/*
 * Copyright 2018 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: AMD
 *
 */

#include <linux/debugfs.h>

#include "dc.h"
#include "amdgpu.h"
#include "amdgpu_dm.h"
#include "amdgpu_dm_debugfs.h"

/* function description
 * get/ set DP configuration: lane_count, link_rate, spread_spectrum
 *
 * valid lane count value: 1, 2, 4
 * valid link rate value:
 * 06h = 1.62Gbps per lane
 * 0Ah = 2.7Gbps per lane
 * 0Ch = 3.24Gbps per lane
 * 14h = 5.4Gbps per lane
 * 1Eh = 8.1Gbps per lane
 *
 * debugfs is located at /sys/kernel/debug/dri/0/DP-x/link_settings
 *
 * --- to get dp configuration
 *
 * cat link_settings
 *
 * It will list current, verified, reported, preferred dp configuration.
 * current -- for current video mode
 * verified --- maximum configuration which pass link training
 * reported --- DP rx report caps (DPCD register offset 0, 1 2)
 * preferred --- user force settings
 *
 * --- set (or force) dp configuration
 *
 * echo <lane_count>  <link_rate> > link_settings
 *
 * for example, to force to  2 lane, 2.7GHz,
 * echo 4 0xa > link_settings
 *
 * spread_spectrum could not be changed dynamically.
 *
 * in case invalid lane count, link rate are force, no hw programming will be
 * done. please check link settings after force operation to see if HW get
 * programming.
 *
 * cat link_settings
 *
 * check current and preferred settings.
 *
 */
static ssize_t dp_link_settings_read(struct file *f, char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
        struct dc_link *link = connector->dc_link;
        char *rd_buf = NULL;
        char *rd_buf_ptr = NULL;
        const uint32_t rd_buf_size = 100;
        uint32_t result = 0;
        uint8_t str_len = 0;
        int r;

        if (*pos & 3 || size & 3)
                return -EINVAL;

        rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
        if (!rd_buf)
                return 0;

        rd_buf_ptr = rd_buf;

        str_len = strlen("Current:  %d  %d  %d  ");
        snprintf(rd_buf_ptr, str_len, "Current:  %d  %d  %d  ",
                        link->cur_link_settings.lane_count,
                        link->cur_link_settings.link_rate,
                        link->cur_link_settings.link_spread);
        rd_buf_ptr += str_len;

        str_len = strlen("Verified:  %d  %d  %d  ");
        snprintf(rd_buf_ptr, str_len, "Verified:  %d  %d  %d  ",
                        link->verified_link_cap.lane_count,
                        link->verified_link_cap.link_rate,
                        link->verified_link_cap.link_spread);
        rd_buf_ptr += str_len;

        str_len = strlen("Reported:  %d  %d  %d  ");
        snprintf(rd_buf_ptr, str_len, "Reported:  %d  %d  %d  ",
                        link->reported_link_cap.lane_count,
                        link->reported_link_cap.link_rate,
                        link->reported_link_cap.link_spread);
        rd_buf_ptr += str_len;

        str_len = strlen("Preferred:  %d  %d  %d  ");
        snprintf(rd_buf_ptr, str_len, "Preferred:  %d  %d  %d\n",
                        link->preferred_link_setting.lane_count,
                        link->preferred_link_setting.link_rate,
                        link->preferred_link_setting.link_spread);

        while (size) {
                if (*pos >= rd_buf_size)
                        break;

                r = put_user(*(rd_buf + result), buf);
                if (r)
                        return r; /* r = -EFAULT */

                buf += 1;
                size -= 1;
                *pos += 1;
                result += 1;
        }

        kfree(rd_buf);
        return result;
}

static ssize_t dp_link_settings_write(struct file *f, const char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
        struct dc_link *link = connector->dc_link;
        struct dc *dc = (struct dc *)link->dc;
        struct dc_link_settings prefer_link_settings;
        char *wr_buf = NULL;
        char *wr_buf_ptr = NULL;
        const uint32_t wr_buf_size = 40;
        int r;
        int bytes_from_user;
        char *sub_str;
        /* 0: lane_count; 1: link_rate */
        uint8_t param_index = 0;
        long param[2];
        const char delimiter[3] = {' ', '\n', '\0'};
        bool valid_input = false;

        if (size == 0)
                return -EINVAL;

        wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
        if (!wr_buf)
                return -EINVAL;
        wr_buf_ptr = wr_buf;

        r = copy_from_user(wr_buf_ptr, buf, wr_buf_size);

