root/drivers/bus/fsl-mc/dprc.c
// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2013-2016 Freescale Semiconductor Inc.
 * Copyright 2020 NXP
 *
 */
#include <linux/kernel.h>
#include <linux/fsl/mc.h>

#include "fsl-mc-private.h"

/*
 * cache the DPRC version to reduce the number of commands
 * towards the mc firmware
 */
static u16 dprc_major_ver;
static u16 dprc_minor_ver;

/**
 * dprc_open() - Open DPRC object for use
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @container_id: Container ID to open
 * @token:      Returned token of DPRC object
 *
 * Return:      '0' on Success; Error code otherwise.
 *
 * @warning     Required before any operation on the object.
 */
int dprc_open(struct fsl_mc_io *mc_io,
              u32 cmd_flags,
              int container_id,
              u16 *token)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_open *cmd_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_OPEN, cmd_flags,
                                          0);
        cmd_params = (struct dprc_cmd_open *)cmd.params;
        cmd_params->container_id = cpu_to_le32(container_id);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        *token = mc_cmd_hdr_read_token(&cmd);

        return 0;
}
EXPORT_SYMBOL_GPL(dprc_open);

/**
 * dprc_close() - Close the control session of the object
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 *
 * After this function is called, no further operations are
 * allowed on the object without opening a new control session.
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_close(struct fsl_mc_io *mc_io,
               u32 cmd_flags,
               u16 token)
{
        struct fsl_mc_command cmd = { 0 };

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_CLOSE, cmd_flags,
                                          token);

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}
EXPORT_SYMBOL_GPL(dprc_close);

/**
 * dprc_reset_container - Reset child container.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @child_container_id: ID of the container to reset
 * @options: 32 bit options:
 *   - 0 (no bits set) - all the objects inside the container are
 *     reset. The child containers are entered recursively and the
 *     objects reset. All the objects (including the child containers)
 *     are closed.
 *   - bit 0 set - all the objects inside the container are reset.
 *     However the child containers are not entered recursively.
 *     This option is supported for API versions >= 6.5
 * In case a software context crashes or becomes non-responsive, the parent
 * may wish to reset its resources container before the software context is
 * restarted.
 *
 * This routine informs all objects assigned to the child container that the
 * container is being reset, so they may perform any cleanup operations that are
 * needed. All objects handles that were owned by the child container shall be
 * closed.
 *
 * Note that such request may be submitted even if the child software context
 * has not crashed, but the resulting object cleanup operations will not be
 * aware of that.
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_reset_container(struct fsl_mc_io *mc_io,
                         u32 cmd_flags,
                         u16 token,
                         int child_container_id,
                         u32 options)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_reset_container *cmd_params;
        u32 cmdid = DPRC_CMDID_RESET_CONT;
        int err;

        /*
         * If the DPRC object version was not yet cached, cache it now.
         * Otherwise use the already cached value.
         */
        if (!dprc_major_ver && !dprc_minor_ver) {
                err = dprc_get_api_version(mc_io, 0,
                                &dprc_major_ver,
                                &dprc_minor_ver);
                if (err)
                        return err;
        }

        /*
         * MC API 6.5 introduced a new field in the command used to pass
         * some flags.
         * Bit 0 indicates that the child containers are not recursively reset.
         */
        if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 5))
                cmdid = DPRC_CMDID_RESET_CONT_V2;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(cmdid, cmd_flags, token);
        cmd_params = (struct dprc_cmd_reset_container *)cmd.params;
        cmd_params->child_container_id = cpu_to_le32(child_container_id);
        cmd_params->options = cpu_to_le32(options);

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}
EXPORT_SYMBOL_GPL(dprc_reset_container);

/**
 * dprc_set_irq() - Set IRQ information for the DPRC to trigger an interrupt.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @irq_index:  Identifies the interrupt index to configure
 * @irq_cfg:    IRQ configuration
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_set_irq(struct fsl_mc_io *mc_io,
                 u32 cmd_flags,
                 u16 token,
                 u8 irq_index,
                 struct dprc_irq_cfg *irq_cfg)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_set_irq *cmd_params;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_SET_IRQ,
                                          cmd_flags,
                                          token);
        cmd_params = (struct dprc_cmd_set_irq *)cmd.params;
        cmd_params->irq_val = cpu_to_le32(irq_cfg->val);
        cmd_params->irq_index = irq_index;
        cmd_params->irq_addr = cpu_to_le64(irq_cfg->paddr);
        cmd_params->irq_num = cpu_to_le32(irq_cfg->irq_num);

