/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <linux/circ_buf.h>
#include <linux/device.h>
#include <scsi/sas.h>
#include "host.h"
#include "isci.h"
#include "port.h"
#include "probe_roms.h"
#include "remote_device.h"
#include "request.h"
#include "scu_completion_codes.h"
#include "scu_event_codes.h"
#include "registers.h"
#include "scu_remote_node_context.h"
#include "scu_task_context.h"

#define SCU_CONTEXT_RAM_INIT_STALL_TIME      200

#define smu_max_ports(dcc_value) \
        (\
                (((dcc_value) & SMU_DEVICE_CONTEXT_CAPACITY_MAX_LP_MASK) \
                 >> SMU_DEVICE_CONTEXT_CAPACITY_MAX_LP_SHIFT) + 1 \
        )

#define smu_max_task_contexts(dcc_value)        \
        (\
                (((dcc_value) & SMU_DEVICE_CONTEXT_CAPACITY_MAX_TC_MASK) \
                 >> SMU_DEVICE_CONTEXT_CAPACITY_MAX_TC_SHIFT) + 1 \
        )

#define smu_max_rncs(dcc_value) \
        (\
                (((dcc_value) & SMU_DEVICE_CONTEXT_CAPACITY_MAX_RNC_MASK) \
                 >> SMU_DEVICE_CONTEXT_CAPACITY_MAX_RNC_SHIFT) + 1 \
        )

#define SCIC_SDS_CONTROLLER_PHY_START_TIMEOUT      100

/*
 * The number of milliseconds to wait while a given phy is consuming power
 * before allowing another set of phys to consume power. Ultimately, this will
 * be specified by OEM parameter.
 */
#define SCIC_SDS_CONTROLLER_POWER_CONTROL_INTERVAL 500

/*
 * NORMALIZE_PUT_POINTER() -
 *
 * This macro will normalize the completion queue put pointer so its value can
 * be used as an array inde
 */
#define NORMALIZE_PUT_POINTER(x) \
        ((x) & SMU_COMPLETION_QUEUE_PUT_POINTER_MASK)


/*
 * NORMALIZE_EVENT_POINTER() -
 *
 * This macro will normalize the completion queue event entry so its value can
 * be used as an index.
 */
#define NORMALIZE_EVENT_POINTER(x) \
        (\
                ((x) & SMU_COMPLETION_QUEUE_GET_EVENT_POINTER_MASK) \
                >> SMU_COMPLETION_QUEUE_GET_EVENT_POINTER_SHIFT \
        )

/*
 * NORMALIZE_GET_POINTER() -
 *
 * This macro will normalize the completion queue get pointer so its value can
 * be used as an index into an array
 */
#define NORMALIZE_GET_POINTER(x) \
        ((x) & SMU_COMPLETION_QUEUE_GET_POINTER_MASK)

/*
 * NORMALIZE_GET_POINTER_CYCLE_BIT() -
 *
 * This macro will normalize the completion queue cycle pointer so it matches
 * the completion queue cycle bit
 */
#define NORMALIZE_GET_POINTER_CYCLE_BIT(x) \
        ((SMU_CQGR_CYCLE_BIT & (x)) << (31 - SMU_COMPLETION_QUEUE_GET_CYCLE_BIT_SHIFT))

/*
 * COMPLETION_QUEUE_CYCLE_BIT() -
 *
 * This macro will return the cycle bit of the completion queue entry
 */
#define COMPLETION_QUEUE_CYCLE_BIT(x) ((x) & 0x80000000)

/* Init the state machine and call the state entry function (if any) */
void sci_init_sm(struct sci_base_state_machine *sm,
                 const struct sci_base_state *state_table, u32 initial_state)
{
        sci_state_transition_t handler;

        sm->initial_state_id    = initial_state;
        sm->previous_state_id   = initial_state;
        sm->current_state_id    = initial_state;
        sm->state_table         = state_table;

        handler = sm->state_table[initial_state].enter_state;
        if (handler)
                handler(sm);
}

/* Call the state exit fn, update the current state, call the state entry fn */
void sci_change_state(struct sci_base_state_machine *sm, u32 next_state)
{
        sci_state_transition_t handler;

        handler = sm->state_table[sm->current_state_id].exit_state;
        if (handler)
                handler(sm);

        sm->previous_state_id = sm->current_state_id;
        sm->current_state_id = next_state;

        handler = sm->state_table[sm->current_state_id].enter_state;
        if (handler)
                handler(sm);
}

static bool sci_controller_completion_queue_has_entries(struct isci_host *ihost)
{
        u32 get_value = ihost->completion_queue_get;
        u32 get_index = get_value & SMU_COMPLETION_QUEUE_GET_POINTER_MASK;

        if (NORMALIZE_GET_POINTER_CYCLE_BIT(get_value) ==
            COMPLETION_QUEUE_CYCLE_BIT(ihost->completion_queue[get_index]))
                return true;

        return false;
}

static bool sci_controller_isr(struct isci_host *ihost)
{
        if (sci_controller_completion_queue_has_entries(ihost))
                return true;

        /* we have a spurious interrupt it could be that we have already
         * emptied the completion queue from a previous interrupt
         * FIXME: really!?
         */
        writel(SMU_ISR_COMPLETION, &ihost->smu_registers->interrupt_status);

        /* There is a race in the hardware that could cause us not to be
         * notified of an interrupt completion if we do not take this
         * step.  We will mask then unmask the interrupts so if there is
         * another interrupt pending the clearing of the interrupt
         * source we get the next interrupt message.
         */
        spin_lock(&ihost->scic_lock);
        if (test_bit(IHOST_IRQ_ENABLED, &ihost->flags)) {
                writel(0xFF000000, &ihost->smu_registers->interrupt_mask);
                writel(0, &ihost->smu_registers->interrupt_mask);
        }
        spin_unlock(&ihost->scic_lock);

        return false;
}

irqreturn_t isci_msix_isr(int vec, void *data)
{
        struct isci_host *ihost = data;

        if (sci_controller_isr(ihost))
                tasklet_schedule(&ihost->completion_tasklet);

        return IRQ_HANDLED;
}

static bool sci_controller_error_isr(struct isci_host *ihost)
{
        u32 interrupt_status;

        interrupt_status =
                readl(&ihost->smu_registers->interrupt_status);
        interrupt_status &= (SMU_ISR_QUEUE_ERROR | SMU_ISR_QUEUE_SUSPEND);

        if (interrupt_status != 0) {
                /*
                 * There is an error interrupt pending so let it through and handle
                 * in the callback */
                return true;
        }

        /*
         * There is a race in the hardware that could cause us not to be notified
         * of an interrupt completion if we do not take this step.  We will mask
         * then unmask the error interrupts so if there was another interrupt
         * pending we will be notified.
         * Could we write the value of (SMU_ISR_QUEUE_ERROR | SMU_ISR_QUEUE_SUSPEND)? */
        writel(0xff, &ihost->smu_registers->interrupt_mask);
        writel(0, &ihost->smu_registers->interrupt_mask);

        return false;
}

static void sci_controller_task_completion(struct isci_host *ihost, u32 ent)
{
        u32 index = SCU_GET_COMPLETION_INDEX(ent);
        struct isci_request *ireq = ihost->reqs[index];

        /* Make sure that we really want to process this IO request */
        if (test_bit(IREQ_ACTIVE, &ireq->flags) &&
            ireq->io_tag != SCI_CONTROLLER_INVALID_IO_TAG &&
            ISCI_TAG_SEQ(ireq->io_tag) == ihost->io_request_sequence[index])
                /* Yep this is a valid io request pass it along to the
                 * io request handler
                 */
                sci_io_request_tc_completion(ireq, ent);
}

static void sci_controller_sdma_completion(struct isci_host *ihost, u32 ent)
{
        u32 index;
        struct isci_request *ireq;
        struct isci_remote_device *idev;

        index = SCU_GET_COMPLETION_INDEX(ent);

        switch (scu_get_command_request_type(ent)) {
        case SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_TC:
        case SCU_CONTEXT_COMMAND_REQUEST_TYPE_DUMP_TC:
                ireq = ihost->reqs[index];
                dev_warn(&ihost->pdev->dev, "%s: %x for io request %p\n",
                         __func__, ent, ireq);
                /* @todo For a post TC operation we need to fail the IO
                 * request
                 */
                break;
        case SCU_CONTEXT_COMMAND_REQUEST_TYPE_DUMP_RNC:
        case SCU_CONTEXT_COMMAND_REQUEST_TYPE_OTHER_RNC:
        case SCU_CONTEXT_COMMAND_REQUEST_TYPE_POST_RNC:
                idev = ihost->device_table[index];
                dev_warn(&ihost->pdev->dev, "%s: %x for device %p\n",
                         __func__, ent, idev);
                /* @todo For a port RNC operation we need to fail the
                 * device
                 */
                break;
        default:
                dev_warn(&ihost->pdev->dev, "%s: unknown completion type %x\n",
                         __func__, ent);
                break;
        }
}

static void sci_controller_unsolicited_frame(struct isci_host *ihost, u32 ent)
{
        u32 index;
        u32 frame_index;

        struct scu_unsolicited_frame_header *frame_header;
        struct isci_phy *iphy;
        struct isci_remote_device *idev;

        enum sci_status result = SCI_FAILURE;

        frame_index = SCU_GET_FRAME_INDEX(ent);

        frame_header = ihost->uf_control.buffers.array[frame_index].header;
        ihost->uf_control.buffers.array[frame_index].state = UNSOLICITED_FRAME_IN_USE;

        if (SCU_GET_FRAME_ERROR(ent)) {
                /*
                 * / @todo If the IAF frame or SIGNATURE FIS frame has an error will
                 * /       this cause a problem? We expect the phy initialization will
                 * /       fail if there is an error in the frame. */
                sci_controller_release_frame(ihost, frame_index);
                return;
        }

        if (frame_header->is_address_frame) {
                index = SCU_GET_PROTOCOL_ENGINE_INDEX(ent);
                iphy = &ihost->phys[index];
                result = sci_phy_frame_handler(iphy, frame_index);
        } else {

                index = SCU_GET_COMPLETION_INDEX(ent);

                if (index == SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
                        /*
                         * This is a signature fis or a frame from a direct attached SATA
                         * device that has not yet been created.  In either case forwared
                         * the frame to the PE and let it take care of the frame data. */
                        index = SCU_GET_PROTOCOL_ENGINE_INDEX(ent);
                        iphy = &ihost->phys[index];
                        result = sci_phy_frame_handler(iphy, frame_index);
                } else {
                        if (index < ihost->remote_node_entries)
                                idev = ihost->device_table[index];
                        else
                                idev = NULL;

                        if (idev != NULL)
                                result = sci_remote_device_frame_handler(idev, frame_index);
                        else
                                sci_controller_release_frame(ihost, frame_index);
                }
        }

        if (result != SCI_SUCCESS) {
                /*
                 * / @todo Is there any reason to report some additional error message
                 * /       when we get this failure notifiction? */
        }
}

static void sci_controller_event_completion(struct isci_host *ihost, u32 ent)
{
        struct isci_remote_device *idev;
        struct isci_request *ireq;
        struct isci_phy *iphy;
        u32 index;

        index = SCU_GET_COMPLETION_INDEX(ent);

        switch (scu_get_event_type(ent)) {
        case SCU_EVENT_TYPE_SMU_COMMAND_ERROR:
                /* / @todo The driver did something wrong and we need to fix the condtion. */
                dev_err(&ihost->pdev->dev,
                        "%s: SCIC Controller 0x%p received SMU command error "
                        "0x%x\n",
                        __func__,
                        ihost,
                        ent);
                break;

        case SCU_EVENT_TYPE_SMU_PCQ_ERROR:
        case SCU_EVENT_TYPE_SMU_ERROR:
        case SCU_EVENT_TYPE_FATAL_MEMORY_ERROR:
                /*
                 * / @todo This is a hardware failure and its likely that we want to
                 * /       reset the controller. */
                dev_err(&ihost->pdev->dev,
                        "%s: SCIC Controller 0x%p received fatal controller "
                        "event  0x%x\n",
                        __func__,
                        ihost,
                        ent);
                break;

        case SCU_EVENT_TYPE_TRANSPORT_ERROR:
                ireq = ihost->reqs[index];
                sci_io_request_event_handler(ireq, ent);
                break;

        case SCU_EVENT_TYPE_PTX_SCHEDULE_EVENT:
                switch (scu_get_event_specifier(ent)) {
                case SCU_EVENT_SPECIFIC_SMP_RESPONSE_NO_PE:
                case SCU_EVENT_SPECIFIC_TASK_TIMEOUT:
                        ireq = ihost->reqs[index];
                        if (ireq != NULL)
                                sci_io_request_event_handler(ireq, ent);
                        else
                                dev_warn(&ihost->pdev->dev,
                                         "%s: SCIC Controller 0x%p received "
                                         "event 0x%x for io request object "
                                         "that doesnt exist.\n",
                                         __func__,
                                         ihost,
                                         ent);