        /* r is bytes not be copied */
        if (r >= wr_buf_size) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("user data not read\n");
                return -EINVAL;
        }

        bytes_from_user = wr_buf_size - r;

        while (isspace(*wr_buf_ptr))
                wr_buf_ptr++;

        while ((*wr_buf_ptr != '\0') && (param_index < 2)) {

                sub_str = strsep(&wr_buf_ptr, delimiter);

                r = kstrtol(sub_str, 16, &param[param_index]);

                if (r)
                        DRM_DEBUG_DRIVER("string to int convert error code: %d\n", r);

                param_index++;
                while (isspace(*wr_buf_ptr))
                        wr_buf_ptr++;
        }

        switch (param[0]) {
        case LANE_COUNT_ONE:
        case LANE_COUNT_TWO:
        case LANE_COUNT_FOUR:
                valid_input = true;
                break;
        default:
                break;
        }

        switch (param[1]) {
        case LINK_RATE_LOW:
        case LINK_RATE_HIGH:
        case LINK_RATE_RBR2:
        case LINK_RATE_HIGH2:
        case LINK_RATE_HIGH3:
                valid_input = true;
                break;
        default:
                break;
        }

        if (!valid_input) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("Invalid Input value No HW will be programmed\n");
                return bytes_from_user;
        }

        /* save user force lane_count, link_rate to preferred settings
         * spread spectrum will not be changed
         */
        prefer_link_settings.link_spread = link->cur_link_settings.link_spread;
        prefer_link_settings.lane_count = param[0];
        prefer_link_settings.link_rate = param[1];

        dc_link_set_preferred_link_settings(dc, &prefer_link_settings, link);

        kfree(wr_buf);
        return bytes_from_user;
}

/* function: get current DP PHY settings: voltage swing, pre-emphasis,
 * post-cursor2 (defined by VESA DP specification)
 *
 * valid values
 * voltage swing: 0,1,2,3
 * pre-emphasis : 0,1,2,3
 * post cursor2 : 0,1,2,3
 *
 *
 * how to use this debugfs
 *
 * debugfs is located at /sys/kernel/debug/dri/0/DP-x
 *
 * there will be directories, like DP-1, DP-2,DP-3, etc. for DP display
 *
 * To figure out which DP-x is the display for DP to be check,
 * cd DP-x
 * ls -ll
 * There should be debugfs file, like link_settings, phy_settings.
 * cat link_settings
 * from lane_count, link_rate to figure which DP-x is for display to be worked
 * on
 *
 * To get current DP PHY settings,
 * cat phy_settings
 *
 * To change DP PHY settings,
 * echo <voltage_swing> <pre-emphasis> <post_cursor2> > phy_settings
 * for examle, to change voltage swing to 2, pre-emphasis to 3, post_cursor2 to
 * 0,
 * echo 2 3 0 > phy_settings
 *
 * To check if change be applied, get current phy settings by
 * cat phy_settings
 *
 * In case invalid values are set by user, like
 * echo 1 4 0 > phy_settings
 *
 * HW will NOT be programmed by these settings.
 * cat phy_settings will show the previous valid settings.
 */
static ssize_t dp_phy_settings_read(struct file *f, char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
        struct dc_link *link = connector->dc_link;
        char *rd_buf = NULL;
        const uint32_t rd_buf_size = 20;
        uint32_t result = 0;
        int r;

        if (*pos & 3 || size & 3)
                return -EINVAL;

        rd_buf = kcalloc(rd_buf_size, sizeof(char), GFP_KERNEL);
        if (!rd_buf)
                return -EINVAL;

        snprintf(rd_buf, rd_buf_size, "  %d  %d  %d  ",
                        link->cur_lane_setting.VOLTAGE_SWING,
                        link->cur_lane_setting.PRE_EMPHASIS,
                        link->cur_lane_setting.POST_CURSOR2);

        while (size) {
                if (*pos >= rd_buf_size)
                        break;

                r = put_user((*(rd_buf + result)), buf);
                if (r)
                        return r; /* r = -EFAULT */