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}

/**
 * dprc_set_irq_enable() - Set overall interrupt state.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @irq_index:  The interrupt index to configure
 * @en:         Interrupt state - enable = 1, disable = 0
 *
 * Allows GPP software to control when interrupts are generated.
 * Each interrupt can have up to 32 causes.  The enable/disable control's the
 * overall interrupt state. if the interrupt is disabled no causes will cause
 * an interrupt.
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_set_irq_enable(struct fsl_mc_io *mc_io,
                        u32 cmd_flags,
                        u16 token,
                        u8 irq_index,
                        u8 en)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_set_irq_enable *cmd_params;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_SET_IRQ_ENABLE,
                                          cmd_flags, token);
        cmd_params = (struct dprc_cmd_set_irq_enable *)cmd.params;
        cmd_params->enable = en & DPRC_ENABLE;
        cmd_params->irq_index = irq_index;

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}

/**
 * dprc_set_irq_mask() - Set interrupt mask.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @irq_index:  The interrupt index to configure
 * @mask:       event mask to trigger interrupt;
 *                      each bit:
 *                              0 = ignore event
 *                              1 = consider event for asserting irq
 *
 * Every interrupt can have up to 32 causes and the interrupt model supports
 * masking/unmasking each cause independently
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_set_irq_mask(struct fsl_mc_io *mc_io,
                      u32 cmd_flags,
                      u16 token,
                      u8 irq_index,
                      u32 mask)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_set_irq_mask *cmd_params;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_SET_IRQ_MASK,
                                          cmd_flags, token);
        cmd_params = (struct dprc_cmd_set_irq_mask *)cmd.params;
        cmd_params->mask = cpu_to_le32(mask);
        cmd_params->irq_index = irq_index;

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}

/**
 * dprc_get_irq_status() - Get the current status of any pending interrupts.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @irq_index:  The interrupt index to configure
 * @status:     Returned interrupts status - one bit per cause:
 *                      0 = no interrupt pending
 *                      1 = interrupt pending
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_irq_status(struct fsl_mc_io *mc_io,
                        u32 cmd_flags,
                        u16 token,
                        u8 irq_index,
                        u32 *status)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_get_irq_status *cmd_params;
        struct dprc_rsp_get_irq_status *rsp_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_IRQ_STATUS,
                                          cmd_flags, token);
        cmd_params = (struct dprc_cmd_get_irq_status *)cmd.params;
        cmd_params->status = cpu_to_le32(*status);
        cmd_params->irq_index = irq_index;

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_irq_status *)cmd.params;
        *status = le32_to_cpu(rsp_params->status);

        return 0;
}

/**
 * dprc_clear_irq_status() - Clear a pending interrupt's status
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @irq_index:  The interrupt index to configure
 * @status:     bits to clear (W1C) - one bit per cause:
 *                                      0 = don't change
 *                                      1 = clear status bit
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_clear_irq_status(struct fsl_mc_io *mc_io,
                          u32 cmd_flags,
                          u16 token,
                          u8 irq_index,
                          u32 status)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_clear_irq_status *cmd_params;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_CLEAR_IRQ_STATUS,
                                          cmd_flags, token);
        cmd_params = (struct dprc_cmd_clear_irq_status *)cmd.params;
        cmd_params->status = cpu_to_le32(status);
        cmd_params->irq_index = irq_index;

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}

/**
 * dprc_get_attributes() - Obtains container attributes
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @attr:       Returned container attributes
 *
 * Return:     '0' on Success; Error code otherwise.
 */
int dprc_get_attributes(struct fsl_mc_io *mc_io,
                        u32 cmd_flags,
                        u16 token,
                        struct dprc_attributes *attr)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_rsp_get_attributes *rsp_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_ATTR,
                                          cmd_flags,
                                          token);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_attributes *)cmd.params;
        attr->container_id = le32_to_cpu(rsp_params->container_id);
        attr->icid = le32_to_cpu(rsp_params->icid);
        attr->options = le32_to_cpu(rsp_params->options);
        attr->portal_id = le32_to_cpu(rsp_params->portal_id);

        return 0;
}

/**
 * dprc_get_obj_count() - Obtains the number of objects in the DPRC
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @obj_count:  Number of objects assigned to the DPRC
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_obj_count(struct fsl_mc_io *mc_io,
                       u32 cmd_flags,
                       u16 token,
                       int *obj_count)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_rsp_get_obj_count *rsp_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_COUNT,
                                          cmd_flags, token);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_obj_count *)cmd.params;
        *obj_count = le32_to_cpu(rsp_params->obj_count);

        return 0;
}
EXPORT_SYMBOL_GPL(dprc_get_obj_count);