                        break;

                case SCU_EVENT_SPECIFIC_IT_NEXUS_TIMEOUT:
                        idev = ihost->device_table[index];
                        if (idev != NULL)
                                sci_remote_device_event_handler(idev, ent);
                        else
                                dev_warn(&ihost->pdev->dev,
                                         "%s: SCIC Controller 0x%p received "
                                         "event 0x%x for remote device object "
                                         "that doesnt exist.\n",
                                         __func__,
                                         ihost,
                                         ent);

                        break;
                }
                break;

        case SCU_EVENT_TYPE_BROADCAST_CHANGE:
        /*
         * direct the broadcast change event to the phy first and then let
         * the phy redirect the broadcast change to the port object */
        case SCU_EVENT_TYPE_ERR_CNT_EVENT:
        /*
         * direct error counter event to the phy object since that is where
         * we get the event notification.  This is a type 4 event. */
        case SCU_EVENT_TYPE_OSSP_EVENT:
                index = SCU_GET_PROTOCOL_ENGINE_INDEX(ent);
                iphy = &ihost->phys[index];
                sci_phy_event_handler(iphy, ent);
                break;

        case SCU_EVENT_TYPE_RNC_SUSPEND_TX:
        case SCU_EVENT_TYPE_RNC_SUSPEND_TX_RX:
        case SCU_EVENT_TYPE_RNC_OPS_MISC:
                if (index < ihost->remote_node_entries) {
                        idev = ihost->device_table[index];

                        if (idev != NULL)
                                sci_remote_device_event_handler(idev, ent);
                } else
                        dev_err(&ihost->pdev->dev,
                                "%s: SCIC Controller 0x%p received event 0x%x "
                                "for remote device object 0x%0x that doesnt "
                                "exist.\n",
                                __func__,
                                ihost,
                                ent,
                                index);

                break;

        default:
                dev_warn(&ihost->pdev->dev,
                         "%s: SCIC Controller received unknown event code %x\n",
                         __func__,
                         ent);
                break;
        }
}

static void sci_controller_process_completions(struct isci_host *ihost)
{
        u32 completion_count = 0;
        u32 ent;
        u32 get_index;
        u32 get_cycle;
        u32 event_get;
        u32 event_cycle;

        dev_dbg(&ihost->pdev->dev,
                "%s: completion queue beginning get:0x%08x\n",
                __func__,
                ihost->completion_queue_get);

        /* Get the component parts of the completion queue */
        get_index = NORMALIZE_GET_POINTER(ihost->completion_queue_get);
        get_cycle = SMU_CQGR_CYCLE_BIT & ihost->completion_queue_get;

        event_get = NORMALIZE_EVENT_POINTER(ihost->completion_queue_get);
        event_cycle = SMU_CQGR_EVENT_CYCLE_BIT & ihost->completion_queue_get;

        while (
                NORMALIZE_GET_POINTER_CYCLE_BIT(get_cycle)
                == COMPLETION_QUEUE_CYCLE_BIT(ihost->completion_queue[get_index])
                ) {
                completion_count++;

                ent = ihost->completion_queue[get_index];

                /* increment the get pointer and check for rollover to toggle the cycle bit */
                get_cycle ^= ((get_index+1) & SCU_MAX_COMPLETION_QUEUE_ENTRIES) <<
                             (SMU_COMPLETION_QUEUE_GET_CYCLE_BIT_SHIFT - SCU_MAX_COMPLETION_QUEUE_SHIFT);
                get_index = (get_index+1) & (SCU_MAX_COMPLETION_QUEUE_ENTRIES-1);

                dev_dbg(&ihost->pdev->dev,
                        "%s: completion queue entry:0x%08x\n",
                        __func__,
                        ent);

                switch (SCU_GET_COMPLETION_TYPE(ent)) {
                case SCU_COMPLETION_TYPE_TASK:
                        sci_controller_task_completion(ihost, ent);
                        break;

                case SCU_COMPLETION_TYPE_SDMA:
                        sci_controller_sdma_completion(ihost, ent);
                        break;

                case SCU_COMPLETION_TYPE_UFI:
                        sci_controller_unsolicited_frame(ihost, ent);
                        break;

                case SCU_COMPLETION_TYPE_EVENT:
                        sci_controller_event_completion(ihost, ent);
                        break;

                case SCU_COMPLETION_TYPE_NOTIFY: {
                        event_cycle ^= ((event_get+1) & SCU_MAX_EVENTS) <<
                                       (SMU_COMPLETION_QUEUE_GET_EVENT_CYCLE_BIT_SHIFT - SCU_MAX_EVENTS_SHIFT);
                        event_get = (event_get+1) & (SCU_MAX_EVENTS-1);

                        sci_controller_event_completion(ihost, ent);
                        break;
                }
                default:
                        dev_warn(&ihost->pdev->dev,
                                 "%s: SCIC Controller received unknown "
                                 "completion type %x\n",
                                 __func__,
                                 ent);
                        break;
                }
        }

        /* Update the get register if we completed one or more entries */
        if (completion_count > 0) {
                ihost->completion_queue_get =
                        SMU_CQGR_GEN_BIT(ENABLE) |
                        SMU_CQGR_GEN_BIT(EVENT_ENABLE) |
                        event_cycle |
                        SMU_CQGR_GEN_VAL(EVENT_POINTER, event_get) |
                        get_cycle |
                        SMU_CQGR_GEN_VAL(POINTER, get_index);

                writel(ihost->completion_queue_get,
                       &ihost->smu_registers->completion_queue_get);

        }

        dev_dbg(&ihost->pdev->dev,
                "%s: completion queue ending get:0x%08x\n",
                __func__,
                ihost->completion_queue_get);

}

static void sci_controller_error_handler(struct isci_host *ihost)
{
        u32 interrupt_status;

        interrupt_status =
                readl(&ihost->smu_registers->interrupt_status);

        if ((interrupt_status & SMU_ISR_QUEUE_SUSPEND) &&
            sci_controller_completion_queue_has_entries(ihost)) {

                sci_controller_process_completions(ihost);
                writel(SMU_ISR_QUEUE_SUSPEND, &ihost->smu_registers->interrupt_status);
        } else {
                dev_err(&ihost->pdev->dev, "%s: status: %#x\n", __func__,
                        interrupt_status);

                sci_change_state(&ihost->sm, SCIC_FAILED);

                return;
        }

        /* If we dont process any completions I am not sure that we want to do this.
         * We are in the middle of a hardware fault and should probably be reset.
         */
        writel(0, &ihost->smu_registers->interrupt_mask);
}

irqreturn_t isci_intx_isr(int vec, void *data)
{
        irqreturn_t ret = IRQ_NONE;
        struct isci_host *ihost = data;

        if (sci_controller_isr(ihost)) {
                writel(SMU_ISR_COMPLETION, &ihost->smu_registers->interrupt_status);
                tasklet_schedule(&ihost->completion_tasklet);
                ret = IRQ_HANDLED;
        } else if (sci_controller_error_isr(ihost)) {
                spin_lock(&ihost->scic_lock);
                sci_controller_error_handler(ihost);
                spin_unlock(&ihost->scic_lock);
                ret = IRQ_HANDLED;
        }

        return ret;
}

irqreturn_t isci_error_isr(int vec, void *data)
{
        struct isci_host *ihost = data;

        if (sci_controller_error_isr(ihost))
                sci_controller_error_handler(ihost);

        return IRQ_HANDLED;
}

/**
 * isci_host_start_complete() - This function is called by the core library,
 *    through the ISCI Module, to indicate controller start status.
 * @ihost: This parameter specifies the ISCI host object
 * @completion_status: This parameter specifies the completion status from the
 *    core library.
 *
 */
static void isci_host_start_complete(struct isci_host *ihost, enum sci_status completion_status)
{
        if (completion_status != SCI_SUCCESS)
                dev_info(&ihost->pdev->dev,
                        "controller start timed out, continuing...\n");
        clear_bit(IHOST_START_PENDING, &ihost->flags);
        wake_up(&ihost->eventq);
}

int isci_host_scan_finished(struct Scsi_Host *shost, unsigned long time)
{
        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
        struct isci_host *ihost = ha->lldd_ha;

        if (test_bit(IHOST_START_PENDING, &ihost->flags))
                return 0;

        sas_drain_work(ha);

        return 1;
}

/**
 * sci_controller_get_suggested_start_timeout() - This method returns the
 *    suggested sci_controller_start() timeout amount.  The user is free to
 *    use any timeout value, but this method provides the suggested minimum
 *    start timeout value.  The returned value is based upon empirical
 *    information determined as a result of interoperability testing.
 * @ihost: the handle to the controller object for which to return the
 *    suggested start timeout.
 *
 * This method returns the number of milliseconds for the suggested start
 * operation timeout.
 */
static u32 sci_controller_get_suggested_start_timeout(struct isci_host *ihost)
{
        /* Validate the user supplied parameters. */
        if (!ihost)
                return 0;

        /*
         * The suggested minimum timeout value for a controller start operation:
         *
         *     Signature FIS Timeout
         *   + Phy Start Timeout
         *   + Number of Phy Spin Up Intervals
         *   ---------------------------------
         *   Number of milliseconds for the controller start operation.
         *
         * NOTE: The number of phy spin up intervals will be equivalent
         *       to the number of phys divided by the number phys allowed
         *       per interval - 1 (once OEM parameters are supported).
         *       Currently we assume only 1 phy per interval. */

        return SCIC_SDS_SIGNATURE_FIS_TIMEOUT
                + SCIC_SDS_CONTROLLER_PHY_START_TIMEOUT
                + ((SCI_MAX_PHYS - 1) * SCIC_SDS_CONTROLLER_POWER_CONTROL_INTERVAL);
}

static void sci_controller_enable_interrupts(struct isci_host *ihost)
{
        set_bit(IHOST_IRQ_ENABLED, &ihost->flags);
        writel(0, &ihost->smu_registers->interrupt_mask);
}

void sci_controller_disable_interrupts(struct isci_host *ihost)
{
        clear_bit(IHOST_IRQ_ENABLED, &ihost->flags);
        writel(0xffffffff, &ihost->smu_registers->interrupt_mask);
        readl(&ihost->smu_registers->interrupt_mask); /* flush */
}

static void sci_controller_enable_port_task_scheduler(struct isci_host *ihost)
{
        u32 port_task_scheduler_value;

        port_task_scheduler_value =
                readl(&ihost->scu_registers->peg0.ptsg.control);
        port_task_scheduler_value |=
                (SCU_PTSGCR_GEN_BIT(ETM_ENABLE) |
                 SCU_PTSGCR_GEN_BIT(PTSG_ENABLE));
        writel(port_task_scheduler_value,
               &ihost->scu_registers->peg0.ptsg.control);
}

static void sci_controller_assign_task_entries(struct isci_host *ihost)
{
        u32 task_assignment;