                buf += 1;
                size -= 1;
                *pos += 1;
                result += 1;
        }

        kfree(rd_buf);
        return result;
}

static ssize_t dp_phy_settings_write(struct file *f, const char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
        struct dc_link *link = connector->dc_link;
        struct dc *dc = (struct dc *)link->dc;
        char *wr_buf = NULL;
        char *wr_buf_ptr = NULL;
        uint32_t wr_buf_size = 40;
        int r;
        int bytes_from_user;
        char *sub_str;
        uint8_t param_index = 0;
        long param[3];
        const char delimiter[3] = {' ', '\n', '\0'};
        bool use_prefer_link_setting;
        struct link_training_settings link_lane_settings;

        if (size == 0)
                return 0;

        wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
        if (!wr_buf)
                return 0;
        wr_buf_ptr = wr_buf;

        r = copy_from_user(wr_buf_ptr, buf, wr_buf_size);

        /* r is bytes not be copied */
        if (r >= wr_buf_size) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("user data not be read\n");
                return 0;
        }

        bytes_from_user = wr_buf_size - r;

        while (isspace(*wr_buf_ptr))
                wr_buf_ptr++;

        while ((*wr_buf_ptr != '\0') && (param_index < 3)) {

                sub_str = strsep(&wr_buf_ptr, delimiter);

                r = kstrtol(sub_str, 16, &param[param_index]);

                if (r)
                        DRM_DEBUG_DRIVER("string to int convert error code: %d\n", r);

                param_index++;
                while (isspace(*wr_buf_ptr))
                        wr_buf_ptr++;
        }

        if ((param[0] > VOLTAGE_SWING_MAX_LEVEL) ||
                        (param[1] > PRE_EMPHASIS_MAX_LEVEL) ||
                        (param[2] > POST_CURSOR2_MAX_LEVEL)) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("Invalid Input No HW will be programmed\n");
                return bytes_from_user;
        }

        /* get link settings: lane count, link rate */
        use_prefer_link_setting =
                ((link->preferred_link_setting.link_rate != LINK_RATE_UNKNOWN) &&
                (link->test_pattern_enabled));

        memset(&link_lane_settings, 0, sizeof(link_lane_settings));

        if (use_prefer_link_setting) {
                link_lane_settings.link_settings.lane_count =
                                link->preferred_link_setting.lane_count;
                link_lane_settings.link_settings.link_rate =
                                link->preferred_link_setting.link_rate;
                link_lane_settings.link_settings.link_spread =
                                link->preferred_link_setting.link_spread;
        } else {
                link_lane_settings.link_settings.lane_count =
                                link->cur_link_settings.lane_count;
                link_lane_settings.link_settings.link_rate =
                                link->cur_link_settings.link_rate;
                link_lane_settings.link_settings.link_spread =
                                link->cur_link_settings.link_spread;
        }

        /* apply phy settings from user */
        for (r = 0; r < link_lane_settings.link_settings.lane_count; r++) {
                link_lane_settings.lane_settings[r].VOLTAGE_SWING =
                                (enum dc_voltage_swing) (param[0]);
                link_lane_settings.lane_settings[r].PRE_EMPHASIS =
                                (enum dc_pre_emphasis) (param[1]);
                link_lane_settings.lane_settings[r].POST_CURSOR2 =
                                (enum dc_post_cursor2) (param[2]);
        }

        /* program ASIC registers and DPCD registers */
        dc_link_set_drive_settings(dc, &link_lane_settings, link);

