp_tx->link_config.pe_level = pe_level_adj_req[index];
}
/*
* Verify that the voltage swing and pre-emphasis combination is
* allowed. Some combinations will result in a differential peak-to-peak
* voltage that is outside the permissible range. See the VESA
* DisplayPort v1.2 Specification, section 3.1.5.2.
* The valid combinations are:
* PE=0 PE=1 PE=2 PE=3
* VS=0 valid valid valid valid
* VS=1 valid valid valid
* VS=2 valid valid
* VS=3 valid
*
* NOTE:
* Xilinix dp_v3_1 driver seems to have an off by one error when
* limiting pe_level which is fixed here.
*/
if (dp_tx->link_config.pe_level > (3 - dp_tx->link_config.vs_level))
dp_tx->link_config.pe_level = 3 - dp_tx->link_config.vs_level;
/*
* Make the adjustments to both the DisplayPort TX core and the RX
* device.
*/
set_vswing_preemp(dev, aux_data);
/*
* Write the voltage swing and pre-emphasis levels for each lane to the
* RX device.
*/
status = aux_write(dev, DPCD_TRAINING_LANE0_SET, 4, aux_data);
if (status)
return -EIO;
return 0;
}
/**
* get_lane_status_adj_reqs() - Read lane status and adjustment requests
* information from the device
* @dev: The LogiCore DP TX device in question
*
* Do a burst AUX read from the RX device over the AUX channel. The contents of
* the status registers will be stored for later use by check_clock_recovery,
* check_channel_equalization, and adj_vswing_preemp.
*
* Return: 0 if the status information were read successfully, -ve on error
*/
static int get_lane_status_adj_reqs(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
/*
* Read and store 4 bytes of lane status and 2 bytes of adjustment
* requests.
*/
status = aux_read(dev, DPCD_STATUS_LANE_0_1, 6,
dp_tx->lane_status_ajd_reqs);
if (status)
return -EIO;
return 0;
}
/**
* check_clock_recovery() - Check clock recovery success
* @dev: The LogiCore DP TX device in question
* @lane_count: The number of lanes for which to check clock recovery success
*
* Check if the RX device's DisplayPort Configuration data (DPCD) indicates
* that the clock recovery sequence during link training was successful - the
* RX device's link clock and data recovery unit has realized and maintained
* the frequency lock for all lanes currently in use.
*
* Return: 0 if clock recovery was successful on all lanes in question, -ve if
* not
*/
static int check_clock_recovery(struct udevice *dev, u8 lane_count)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u8 *lane_status = dp_tx->lane_status_ajd_reqs;
/* Check that all LANEx_CR_DONE bits are set. */
switch (lane_count) {
case LANE_COUNT_SET_4:
if (!(lane_status[1] & DPCD_STATUS_LANE_3_CR_DONE_MASK))
goto out_fail;
if (!(lane_status[1] & DPCD_STATUS_LANE_2_CR_DONE_MASK))
goto out_fail;
/* Drop through and check lane 1. */
case LANE_COUNT_SET_2:
if (!(lane_status[0] & DPCD_STATUS_LANE_1_CR_DONE_MASK))
goto out_fail;
/* Drop through and check lane 0. */
case LANE_COUNT_SET_1:
if (!(lane_status[0] & DPCD_STATUS_LANE_0_CR_DONE_MASK))
goto out_fail;
default:
/* All (lane_count) lanes have achieved clock recovery. */
break;
}
return 0;
out_fail:
return -EIO;
}
/**
* check_channel_equalization() - Check channel equalization success
* @dev: The LogiCore DP TX device in question
* @lane_count: The number of lanes for which to check channel equalization
* success
*
* Check if the RX device's DisplayPort Configuration data (DPCD) indicates
* that the channel equalization sequence during link training was successful -
* the RX device has achieved channel equalization, symbol lock, and interlane
* alignment for all lanes currently in use.