        /*
         * Assign all the TCs to function 0
         * TODO: Do we actually need to read this register to write it back?
         */

        task_assignment =
                readl(&ihost->smu_registers->task_context_assignment[0]);

        task_assignment |= (SMU_TCA_GEN_VAL(STARTING, 0)) |
                (SMU_TCA_GEN_VAL(ENDING,  ihost->task_context_entries - 1)) |
                (SMU_TCA_GEN_BIT(RANGE_CHECK_ENABLE));

        writel(task_assignment,
                &ihost->smu_registers->task_context_assignment[0]);

}

static void sci_controller_initialize_completion_queue(struct isci_host *ihost)
{
        u32 index;
        u32 completion_queue_control_value;
        u32 completion_queue_get_value;
        u32 completion_queue_put_value;

        ihost->completion_queue_get = 0;

        completion_queue_control_value =
                (SMU_CQC_QUEUE_LIMIT_SET(SCU_MAX_COMPLETION_QUEUE_ENTRIES - 1) |
                 SMU_CQC_EVENT_LIMIT_SET(SCU_MAX_EVENTS - 1));

        writel(completion_queue_control_value,
               &ihost->smu_registers->completion_queue_control);


        /* Set the completion queue get pointer and enable the queue */
        completion_queue_get_value = (
                (SMU_CQGR_GEN_VAL(POINTER, 0))
                | (SMU_CQGR_GEN_VAL(EVENT_POINTER, 0))
                | (SMU_CQGR_GEN_BIT(ENABLE))
                | (SMU_CQGR_GEN_BIT(EVENT_ENABLE))
                );

        writel(completion_queue_get_value,
               &ihost->smu_registers->completion_queue_get);

        /* Set the completion queue put pointer */
        completion_queue_put_value = (
                (SMU_CQPR_GEN_VAL(POINTER, 0))
                | (SMU_CQPR_GEN_VAL(EVENT_POINTER, 0))
                );

        writel(completion_queue_put_value,
               &ihost->smu_registers->completion_queue_put);

        /* Initialize the cycle bit of the completion queue entries */
        for (index = 0; index < SCU_MAX_COMPLETION_QUEUE_ENTRIES; index++) {
                /*
                 * If get.cycle_bit != completion_queue.cycle_bit
                 * its not a valid completion queue entry
                 * so at system start all entries are invalid */
                ihost->completion_queue[index] = 0x80000000;
        }
}

static void sci_controller_initialize_unsolicited_frame_queue(struct isci_host *ihost)
{
        u32 frame_queue_control_value;
        u32 frame_queue_get_value;
        u32 frame_queue_put_value;

        /* Write the queue size */
        frame_queue_control_value =
                SCU_UFQC_GEN_VAL(QUEUE_SIZE, SCU_MAX_UNSOLICITED_FRAMES);

        writel(frame_queue_control_value,
               &ihost->scu_registers->sdma.unsolicited_frame_queue_control);

        /* Setup the get pointer for the unsolicited frame queue */
        frame_queue_get_value = (
                SCU_UFQGP_GEN_VAL(POINTER, 0)
                |  SCU_UFQGP_GEN_BIT(ENABLE_BIT)
                );

        writel(frame_queue_get_value,
               &ihost->scu_registers->sdma.unsolicited_frame_get_pointer);
        /* Setup the put pointer for the unsolicited frame queue */
        frame_queue_put_value = SCU_UFQPP_GEN_VAL(POINTER, 0);
        writel(frame_queue_put_value,
               &ihost->scu_registers->sdma.unsolicited_frame_put_pointer);
}

void sci_controller_transition_to_ready(struct isci_host *ihost, enum sci_status status)
{
        if (ihost->sm.current_state_id == SCIC_STARTING) {
                /*
                 * We move into the ready state, because some of the phys/ports
                 * may be up and operational.
                 */
                sci_change_state(&ihost->sm, SCIC_READY);

                isci_host_start_complete(ihost, status);
        }
}

static bool is_phy_starting(struct isci_phy *iphy)
{
        enum sci_phy_states state;

        state = iphy->sm.current_state_id;
        switch (state) {
        case SCI_PHY_STARTING:
        case SCI_PHY_SUB_INITIAL:
        case SCI_PHY_SUB_AWAIT_SAS_SPEED_EN:
        case SCI_PHY_SUB_AWAIT_IAF_UF:
        case SCI_PHY_SUB_AWAIT_SAS_POWER:
        case SCI_PHY_SUB_AWAIT_SATA_POWER:
        case SCI_PHY_SUB_AWAIT_SATA_PHY_EN:
        case SCI_PHY_SUB_AWAIT_SATA_SPEED_EN:
        case SCI_PHY_SUB_AWAIT_OSSP_EN:
        case SCI_PHY_SUB_AWAIT_SIG_FIS_UF:
        case SCI_PHY_SUB_FINAL:
                return true;
        default:
                return false;
        }
}

bool is_controller_start_complete(struct isci_host *ihost)
{
        int i;

        for (i = 0; i < SCI_MAX_PHYS; i++) {
                struct isci_phy *iphy = &ihost->phys[i];
                u32 state = iphy->sm.current_state_id;

                /* in apc mode we need to check every phy, in
                 * mpc mode we only need to check phys that have
                 * been configured into a port
                 */
                if (is_port_config_apc(ihost))
                        /* pass */;
                else if (!phy_get_non_dummy_port(iphy))
                        continue;

                /* The controller start operation is complete iff:
                 * - all links have been given an opportunity to start
                 * - have no indication of a connected device
                 * - have an indication of a connected device and it has
                 *   finished the link training process.
                 */
                if ((iphy->is_in_link_training == false && state == SCI_PHY_INITIAL) ||
                    (iphy->is_in_link_training == false && state == SCI_PHY_STOPPED) ||
                    (iphy->is_in_link_training == true && is_phy_starting(iphy)) ||
                    (ihost->port_agent.phy_ready_mask != ihost->port_agent.phy_configured_mask))
                        return false;
        }

        return true;
}

/**
 * sci_controller_start_next_phy - start phy
 * @ihost: controller
 *
 * If all the phys have been started, then attempt to transition the
 * controller to the READY state and inform the user
 * (sci_cb_controller_start_complete()).
 */
static enum sci_status sci_controller_start_next_phy(struct isci_host *ihost)
{
        struct sci_oem_params *oem = &ihost->oem_parameters;
        struct isci_phy *iphy;
        enum sci_status status;

        status = SCI_SUCCESS;

        if (ihost->phy_startup_timer_pending)
                return status;

        if (ihost->next_phy_to_start >= SCI_MAX_PHYS) {
                if (is_controller_start_complete(ihost)) {
                        sci_controller_transition_to_ready(ihost, SCI_SUCCESS);
                        sci_del_timer(&ihost->phy_timer);
                        ihost->phy_startup_timer_pending = false;
                }
        } else {
                iphy = &ihost->phys[ihost->next_phy_to_start];

                if (oem->controller.mode_type == SCIC_PORT_MANUAL_CONFIGURATION_MODE) {
                        if (phy_get_non_dummy_port(iphy) == NULL) {
                                ihost->next_phy_to_start++;

                                /* Caution recursion ahead be forwarned
                                 *
                                 * The PHY was never added to a PORT in MPC mode
                                 * so start the next phy in sequence This phy
                                 * will never go link up and will not draw power
                                 * the OEM parameters either configured the phy
                                 * incorrectly for the PORT or it was never
                                 * assigned to a PORT
                                 */
                                return sci_controller_start_next_phy(ihost);
                        }
                }

                status = sci_phy_start(iphy);

                if (status == SCI_SUCCESS) {
                        sci_mod_timer(&ihost->phy_timer,
                                      SCIC_SDS_CONTROLLER_PHY_START_TIMEOUT);
                        ihost->phy_startup_timer_pending = true;
                } else {
                        dev_warn(&ihost->pdev->dev,
                                 "%s: Controller stop operation failed "
                                 "to stop phy %d because of status "
                                 "%d.\n",
                                 __func__,
                                 ihost->phys[ihost->next_phy_to_start].phy_index,
                                 status);
                }

                ihost->next_phy_to_start++;
        }

        return status;
}

static void phy_startup_timeout(struct timer_list *t)
{
        struct sci_timer *tmr = from_timer(tmr, t, timer);
        struct isci_host *ihost = container_of(tmr, typeof(*ihost), phy_timer);
        unsigned long flags;
        enum sci_status status;

        spin_lock_irqsave(&ihost->scic_lock, flags);

        if (tmr->cancel)
                goto done;

        ihost->phy_startup_timer_pending = false;

        do {
                status = sci_controller_start_next_phy(ihost);
        } while (status != SCI_SUCCESS);

done:
        spin_unlock_irqrestore(&ihost->scic_lock, flags);
}

static u16 isci_tci_active(struct isci_host *ihost)
{
        return CIRC_CNT(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
}

static enum sci_status sci_controller_start(struct isci_host *ihost,
                                             u32 timeout)
{
        enum sci_status result;
        u16 index;

        if (ihost->sm.current_state_id != SCIC_INITIALIZED) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

        /* Build the TCi free pool */
        BUILD_BUG_ON(SCI_MAX_IO_REQUESTS > 1 << sizeof(ihost->tci_pool[0]) * 8);
        ihost->tci_head = 0;

        ihost->tci_tail = 0;
        for (index = 0; index < ihost->task_context_entries; index++)
                isci_tci_free(ihost, index);

        /* Build the RNi free pool */
        sci_remote_node_table_initialize(&ihost->available_remote_nodes,
                                         ihost->remote_node_entries);

        /*
         * Before anything else lets make sure we will not be
         * interrupted by the hardware.
         */
        sci_controller_disable_interrupts(ihost);

        /* Enable the port task scheduler */
        sci_controller_enable_port_task_scheduler(ihost);

        /* Assign all the task entries to ihost physical function */
        sci_controller_assign_task_entries(ihost);

        /* Now initialize the completion queue */
        sci_controller_initialize_completion_queue(ihost);

        /* Initialize the unsolicited frame queue for use */
        sci_controller_initialize_unsolicited_frame_queue(ihost);

        /* Start all of the ports on this controller */
        for (index = 0; index < ihost->logical_port_entries; index++) {
                struct isci_port *iport = &ihost->ports[index];

                result = sci_port_start(iport);
                if (result)
                        return result;
        }

        sci_controller_start_next_phy(ihost);

        sci_mod_timer(&ihost->timer, timeout);

        sci_change_state(&ihost->sm, SCIC_STARTING);

        return SCI_SUCCESS;
}

void isci_host_start(struct Scsi_Host *shost)
{
        struct isci_host *ihost = SHOST_TO_SAS_HA(shost)->lldd_ha;
        unsigned long tmo = sci_controller_get_suggested_start_timeout(ihost);

        set_bit(IHOST_START_PENDING, &ihost->flags);

        spin_lock_irq(&ihost->scic_lock);
        sci_controller_start(ihost, tmo);
        sci_controller_enable_interrupts(ihost);
        spin_unlock_irq(&ihost->scic_lock);
}

static void isci_host_stop_complete(struct isci_host *ihost)
{
        sci_controller_disable_interrupts(ihost);
        clear_bit(IHOST_STOP_PENDING, &ihost->flags);
        wake_up(&ihost->eventq);
}

static void sci_controller_completion_handler(struct isci_host *ihost)
{
        /* Empty out the completion queue */
        if (sci_controller_completion_queue_has_entries(ihost))
                sci_controller_process_completions(ihost);