        kfree(wr_buf);
        return bytes_from_user;
}

/* function description
 *
 * set PHY layer or Link layer test pattern
 * PHY test pattern is used for PHY SI check.
 * Link layer test will not affect PHY SI.
 *
 * Reset Test Pattern:
 * 0 = DP_TEST_PATTERN_VIDEO_MODE
 *
 * PHY test pattern supported:
 * 1 = DP_TEST_PATTERN_D102
 * 2 = DP_TEST_PATTERN_SYMBOL_ERROR
 * 3 = DP_TEST_PATTERN_PRBS7
 * 4 = DP_TEST_PATTERN_80BIT_CUSTOM
 * 5 = DP_TEST_PATTERN_CP2520_1
 * 6 = DP_TEST_PATTERN_CP2520_2 = DP_TEST_PATTERN_HBR2_COMPLIANCE_EYE
 * 7 = DP_TEST_PATTERN_CP2520_3
 *
 * DP PHY Link Training Patterns
 * 8 = DP_TEST_PATTERN_TRAINING_PATTERN1
 * 9 = DP_TEST_PATTERN_TRAINING_PATTERN2
 * a = DP_TEST_PATTERN_TRAINING_PATTERN3
 * b = DP_TEST_PATTERN_TRAINING_PATTERN4
 *
 * DP Link Layer Test pattern
 * c = DP_TEST_PATTERN_COLOR_SQUARES
 * d = DP_TEST_PATTERN_COLOR_SQUARES_CEA
 * e = DP_TEST_PATTERN_VERTICAL_BARS
 * f = DP_TEST_PATTERN_HORIZONTAL_BARS
 * 10= DP_TEST_PATTERN_COLOR_RAMP
 *
 * debugfs phy_test_pattern is located at /syskernel/debug/dri/0/DP-x
 *
 * --- set test pattern
 * echo <test pattern #> > test_pattern
 *
 * If test pattern # is not supported, NO HW programming will be done.
 * for DP_TEST_PATTERN_80BIT_CUSTOM, it needs extra 10 bytes of data
 * for the user pattern. input 10 bytes data are separated by space
 *
 * echo 0x4 0x11 0x22 0x33 0x44 0x55 0x66 0x77 0x88 0x99 0xaa > test_pattern
 *
 * --- reset test pattern
 * echo 0 > test_pattern
 *
 * --- HPD detection is disabled when set PHY test pattern
 *
 * when PHY test pattern (pattern # within [1,7]) is set, HPD pin of HW ASIC
 * is disable. User could unplug DP display from DP connected and plug scope to
 * check test pattern PHY SI.
 * If there is need unplug scope and plug DP display back, do steps below:
 * echo 0 > phy_test_pattern
 * unplug scope
 * plug DP display.
 *
 * "echo 0 > phy_test_pattern" will re-enable HPD pin again so that video sw
 * driver could detect "unplug scope" and "plug DP display"
 */
static ssize_t dp_phy_test_pattern_debugfs_write(struct file *f, const char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_dm_connector *connector = file_inode(f)->i_private;
        struct dc_link *link = connector->dc_link;
        char *wr_buf = NULL;
        char *wr_buf_ptr = NULL;
        uint32_t wr_buf_size = 100;
        uint32_t wr_buf_count = 0;
        int r;
        int bytes_from_user;
        char *sub_str = NULL;
        uint8_t param_index = 0;
        uint8_t param_nums = 0;
        long param[11] = {0x0};
        const char delimiter[3] = {' ', '\n', '\0'};
        enum dp_test_pattern test_pattern = DP_TEST_PATTERN_UNSUPPORTED;
        bool disable_hpd = false;
        bool valid_test_pattern = false;
        /* init with defalut 80bit custom pattern */
        uint8_t custom_pattern[10] = {
                        0x1f, 0x7c, 0xf0, 0xc1, 0x07,
                        0x1f, 0x7c, 0xf0, 0xc1, 0x07
                        };
        struct dc_link_settings prefer_link_settings = {LANE_COUNT_UNKNOWN,
                        LINK_RATE_UNKNOWN, LINK_SPREAD_DISABLED};
        struct dc_link_settings cur_link_settings = {LANE_COUNT_UNKNOWN,
                        LINK_RATE_UNKNOWN, LINK_SPREAD_DISABLED};
        struct link_training_settings link_training_settings;
        int i;

        if (size == 0)
                return 0;

        wr_buf = kcalloc(wr_buf_size, sizeof(char), GFP_KERNEL);
        if (!wr_buf)
                return 0;
        wr_buf_ptr = wr_buf;

        r = copy_from_user(wr_buf_ptr, buf, wr_buf_size);

        /* r is bytes not be copied */
        if (r >= wr_buf_size) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("user data not be read\n");
                return 0;
        }

        bytes_from_user = wr_buf_size - r;

        /* check number of parameters. isspace could not differ space and \n */
        while ((*wr_buf_ptr != 0xa) && (wr_buf_count < wr_buf_size)) {
                /* skip space*/
                while (isspace(*wr_buf_ptr) && (wr_buf_count < wr_buf_size)) {
                        wr_buf_ptr++;
                        wr_buf_count++;
                        }

                if (wr_buf_count == wr_buf_size)
                        break;