*
* Return: 0 if channel equalization was successful on all lanes in question,
* -ve if not
*/
static int check_channel_equalization(struct udevice *dev, u8 lane_count)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u8 *lane_status = dp_tx->lane_status_ajd_reqs;
/* Check that all LANEx_CHANNEL_EQ_DONE bits are set. */
switch (lane_count) {
case LANE_COUNT_SET_4:
if (!(lane_status[1] & DPCD_STATUS_LANE_3_CE_DONE_MASK))
goto out_fail;
if (!(lane_status[1] & DPCD_STATUS_LANE_2_CE_DONE_MASK))
goto out_fail;
/* Drop through and check lane 1. */
case LANE_COUNT_SET_2:
if (!(lane_status[0] & DPCD_STATUS_LANE_1_CE_DONE_MASK))
goto out_fail;
/* Drop through and check lane 0. */
case LANE_COUNT_SET_1:
if (!(lane_status[0] & DPCD_STATUS_LANE_0_CE_DONE_MASK))
goto out_fail;
default:
/* All (lane_count) lanes have achieved channel equalization. */
break;
}
/* Check that all LANEx_SYMBOL_LOCKED bits are set. */
switch (lane_count) {
case LANE_COUNT_SET_4:
if (!(lane_status[1] & DPCD_STATUS_LANE_3_SL_DONE_MASK))
goto out_fail;
if (!(lane_status[1] & DPCD_STATUS_LANE_2_SL_DONE_MASK))
goto out_fail;
/* Drop through and check lane 1. */
case LANE_COUNT_SET_2:
if (!(lane_status[0] & DPCD_STATUS_LANE_1_SL_DONE_MASK))
goto out_fail;
/* Drop through and check lane 0. */
case LANE_COUNT_SET_1:
if (!(lane_status[0] & DPCD_STATUS_LANE_0_SL_DONE_MASK))
goto out_fail;
default:
/* All (lane_count) lanes have achieved symbol lock. */
break;
}
/* Check that interlane alignment is done. */
if (!(lane_status[2] & DPCD_LANE_ALIGN_STATUS_UPDATED_IA_DONE_MASK))
goto out_fail;
return 0;
out_fail:
return -EIO;
}
/**
* set_training_pattern() - Set training pattern for link training
* @dev: The LogiCore DP TX device in question
* @pattern: The training pattern to set
*
* Set the training pattern to be used during link training for both the
* DisplayPort TX core and the RX device.
*
* Return: 0 if the training pattern could be set successfully, -ve if not
*/
static int set_training_pattern(struct udevice *dev, u32 pattern)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u8 aux_data[5];
/* Write to the DisplayPort TX core. */
set_reg(dev, REG_TRAINING_PATTERN_SET, pattern);
aux_data[0] = pattern;
/* Write scrambler disable to the DisplayPort TX core. */
switch (pattern) {
case TRAINING_PATTERN_SET_OFF:
set_reg(dev, REG_SCRAMBLING_DISABLE, 0);
dp_tx->link_config.scrambler_en = 1;
break;
case TRAINING_PATTERN_SET_TP1:
case TRAINING_PATTERN_SET_TP2:
case TRAINING_PATTERN_SET_TP3:
aux_data[0] |= DPCD_TP_SET_SCRAMB_DIS_MASK;
set_reg(dev, REG_SCRAMBLING_DISABLE, 1);
dp_tx->link_config.scrambler_en = 0;
break;
default:
break;
}
/*
* Make the adjustments to both the DisplayPort TX core and the RX
* device.
*/
set_vswing_preemp(dev, &aux_data[1]);
/*
* Write the voltage swing and pre-emphasis levels for each lane to the
* RX device.
*/
if (pattern == TRAINING_PATTERN_SET_OFF)
status = aux_write(dev, DPCD_TP_SET, 1, aux_data);
else
status = aux_write(dev, DPCD_TP_SET, 5, aux_data);
if (status)
return -EIO;
return 0;
}
/**
* training_state_clock_recovery() - Run clock recovery part of link training
* @dev: The LogiCore DP TX device in question
*
* Run the clock recovery sequence as part of link training. The
* sequence is as follows:
*
* 0) Start signaling at the minimum voltage swing, pre-emphasis, and
* post- cursor levels.
* 1) Transmit training pattern 1 over the main link with symbol
* scrambling disabled.
* 2) The clock recovery loop. If clock recovery is unsuccessful after
* MaxIterations loop iterations, return.
* 2a) Wait for at least the period of time specified in the RX device's
* DisplayPort Configuration data (DPCD) register,
* TRAINING_AUX_RD_INTERVAL.
* 2b) Check if all lanes have achieved clock recovery lock. If so,
* return.
* 2c) Check if the same voltage swing level has been used 5 consecutive
* times or if the maximum level has been reached. If so, return.
* 2d) Adjust the voltage swing, pre-emphasis, and post-cursor levels as
* requested by the RX device.
* 2e) Loop back to 2a.
*
* For a more detailed description of the clock recovery sequence, see section
* 3.5.1.2.1 of the DisplayPort 1.2a specification document.
*
* Return: The next state machine state to advance to
*/
static unsigned int training_state_clock_recovery(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u32 delay_us;
u8 prev_vs_level = 0;
u8 same_vs_level_count = 0;
/*
* Obtain the required delay for clock recovery as specified by the
* RX device.