        /* Clear the interrupt and enable all interrupts again */
        writel(SMU_ISR_COMPLETION, &ihost->smu_registers->interrupt_status);
        /* Could we write the value of SMU_ISR_COMPLETION? */
        writel(0xFF000000, &ihost->smu_registers->interrupt_mask);
        writel(0, &ihost->smu_registers->interrupt_mask);
}

void ireq_done(struct isci_host *ihost, struct isci_request *ireq, struct sas_task *task)
{
        if (!test_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags) &&
            !(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
                if (test_bit(IREQ_COMPLETE_IN_TARGET, &ireq->flags)) {
                        /* Normal notification (task_done) */
                        dev_dbg(&ihost->pdev->dev,
                                "%s: Normal - ireq/task = %p/%p\n",
                                __func__, ireq, task);
                        task->lldd_task = NULL;
                        task->task_done(task);
                } else {
                        dev_dbg(&ihost->pdev->dev,
                                "%s: Error - ireq/task = %p/%p\n",
                                __func__, ireq, task);
                        if (sas_protocol_ata(task->task_proto))
                                task->lldd_task = NULL;
                        sas_task_abort(task);
                }
        } else
                task->lldd_task = NULL;

        if (test_and_clear_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags))
                wake_up_all(&ihost->eventq);

        if (!test_bit(IREQ_NO_AUTO_FREE_TAG, &ireq->flags))
                isci_free_tag(ihost, ireq->io_tag);
}
/**
 * isci_host_completion_routine() - This function is the delayed service
 *    routine that calls the sci core library's completion handler. It's
 *    scheduled as a tasklet from the interrupt service routine when interrupts
 *    in use, or set as the timeout function in polled mode.
 * @data: This parameter specifies the ISCI host object
 *
 */
void isci_host_completion_routine(unsigned long data)
{
        struct isci_host *ihost = (struct isci_host *)data;
        u16 active;

        spin_lock_irq(&ihost->scic_lock);
        sci_controller_completion_handler(ihost);
        spin_unlock_irq(&ihost->scic_lock);

        /*
         * we subtract SCI_MAX_PORTS to account for the number of dummy TCs
         * issued for hardware issue workaround
         */
        active = isci_tci_active(ihost) - SCI_MAX_PORTS;

        /*
         * the coalesence timeout doubles at each encoding step, so
         * update it based on the ilog2 value of the outstanding requests
         */
        writel(SMU_ICC_GEN_VAL(NUMBER, active) |
               SMU_ICC_GEN_VAL(TIMER, ISCI_COALESCE_BASE + ilog2(active)),
               &ihost->smu_registers->interrupt_coalesce_control);
}

/**
 * sci_controller_stop() - This method will stop an individual controller
 *    object.This method will invoke the associated user callback upon
 *    completion.  The completion callback is called when the following
 *    conditions are met: -# the method return status is SCI_SUCCESS. -# the
 *    controller has been quiesced. This method will ensure that all IO
 *    requests are quiesced, phys are stopped, and all additional operation by
 *    the hardware is halted.
 * @ihost: the handle to the controller object to stop.
 * @timeout: This parameter specifies the number of milliseconds in which the
 *    stop operation should complete.
 *
 * The controller must be in the STARTED or STOPPED state. Indicate if the
 * controller stop method succeeded or failed in some way. SCI_SUCCESS if the
 * stop operation successfully began. SCI_WARNING_ALREADY_IN_STATE if the
 * controller is already in the STOPPED state. SCI_FAILURE_INVALID_STATE if the
 * controller is not either in the STARTED or STOPPED states.
 */
static enum sci_status sci_controller_stop(struct isci_host *ihost, u32 timeout)
{
        if (ihost->sm.current_state_id != SCIC_READY) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

        sci_mod_timer(&ihost->timer, timeout);
        sci_change_state(&ihost->sm, SCIC_STOPPING);
        return SCI_SUCCESS;
}

/**
 * sci_controller_reset() - This method will reset the supplied core
 *    controller regardless of the state of said controller.  This operation is
 *    considered destructive.  In other words, all current operations are wiped
 *    out.  No IO completions for outstanding devices occur.  Outstanding IO
 *    requests are not aborted or completed at the actual remote device.
 * @ihost: the handle to the controller object to reset.
 *
 * Indicate if the controller reset method succeeded or failed in some way.
 * SCI_SUCCESS if the reset operation successfully started. SCI_FATAL_ERROR if
 * the controller reset operation is unable to complete.
 */
static enum sci_status sci_controller_reset(struct isci_host *ihost)
{
        switch (ihost->sm.current_state_id) {
        case SCIC_RESET:
        case SCIC_READY:
        case SCIC_STOPPING:
        case SCIC_FAILED:
                /*
                 * The reset operation is not a graceful cleanup, just
                 * perform the state transition.
                 */
                sci_change_state(&ihost->sm, SCIC_RESETTING);
                return SCI_SUCCESS;
        default:
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }
}

static enum sci_status sci_controller_stop_phys(struct isci_host *ihost)
{
        u32 index;
        enum sci_status status;
        enum sci_status phy_status;

        status = SCI_SUCCESS;

        for (index = 0; index < SCI_MAX_PHYS; index++) {
                phy_status = sci_phy_stop(&ihost->phys[index]);

                if (phy_status != SCI_SUCCESS &&
                    phy_status != SCI_FAILURE_INVALID_STATE) {
                        status = SCI_FAILURE;

                        dev_warn(&ihost->pdev->dev,
                                 "%s: Controller stop operation failed to stop "
                                 "phy %d because of status %d.\n",
                                 __func__,
                                 ihost->phys[index].phy_index, phy_status);
                }
        }

        return status;
}


/**
 * isci_host_deinit - shutdown frame reception and dma
 * @ihost: host to take down
 *
 * This is called in either the driver shutdown or the suspend path.  In
 * the shutdown case libsas went through port teardown and normal device
 * removal (i.e. physical links stayed up to service scsi_device removal
 * commands).  In the suspend case we disable the hardware without
 * notifying libsas of the link down events since we want libsas to
 * remember the domain across the suspend/resume cycle
 */
void isci_host_deinit(struct isci_host *ihost)
{
        int i;

        /* disable output data selects */
        for (i = 0; i < isci_gpio_count(ihost); i++)
                writel(SGPIO_HW_CONTROL, &ihost->scu_registers->peg0.sgpio.output_data_select[i]);

        set_bit(IHOST_STOP_PENDING, &ihost->flags);

        spin_lock_irq(&ihost->scic_lock);
        sci_controller_stop(ihost, SCIC_CONTROLLER_STOP_TIMEOUT);
        spin_unlock_irq(&ihost->scic_lock);

        wait_for_stop(ihost);

        /* phy stop is after controller stop to allow port and device to
         * go idle before shutting down the phys, but the expectation is
         * that i/o has been shut off well before we reach this
         * function.
         */
        sci_controller_stop_phys(ihost);

        /* disable sgpio: where the above wait should give time for the
         * enclosure to sample the gpios going inactive
         */
        writel(0, &ihost->scu_registers->peg0.sgpio.interface_control);

        spin_lock_irq(&ihost->scic_lock);
        sci_controller_reset(ihost);
        spin_unlock_irq(&ihost->scic_lock);

        /* Cancel any/all outstanding port timers */
        for (i = 0; i < ihost->logical_port_entries; i++) {
                struct isci_port *iport = &ihost->ports[i];
                del_timer_sync(&iport->timer.timer);
        }

        /* Cancel any/all outstanding phy timers */
        for (i = 0; i < SCI_MAX_PHYS; i++) {
                struct isci_phy *iphy = &ihost->phys[i];
                del_timer_sync(&iphy->sata_timer.timer);
        }

        del_timer_sync(&ihost->port_agent.timer.timer);

        del_timer_sync(&ihost->power_control.timer.timer);

        del_timer_sync(&ihost->timer.timer);

        del_timer_sync(&ihost->phy_timer.timer);
}

static void __iomem *scu_base(struct isci_host *isci_host)
{
        struct pci_dev *pdev = isci_host->pdev;
        int id = isci_host->id;

        return pcim_iomap_table(pdev)[SCI_SCU_BAR * 2] + SCI_SCU_BAR_SIZE * id;
}

static void __iomem *smu_base(struct isci_host *isci_host)
{
        struct pci_dev *pdev = isci_host->pdev;
        int id = isci_host->id;

        return pcim_iomap_table(pdev)[SCI_SMU_BAR * 2] + SCI_SMU_BAR_SIZE * id;
}

static void sci_controller_initial_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        sci_change_state(&ihost->sm, SCIC_RESET);
}

static inline void sci_controller_starting_state_exit(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        sci_del_timer(&ihost->timer);
}

#define INTERRUPT_COALESCE_TIMEOUT_BASE_RANGE_LOWER_BOUND_NS 853
#define INTERRUPT_COALESCE_TIMEOUT_BASE_RANGE_UPPER_BOUND_NS 1280
#define INTERRUPT_COALESCE_TIMEOUT_MAX_US                    2700000
#define INTERRUPT_COALESCE_NUMBER_MAX                        256
#define INTERRUPT_COALESCE_TIMEOUT_ENCODE_MIN                7
#define INTERRUPT_COALESCE_TIMEOUT_ENCODE_MAX                28

/**
 * sci_controller_set_interrupt_coalescence() - This method allows the user to
 *    configure the interrupt coalescence.
 * @ihost: This parameter represents the handle to the controller object
 *    for which its interrupt coalesce register is overridden.
 * @coalesce_number: Used to control the number of entries in the Completion
 *    Queue before an interrupt is generated. If the number of entries exceed
 *    this number, an interrupt will be generated. The valid range of the input
 *    is [0, 256]. A setting of 0 results in coalescing being disabled.
 * @coalesce_timeout: Timeout value in microseconds. The valid range of the
 *    input is [0, 2700000] . A setting of 0 is allowed and results in no
 *    interrupt coalescing timeout.
 *
 * Indicate if the user successfully set the interrupt coalesce parameters.
 * SCI_SUCCESS The user successfully updated the interrutp coalescence.
 * SCI_FAILURE_INVALID_PARAMETER_VALUE The user input value is out of range.
 */
static enum sci_status
sci_controller_set_interrupt_coalescence(struct isci_host *ihost,
                                         u32 coalesce_number,
                                         u32 coalesce_timeout)
{
        u8 timeout_encode = 0;
        u32 min = 0;
        u32 max = 0;

        /* Check if the input parameters fall in the range. */
        if (coalesce_number > INTERRUPT_COALESCE_NUMBER_MAX)
                return SCI_FAILURE_INVALID_PARAMETER_VALUE;

        /*
         *  Defined encoding for interrupt coalescing timeout:
         *              Value   Min      Max     Units
         *              -----   ---      ---     -----
         *              0       -        -       Disabled
         *              1       13.3     20.0    ns
         *              2       26.7     40.0
         *              3       53.3     80.0
         *              4       106.7    160.0
         *              5       213.3    320.0
         *              6       426.7    640.0
         *              7       853.3    1280.0
         *              8       1.7      2.6     us
         *              9       3.4      5.1
         *              10      6.8      10.2
         *              11      13.7     20.5
         *              12      27.3     41.0
         *              13      54.6     81.9
         *              14      109.2    163.8
         *              15      218.5    327.7
         *              16      436.9    655.4
         *              17      873.8    1310.7
         *              18      1.7      2.6     ms
         *              19      3.5      5.2
         *              20      7.0      10.5
         *              21      14.0     21.0
         *              22      28.0     41.9
         *              23      55.9     83.9
         *              24      111.8    167.8
         *              25      223.7    335.5
         *              26      447.4    671.1
         *              27      894.8    1342.2
         *              28      1.8      2.7     s
         *              Others Undefined */

        /*
         * Use the table above to decide the encode of interrupt coalescing timeout
         * value for register writing. */
        if (coalesce_timeout == 0)
                timeout_encode = 0;
        else{
                /* make the timeout value in unit of (10 ns). */
                coalesce_timeout = coalesce_timeout * 100;
                min = INTERRUPT_COALESCE_TIMEOUT_BASE_RANGE_LOWER_BOUND_NS / 10;
                max = INTERRUPT_COALESCE_TIMEOUT_BASE_RANGE_UPPER_BOUND_NS / 10;

