/*
 * Universal Flash Storage Host controller driver Core
 *
 * This code is based on drivers/scsi/ufs/ufshcd.c
 * Copyright (C) 2011-2013 Samsung India Software Operations
 *
 * Authors:
 *      Santosh Yaraganavi <santosh.sy@samsung.com>
 *      Vinayak Holikatti <h.vinayak@samsung.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * See the COPYING file in the top-level directory or visit
 * <http://www.gnu.org/licenses/gpl-2.0.html>
 *
 * 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.
 *
 * This program is provided "AS IS" and "WITH ALL FAULTS" and
 * without warranty of any kind. You are solely responsible for
 * determining the appropriateness of using and distributing
 * the program and assume all risks associated with your exercise
 * of rights with respect to the program, including but not limited
 * to infringement of third party rights, the risks and costs of
 * program errors, damage to or loss of data, programs or equipment,
 * and unavailability or interruption of operations. Under no
 * circumstances will the contributor of this Program be liable for
 * any damages of any kind arising from your use or distribution of
 * this program.
 */

#include "ufshcd.h"

enum {
        UFSHCD_MAX_CHANNEL      = 0,
        UFSHCD_MAX_ID           = 1,
        UFSHCD_MAX_LUNS         = 8,
        UFSHCD_CMD_PER_LUN      = 32,
        UFSHCD_CAN_QUEUE        = 32,
};

/* UFSHCD states */
enum {
        UFSHCD_STATE_OPERATIONAL,
        UFSHCD_STATE_RESET,
        UFSHCD_STATE_ERROR,
};

/* Interrupt configuration options */
enum {
        UFSHCD_INT_DISABLE,
        UFSHCD_INT_ENABLE,
        UFSHCD_INT_CLEAR,
};

/* Interrupt aggregation options */
enum {
        INT_AGGR_RESET,
        INT_AGGR_CONFIG,
};

/**
 * ufshcd_get_ufs_version - Get the UFS version supported by the HBA
 * @hba - Pointer to adapter instance
 *
 * Returns UFSHCI version supported by the controller
 */
static inline u32 ufshcd_get_ufs_version(struct ufs_hba *hba)
{
        return readl(hba->mmio_base + REG_UFS_VERSION);
}

/**
 * ufshcd_is_device_present - Check if any device connected to
 *                            the host controller
 * @reg_hcs - host controller status register value
 *
 * Returns 1 if device present, 0 if no device detected
 */
static inline int ufshcd_is_device_present(u32 reg_hcs)
{
        return (DEVICE_PRESENT & reg_hcs) ? 1 : 0;
}

/**
 * ufshcd_get_tr_ocs - Get the UTRD Overall Command Status
 * @lrb: pointer to local command reference block
 *
 * This function is used to get the OCS field from UTRD
 * Returns the OCS field in the UTRD
 */
static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
{
        return lrbp->utr_descriptor_ptr->header.dword_2 & MASK_OCS;
}

/**
 * ufshcd_get_tmr_ocs - Get the UTMRD Overall Command Status
 * @task_req_descp: pointer to utp_task_req_desc structure
 *
 * This function is used to get the OCS field from UTMRD
 * Returns the OCS field in the UTMRD
 */
static inline int
ufshcd_get_tmr_ocs(struct utp_task_req_desc *task_req_descp)
{
        return task_req_descp->header.dword_2 & MASK_OCS;
}

/**
 * ufshcd_get_tm_free_slot - get a free slot for task management request
 * @hba: per adapter instance
 *
 * Returns maximum number of task management request slots in case of
 * task management queue full or returns the free slot number
 */
static inline int ufshcd_get_tm_free_slot(struct ufs_hba *hba)
{
        return find_first_zero_bit(&hba->outstanding_tasks, hba->nutmrs);
}

/**
 * ufshcd_utrl_clear - Clear a bit in UTRLCLR register
 * @hba: per adapter instance
 * @pos: position of the bit to be cleared
 */
static inline void ufshcd_utrl_clear(struct ufs_hba *hba, u32 pos)
{
        writel(~(1 << pos),
                (hba->mmio_base + REG_UTP_TRANSFER_REQ_LIST_CLEAR));
}