*/
delay_us = get_training_delay(dev, TS_CLOCK_RECOVERY);
/* Start CRLock. */
/* Transmit training pattern 1. */
/* Disable the scrambler. */
/* Start from minimal voltage swing and pre-emphasis levels. */
dp_tx->link_config.vs_level = 0;
dp_tx->link_config.pe_level = 0;
status = set_training_pattern(dev, TRAINING_PATTERN_SET_TP1);
if (status)
return TS_FAILURE;
while (1) {
/* Wait delay specified in TRAINING_AUX_RD_INTERVAL. */
udelay(delay_us);
/* Get lane and adjustment requests. */
status = get_lane_status_adj_reqs(dev);
if (status)
return TS_FAILURE;
/*
* Check if all lanes have realized and maintained the frequency
* lock and get adjustment requests.
*/
status = check_clock_recovery(dev,
dp_tx->link_config.lane_count);
if (!status)
return TS_CHANNEL_EQUALIZATION;
/*
* Check if the same voltage swing for each lane has been used 5
* consecutive times.
*/
if (prev_vs_level == dp_tx->link_config.vs_level) {
same_vs_level_count++;
} else {
same_vs_level_count = 0;
prev_vs_level = dp_tx->link_config.vs_level;
}
if (same_vs_level_count >= 5)
break;
/* Only try maximum voltage swing once. */
if (dp_tx->link_config.vs_level == MAXIMUM_VS_LEVEL)
break;
/* Adjust the drive settings as requested by the RX device. */
status = adj_vswing_preemp(dev);
if (status)
/* The AUX write failed. */
return TS_FAILURE;
}
return TS_ADJUST_LINK_RATE;
}
/**
* training_state_channel_equalization() - Run channel equalization part of
* link training
* @dev: The LogiCore DP TX device in question
*
* Run the channel equalization sequence as part of link
* training. The sequence is as follows:
*
* 0) Start signaling with the same drive settings used at the end of the
* clock recovery sequence.
* 1) Transmit training pattern 2 (or 3) over the main link with symbol
* scrambling disabled.
* 2) The channel equalization loop. If channel equalization is
* unsuccessful after 5 loop iterations, return.
* 2a) Wait for at least the period of time specified in the RX device's
* DisplayPort Configuration data (DPCD) register,
* TRAINING_AUX_RD_INTERVAL.
* 2b) Check if all lanes have achieved channel equalization, symbol lock,
* and interlane alignment. If so, return.
* 2c) Check if the same voltage swing level has been used 5 consecutive
* times or if the maximum level has been reached. If so, return.
* 2d) Adjust the voltage swing, pre-emphasis, and post-cursor levels as
* requested by the RX device.
* 2e) Loop back to 2a.
*
* For a more detailed description of the channel equalization sequence, see
* section 3.5.1.2.2 of the DisplayPort 1.2a specification document.
*
* Return: The next state machine state to advance to
*/
static int training_state_channel_equalization(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
u32 delay_us;
u32 iteration_count = 0;
/*
* Obtain the required delay for channel equalization as specified by
* the RX device.
*/
delay_us = get_training_delay(dev, TS_CHANNEL_EQUALIZATION);
/* Start channel equalization. */
/* Write the current drive settings. */
/* Transmit training pattern 2/3. */
if (dp_tx->dpcd_rx_caps[DPCD_MAX_LANE_COUNT] & DPCD_TPS3_SUPPORT_MASK)
status = set_training_pattern(dev, TRAINING_PATTERN_SET_TP3);
else
status = set_training_pattern(dev, TRAINING_PATTERN_SET_TP2);
if (status)
return TS_FAILURE;
while (iteration_count < 5) {
/* Wait delay specified in TRAINING_AUX_RD_INTERVAL. */
udelay(delay_us);
/* Get lane and adjustment requests. */
status = get_lane_status_adj_reqs(dev);
if (status)
/* The AUX read failed. */
return TS_FAILURE;
/* Check that all lanes still have their clocks locked. */
status = check_clock_recovery(dev,
dp_tx->link_config.lane_count);
if (status)
break;
/*
* Check if all lanes have accomplished channel equalization,
* symbol lock, and interlane alignment.
*/
status =
check_channel_equalization(dev,
dp_tx->link_config.lane_count);
if (!status)
return TS_SUCCESS;
/* Adjust the drive settings as requested by the RX device. */
status = adj_vswing_preemp(dev);
if (status)
/* The AUX write failed. */
return TS_FAILURE;
iteration_count++;
}
/*
* Tried 5 times with no success. Try a reduced bitrate first, then
* reduce the number of lanes.
*/
return TS_ADJUST_LINK_RATE;
}
/**
* training_state_adjust_link_rate() - Downshift data rate and/or lane count
* @dev: The LogiCore DP TX device in question
*
* This function is reached if either the clock recovery or the channel
* equalization process failed during training. As a result, the data rate will
* be downshifted, and training will be re-attempted (starting with clock
* recovery) at the reduced data rate. If the data rate is already at 1.62
* Gbps, a downshift in lane count will be attempted.