                /* get the encode of timeout for register writing. */
                for (timeout_encode = INTERRUPT_COALESCE_TIMEOUT_ENCODE_MIN;
                      timeout_encode <= INTERRUPT_COALESCE_TIMEOUT_ENCODE_MAX;
                      timeout_encode++) {
                        if (min <= coalesce_timeout &&  max > coalesce_timeout)
                                break;
                        else if (coalesce_timeout >= max && coalesce_timeout < min * 2
                                 && coalesce_timeout <= INTERRUPT_COALESCE_TIMEOUT_MAX_US * 100) {
                                if ((coalesce_timeout - max) < (2 * min - coalesce_timeout))
                                        break;
                                else{
                                        timeout_encode++;
                                        break;
                                }
                        } else {
                                max = max * 2;
                                min = min * 2;
                        }
                }

                if (timeout_encode == INTERRUPT_COALESCE_TIMEOUT_ENCODE_MAX + 1)
                        /* the value is out of range. */
                        return SCI_FAILURE_INVALID_PARAMETER_VALUE;
        }

        writel(SMU_ICC_GEN_VAL(NUMBER, coalesce_number) |
               SMU_ICC_GEN_VAL(TIMER, timeout_encode),
               &ihost->smu_registers->interrupt_coalesce_control);


        ihost->interrupt_coalesce_number = (u16)coalesce_number;
        ihost->interrupt_coalesce_timeout = coalesce_timeout / 100;

        return SCI_SUCCESS;
}


static void sci_controller_ready_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);
        u32 val;

        /* enable clock gating for power control of the scu unit */
        val = readl(&ihost->smu_registers->clock_gating_control);
        val &= ~(SMU_CGUCR_GEN_BIT(REGCLK_ENABLE) |
                 SMU_CGUCR_GEN_BIT(TXCLK_ENABLE) |
                 SMU_CGUCR_GEN_BIT(XCLK_ENABLE));
        val |= SMU_CGUCR_GEN_BIT(IDLE_ENABLE);
        writel(val, &ihost->smu_registers->clock_gating_control);

        /* set the default interrupt coalescence number and timeout value. */
        sci_controller_set_interrupt_coalescence(ihost, 0, 0);
}

static void sci_controller_ready_state_exit(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        /* disable interrupt coalescence. */
        sci_controller_set_interrupt_coalescence(ihost, 0, 0);
}

static enum sci_status sci_controller_stop_ports(struct isci_host *ihost)
{
        u32 index;
        enum sci_status port_status;
        enum sci_status status = SCI_SUCCESS;

        for (index = 0; index < ihost->logical_port_entries; index++) {
                struct isci_port *iport = &ihost->ports[index];

                port_status = sci_port_stop(iport);

                if ((port_status != SCI_SUCCESS) &&
                    (port_status != SCI_FAILURE_INVALID_STATE)) {
                        status = SCI_FAILURE;

                        dev_warn(&ihost->pdev->dev,
                                 "%s: Controller stop operation failed to "
                                 "stop port %d because of status %d.\n",
                                 __func__,
                                 iport->logical_port_index,
                                 port_status);
                }
        }

        return status;
}

static enum sci_status sci_controller_stop_devices(struct isci_host *ihost)
{
        u32 index;
        enum sci_status status;
        enum sci_status device_status;

        status = SCI_SUCCESS;

        for (index = 0; index < ihost->remote_node_entries; index++) {
                if (ihost->device_table[index] != NULL) {
                        /* / @todo What timeout value do we want to provide to this request? */
                        device_status = sci_remote_device_stop(ihost->device_table[index], 0);

                        if ((device_status != SCI_SUCCESS) &&
                            (device_status != SCI_FAILURE_INVALID_STATE)) {
                                dev_warn(&ihost->pdev->dev,
                                         "%s: Controller stop operation failed "
                                         "to stop device 0x%p because of "
                                         "status %d.\n",
                                         __func__,
                                         ihost->device_table[index], device_status);
                        }
                }
        }

        return status;
}

static void sci_controller_stopping_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        sci_controller_stop_devices(ihost);
        sci_controller_stop_ports(ihost);

        if (!sci_controller_has_remote_devices_stopping(ihost))
                isci_host_stop_complete(ihost);
}

static void sci_controller_stopping_state_exit(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        sci_del_timer(&ihost->timer);
}

static void sci_controller_reset_hardware(struct isci_host *ihost)
{
        /* Disable interrupts so we dont take any spurious interrupts */
        sci_controller_disable_interrupts(ihost);

        /* Reset the SCU */
        writel(0xFFFFFFFF, &ihost->smu_registers->soft_reset_control);

        /* Delay for 1ms to before clearing the CQP and UFQPR. */
        udelay(1000);

        /* The write to the CQGR clears the CQP */
        writel(0x00000000, &ihost->smu_registers->completion_queue_get);

        /* The write to the UFQGP clears the UFQPR */
        writel(0, &ihost->scu_registers->sdma.unsolicited_frame_get_pointer);

        /* clear all interrupts */
        writel(~SMU_INTERRUPT_STATUS_RESERVED_MASK, &ihost->smu_registers->interrupt_status);
}

static void sci_controller_resetting_state_enter(struct sci_base_state_machine *sm)
{
        struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);

        sci_controller_reset_hardware(ihost);
        sci_change_state(&ihost->sm, SCIC_RESET);
}

static const struct sci_base_state sci_controller_state_table[] = {
        [SCIC_INITIAL] = {
                .enter_state = sci_controller_initial_state_enter,
        },
        [SCIC_RESET] = {},
        [SCIC_INITIALIZING] = {},
        [SCIC_INITIALIZED] = {},
        [SCIC_STARTING] = {
                .exit_state  = sci_controller_starting_state_exit,
        },
        [SCIC_READY] = {
                .enter_state = sci_controller_ready_state_enter,
                .exit_state  = sci_controller_ready_state_exit,
        },
        [SCIC_RESETTING] = {
                .enter_state = sci_controller_resetting_state_enter,
        },
        [SCIC_STOPPING] = {
                .enter_state = sci_controller_stopping_state_enter,
                .exit_state = sci_controller_stopping_state_exit,
        },
        [SCIC_FAILED] = {}
};

static void controller_timeout(struct timer_list *t)
{
        struct sci_timer *tmr = from_timer(tmr, t, timer);
        struct isci_host *ihost = container_of(tmr, typeof(*ihost), timer);
        struct sci_base_state_machine *sm = &ihost->sm;
        unsigned long flags;

        spin_lock_irqsave(&ihost->scic_lock, flags);

        if (tmr->cancel)
                goto done;

        if (sm->current_state_id == SCIC_STARTING)
                sci_controller_transition_to_ready(ihost, SCI_FAILURE_TIMEOUT);
        else if (sm->current_state_id == SCIC_STOPPING) {
                sci_change_state(sm, SCIC_FAILED);
                isci_host_stop_complete(ihost);
        } else  /* / @todo Now what do we want to do in this case? */
                dev_err(&ihost->pdev->dev,
                        "%s: Controller timer fired when controller was not "
                        "in a state being timed.\n",
                        __func__);

done:
        spin_unlock_irqrestore(&ihost->scic_lock, flags);
}

static enum sci_status sci_controller_construct(struct isci_host *ihost,
                                                void __iomem *scu_base,
                                                void __iomem *smu_base)
{
        u8 i;

        sci_init_sm(&ihost->sm, sci_controller_state_table, SCIC_INITIAL);

        ihost->scu_registers = scu_base;
        ihost->smu_registers = smu_base;

        sci_port_configuration_agent_construct(&ihost->port_agent);

        /* Construct the ports for this controller */
        for (i = 0; i < SCI_MAX_PORTS; i++)
                sci_port_construct(&ihost->ports[i], i, ihost);
        sci_port_construct(&ihost->ports[i], SCIC_SDS_DUMMY_PORT, ihost);

        /* Construct the phys for this controller */
        for (i = 0; i < SCI_MAX_PHYS; i++) {
                /* Add all the PHYs to the dummy port */
                sci_phy_construct(&ihost->phys[i],
                                  &ihost->ports[SCI_MAX_PORTS], i);
        }

        ihost->invalid_phy_mask = 0;

        sci_init_timer(&ihost->timer, controller_timeout);

        return sci_controller_reset(ihost);
}

int sci_oem_parameters_validate(struct sci_oem_params *oem, u8 version)
{
        int i;

        for (i = 0; i < SCI_MAX_PORTS; i++)
                if (oem->ports[i].phy_mask > SCIC_SDS_PARM_PHY_MASK_MAX)
                        return -EINVAL;

        for (i = 0; i < SCI_MAX_PHYS; i++)
                if (oem->phys[i].sas_address.high == 0 &&
                    oem->phys[i].sas_address.low == 0)
                        return -EINVAL;

        if (oem->controller.mode_type == SCIC_PORT_AUTOMATIC_CONFIGURATION_MODE) {
                for (i = 0; i < SCI_MAX_PHYS; i++)
                        if (oem->ports[i].phy_mask != 0)
                                return -EINVAL;
        } else if (oem->controller.mode_type == SCIC_PORT_MANUAL_CONFIGURATION_MODE) {
                u8 phy_mask = 0;

                for (i = 0; i < SCI_MAX_PHYS; i++)
                        phy_mask |= oem->ports[i].phy_mask;

                if (phy_mask == 0)
                        return -EINVAL;
        } else
                return -EINVAL;

        if (oem->controller.max_concurr_spin_up > MAX_CONCURRENT_DEVICE_SPIN_UP_COUNT ||
            oem->controller.max_concurr_spin_up < 1)
                return -EINVAL;

        if (oem->controller.do_enable_ssc) {
                if (version < ISCI_ROM_VER_1_1 && oem->controller.do_enable_ssc != 1)
                        return -EINVAL;

                if (version >= ISCI_ROM_VER_1_1) {
                        u8 test = oem->controller.ssc_sata_tx_spread_level;

                        switch (test) {
                        case 0:
                        case 2:
                        case 3:
                        case 6:
                        case 7:
                                break;
                        default:
                                return -EINVAL;
                        }

                        test = oem->controller.ssc_sas_tx_spread_level;
                        if (oem->controller.ssc_sas_tx_type == 0) {
                                switch (test) {
                                case 0:
                                case 2:
                                case 3:
                                        break;
                                default:
                                        return -EINVAL;
                                }
                        } else if (oem->controller.ssc_sas_tx_type == 1) {
                                switch (test) {
                                case 0:
                                case 3:
                                case 6:
                                        break;
                                default:
                                        return -EINVAL;
                                }
                        }
                }
        }

        return 0;
}

static u8 max_spin_up(struct isci_host *ihost)
{
        if (ihost->user_parameters.max_concurr_spinup)
                return min_t(u8, ihost->user_parameters.max_concurr_spinup,
                             MAX_CONCURRENT_DEVICE_SPIN_UP_COUNT);
        else
                return min_t(u8, ihost->oem_parameters.controller.max_concurr_spin_up,
                             MAX_CONCURRENT_DEVICE_SPIN_UP_COUNT);
}

static void power_control_timeout(struct timer_list *t)
{
        struct sci_timer *tmr = from_timer(tmr, t, timer);
        struct isci_host *ihost = container_of(tmr, typeof(*ihost), power_control.timer);
        struct isci_phy *iphy;
        unsigned long flags;
        u8 i;

        spin_lock_irqsave(&ihost->scic_lock, flags);

        if (tmr->cancel)
                goto done;

        ihost->power_control.phys_granted_power = 0;

        if (ihost->power_control.phys_waiting == 0) {
                ihost->power_control.timer_started = false;
                goto done;
        }

        for (i = 0; i < SCI_MAX_PHYS; i++) {

                if (ihost->power_control.phys_waiting == 0)
                        break;

                iphy = ihost->power_control.requesters[i];
                if (iphy == NULL)
                        continue;

                if (ihost->power_control.phys_granted_power >= max_spin_up(ihost))
                        break;

                ihost->power_control.requesters[i] = NULL;
                ihost->power_control.phys_waiting--;
                ihost->power_control.phys_granted_power++;
                sci_phy_consume_power_handler(iphy);

                if (iphy->protocol == SAS_PROTOCOL_SSP) {
                        u8 j;