/**
 * ufshcd_get_lists_status - Check UCRDY, UTRLRDY and UTMRLRDY
 * @reg: Register value of host controller status
 *
 * Returns integer, 0 on Success and positive value if failed
 */
static inline int ufshcd_get_lists_status(u32 reg)
{
        /*
         * The mask 0xFF is for the following HCS register bits
         * Bit          Description
         *  0           Device Present
         *  1           UTRLRDY
         *  2           UTMRLRDY
         *  3           UCRDY
         *  4           HEI
         *  5           DEI
         * 6-7          reserved
         */
        return (((reg) & (0xFF)) >> 1) ^ (0x07);
}

/**
 * ufshcd_get_uic_cmd_result - Get the UIC command result
 * @hba: Pointer to adapter instance
 *
 * This function gets the result of UIC command completion
 * Returns 0 on success, non zero value on error
 */
static inline int ufshcd_get_uic_cmd_result(struct ufs_hba *hba)
{
        return readl(hba->mmio_base + REG_UIC_COMMAND_ARG_2) &
               MASK_UIC_COMMAND_RESULT;
}

/**
 * ufshcd_free_hba_memory - Free allocated memory for LRB, request
 *                          and task lists
 * @hba: Pointer to adapter instance
 */
static inline void ufshcd_free_hba_memory(struct ufs_hba *hba)
{
        size_t utmrdl_size, utrdl_size, ucdl_size;

        kfree(hba->lrb);

        if (hba->utmrdl_base_addr) {
                utmrdl_size = sizeof(struct utp_task_req_desc) * hba->nutmrs;
                dma_free_coherent(hba->dev, utmrdl_size,
                                  hba->utmrdl_base_addr, hba->utmrdl_dma_addr);
        }

        if (hba->utrdl_base_addr) {
                utrdl_size =
                (sizeof(struct utp_transfer_req_desc) * hba->nutrs);
                dma_free_coherent(hba->dev, utrdl_size,
                                  hba->utrdl_base_addr, hba->utrdl_dma_addr);
        }

        if (hba->ucdl_base_addr) {
                ucdl_size =
                (sizeof(struct utp_transfer_cmd_desc) * hba->nutrs);
                dma_free_coherent(hba->dev, ucdl_size,
                                  hba->ucdl_base_addr, hba->ucdl_dma_addr);
        }
}

/**
 * ufshcd_is_valid_req_rsp - checks if controller TR response is valid
 * @ucd_rsp_ptr: pointer to response UPIU
 *
 * This function checks the response UPIU for valid transaction type in
 * response field
 * Returns 0 on success, non-zero on failure
 */
static inline int
ufshcd_is_valid_req_rsp(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return ((be32_to_cpu(ucd_rsp_ptr->header.dword_0) >> 24) ==
                 UPIU_TRANSACTION_RESPONSE) ? 0 : DID_ERROR << 16;
}

/**
 * ufshcd_get_rsp_upiu_result - Get the result from response UPIU
 * @ucd_rsp_ptr: pointer to response UPIU
 *
 * This function gets the response status and scsi_status from response UPIU
 * Returns the response result code.
 */
static inline int
ufshcd_get_rsp_upiu_result(struct utp_upiu_rsp *ucd_rsp_ptr)
{
        return be32_to_cpu(ucd_rsp_ptr->header.dword_1) & MASK_RSP_UPIU_RESULT;
}

/**
 * ufshcd_config_int_aggr - Configure interrupt aggregation values.
 *              Currently there is no use case where we want to configure
 *              interrupt aggregation dynamically. So to configure interrupt
 *              aggregation, #define INT_AGGR_COUNTER_THRESHOLD_VALUE and
 *              INT_AGGR_TIMEOUT_VALUE are used.
 * @hba: per adapter instance
 * @option: Interrupt aggregation option
 */
static inline void
ufshcd_config_int_aggr(struct ufs_hba *hba, int option)
{
        switch (option) {
        case INT_AGGR_RESET:
                writel((INT_AGGR_ENABLE |
                        INT_AGGR_COUNTER_AND_TIMER_RESET),
                        (hba->mmio_base +
                         REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL));
                break;
        case INT_AGGR_CONFIG:
                writel((INT_AGGR_ENABLE |
                        INT_AGGR_PARAM_WRITE |
                        INT_AGGR_COUNTER_THRESHOLD_VALUE |
                        INT_AGGR_TIMEOUT_VALUE),
                        (hba->mmio_base +
                         REG_UTP_TRANSFER_REQ_INT_AGG_CONTROL));
                break;
        }
}