*
* Return: The next state machine state to advance to
*/
static int training_state_adjust_link_rate(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
switch (dp_tx->link_config.link_rate) {
case LINK_BW_SET_540GBPS:
status = set_link_rate(dev, LINK_BW_SET_270GBPS);
if (status) {
status = TS_FAILURE;
break;
}
status = TS_CLOCK_RECOVERY;
break;
case LINK_BW_SET_270GBPS:
status = set_link_rate(dev, LINK_BW_SET_162GBPS);
if (status) {
status = TS_FAILURE;
break;
}
status = TS_CLOCK_RECOVERY;
break;
default:
/*
* Already at the lowest link rate. Try reducing the lane
* count next.
*/
status = TS_ADJUST_LANE_COUNT;
break;
}
return status;
}
/**
* trainig_state_adjust_lane_count - Downshift lane count
* @dev: The LogiCore DP TX device in question
*
* This function is reached if either the clock recovery or the channel
* equalization process failed during training, and a minimal data rate of 1.62
* Gbps was being used. As a result, the number of lanes in use will be
* reduced, and training will be re-attempted (starting with clock recovery) at
* this lower lane count.
*
* Return: The next state machine state to advance to
*/
static int trainig_state_adjust_lane_count(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
switch (dp_tx->link_config.lane_count) {
case LANE_COUNT_SET_4:
status = set_lane_count(dev, LANE_COUNT_SET_2);
if (status) {
status = TS_FAILURE;
break;
}
status = set_link_rate(dev, dp_tx->link_config.max_link_rate);
if (status) {
status = TS_FAILURE;
break;
}
status = TS_CLOCK_RECOVERY;
break;
case LANE_COUNT_SET_2:
status = set_lane_count(dev, LANE_COUNT_SET_1);
if (status) {
status = TS_FAILURE;
break;
}
status = set_link_rate(dev, dp_tx->link_config.max_link_rate);
if (status) {
status = TS_FAILURE;
break;
}
status = TS_CLOCK_RECOVERY;
break;
default:
/*
* Already at the lowest lane count. Training has failed at the
* lowest lane count and link rate.
*/
status = TS_FAILURE;
break;
}
return status;
}
/**
* check_link_status() - Check status of link
* @dev: The LogiCore DP TX device in question
* @lane_count: The lane count to use for the check
*
* Check if the receiver's DisplayPort Configuration data (DPCD) indicates the
* receiver has achieved and maintained clock recovery, channel equalization,
* symbol lock, and interlane alignment for all lanes currently in use.
*
* Return: 0 if the link status is OK, -ve if a error occurred during checking
*/
static int check_link_status(struct udevice *dev, u8 lane_count)
{
u8 retry_count = 0;
if (!is_connected(dev))
return -ENODEV;
/* Retrieve AUX info. */
do {
int status;
/* Get lane and adjustment requests. */
status = get_lane_status_adj_reqs(dev);
if (status)
return -EIO;
/* Check if the link needs training. */
if ((check_clock_recovery(dev, lane_count) == 0) &&
(check_channel_equalization(dev, lane_count) == 0))
return 0;
retry_count++;
} while (retry_count < 5); /* Retry up to 5 times. */
return -EIO;
}
/**
* run_training() - Run link training
* @dev: The LogiCore DP TX device in question
*
* Run the link training process. It is implemented as a state machine, with
* each state returning the next state. First, the clock recovery sequence will
* be run; if successful, the channel equalization sequence will run. If either
* the clock recovery or channel equalization sequence failed, the link rate or
* the number of lanes used will be reduced and training will be re-attempted.
* If training fails at the minimal data rate, 1.62 Gbps with a single lane,
* training will no longer re-attempt and fail.
*
* ### Here be dragons ###
* There are undocumented timeout constraints in the link training process. In
* DP v1.2a spec, Chapter 3.5.1.2.2 a 10ms limit for the complete training
* process is mentioned. Which individual timeouts are derived and implemented
* by sink manufacturers is unknown. So each step should be as short as
* possible and link training should start as soon as possible after HPD.