/**
 * dprc_get_obj() - Get general information on an object
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @obj_index:  Index of the object to be queried (< obj_count)
 * @obj_desc:   Returns the requested object descriptor
 *
 * The object descriptors are retrieved one by one by incrementing
 * obj_index up to (not including) the value of obj_count returned
 * from dprc_get_obj_count(). dprc_get_obj_count() must
 * be called prior to dprc_get_obj().
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_obj(struct fsl_mc_io *mc_io,
                 u32 cmd_flags,
                 u16 token,
                 int obj_index,
                 struct fsl_mc_obj_desc *obj_desc)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_get_obj *cmd_params;
        struct dprc_rsp_get_obj *rsp_params;
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ,
                                          cmd_flags,
                                          token);
        cmd_params = (struct dprc_cmd_get_obj *)cmd.params;
        cmd_params->obj_index = cpu_to_le32(obj_index);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_obj *)cmd.params;
        obj_desc->id = le32_to_cpu(rsp_params->id);
        obj_desc->vendor = le16_to_cpu(rsp_params->vendor);
        obj_desc->irq_count = rsp_params->irq_count;
        obj_desc->region_count = rsp_params->region_count;
        obj_desc->state = le32_to_cpu(rsp_params->state);
        obj_desc->ver_major = le16_to_cpu(rsp_params->version_major);
        obj_desc->ver_minor = le16_to_cpu(rsp_params->version_minor);
        obj_desc->flags = le16_to_cpu(rsp_params->flags);
        strscpy_pad(obj_desc->type, rsp_params->type, 16);
        strscpy_pad(obj_desc->label, rsp_params->label, 16);
        return 0;
}
EXPORT_SYMBOL_GPL(dprc_get_obj);

/**
 * dprc_set_obj_irq() - Set IRQ information for object to trigger an interrupt.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @obj_type:   Type of the object to set its IRQ
 * @obj_id:     ID of the object to set its IRQ
 * @irq_index:  The interrupt index to configure
 * @irq_cfg:    IRQ configuration
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_set_obj_irq(struct fsl_mc_io *mc_io,
                     u32 cmd_flags,
                     u16 token,
                     char *obj_type,
                     int obj_id,
                     u8 irq_index,
                     struct dprc_irq_cfg *irq_cfg)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_set_obj_irq *cmd_params;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_SET_OBJ_IRQ,
                                          cmd_flags,
                                          token);
        cmd_params = (struct dprc_cmd_set_obj_irq *)cmd.params;
        cmd_params->irq_val = cpu_to_le32(irq_cfg->val);
        cmd_params->irq_index = irq_index;
        cmd_params->irq_addr = cpu_to_le64(irq_cfg->paddr);
        cmd_params->irq_num = cpu_to_le32(irq_cfg->irq_num);
        cmd_params->obj_id = cpu_to_le32(obj_id);
        strscpy(cmd_params->obj_type, obj_type);

        /* send command to mc*/
        return mc_send_command(mc_io, &cmd);
}
EXPORT_SYMBOL_GPL(dprc_set_obj_irq);

/**
 * dprc_get_obj_region() - Get region information for a specified object.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @obj_type:   Object type as returned in dprc_get_obj()
 * @obj_id:     Unique object instance as returned in dprc_get_obj()
 * @region_index: The specific region to query
 * @region_desc:  Returns the requested region descriptor
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_obj_region(struct fsl_mc_io *mc_io,
                        u32 cmd_flags,
                        u16 token,
                        char *obj_type,
                        int obj_id,
                        u8 region_index,
                        struct dprc_region_desc *region_desc)
{
        struct fsl_mc_command cmd = { 0 };
        struct dprc_cmd_get_obj_region *cmd_params;
        struct dprc_rsp_get_obj_region *rsp_params;
        int err;

    /*
     * If the DPRC object version was not yet cached, cache it now.
     * Otherwise use the already cached value.
     */
        if (!dprc_major_ver && !dprc_minor_ver) {
                err = dprc_get_api_version(mc_io, 0,
                                      &dprc_major_ver,
                                      &dprc_minor_ver);
                if (err)
                        return err;
        }

        if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 6)) {
                /*
                 * MC API version 6.6 changed the size of the MC portals and software
                 * portals to 64K (as implemented by hardware). If older API is in use the
                 * size reported is less (64 bytes for mc portals and 4K for software
                 * portals).
                 */

                cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG_V3,
                                                  cmd_flags, token);