                        for (j = 0; j < SCI_MAX_PHYS; j++) {
                                struct isci_phy *requester = ihost->power_control.requesters[j];

                                /*
                                 * Search the power_control queue to see if there are other phys
                                 * attached to the same remote device. If found, take all of
                                 * them out of await_sas_power state.
                                 */
                                if (requester != NULL && requester != iphy) {
                                        u8 other = memcmp(requester->frame_rcvd.iaf.sas_addr,
                                                          iphy->frame_rcvd.iaf.sas_addr,
                                                          sizeof(requester->frame_rcvd.iaf.sas_addr));

                                        if (other == 0) {
                                                ihost->power_control.requesters[j] = NULL;
                                                ihost->power_control.phys_waiting--;
                                                sci_phy_consume_power_handler(requester);
                                        }
                                }
                        }
                }
        }

        /*
         * It doesn't matter if the power list is empty, we need to start the
         * timer in case another phy becomes ready.
         */
        sci_mod_timer(tmr, SCIC_SDS_CONTROLLER_POWER_CONTROL_INTERVAL);
        ihost->power_control.timer_started = true;

done:
        spin_unlock_irqrestore(&ihost->scic_lock, flags);
}

void sci_controller_power_control_queue_insert(struct isci_host *ihost,
                                               struct isci_phy *iphy)
{
        BUG_ON(iphy == NULL);

        if (ihost->power_control.phys_granted_power < max_spin_up(ihost)) {
                ihost->power_control.phys_granted_power++;
                sci_phy_consume_power_handler(iphy);

                /*
                 * stop and start the power_control timer. When the timer fires, the
                 * no_of_phys_granted_power will be set to 0
                 */
                if (ihost->power_control.timer_started)
                        sci_del_timer(&ihost->power_control.timer);

                sci_mod_timer(&ihost->power_control.timer,
                                 SCIC_SDS_CONTROLLER_POWER_CONTROL_INTERVAL);
                ihost->power_control.timer_started = true;

        } else {
                /*
                 * There are phys, attached to the same sas address as this phy, are
                 * already in READY state, this phy don't need wait.
                 */
                u8 i;
                struct isci_phy *current_phy;

                for (i = 0; i < SCI_MAX_PHYS; i++) {
                        u8 other;
                        current_phy = &ihost->phys[i];

                        other = memcmp(current_phy->frame_rcvd.iaf.sas_addr,
                                       iphy->frame_rcvd.iaf.sas_addr,
                                       sizeof(current_phy->frame_rcvd.iaf.sas_addr));

                        if (current_phy->sm.current_state_id == SCI_PHY_READY &&
                            current_phy->protocol == SAS_PROTOCOL_SSP &&
                            other == 0) {
                                sci_phy_consume_power_handler(iphy);
                                break;
                        }
                }

                if (i == SCI_MAX_PHYS) {
                        /* Add the phy in the waiting list */
                        ihost->power_control.requesters[iphy->phy_index] = iphy;
                        ihost->power_control.phys_waiting++;
                }
        }
}

void sci_controller_power_control_queue_remove(struct isci_host *ihost,
                                               struct isci_phy *iphy)
{
        BUG_ON(iphy == NULL);

        if (ihost->power_control.requesters[iphy->phy_index])
                ihost->power_control.phys_waiting--;

        ihost->power_control.requesters[iphy->phy_index] = NULL;
}

static int is_long_cable(int phy, unsigned char selection_byte)
{
        return !!(selection_byte & (1 << phy));
}

static int is_medium_cable(int phy, unsigned char selection_byte)
{
        return !!(selection_byte & (1 << (phy + 4)));
}

static enum cable_selections decode_selection_byte(
        int phy,
        unsigned char selection_byte)
{
        return ((selection_byte & (1 << phy)) ? 1 : 0)
                + (selection_byte & (1 << (phy + 4)) ? 2 : 0);
}

static unsigned char *to_cable_select(struct isci_host *ihost)
{
        if (is_cable_select_overridden())
                return ((unsigned char *)&cable_selection_override)
                        + ihost->id;
        else
                return &ihost->oem_parameters.controller.cable_selection_mask;
}

enum cable_selections decode_cable_selection(struct isci_host *ihost, int phy)
{
        return decode_selection_byte(phy, *to_cable_select(ihost));
}

char *lookup_cable_names(enum cable_selections selection)
{
        static char *cable_names[] = {
                [short_cable]     = "short",
                [long_cable]      = "long",
                [medium_cable]    = "medium",
                [undefined_cable] = "<undefined, assumed long>" /* bit 0==1 */
        };
        return (selection <= undefined_cable) ? cable_names[selection]
                                              : cable_names[undefined_cable];
}

#define AFE_REGISTER_WRITE_DELAY 10

static void sci_controller_afe_initialization(struct isci_host *ihost)
{
        struct scu_afe_registers __iomem *afe = &ihost->scu_registers->afe;
        const struct sci_oem_params *oem = &ihost->oem_parameters;
        struct pci_dev *pdev = ihost->pdev;
        u32 afe_status;
        u32 phy_id;
        unsigned char cable_selection_mask = *to_cable_select(ihost);

        /* Clear DFX Status registers */
        writel(0x0081000f, &afe->afe_dfx_master_control0);
        udelay(AFE_REGISTER_WRITE_DELAY);

        if (is_b0(pdev) || is_c0(pdev) || is_c1(pdev)) {
                /* PM Rx Equalization Save, PM SPhy Rx Acknowledgement
                 * Timer, PM Stagger Timer
                 */
                writel(0x0007FFFF, &afe->afe_pmsn_master_control2);
                udelay(AFE_REGISTER_WRITE_DELAY);
        }

        /* Configure bias currents to normal */
        if (is_a2(pdev))
                writel(0x00005A00, &afe->afe_bias_control);
        else if (is_b0(pdev) || is_c0(pdev))
                writel(0x00005F00, &afe->afe_bias_control);
        else if (is_c1(pdev))
                writel(0x00005500, &afe->afe_bias_control);

        udelay(AFE_REGISTER_WRITE_DELAY);

        /* Enable PLL */
        if (is_a2(pdev))
                writel(0x80040908, &afe->afe_pll_control0);
        else if (is_b0(pdev) || is_c0(pdev))
                writel(0x80040A08, &afe->afe_pll_control0);
        else if (is_c1(pdev)) {
                writel(0x80000B08, &afe->afe_pll_control0);
                udelay(AFE_REGISTER_WRITE_DELAY);
                writel(0x00000B08, &afe->afe_pll_control0);
                udelay(AFE_REGISTER_WRITE_DELAY);
                writel(0x80000B08, &afe->afe_pll_control0);
        }

        udelay(AFE_REGISTER_WRITE_DELAY);

        /* Wait for the PLL to lock */
        do {
                afe_status = readl(&afe->afe_common_block_status);
                udelay(AFE_REGISTER_WRITE_DELAY);
        } while ((afe_status & 0x00001000) == 0);

        if (is_a2(pdev)) {
                /* Shorten SAS SNW lock time (RxLock timer value from 76
                 * us to 50 us)
                 */
                writel(0x7bcc96ad, &afe->afe_pmsn_master_control0);
                udelay(AFE_REGISTER_WRITE_DELAY);
        }

        for (phy_id = 0; phy_id < SCI_MAX_PHYS; phy_id++) {
                struct scu_afe_transceiver __iomem *xcvr = &afe->scu_afe_xcvr[phy_id];
                const struct sci_phy_oem_params *oem_phy = &oem->phys[phy_id];
                int cable_length_long =
                        is_long_cable(phy_id, cable_selection_mask);
                int cable_length_medium =
                        is_medium_cable(phy_id, cable_selection_mask);

                if (is_a2(pdev)) {
                        /* All defaults, except the Receive Word
                         * Alignament/Comma Detect Enable....(0xe800)
                         */
                        writel(0x00004512, &xcvr->afe_xcvr_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(0x0050100F, &xcvr->afe_xcvr_control1);
                        udelay(AFE_REGISTER_WRITE_DELAY);
                } else if (is_b0(pdev)) {
                        /* Configure transmitter SSC parameters */
                        writel(0x00030000, &xcvr->afe_tx_ssc_control);

                        udelay(AFE_REGISTER_WRITE_DELAY);
                } else if (is_c0(pdev)) {
                        /* Configure transmitter SSC parameters */
                        writel(0x00010202, &xcvr->afe_tx_ssc_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        /* All defaults, except the Receive Word
                         * Alignament/Comma Detect Enable....(0xe800)
                         */
                        writel(0x00014500, &xcvr->afe_xcvr_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);
                } else if (is_c1(pdev)) {
                        /* Configure transmitter SSC parameters */
                        writel(0x00010202, &xcvr->afe_tx_ssc_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        /* All defaults, except the Receive Word
                         * Alignament/Comma Detect Enable....(0xe800)
                         */
                        writel(0x0001C500, &xcvr->afe_xcvr_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);
                }

                /* Power up TX and RX out from power down (PWRDNTX and
                 * PWRDNRX) & increase TX int & ext bias 20%....(0xe85c)
                 */
                if (is_a2(pdev))
                        writel(0x000003F0, &xcvr->afe_channel_control);
                else if (is_b0(pdev)) {
                        writel(0x000003D7, &xcvr->afe_channel_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(0x000003D4, &xcvr->afe_channel_control);
                } else if (is_c0(pdev)) {
                        writel(0x000001E7, &xcvr->afe_channel_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(0x000001E4, &xcvr->afe_channel_control);
                } else if (is_c1(pdev)) {
                        writel(cable_length_long ? 0x000002F7 : 0x000001F7,
                               &xcvr->afe_channel_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(cable_length_long ? 0x000002F4 : 0x000001F4,
                               &xcvr->afe_channel_control);
                }
                udelay(AFE_REGISTER_WRITE_DELAY);

                if (is_a2(pdev)) {
                        /* Enable TX equalization (0xe824) */
                        writel(0x00040000, &xcvr->afe_tx_control);
                        udelay(AFE_REGISTER_WRITE_DELAY);
                }

                if (is_a2(pdev) || is_b0(pdev))
                        /* RDPI=0x0(RX Power On), RXOOBDETPDNC=0x0,
                         * TPD=0x0(TX Power On), RDD=0x0(RX Detect
                         * Enabled) ....(0xe800)
                         */
                        writel(0x00004100, &xcvr->afe_xcvr_control0);
                else if (is_c0(pdev))
                        writel(0x00014100, &xcvr->afe_xcvr_control0);
                else if (is_c1(pdev))
                        writel(0x0001C100, &xcvr->afe_xcvr_control0);
                udelay(AFE_REGISTER_WRITE_DELAY);

                /* Leave DFE/FFE on */
                if (is_a2(pdev))
                        writel(0x3F11103F, &xcvr->afe_rx_ssc_control0);
                else if (is_b0(pdev)) {
                        writel(0x3F11103F, &xcvr->afe_rx_ssc_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);
                        /* Enable TX equalization (0xe824) */
                        writel(0x00040000, &xcvr->afe_tx_control);
                } else if (is_c0(pdev)) {
                        writel(0x01400C0F, &xcvr->afe_rx_ssc_control1);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(0x3F6F103F, &xcvr->afe_rx_ssc_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        /* Enable TX equalization (0xe824) */
                        writel(0x00040000, &xcvr->afe_tx_control);
                } else if (is_c1(pdev)) {
                        writel(cable_length_long ? 0x01500C0C :
                               cable_length_medium ? 0x01400C0D : 0x02400C0D,
                               &xcvr->afe_xcvr_control1);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(0x000003E0, &xcvr->afe_dfx_rx_control1);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        writel(cable_length_long ? 0x33091C1F :
                               cable_length_medium ? 0x3315181F : 0x2B17161F,
                               &xcvr->afe_rx_ssc_control0);
                        udelay(AFE_REGISTER_WRITE_DELAY);