*
* Return: 0 if the training sequence ran successfully, -ve if a error occurred
* or the training failed
*/
static int run_training(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
int training_state = TS_CLOCK_RECOVERY;
while (1) {
switch (training_state) {
case TS_CLOCK_RECOVERY:
training_state =
training_state_clock_recovery(dev);
break;
case TS_CHANNEL_EQUALIZATION:
training_state =
training_state_channel_equalization(dev);
break;
case TS_ADJUST_LINK_RATE:
training_state =
training_state_adjust_link_rate(dev);
break;
case TS_ADJUST_LANE_COUNT:
training_state =
trainig_state_adjust_lane_count(dev);
break;
default:
break;
}
if (training_state == TS_SUCCESS)
break;
else if (training_state == TS_FAILURE)
return -EIO;
if (training_state == TS_ADJUST_LINK_RATE ||
training_state == TS_ADJUST_LANE_COUNT) {
if (!dp_tx->train_adaptive)
return -EIO;
status = set_training_pattern(dev,
TRAINING_PATTERN_SET_OFF);
if (status)
return -EIO;
}
}
/* Final status check. */
status = check_link_status(dev, dp_tx->link_config.lane_count);
if (status)
return -EIO;
return 0;
}
/* Link policy maker */
/**
* cfg_main_link_max() - Determine best common capabilities
* @dev: The LogiCore DP TX device in question
*
* Determine the common capabilities between the DisplayPort TX core and the RX
* device.
*
* Return: 0 if the determination succeeded, -ve on error
*/
static int cfg_main_link_max(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
if (!is_connected(dev))
return -ENODEV;
/*
* Configure the main link to the maximum common link rate between the
* DisplayPort TX core and the RX device.
*/
status = set_link_rate(dev, dp_tx->link_config.max_link_rate);
if (status)
return status;
/*
* Configure the main link to the maximum common lane count between the
* DisplayPort TX core and the RX device.
*/
status = set_lane_count(dev, dp_tx->link_config.max_lane_count);
if (status)
return status;
return 0;
}
/**
* establish_link() - Establish a link
* @dev: The LogiCore DP TX device in question
*
* Check if the link needs training and run the training sequence if training
* is required.
*
* Return: 0 if the link was established successfully, -ve on error
*/
static int establish_link(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int status;
int status2;
u32 mask;
reset_dp_phy(dev, PHY_CONFIG_PHY_RESET_MASK);
/* Disable main link during training. */
disable_main_link(dev);
/* Wait for the PHY to be ready. */
mask = phy_status_lanes_ready_mask(dp_tx->max_lane_count);
status = wait_phy_ready(dev, mask);
if (status)
return -EIO;
/* Train main link. */
status = run_training(dev);
/* Turn off the training pattern and enable scrambler. */
status2 = set_training_pattern(dev, TRAINING_PATTERN_SET_OFF);
if (status || status2)
return -EIO;
return 0;
}
/*
* Stream policy maker
*/
/**
* cfg_msa_recalculate() - Calculate MSA parameters
* @dev: The LogiCore DP TX device in question
*
* Calculate the following Main Stream Attributes (MSA):
* - Transfer unit size
* - User pixel width
* - Horizontal total clock
* - Vertical total clock
* - misc_0
* - misc_1
* - Data per lane
* - Average number of bytes per transfer unit
* - Number of initial wait cycles
*
* These values are derived from:
* - Bits per color
* - Horizontal resolution
* - Vertical resolution
* - Horizontal blank start
* - Vertical blank start
* - Pixel clock (in KHz)
* - Horizontal sync polarity
* - Vertical sync polarity
* - Horizontal sync pulse width
* - Vertical sync pulse width
*/
static void cfg_msa_recalculate(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u32 video_bw;
u32 link_bw;
u32 words_per_line;
u8 bits_per_pixel;
struct main_stream_attributes *msa_config;
struct link_config *link_config;
msa_config = &dp_tx->main_stream_attributes;
link_config = &dp_tx->link_config;
/*
* Set the user pixel width to handle clocks that exceed the
* capabilities of the DisplayPort TX core.
*/
if (msa_config->override_user_pixel_width == 0) {
if (msa_config->pixel_clock_hz > 300000000 &&
link_config->lane_count == LANE_COUNT_SET_4) {
msa_config->user_pixel_width = 4;
} /*
* Xilinx driver used 75 MHz as a limit here, 150 MHZ should
* be more sane
*/
else if ((msa_config->pixel_clock_hz > 150000000) &&
(link_config->lane_count != LANE_COUNT_SET_1)) {
msa_config->user_pixel_width = 2;
} else {
msa_config->user_pixel_width = 1;
}
}
/* Compute the rest of the MSA values. */
msa_config->n_vid = 27 * 1000 * link_config->link_rate;
/* Miscellaneous attributes. */
if (msa_config->bits_per_color == 6)
msa_config->misc_0 = MAIN_STREAMX_MISC0_BDC_6BPC;
else if (msa_config->bits_per_color == 8)
msa_config->misc_0 = MAIN_STREAMX_MISC0_BDC_8BPC;
else if (msa_config->bits_per_color == 10)
msa_config->misc_0 = MAIN_STREAMX_MISC0_BDC_10BPC;
else if (msa_config->bits_per_color == 12)
msa_config->misc_0 = MAIN_STREAMX_MISC0_BDC_12BPC;
else if (msa_config->bits_per_color == 16)
msa_config->misc_0 = MAIN_STREAMX_MISC0_BDC_16BPC;
msa_config->misc_0 = (msa_config->misc_0 <<
MAIN_STREAMX_MISC0_BDC_SHIFT) |
(msa_config->y_cb_cr_colorimetry <<
MAIN_STREAMX_MISC0_YCBCR_COLORIMETRY_SHIFT) |
(msa_config->dynamic_range <<
MAIN_STREAMX_MISC0_DYNAMIC_RANGE_SHIFT) |
(msa_config->component_format <<
MAIN_STREAMX_MISC0_COMPONENT_FORMAT_SHIFT) |
(msa_config->synchronous_clock_mode);
msa_config->misc_1 = 0;
/*
* Determine the number of bits per pixel for the specified color
* component format.