/**
 * ufshcd_enable_run_stop_reg - Enable run-stop registers,
 *                      When run-stop registers are set to 1, it indicates the
 *                      host controller that it can process the requests
 * @hba: per adapter instance
 */
static void ufshcd_enable_run_stop_reg(struct ufs_hba *hba)
{
        writel(UTP_TASK_REQ_LIST_RUN_STOP_BIT,
               (hba->mmio_base +
                REG_UTP_TASK_REQ_LIST_RUN_STOP));
        writel(UTP_TRANSFER_REQ_LIST_RUN_STOP_BIT,
               (hba->mmio_base +
                REG_UTP_TRANSFER_REQ_LIST_RUN_STOP));
}

/**
 * ufshcd_hba_start - Start controller initialization sequence
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_start(struct ufs_hba *hba)
{
        writel(CONTROLLER_ENABLE , (hba->mmio_base + REG_CONTROLLER_ENABLE));
}

/**
 * ufshcd_is_hba_active - Get controller state
 * @hba: per adapter instance
 *
 * Returns zero if controller is active, 1 otherwise
 */
static inline int ufshcd_is_hba_active(struct ufs_hba *hba)
{
        return (readl(hba->mmio_base + REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
}

/**
 * ufshcd_send_command - Send SCSI or device management commands
 * @hba: per adapter instance
 * @task_tag: Task tag of the command
 */
static inline
void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
{
        __set_bit(task_tag, &hba->outstanding_reqs);
        writel((1 << task_tag),
               (hba->mmio_base + REG_UTP_TRANSFER_REQ_DOOR_BELL));
}

/**
 * ufshcd_copy_sense_data - Copy sense data in case of check condition
 * @lrb - pointer to local reference block
 */
static inline void ufshcd_copy_sense_data(struct ufshcd_lrb *lrbp)
{
        int len;
        if (lrbp->sense_buffer) {
                len = be16_to_cpu(lrbp->ucd_rsp_ptr->sense_data_len);
                memcpy(lrbp->sense_buffer,
                        lrbp->ucd_rsp_ptr->sense_data,
                        min_t(int, len, SCSI_SENSE_BUFFERSIZE));
        }
}

/**
 * ufshcd_hba_capabilities - Read controller capabilities
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_capabilities(struct ufs_hba *hba)
{
        hba->capabilities =
                readl(hba->mmio_base + REG_CONTROLLER_CAPABILITIES);

        /* nutrs and nutmrs are 0 based values */
        hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1;
        hba->nutmrs =
        ((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1;
}

/**
 * ufshcd_send_uic_command - Send UIC commands to unipro layers
 * @hba: per adapter instance
 * @uic_command: UIC command
 */
static inline void
ufshcd_send_uic_command(struct ufs_hba *hba, struct uic_command *uic_cmnd)
{
        /* Write Args */
        writel(uic_cmnd->argument1,
              (hba->mmio_base + REG_UIC_COMMAND_ARG_1));
        writel(uic_cmnd->argument2,
              (hba->mmio_base + REG_UIC_COMMAND_ARG_2));
        writel(uic_cmnd->argument3,
              (hba->mmio_base + REG_UIC_COMMAND_ARG_3));

        /* Write UIC Cmd */
        writel((uic_cmnd->command & COMMAND_OPCODE_MASK),
               (hba->mmio_base + REG_UIC_COMMAND));
}