                /* skip non-space*/
                while ((!isspace(*wr_buf_ptr)) && (wr_buf_count < wr_buf_size)) {
                        wr_buf_ptr++;
                        wr_buf_count++;
                        }

                param_nums++;

                if (wr_buf_count == wr_buf_size)
                        break;
        }

        /* max 11 parameters */
        if (param_nums > 11)
                param_nums = 11;

        wr_buf_ptr = wr_buf; /* reset buf pinter */
        wr_buf_count = 0; /* number of char already checked */

        while (isspace(*wr_buf_ptr) && (wr_buf_count < wr_buf_size)) {
                wr_buf_ptr++;
                wr_buf_count++;
        }

        while (param_index < param_nums) {
                /* after strsep, wr_buf_ptr will be moved to after space */
                sub_str = strsep(&wr_buf_ptr, delimiter);

                r = kstrtol(sub_str, 16, &param[param_index]);

                if (r)
                        DRM_DEBUG_DRIVER("string to int convert error code: %d\n", r);

                param_index++;
        }

        test_pattern = param[0];

        switch (test_pattern) {
        case DP_TEST_PATTERN_VIDEO_MODE:
        case DP_TEST_PATTERN_COLOR_SQUARES:
        case DP_TEST_PATTERN_COLOR_SQUARES_CEA:
        case DP_TEST_PATTERN_VERTICAL_BARS:
        case DP_TEST_PATTERN_HORIZONTAL_BARS:
        case DP_TEST_PATTERN_COLOR_RAMP:
                valid_test_pattern = true;
                break;

        case DP_TEST_PATTERN_D102:
        case DP_TEST_PATTERN_SYMBOL_ERROR:
        case DP_TEST_PATTERN_PRBS7:
        case DP_TEST_PATTERN_80BIT_CUSTOM:
        case DP_TEST_PATTERN_HBR2_COMPLIANCE_EYE:
        case DP_TEST_PATTERN_TRAINING_PATTERN4:
                disable_hpd = true;
                valid_test_pattern = true;
                break;

        default:
                valid_test_pattern = false;
                test_pattern = DP_TEST_PATTERN_UNSUPPORTED;
                break;
        }

        if (!valid_test_pattern) {
                kfree(wr_buf);
                DRM_DEBUG_DRIVER("Invalid Test Pattern Parameters\n");
                return bytes_from_user;
        }

        if (test_pattern == DP_TEST_PATTERN_80BIT_CUSTOM) {
                for (i = 0; i < 10; i++) {
                        if ((uint8_t) param[i + 1] != 0x0)
                                break;
                }

                if (i < 10) {
                        /* not use default value */
                        for (i = 0; i < 10; i++)
                                custom_pattern[i] = (uint8_t) param[i + 1];
                }
        }

        /* Usage: set DP physical test pattern using debugfs with normal DP
         * panel. Then plug out DP panel and connect a scope to measure
         * For normal video mode and test pattern generated from CRCT,
         * they are visibile to user. So do not disable HPD.
         * Video Mode is also set to clear the test pattern, so enable HPD
         * because it might have been disabled after a test pattern was set.
         * AUX depends on HPD * sequence dependent, do not move!
         */
        if (!disable_hpd)
                dc_link_enable_hpd(link);

        prefer_link_settings.lane_count = link->verified_link_cap.lane_count;
        prefer_link_settings.link_rate = link->verified_link_cap.link_rate;
        prefer_link_settings.link_spread = link->verified_link_cap.link_spread;

        cur_link_settings.lane_count = link->cur_link_settings.lane_count;
        cur_link_settings.link_rate = link->cur_link_settings.link_rate;
        cur_link_settings.link_spread = link->cur_link_settings.link_spread;

        link_training_settings.link_settings = cur_link_settings;


        if (test_pattern != DP_TEST_PATTERN_VIDEO_MODE) {
                if (prefer_link_settings.lane_count != LANE_COUNT_UNKNOWN &&
                        prefer_link_settings.link_rate !=  LINK_RATE_UNKNOWN &&
                        (prefer_link_settings.lane_count != cur_link_settings.lane_count ||
                        prefer_link_settings.link_rate != cur_link_settings.link_rate))
                        link_training_settings.link_settings = prefer_link_settings;
        }

        for (i = 0; i < (unsigned int)(link_training_settings.link_settings.lane_count); i++)
                link_training_settings.lane_settings[i] = link->cur_lane_setting;

        dc_link_set_test_pattern(
                link,
                test_pattern,
                &link_training_settings,
                custom_pattern,
                10);