*/
if (msa_config->component_format ==
MAIN_STREAMX_MISC0_COMPONENT_FORMAT_YCBCR422)
/* YCbCr422 color component format. */
bits_per_pixel = msa_config->bits_per_color * 2;
else
/* RGB or YCbCr 4:4:4 color component format. */
bits_per_pixel = msa_config->bits_per_color * 3;
/* Calculate the data per lane. */
words_per_line = (msa_config->h_active * bits_per_pixel);
if (words_per_line % 16)
words_per_line += 16;
words_per_line /= 16;
msa_config->data_per_lane = words_per_line - link_config->lane_count;
if (words_per_line % link_config->lane_count)
msa_config->data_per_lane += (words_per_line %
link_config->lane_count);
/*
* Allocate a fixed size for single-stream transport (SST)
* operation.
*/
msa_config->transfer_unit_size = 64;
/*
* Calculate the average number of bytes per transfer unit.
* Note: Both the integer and the fractional part is stored in
* avg_bytes_per_tu.
*/
video_bw = ((msa_config->pixel_clock_hz / 1000) * bits_per_pixel) / 8;
link_bw = (link_config->lane_count * link_config->link_rate * 27);
msa_config->avg_bytes_per_tu = (video_bw *
msa_config->transfer_unit_size) /
link_bw;
/*
* The number of initial wait cycles at the start of a new line
* by the framing logic. This allows enough data to be buffered
* in the input FIFO before video is sent.
*/
if ((msa_config->avg_bytes_per_tu / 1000) <= 4)
msa_config->init_wait = 64;
else
msa_config->init_wait = msa_config->transfer_unit_size -
(msa_config->avg_bytes_per_tu / 1000);
}
/**
* set_line_reset() - Enable/Disable end-of-line-reset
* @dev: The LogiCore DP TX device in question
*
* Disable/enable the end-of-line-reset to the internal video pipe in case of
* reduced blanking as required.
*/
static void set_line_reset(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
u32 reg_val;
u16 h_blank;
u16 h_reduced_blank;
struct main_stream_attributes *msa_config =
&dp_tx->main_stream_attributes;
h_blank = msa_config->h_total - msa_config->h_active;
/* Reduced blanking starts at ceil(0.2 * HTotal). */
h_reduced_blank = 2 * msa_config->h_total;
if (h_reduced_blank % 10)
h_reduced_blank += 10;
h_reduced_blank /= 10;
/* CVT spec. states h_blank is either 80 or 160 for reduced blanking. */
reg_val = get_reg(dev, REG_LINE_RESET_DISABLE);
if (h_blank < h_reduced_blank &&
(h_blank == 80 || h_blank == 160)) {
reg_val |= LINE_RESET_DISABLE_MASK;
} else {
reg_val &= ~LINE_RESET_DISABLE_MASK;
}
set_reg(dev, REG_LINE_RESET_DISABLE, reg_val);
}
/**
* clear_msa_values() - Clear MSA values
* @dev: The LogiCore DP TX device in question
*
* Clear the main stream attributes registers of the DisplayPort TX core.