                        /* Enable TX equalization (0xe824) */
                        writel(0x00040000, &xcvr->afe_tx_control);
                }

                udelay(AFE_REGISTER_WRITE_DELAY);

                writel(oem_phy->afe_tx_amp_control0, &xcvr->afe_tx_amp_control0);
                udelay(AFE_REGISTER_WRITE_DELAY);

                writel(oem_phy->afe_tx_amp_control1, &xcvr->afe_tx_amp_control1);
                udelay(AFE_REGISTER_WRITE_DELAY);

                writel(oem_phy->afe_tx_amp_control2, &xcvr->afe_tx_amp_control2);
                udelay(AFE_REGISTER_WRITE_DELAY);

                writel(oem_phy->afe_tx_amp_control3, &xcvr->afe_tx_amp_control3);
                udelay(AFE_REGISTER_WRITE_DELAY);
        }

        /* Transfer control to the PEs */
        writel(0x00010f00, &afe->afe_dfx_master_control0);
        udelay(AFE_REGISTER_WRITE_DELAY);
}

static void sci_controller_initialize_power_control(struct isci_host *ihost)
{
        sci_init_timer(&ihost->power_control.timer, power_control_timeout);

        memset(ihost->power_control.requesters, 0,
               sizeof(ihost->power_control.requesters));

        ihost->power_control.phys_waiting = 0;
        ihost->power_control.phys_granted_power = 0;
}

static enum sci_status sci_controller_initialize(struct isci_host *ihost)
{
        struct sci_base_state_machine *sm = &ihost->sm;
        enum sci_status result = SCI_FAILURE;
        unsigned long i, state, val;

        if (ihost->sm.current_state_id != SCIC_RESET) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

        sci_change_state(sm, SCIC_INITIALIZING);

        sci_init_timer(&ihost->phy_timer, phy_startup_timeout);

        ihost->next_phy_to_start = 0;
        ihost->phy_startup_timer_pending = false;

        sci_controller_initialize_power_control(ihost);

        /*
         * There is nothing to do here for B0 since we do not have to
         * program the AFE registers.
         * / @todo The AFE settings are supposed to be correct for the B0 but
         * /       presently they seem to be wrong. */
        sci_controller_afe_initialization(ihost);


        /* Take the hardware out of reset */
        writel(0, &ihost->smu_registers->soft_reset_control);

        /*
         * / @todo Provide meaningfull error code for hardware failure
         * result = SCI_FAILURE_CONTROLLER_HARDWARE; */
        for (i = 100; i >= 1; i--) {
                u32 status;

                /* Loop until the hardware reports success */
                udelay(SCU_CONTEXT_RAM_INIT_STALL_TIME);
                status = readl(&ihost->smu_registers->control_status);

                if ((status & SCU_RAM_INIT_COMPLETED) == SCU_RAM_INIT_COMPLETED)
                        break;
        }
        if (i == 0)
                goto out;

        /*
         * Determine what are the actaul device capacities that the
         * hardware will support */
        val = readl(&ihost->smu_registers->device_context_capacity);

        /* Record the smaller of the two capacity values */
        ihost->logical_port_entries = min(smu_max_ports(val), SCI_MAX_PORTS);
        ihost->task_context_entries = min(smu_max_task_contexts(val), SCI_MAX_IO_REQUESTS);
        ihost->remote_node_entries = min(smu_max_rncs(val), SCI_MAX_REMOTE_DEVICES);

        /*
         * Make all PEs that are unassigned match up with the
         * logical ports
         */
        for (i = 0; i < ihost->logical_port_entries; i++) {
                struct scu_port_task_scheduler_group_registers __iomem
                        *ptsg = &ihost->scu_registers->peg0.ptsg;

                writel(i, &ptsg->protocol_engine[i]);
        }

        /* Initialize hardware PCI Relaxed ordering in DMA engines */
        val = readl(&ihost->scu_registers->sdma.pdma_configuration);
        val |= SCU_PDMACR_GEN_BIT(PCI_RELAXED_ORDERING_ENABLE);
        writel(val, &ihost->scu_registers->sdma.pdma_configuration);

        val = readl(&ihost->scu_registers->sdma.cdma_configuration);
        val |= SCU_CDMACR_GEN_BIT(PCI_RELAXED_ORDERING_ENABLE);
        writel(val, &ihost->scu_registers->sdma.cdma_configuration);

        /*
         * Initialize the PHYs before the PORTs because the PHY registers
         * are accessed during the port initialization.
         */
        for (i = 0; i < SCI_MAX_PHYS; i++) {
                result = sci_phy_initialize(&ihost->phys[i],
                                            &ihost->scu_registers->peg0.pe[i].tl,
                                            &ihost->scu_registers->peg0.pe[i].ll);
                if (result != SCI_SUCCESS)
                        goto out;
        }

        for (i = 0; i < ihost->logical_port_entries; i++) {
                struct isci_port *iport = &ihost->ports[i];

                iport->port_task_scheduler_registers = &ihost->scu_registers->peg0.ptsg.port[i];
                iport->port_pe_configuration_register = &ihost->scu_registers->peg0.ptsg.protocol_engine[0];
                iport->viit_registers = &ihost->scu_registers->peg0.viit[i];
        }

        result = sci_port_configuration_agent_initialize(ihost, &ihost->port_agent);

 out:
        /* Advance the controller state machine */
        if (result == SCI_SUCCESS)
                state = SCIC_INITIALIZED;
        else
                state = SCIC_FAILED;
        sci_change_state(sm, state);

        return result;
}

static int sci_controller_dma_alloc(struct isci_host *ihost)
{
        struct device *dev = &ihost->pdev->dev;
        size_t size;
        int i;

        /* detect re-initialization */
        if (ihost->completion_queue)
                return 0;

        size = SCU_MAX_COMPLETION_QUEUE_ENTRIES * sizeof(u32);
        ihost->completion_queue = dmam_alloc_coherent(dev, size, &ihost->cq_dma,
                                                      GFP_KERNEL);
        if (!ihost->completion_queue)
                return -ENOMEM;

        size = ihost->remote_node_entries * sizeof(union scu_remote_node_context);
        ihost->remote_node_context_table = dmam_alloc_coherent(dev, size, &ihost->rnc_dma,
                                                               GFP_KERNEL);

        if (!ihost->remote_node_context_table)
                return -ENOMEM;

        size = ihost->task_context_entries * sizeof(struct scu_task_context),
        ihost->task_context_table = dmam_alloc_coherent(dev, size, &ihost->tc_dma,
                                                        GFP_KERNEL);
        if (!ihost->task_context_table)
                return -ENOMEM;

        size = SCI_UFI_TOTAL_SIZE;
        ihost->ufi_buf = dmam_alloc_coherent(dev, size, &ihost->ufi_dma, GFP_KERNEL);
        if (!ihost->ufi_buf)
                return -ENOMEM;

        for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
                struct isci_request *ireq;
                dma_addr_t dma;

                ireq = dmam_alloc_coherent(dev, sizeof(*ireq), &dma, GFP_KERNEL);
                if (!ireq)
                        return -ENOMEM;

                ireq->tc = &ihost->task_context_table[i];
                ireq->owning_controller = ihost;
                ireq->request_daddr = dma;
                ireq->isci_host = ihost;
                ihost->reqs[i] = ireq;
        }

        return 0;
}

static int sci_controller_mem_init(struct isci_host *ihost)
{
        int err = sci_controller_dma_alloc(ihost);

        if (err)
                return err;

        writel(lower_32_bits(ihost->cq_dma), &ihost->smu_registers->completion_queue_lower);
        writel(upper_32_bits(ihost->cq_dma), &ihost->smu_registers->completion_queue_upper);

        writel(lower_32_bits(ihost->rnc_dma), &ihost->smu_registers->remote_node_context_lower);
        writel(upper_32_bits(ihost->rnc_dma), &ihost->smu_registers->remote_node_context_upper);

        writel(lower_32_bits(ihost->tc_dma), &ihost->smu_registers->host_task_table_lower);
        writel(upper_32_bits(ihost->tc_dma), &ihost->smu_registers->host_task_table_upper);

        sci_unsolicited_frame_control_construct(ihost);

        /*
         * Inform the silicon as to the location of the UF headers and
         * address table.
         */
        writel(lower_32_bits(ihost->uf_control.headers.physical_address),
                &ihost->scu_registers->sdma.uf_header_base_address_lower);
        writel(upper_32_bits(ihost->uf_control.headers.physical_address),
                &ihost->scu_registers->sdma.uf_header_base_address_upper);

        writel(lower_32_bits(ihost->uf_control.address_table.physical_address),
                &ihost->scu_registers->sdma.uf_address_table_lower);
        writel(upper_32_bits(ihost->uf_control.address_table.physical_address),
                &ihost->scu_registers->sdma.uf_address_table_upper);

        return 0;
}

/**
 * isci_host_init - (re-)initialize hardware and internal (private) state
 * @ihost: host to init
 *
 * Any public facing objects (like asd_sas_port, and asd_sas_phys), or
 * one-time initialization objects like locks and waitqueues, are
 * not touched (they are initialized in isci_host_alloc)
 */
int isci_host_init(struct isci_host *ihost)
{
        int i, err;
        enum sci_status status;

        spin_lock_irq(&ihost->scic_lock);
        status = sci_controller_construct(ihost, scu_base(ihost), smu_base(ihost));
        spin_unlock_irq(&ihost->scic_lock);
        if (status != SCI_SUCCESS) {
                dev_err(&ihost->pdev->dev,
                        "%s: sci_controller_construct failed - status = %x\n",
                        __func__,
                        status);
                return -ENODEV;
        }

        spin_lock_irq(&ihost->scic_lock);
        status = sci_controller_initialize(ihost);
        spin_unlock_irq(&ihost->scic_lock);
        if (status != SCI_SUCCESS) {
                dev_warn(&ihost->pdev->dev,
                         "%s: sci_controller_initialize failed -"
                         " status = 0x%x\n",
                         __func__, status);
                return -ENODEV;
        }

        err = sci_controller_mem_init(ihost);
        if (err)
                return err;