        } else if (dprc_major_ver == 6 && dprc_minor_ver >= 3) {
                /*
                 * MC API version 6.3 introduced a new field to the region
                 * descriptor: base_address. If the older API is in use then the base
                 * address is set to zero to indicate it needs to be obtained elsewhere
                 * (typically the device tree).
                 */
                cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG_V2,
                                                  cmd_flags, token);
        } else {
                cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_OBJ_REG,
                                                  cmd_flags, token);
        }

        cmd_params = (struct dprc_cmd_get_obj_region *)cmd.params;
        cmd_params->obj_id = cpu_to_le32(obj_id);
        cmd_params->region_index = region_index;
        strscpy(cmd_params->obj_type, obj_type);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_obj_region *)cmd.params;
        region_desc->base_offset = le64_to_cpu(rsp_params->base_offset);
        region_desc->size = le32_to_cpu(rsp_params->size);
        region_desc->type = rsp_params->type;
        region_desc->flags = le32_to_cpu(rsp_params->flags);
        if (dprc_major_ver > 6 || (dprc_major_ver == 6 && dprc_minor_ver >= 3))
                region_desc->base_address = le64_to_cpu(rsp_params->base_addr);
        else
                region_desc->base_address = 0;

        return 0;
}
EXPORT_SYMBOL_GPL(dprc_get_obj_region);

/**
 * dprc_get_api_version - Get Data Path Resource Container API version
 * @mc_io:      Pointer to Mc portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @major_ver:  Major version of Data Path Resource Container API
 * @minor_ver:  Minor version of Data Path Resource Container API
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_api_version(struct fsl_mc_io *mc_io,
                         u32 cmd_flags,
                         u16 *major_ver,
                         u16 *minor_ver)
{
        struct fsl_mc_command cmd = { 0 };
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_API_VERSION,
                                          cmd_flags, 0);

        /* send command to mc */
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        mc_cmd_read_api_version(&cmd, major_ver, minor_ver);

        return 0;
}

/**
 * dprc_get_container_id - Get container ID associated with a given portal.
 * @mc_io:              Pointer to Mc portal's I/O object
 * @cmd_flags:          Command flags; one or more of 'MC_CMD_FLAG_'
 * @container_id:       Requested container id
 *
 * Return:      '0' on Success; Error code otherwise.
 */
int dprc_get_container_id(struct fsl_mc_io *mc_io,
                          u32 cmd_flags,
                          int *container_id)
{
        struct fsl_mc_command cmd = { 0 };
        int err;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_CONT_ID,
                                          cmd_flags,
                                          0);

        /* send command to mc*/
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return err;

        /* retrieve response parameters */
        *container_id = (int)mc_cmd_read_object_id(&cmd);

        return 0;
}

/**
 * dprc_get_connection() - Get connected endpoint and link status if connection
 *                      exists.
 * @mc_io:      Pointer to MC portal's I/O object
 * @cmd_flags:  Command flags; one or more of 'MC_CMD_FLAG_'
 * @token:      Token of DPRC object
 * @endpoint1:  Endpoint 1 configuration parameters
 * @endpoint2:  Returned endpoint 2 configuration parameters
 * @state:      Returned link state:
 *              1 - link is up;
 *              0 - link is down;
 *              -1 - no connection (endpoint2 information is irrelevant)
 *
 * Return:     '0' on Success; -ENOTCONN if connection does not exist.
 */
int dprc_get_connection(struct fsl_mc_io *mc_io,
                        u32 cmd_flags,
                        u16 token,
                        const struct dprc_endpoint *endpoint1,
                        struct dprc_endpoint *endpoint2,
                        int *state)
{
        struct dprc_cmd_get_connection *cmd_params;
        struct dprc_rsp_get_connection *rsp_params;
        struct fsl_mc_command cmd = { 0 };
        int err, i;

        /* prepare command */
        cmd.header = mc_encode_cmd_header(DPRC_CMDID_GET_CONNECTION,
                                          cmd_flags,
                                          token);
        cmd_params = (struct dprc_cmd_get_connection *)cmd.params;
        cmd_params->ep1_id = cpu_to_le32(endpoint1->id);
        cmd_params->ep1_interface_id = cpu_to_le16(endpoint1->if_id);
        for (i = 0; i < 16; i++)
                cmd_params->ep1_type[i] = endpoint1->type[i];

        /* send command to mc */
        err = mc_send_command(mc_io, &cmd);
        if (err)
                return -ENOTCONN;

        /* retrieve response parameters */
        rsp_params = (struct dprc_rsp_get_connection *)cmd.params;
        endpoint2->id = le32_to_cpu(rsp_params->ep2_id);
        endpoint2->if_id = le16_to_cpu(rsp_params->ep2_interface_id);
        *state = le32_to_cpu(rsp_params->state);
        for (i = 0; i < 16; i++)
                endpoint2->type[i] = rsp_params->ep2_type[i];

        return 0;
}