*/
static void clear_msa_values(struct udevice *dev)
{
set_reg(dev, REG_MAIN_STREAM_HTOTAL, 0);
set_reg(dev, REG_MAIN_STREAM_VTOTAL, 0);
set_reg(dev, REG_MAIN_STREAM_POLARITY, 0);
set_reg(dev, REG_MAIN_STREAM_HSWIDTH, 0);
set_reg(dev, REG_MAIN_STREAM_VSWIDTH, 0);
set_reg(dev, REG_MAIN_STREAM_HRES, 0);
set_reg(dev, REG_MAIN_STREAM_VRES, 0);
set_reg(dev, REG_MAIN_STREAM_HSTART, 0);
set_reg(dev, REG_MAIN_STREAM_VSTART, 0);
set_reg(dev, REG_MAIN_STREAM_MISC0, 0);
set_reg(dev, REG_MAIN_STREAM_MISC1, 0);
set_reg(dev, REG_USER_PIXEL_WIDTH, 0);
set_reg(dev, REG_USER_DATA_COUNT_PER_LANE, 0);
set_reg(dev, REG_M_VID, 0);
set_reg(dev, REG_N_VID, 0);
set_reg(dev, REG_STREAM1, 0);
set_reg(dev, REG_TU_SIZE, 0);
set_reg(dev, REG_MIN_BYTES_PER_TU, 0);
set_reg(dev, REG_FRAC_BYTES_PER_TU, 0);
set_reg(dev, REG_INIT_WAIT, 0);
}
/**
* set_msa_values() - Set MSA values
* @dev: The LogiCore DP TX device in question
*
* Set the main stream attributes registers of the DisplayPort TX
* core with the values specified in the main stream attributes configuration
* structure.
*/
static void set_msa_values(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
struct main_stream_attributes *msa_config =
&dp_tx->main_stream_attributes;
printf(" set MSA %u x %u\n", msa_config->h_active,
msa_config->v_active);
set_reg(dev, REG_MAIN_STREAM_HTOTAL, msa_config->h_total);
set_reg(dev, REG_MAIN_STREAM_VTOTAL, msa_config->v_total);
set_reg(dev, REG_MAIN_STREAM_POLARITY,
msa_config->h_sync_polarity |
(msa_config->v_sync_polarity <<
MAIN_STREAMX_POLARITY_VSYNC_POL_SHIFT));
set_reg(dev, REG_MAIN_STREAM_HSWIDTH, msa_config->h_sync_width);
set_reg(dev, REG_MAIN_STREAM_VSWIDTH, msa_config->v_sync_width);
set_reg(dev, REG_MAIN_STREAM_HRES, msa_config->h_active);
set_reg(dev, REG_MAIN_STREAM_VRES, msa_config->v_active);
set_reg(dev, REG_MAIN_STREAM_HSTART, msa_config->h_start);
set_reg(dev, REG_MAIN_STREAM_VSTART, msa_config->v_start);
set_reg(dev, REG_MAIN_STREAM_MISC0, msa_config->misc_0);
set_reg(dev, REG_MAIN_STREAM_MISC1, msa_config->misc_1);
set_reg(dev, REG_USER_PIXEL_WIDTH, msa_config->user_pixel_width);
set_reg(dev, REG_M_VID, msa_config->pixel_clock_hz / 1000);
set_reg(dev, REG_N_VID, msa_config->n_vid);
set_reg(dev, REG_USER_DATA_COUNT_PER_LANE, msa_config->data_per_lane);
set_line_reset(dev);
set_reg(dev, REG_TU_SIZE, msa_config->transfer_unit_size);
set_reg(dev, REG_MIN_BYTES_PER_TU, msa_config->avg_bytes_per_tu / 1000);
set_reg(dev, REG_FRAC_BYTES_PER_TU,
(msa_config->avg_bytes_per_tu % 1000) * 1024 / 1000);
set_reg(dev, REG_INIT_WAIT, msa_config->init_wait);
}
/*
* external API
*/
/**
* logicore_dp_tx_set_msa() - Set given MSA values on device
* @dev: The LogiCore DP TX device in question
* @msa: The MSA values to set for the device
*/
static void logicore_dp_tx_set_msa(struct udevice *dev,
struct logicore_dp_tx_msa *msa)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
memset(&dp_tx->main_stream_attributes, 0,
sizeof(struct main_stream_attributes));
dp_tx->main_stream_attributes.pixel_clock_hz = msa->pixel_clock_hz;
dp_tx->main_stream_attributes.bits_per_color = msa->bits_per_color;
dp_tx->main_stream_attributes.h_active = msa->h_active;
dp_tx->main_stream_attributes.h_start = msa->h_start;
dp_tx->main_stream_attributes.h_sync_polarity = msa->h_sync_polarity;
dp_tx->main_stream_attributes.h_sync_width = msa->h_sync_width;
dp_tx->main_stream_attributes.h_total = msa->h_total;
dp_tx->main_stream_attributes.v_active = msa->v_active;
dp_tx->main_stream_attributes.v_start = msa->v_start;
dp_tx->main_stream_attributes.v_sync_polarity = msa->v_sync_polarity;
dp_tx->main_stream_attributes.v_sync_width = msa->v_sync_width;