/**
 * ufshcd_map_sg - Map scatter-gather list to prdt
 * @lrbp - pointer to local reference block
 *
 * Returns 0 in case of success, non-zero value in case of failure
 */
static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
{
        struct ufshcd_sg_entry *prd_table;
        struct scatterlist *sg;
        struct scsi_cmnd *cmd;
        int sg_segments;
        int i;

        cmd = lrbp->cmd;
        sg_segments = scsi_dma_map(cmd);
        if (sg_segments < 0)
                return sg_segments;

        if (sg_segments) {
                lrbp->utr_descriptor_ptr->prd_table_length =
                                        cpu_to_le16((u16) (sg_segments));

                prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;

                scsi_for_each_sg(cmd, sg, sg_segments, i) {
                        prd_table[i].size  =
                                cpu_to_le32(((u32) sg_dma_len(sg))-1);
                        prd_table[i].base_addr =
                                cpu_to_le32(lower_32_bits(sg->dma_address));
                        prd_table[i].upper_addr =
                                cpu_to_le32(upper_32_bits(sg->dma_address));
                }
        } else {
                lrbp->utr_descriptor_ptr->prd_table_length = 0;
        }

        return 0;
}

/**
 * ufshcd_int_config - enable/disable interrupts
 * @hba: per adapter instance
 * @option: interrupt option
 */
static void ufshcd_int_config(struct ufs_hba *hba, u32 option)
{
        switch (option) {
        case UFSHCD_INT_ENABLE:
                writel(hba->int_enable_mask,
                      (hba->mmio_base + REG_INTERRUPT_ENABLE));
                break;
        case UFSHCD_INT_DISABLE:
                if (hba->ufs_version == UFSHCI_VERSION_10)
                        writel(INTERRUPT_DISABLE_MASK_10,
                              (hba->mmio_base + REG_INTERRUPT_ENABLE));
                else
                        writel(INTERRUPT_DISABLE_MASK_11,
                               (hba->mmio_base + REG_INTERRUPT_ENABLE));
                break;
        }
}

/**
 * ufshcd_compose_upiu - form UFS Protocol Information Unit(UPIU)
 * @lrb - pointer to local reference block
 */
static void ufshcd_compose_upiu(struct ufshcd_lrb *lrbp)
{
        struct utp_transfer_req_desc *req_desc;
        struct utp_upiu_cmd *ucd_cmd_ptr;
        u32 data_direction;
        u32 upiu_flags;

        ucd_cmd_ptr = lrbp->ucd_cmd_ptr;
        req_desc = lrbp->utr_descriptor_ptr;

        switch (lrbp->command_type) {
        case UTP_CMD_TYPE_SCSI:
                if (lrbp->cmd->sc_data_direction == DMA_FROM_DEVICE) {
                        data_direction = UTP_DEVICE_TO_HOST;
                        upiu_flags = UPIU_CMD_FLAGS_READ;
                } else if (lrbp->cmd->sc_data_direction == DMA_TO_DEVICE) {
                        data_direction = UTP_HOST_TO_DEVICE;
                        upiu_flags = UPIU_CMD_FLAGS_WRITE;
                } else {
                        data_direction = UTP_NO_DATA_TRANSFER;
                        upiu_flags = UPIU_CMD_FLAGS_NONE;
                }

                /* Transfer request descriptor header fields */
                req_desc->header.dword_0 =
                        cpu_to_le32(data_direction | UTP_SCSI_COMMAND);

                /*
                 * assigning invalid value for command status. Controller
                 * updates OCS on command completion, with the command
                 * status
                 */
                req_desc->header.dword_2 =
                        cpu_to_le32(OCS_INVALID_COMMAND_STATUS);

                /* command descriptor fields */
                ucd_cmd_ptr->header.dword_0 =
                        cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_COMMAND,
                                                      upiu_flags,
                                                      lrbp->lun,
                                                      lrbp->task_tag));
                ucd_cmd_ptr->header.dword_1 =
                        cpu_to_be32(
                                UPIU_HEADER_DWORD(UPIU_COMMAND_SET_TYPE_SCSI,
                                                  0,
                                                  0,
                                                  0));

                /* Total EHS length and Data segment length will be zero */
                ucd_cmd_ptr->header.dword_2 = 0;

                ucd_cmd_ptr->exp_data_transfer_len =
                        cpu_to_be32(lrbp->cmd->sdb.length);

                memcpy(ucd_cmd_ptr->cdb,
                       lrbp->cmd->cmnd,
                       (min_t(unsigned short,
                              lrbp->cmd->cmd_len,
                              MAX_CDB_SIZE)));
                break;
        case UTP_CMD_TYPE_DEV_MANAGE:
                /* For query function implementation */
                break;
        case UTP_CMD_TYPE_UFS:
                /* For UFS native command implementation */
                break;
        } /* end of switch */
}