        /* enable sgpio */
        writel(1, &ihost->scu_registers->peg0.sgpio.interface_control);
        for (i = 0; i < isci_gpio_count(ihost); i++)
                writel(SGPIO_HW_CONTROL, &ihost->scu_registers->peg0.sgpio.output_data_select[i]);
        writel(0, &ihost->scu_registers->peg0.sgpio.vendor_specific_code);

        return 0;
}

void sci_controller_link_up(struct isci_host *ihost, struct isci_port *iport,
                            struct isci_phy *iphy)
{
        switch (ihost->sm.current_state_id) {
        case SCIC_STARTING:
                sci_del_timer(&ihost->phy_timer);
                ihost->phy_startup_timer_pending = false;
                ihost->port_agent.link_up_handler(ihost, &ihost->port_agent,
                                                  iport, iphy);
                sci_controller_start_next_phy(ihost);
                break;
        case SCIC_READY:
                ihost->port_agent.link_up_handler(ihost, &ihost->port_agent,
                                                  iport, iphy);
                break;
        default:
                dev_dbg(&ihost->pdev->dev,
                        "%s: SCIC Controller linkup event from phy %d in "
                        "unexpected state %d\n", __func__, iphy->phy_index,
                        ihost->sm.current_state_id);
        }
}

void sci_controller_link_down(struct isci_host *ihost, struct isci_port *iport,
                              struct isci_phy *iphy)
{
        switch (ihost->sm.current_state_id) {
        case SCIC_STARTING:
        case SCIC_READY:
                ihost->port_agent.link_down_handler(ihost, &ihost->port_agent,
                                                   iport, iphy);
                break;
        default:
                dev_dbg(&ihost->pdev->dev,
                        "%s: SCIC Controller linkdown event from phy %d in "
                        "unexpected state %d\n",
                        __func__,
                        iphy->phy_index,
                        ihost->sm.current_state_id);
        }
}

bool sci_controller_has_remote_devices_stopping(struct isci_host *ihost)
{
        u32 index;

        for (index = 0; index < ihost->remote_node_entries; index++) {
                if ((ihost->device_table[index] != NULL) &&
                   (ihost->device_table[index]->sm.current_state_id == SCI_DEV_STOPPING))
                        return true;
        }

        return false;
}

void sci_controller_remote_device_stopped(struct isci_host *ihost,
                                          struct isci_remote_device *idev)
{
        if (ihost->sm.current_state_id != SCIC_STOPPING) {
                dev_dbg(&ihost->pdev->dev,
                        "SCIC Controller 0x%p remote device stopped event "
                        "from device 0x%p in unexpected state %d\n",
                        ihost, idev,
                        ihost->sm.current_state_id);
                return;
        }

        if (!sci_controller_has_remote_devices_stopping(ihost))
                isci_host_stop_complete(ihost);
}

void sci_controller_post_request(struct isci_host *ihost, u32 request)
{
        dev_dbg(&ihost->pdev->dev, "%s[%d]: %#x\n",
                __func__, ihost->id, request);

        writel(request, &ihost->smu_registers->post_context_port);
}

struct isci_request *sci_request_by_tag(struct isci_host *ihost, u16 io_tag)
{
        u16 task_index;
        u16 task_sequence;

        task_index = ISCI_TAG_TCI(io_tag);

        if (task_index < ihost->task_context_entries) {
                struct isci_request *ireq = ihost->reqs[task_index];

                if (test_bit(IREQ_ACTIVE, &ireq->flags)) {
                        task_sequence = ISCI_TAG_SEQ(io_tag);

                        if (task_sequence == ihost->io_request_sequence[task_index])
                                return ireq;
                }
        }

        return NULL;
}

/**
 * sci_controller_allocate_remote_node_context()
 * This method allocates remote node index and the reserves the remote node
 *    context space for use. This method can fail if there are no more remote
 *    node index available.
 * @ihost: This is the controller object which contains the set of
 *    free remote node ids
 * @idev: This is the device object which is requesting the a remote node
 *    id
 * @node_id: This is the remote node id that is assinged to the device if one
 *    is available
 *
 * enum sci_status SCI_FAILURE_OUT_OF_RESOURCES if there are no available remote
 * node index available.
 */
enum sci_status sci_controller_allocate_remote_node_context(struct isci_host *ihost,
                                                            struct isci_remote_device *idev,
                                                            u16 *node_id)
{
        u16 node_index;
        u32 remote_node_count = sci_remote_device_node_count(idev);

        node_index = sci_remote_node_table_allocate_remote_node(
                &ihost->available_remote_nodes, remote_node_count
                );

        if (node_index != SCIC_SDS_REMOTE_NODE_CONTEXT_INVALID_INDEX) {
                ihost->device_table[node_index] = idev;

                *node_id = node_index;

                return SCI_SUCCESS;
        }

        return SCI_FAILURE_INSUFFICIENT_RESOURCES;
}

void sci_controller_free_remote_node_context(struct isci_host *ihost,
                                             struct isci_remote_device *idev,
                                             u16 node_id)
{
        u32 remote_node_count = sci_remote_device_node_count(idev);

        if (ihost->device_table[node_id] == idev) {
                ihost->device_table[node_id] = NULL;

                sci_remote_node_table_release_remote_node_index(
                        &ihost->available_remote_nodes, remote_node_count, node_id
                        );
        }
}

void sci_controller_copy_sata_response(void *response_buffer,
                                       void *frame_header,
                                       void *frame_buffer)
{
        /* XXX type safety? */
        memcpy(response_buffer, frame_header, sizeof(u32));

        memcpy(response_buffer + sizeof(u32),
               frame_buffer,
               sizeof(struct dev_to_host_fis) - sizeof(u32));
}

void sci_controller_release_frame(struct isci_host *ihost, u32 frame_index)
{
        if (sci_unsolicited_frame_control_release_frame(&ihost->uf_control, frame_index))
                writel(ihost->uf_control.get,
                        &ihost->scu_registers->sdma.unsolicited_frame_get_pointer);
}

void isci_tci_free(struct isci_host *ihost, u16 tci)
{
        u16 tail = ihost->tci_tail & (SCI_MAX_IO_REQUESTS-1);

        ihost->tci_pool[tail] = tci;
        ihost->tci_tail = tail + 1;
}

static u16 isci_tci_alloc(struct isci_host *ihost)
{
        u16 head = ihost->tci_head & (SCI_MAX_IO_REQUESTS-1);
        u16 tci = ihost->tci_pool[head];

        ihost->tci_head = head + 1;
        return tci;
}

static u16 isci_tci_space(struct isci_host *ihost)
{
        return CIRC_SPACE(ihost->tci_head, ihost->tci_tail, SCI_MAX_IO_REQUESTS);
}

u16 isci_alloc_tag(struct isci_host *ihost)
{
        if (isci_tci_space(ihost)) {
                u16 tci = isci_tci_alloc(ihost);
                u8 seq = ihost->io_request_sequence[tci];

                return ISCI_TAG(seq, tci);
        }

        return SCI_CONTROLLER_INVALID_IO_TAG;
}

enum sci_status isci_free_tag(struct isci_host *ihost, u16 io_tag)
{
        u16 tci = ISCI_TAG_TCI(io_tag);
        u16 seq = ISCI_TAG_SEQ(io_tag);

        /* prevent tail from passing head */
        if (isci_tci_active(ihost) == 0)
                return SCI_FAILURE_INVALID_IO_TAG;

        if (seq == ihost->io_request_sequence[tci]) {
                ihost->io_request_sequence[tci] = (seq+1) & (SCI_MAX_SEQ-1);

                isci_tci_free(ihost, tci);

                return SCI_SUCCESS;
        }
        return SCI_FAILURE_INVALID_IO_TAG;
}

enum sci_status sci_controller_start_io(struct isci_host *ihost,
                                        struct isci_remote_device *idev,
                                        struct isci_request *ireq)
{
        enum sci_status status;

        if (ihost->sm.current_state_id != SCIC_READY) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

        status = sci_remote_device_start_io(ihost, idev, ireq);
        if (status != SCI_SUCCESS)
                return status;

        set_bit(IREQ_ACTIVE, &ireq->flags);
        sci_controller_post_request(ihost, ireq->post_context);
        return SCI_SUCCESS;
}

enum sci_status sci_controller_terminate_request(struct isci_host *ihost,
                                                 struct isci_remote_device *idev,
                                                 struct isci_request *ireq)
{
        /* terminate an ongoing (i.e. started) core IO request.  This does not
         * abort the IO request at the target, but rather removes the IO
         * request from the host controller.
         */
        enum sci_status status;

        if (ihost->sm.current_state_id != SCIC_READY) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }
        status = sci_io_request_terminate(ireq);

        dev_dbg(&ihost->pdev->dev, "%s: status=%d; ireq=%p; flags=%lx\n",
                __func__, status, ireq, ireq->flags);

        if ((status == SCI_SUCCESS) &&
            !test_bit(IREQ_PENDING_ABORT, &ireq->flags) &&
            !test_and_set_bit(IREQ_TC_ABORT_POSTED, &ireq->flags)) {
                /* Utilize the original post context command and or in the
                 * POST_TC_ABORT request sub-type.
                 */
                sci_controller_post_request(
                        ihost, ireq->post_context |
                                SCU_CONTEXT_COMMAND_REQUEST_POST_TC_ABORT);
        }
        return status;
}

/**
 * sci_controller_complete_io() - This method will perform core specific
 *    completion operations for an IO request.  After this method is invoked,
 *    the user should consider the IO request as invalid until it is properly
 *    reused (i.e. re-constructed).
 * @ihost: The handle to the controller object for which to complete the
 *    IO request.
 * @idev: The handle to the remote device object for which to complete
 *    the IO request.
 * @ireq: the handle to the io request object to complete.
 */
enum sci_status sci_controller_complete_io(struct isci_host *ihost,
                                           struct isci_remote_device *idev,
                                           struct isci_request *ireq)
{
        enum sci_status status;

        switch (ihost->sm.current_state_id) {
        case SCIC_STOPPING:
                /* XXX: Implement this function */
                return SCI_FAILURE;
        case SCIC_READY:
                status = sci_remote_device_complete_io(ihost, idev, ireq);
                if (status != SCI_SUCCESS)
                        return status;

                clear_bit(IREQ_ACTIVE, &ireq->flags);
                return SCI_SUCCESS;
        default:
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

}

enum sci_status sci_controller_continue_io(struct isci_request *ireq)
{
        struct isci_host *ihost = ireq->owning_controller;

        if (ihost->sm.current_state_id != SCIC_READY) {
                dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
                         __func__, ihost->sm.current_state_id);
                return SCI_FAILURE_INVALID_STATE;
        }

        set_bit(IREQ_ACTIVE, &ireq->flags);
        sci_controller_post_request(ihost, ireq->post_context);
        return SCI_SUCCESS;
}

/**
 * sci_controller_start_task() - This method is called by the SCIC user to
 *    send/start a framework task management request.
 * @ihost: the handle to the controller object for which to start the task
 *    management request.
 * @idev: the handle to the remote device object for which to start
 *    the task management request.
 * @ireq: the handle to the task request object to start.
 */
enum sci_status sci_controller_start_task(struct isci_host *ihost,
                                          struct isci_remote_device *idev,
                                          struct isci_request *ireq)
{
        enum sci_status status;

        if (ihost->sm.current_state_id != SCIC_READY) {
                dev_warn(&ihost->pdev->dev,
                         "%s: SCIC Controller starting task from invalid "
                         "state\n",
                         __func__);
                return SCI_FAILURE_INVALID_STATE;
        }

        status = sci_remote_device_start_task(ihost, idev, ireq);
        switch (status) {
        case SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS:
                set_bit(IREQ_ACTIVE, &ireq->flags);

                /*
                 * We will let framework know this task request started successfully,
                 * although core is still woring on starting the request (to post tc when
                 * RNC is resumed.)
                 */
                return SCI_SUCCESS;
        case SCI_SUCCESS:
                set_bit(IREQ_ACTIVE, &ireq->flags);
                sci_controller_post_request(ihost, ireq->post_context);
                break;
        default:
                break;
        }

        return status;
}

static int sci_write_gpio_tx_gp(struct isci_host *ihost, u8 reg_index, u8 reg_count, u8 *write_data)
{
        int d;

        /* no support for TX_GP_CFG */
        if (reg_index == 0)
                return -EINVAL;

        for (d = 0; d < isci_gpio_count(ihost); d++) {
                u32 val = 0x444; /* all ODx.n clear */
                int i;

                for (i = 0; i < 3; i++) {
                        int bit;

                        bit = try_test_sas_gpio_gp_bit(to_sas_gpio_od(d, i),
                                                       write_data, reg_index,
                                                       reg_count);
                        if (bit < 0)
                                break;

                        /* if od is set, clear the 'invert' bit */
                        val &= ~(bit << ((i << 2) + 2));
                }

                if (i < 3)
                        break;
                writel(val, &ihost->scu_registers->peg0.sgpio.output_data_select[d]);
        }

        /* unless reg_index is > 1, we should always be able to write at
         * least one register
         */
        return d > 0;
}

int isci_gpio_write(struct sas_ha_struct *sas_ha, u8 reg_type, u8 reg_index,
                    u8 reg_count, u8 *write_data)
{
        struct isci_host *ihost = sas_ha->lldd_ha;
        int written;

        switch (reg_type) {
        case SAS_GPIO_REG_TX_GP:
                written = sci_write_gpio_tx_gp(ihost, reg_index, reg_count, write_data);
                break;
        default:
                written = -EINVAL;
        }

        return written;
}