dp_tx->main_stream_attributes.v_total = msa->v_total;
dp_tx->main_stream_attributes.override_user_pixel_width =
msa->override_user_pixel_width;
dp_tx->main_stream_attributes.user_pixel_width = msa->user_pixel_width;
dp_tx->main_stream_attributes.synchronous_clock_mode = 0;
}
/**
* logicore_dp_tx_video_enable() - Enable video output
* @dev: The LogiCore DP TX device in question
* @msa: The MSA values to set for the device
*
* Return: 0 if the video was enabled successfully, -ve on error
*/
static int logicore_dp_tx_video_enable(struct udevice *dev,
struct logicore_dp_tx_msa *msa)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
int res;
u8 power = 0x01;
if (!is_connected(dev)) {
printf(" no DP sink connected\n");
return -EIO;
}
initialize(dev);
disable_main_link(dev);
logicore_dp_tx_set_msa(dev, msa);
get_rx_capabilities(dev);
printf(" DP sink connected\n");
aux_write(dev, DPCD_SET_POWER_DP_PWR_VOLTAGE, 1, &power);
set_enhanced_frame_mode(dev, true);
cfg_main_link_max(dev);
res = establish_link(dev);
printf(" establish_link: %s, vs: %d, pe: %d\n",
res ? "failed" : "ok", dp_tx->link_config.vs_level,
dp_tx->link_config.pe_level);
cfg_msa_recalculate(dev);
clear_msa_values(dev);
set_msa_values(dev);
enable_main_link(dev);
return 0;
}
/*
* Driver functions
*/
static int logicore_dp_tx_enable(struct udevice *dev, int panel_bpp,
const struct display_timing *timing)
{
struct clk pixclock;
struct logicore_dp_tx_msa *msa;
struct logicore_dp_tx_msa mode_640_480_60 = {
.pixel_clock_hz = 25175000,
.bits_per_color = 8,
.h_active = 640,
.h_start = 144,
.h_sync_polarity = false,
.h_sync_width = 96,
.h_total = 800,
.v_active = 480,
.v_start = 35,
.v_sync_polarity = false,
.v_sync_width = 2,
.v_total = 525,
.override_user_pixel_width = false,
.user_pixel_width = 0,
};
struct logicore_dp_tx_msa mode_720_400_70 = {
.pixel_clock_hz = 28300000,
.bits_per_color = 8,
.h_active = 720,
.h_start = 162,
.h_sync_polarity = false,
.h_sync_width = 108,
.h_total = 900,
.v_active = 400,
.v_start = 37,
.v_sync_polarity = true,
.v_sync_width = 2,
.v_total = 449,
.override_user_pixel_width = false,
.user_pixel_width = 0,
};
struct logicore_dp_tx_msa mode_1024_768_60 = {
.pixel_clock_hz = 65000000,
.bits_per_color = 8,
.h_active = 1024,
.h_start = 296,
.h_sync_polarity = false,
.h_sync_width = 136,
.h_total = 1344,
.v_active = 768,
.v_start = 35,
.v_sync_polarity = false,
.v_sync_width = 2,
.v_total = 806,
.override_user_pixel_width = false,
.user_pixel_width = 0,
};
if (timing->hactive.typ == 1024 && timing->vactive.typ == 768)
msa = &mode_1024_768_60;
else if (timing->hactive.typ == 720 && timing->vactive.typ == 400)
msa = &mode_720_400_70;
else
msa = &mode_640_480_60;
if (clk_get_by_index(dev, 0, &pixclock)) {
printf("%s: Could not get pixelclock\n", dev->name);
return -1;
}
clk_set_rate(&pixclock, msa->pixel_clock_hz);
return logicore_dp_tx_video_enable(dev, msa);
}
static int logicore_dp_tx_probe(struct udevice *dev)
{
struct dp_tx *dp_tx = dev_get_priv(dev);
dp_tx->s_axi_clk = S_AXI_CLK_DEFAULT;
dp_tx->train_adaptive = false;
dp_tx->max_link_rate = DPCD_MAX_LINK_RATE_540GBPS;
dp_tx->max_lane_count = DPCD_MAX_LANE_COUNT_4;
dp_tx->base = dev_read_u32_default(dev, "reg", -1);
return 0;
}
static const struct dm_display_ops logicore_dp_tx_ops = {
.enable = logicore_dp_tx_enable,
};
static const struct udevice_id logicore_dp_tx_ids[] = {
{ .compatible = "gdsys,logicore_dp_tx" },
{ /* sentinel */ }
};
U_BOOT_DRIVER(logicore_dp_tx) = {
.name = "logicore_dp_tx",
.id = UCLASS_DISPLAY,
.of_match = logicore_dp_tx_ids,
.probe = logicore_dp_tx_probe,
.priv_auto_alloc_size = sizeof(struct dp_tx),
.ops = &logicore_dp_tx_ops,
};
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