        /* Usage: Set DP physical test pattern using AMDDP with normal DP panel
         * Then plug out DP panel and connect a scope to measure DP PHY signal.
         * Need disable interrupt to avoid SW driver disable DP output. This is
         * done after the test pattern is set.
         */
        if (valid_test_pattern && disable_hpd)
                dc_link_disable_hpd(link);

        kfree(wr_buf);

        return bytes_from_user;
}

static const struct file_operations dp_link_settings_debugfs_fops = {
        .owner = THIS_MODULE,
        .read = dp_link_settings_read,
        .write = dp_link_settings_write,
        .llseek = default_llseek
};

static const struct file_operations dp_phy_settings_debugfs_fop = {
        .owner = THIS_MODULE,
        .read = dp_phy_settings_read,
        .write = dp_phy_settings_write,
        .llseek = default_llseek
};

static const struct file_operations dp_phy_test_pattern_fops = {
        .owner = THIS_MODULE,
        .write = dp_phy_test_pattern_debugfs_write,
        .llseek = default_llseek
};

static const struct {
        char *name;
        const struct file_operations *fops;
} dp_debugfs_entries[] = {
                {"link_settings", &dp_link_settings_debugfs_fops},
                {"phy_settings", &dp_phy_settings_debugfs_fop},
                {"test_pattern", &dp_phy_test_pattern_fops}
};

int connector_debugfs_init(struct amdgpu_dm_connector *connector)
{
        int i;
        struct dentry *ent, *dir = connector->base.debugfs_entry;

        if (connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
            connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
                for (i = 0; i < ARRAY_SIZE(dp_debugfs_entries); i++) {
                        ent = debugfs_create_file(dp_debugfs_entries[i].name,
                                                  0644,
                                                  dir,
                                                  connector,
                                                  dp_debugfs_entries[i].fops);
                        if (IS_ERR(ent))
                                return PTR_ERR(ent);
                }
        }

        return 0;
}

/*
 * Writes DTN log state to the user supplied buffer.
 * Example usage: cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log
 */
static ssize_t dtn_log_read(
        struct file *f,
        char __user *buf,
        size_t size,
        loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        struct dc *dc = adev->dm.dc;
        struct dc_log_buffer_ctx log_ctx = { 0 };
        ssize_t result = 0;

        if (!buf || !size)
                return -EINVAL;

        if (!dc->hwss.log_hw_state)
                return 0;

        dc->hwss.log_hw_state(dc, &log_ctx);

        if (*pos < log_ctx.pos) {
                size_t to_copy = log_ctx.pos - *pos;

                to_copy = min(to_copy, size);

                if (!copy_to_user(buf, log_ctx.buf + *pos, to_copy)) {
                        *pos += to_copy;
                        result = to_copy;
                }
        }

        kfree(log_ctx.buf);

        return result;
}

/*
 * Writes DTN log state to dmesg when triggered via a write.
 * Example usage: echo 1 > /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log
 */
static ssize_t dtn_log_write(
        struct file *f,
        const char __user *buf,
        size_t size,
        loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        struct dc *dc = adev->dm.dc;

        /* Write triggers log output via dmesg. */
        if (size == 0)
                return 0;

        if (dc->hwss.log_hw_state)
                dc->hwss.log_hw_state(dc, NULL);

        return size;
}

int dtn_debugfs_init(struct amdgpu_device *adev)
{
        static const struct file_operations dtn_log_fops = {
                .owner = THIS_MODULE,
                .read = dtn_log_read,
                .write = dtn_log_write,
                .llseek = default_llseek
        };

        struct drm_minor *minor = adev->ddev->primary;
        struct dentry *root = minor->debugfs_root;

        struct dentry *ent = debugfs_create_file(
                "amdgpu_dm_dtn_log",
                0644,
                root,
                adev,
                &dtn_log_fops);

        return PTR_ERR_OR_ZERO(ent);
}