/**
 * ufshcd_queuecommand - main entry point for SCSI requests
 * @cmd: command from SCSI Midlayer
 * @done: call back function
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
{
        struct ufshcd_lrb *lrbp;
        struct ufs_hba *hba;
        unsigned long flags;
        int tag;
        int err = 0;

        hba = shost_priv(host);

        tag = cmd->request->tag;

        if (hba->ufshcd_state != UFSHCD_STATE_OPERATIONAL) {
                err = SCSI_MLQUEUE_HOST_BUSY;
                goto out;
        }

        lrbp = &hba->lrb[tag];

        lrbp->cmd = cmd;
        lrbp->sense_bufflen = SCSI_SENSE_BUFFERSIZE;
        lrbp->sense_buffer = cmd->sense_buffer;
        lrbp->task_tag = tag;
        lrbp->lun = cmd->device->lun;

        lrbp->command_type = UTP_CMD_TYPE_SCSI;

        /* form UPIU before issuing the command */
        ufshcd_compose_upiu(lrbp);
        err = ufshcd_map_sg(lrbp);
        if (err)
                goto out;

        /* issue command to the controller */
        spin_lock_irqsave(hba->host->host_lock, flags);
        ufshcd_send_command(hba, tag);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
out:
        return err;
}

/**
 * ufshcd_memory_alloc - allocate memory for host memory space data structures
 * @hba: per adapter instance
 *
 * 1. Allocate DMA memory for Command Descriptor array
 *      Each command descriptor consist of Command UPIU, Response UPIU and PRDT
 * 2. Allocate DMA memory for UTP Transfer Request Descriptor List (UTRDL).
 * 3. Allocate DMA memory for UTP Task Management Request Descriptor List
 *      (UTMRDL)
 * 4. Allocate memory for local reference block(lrb).
 *
 * Returns 0 for success, non-zero in case of failure
 */
static int ufshcd_memory_alloc(struct ufs_hba *hba)
{
        size_t utmrdl_size, utrdl_size, ucdl_size;

        /* Allocate memory for UTP command descriptors */
        ucdl_size = (sizeof(struct utp_transfer_cmd_desc) * hba->nutrs);
        hba->ucdl_base_addr = dma_alloc_coherent(hba->dev,
                                                 ucdl_size,
                                                 &hba->ucdl_dma_addr,
                                                 GFP_KERNEL);

        /*
         * UFSHCI requires UTP command descriptor to be 128 byte aligned.
         * make sure hba->ucdl_dma_addr is aligned to PAGE_SIZE
         * if hba->ucdl_dma_addr is aligned to PAGE_SIZE, then it will
         * be aligned to 128 bytes as well
         */
        if (!hba->ucdl_base_addr ||
            WARN_ON(hba->ucdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                        "Command Descriptor Memory allocation failed\n");
                goto out;
        }

        /*
         * Allocate memory for UTP Transfer descriptors
         * UFSHCI requires 1024 byte alignment of UTRD
         */
        utrdl_size = (sizeof(struct utp_transfer_req_desc) * hba->nutrs);
        hba->utrdl_base_addr = dma_alloc_coherent(hba->dev,
                                                  utrdl_size,
                                                  &hba->utrdl_dma_addr,
                                                  GFP_KERNEL);
        if (!hba->utrdl_base_addr ||
            WARN_ON(hba->utrdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                        "Transfer Descriptor Memory allocation failed\n");
                goto out;
        }

        /*
         * Allocate memory for UTP Task Management descriptors
         * UFSHCI requires 1024 byte alignment of UTMRD
         */
        utmrdl_size = sizeof(struct utp_task_req_desc) * hba->nutmrs;
        hba->utmrdl_base_addr = dma_alloc_coherent(hba->dev,
                                                   utmrdl_size,
                                                   &hba->utmrdl_dma_addr,
                                                   GFP_KERNEL);
        if (!hba->utmrdl_base_addr ||
            WARN_ON(hba->utmrdl_dma_addr & (PAGE_SIZE - 1))) {
                dev_err(hba->dev,
                "Task Management Descriptor Memory allocation failed\n");
                goto out;
        }

        /* Allocate memory for local reference block */
        hba->lrb = kcalloc(hba->nutrs, sizeof(struct ufshcd_lrb), GFP_KERNEL);
        if (!hba->lrb) {
                dev_err(hba->dev, "LRB Memory allocation failed\n");
                goto out;
        }
        return 0;
out:
        ufshcd_free_hba_memory(hba);
        return -ENOMEM;
}

/**
 * ufshcd_host_memory_configure - configure local reference block with
 *                              memory offsets
 * @hba: per adapter instance
 *
 * Configure Host memory space
 * 1. Update Corresponding UTRD.UCDBA and UTRD.UCDBAU with UCD DMA
 * address.
 * 2. Update each UTRD with Response UPIU offset, Response UPIU length
 * and PRDT offset.
 * 3. Save the corresponding addresses of UTRD, UCD.CMD, UCD.RSP and UCD.PRDT
 * into local reference block.
 */
static void ufshcd_host_memory_configure(struct ufs_hba *hba)
{
        struct utp_transfer_cmd_desc *cmd_descp;
        struct utp_transfer_req_desc *utrdlp;
        dma_addr_t cmd_desc_dma_addr;
        dma_addr_t cmd_desc_element_addr;
        u16 response_offset;
        u16 prdt_offset;
        int cmd_desc_size;
        int i;

        utrdlp = hba->utrdl_base_addr;
        cmd_descp = hba->ucdl_base_addr;

        response_offset =
                offsetof(struct utp_transfer_cmd_desc, response_upiu);
        prdt_offset =
                offsetof(struct utp_transfer_cmd_desc, prd_table);

        cmd_desc_size = sizeof(struct utp_transfer_cmd_desc);
        cmd_desc_dma_addr = hba->ucdl_dma_addr;

        for (i = 0; i < hba->nutrs; i++) {
                /* Configure UTRD with command descriptor base address */
                cmd_desc_element_addr =
                                (cmd_desc_dma_addr + (cmd_desc_size * i));
                utrdlp[i].command_desc_base_addr_lo =
                                cpu_to_le32(lower_32_bits(cmd_desc_element_addr));
                utrdlp[i].command_desc_base_addr_hi =
                                cpu_to_le32(upper_32_bits(cmd_desc_element_addr));

                /* Response upiu and prdt offset should be in double words */
                utrdlp[i].response_upiu_offset =
                                cpu_to_le16((response_offset >> 2));
                utrdlp[i].prd_table_offset =
                                cpu_to_le16((prdt_offset >> 2));
                utrdlp[i].response_upiu_length =
                                cpu_to_le16(ALIGNED_UPIU_SIZE);

                hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
                hba->lrb[i].ucd_cmd_ptr =
                        (struct utp_upiu_cmd *)(cmd_descp + i);
                hba->lrb[i].ucd_rsp_ptr =
                        (struct utp_upiu_rsp *)cmd_descp[i].response_upiu;
                hba->lrb[i].ucd_prdt_ptr =
                        (struct ufshcd_sg_entry *)cmd_descp[i].prd_table;
        }
}

/**
 * ufshcd_dme_link_startup - Notify Unipro to perform link startup
 * @hba: per adapter instance
 *
 * UIC_CMD_DME_LINK_STARTUP command must be issued to Unipro layer,
 * in order to initialize the Unipro link startup procedure.
 * Once the Unipro links are up, the device connected to the controller
 * is detected.
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_dme_link_startup(struct ufs_hba *hba)
{
        struct uic_command *uic_cmd;
        unsigned long flags;

        /* check if controller is ready to accept UIC commands */
        if (((readl(hba->mmio_base + REG_CONTROLLER_STATUS)) &
            UIC_COMMAND_READY) == 0x0) {
                dev_err(hba->dev,
                        "Controller not ready"
                        " to accept UIC commands\n");
                return -EIO;
        }

        spin_lock_irqsave(hba->host->host_lock, flags);

        /* form UIC command */
        uic_cmd = &hba->active_uic_cmd;
        uic_cmd->command = UIC_CMD_DME_LINK_STARTUP;
        uic_cmd->argument1 = 0;
        uic_cmd->argument2 = 0;
        uic_cmd->argument3 = 0;

        /* enable UIC related interrupts */
        hba->int_enable_mask |= UIC_COMMAND_COMPL;
        ufshcd_int_config(hba, UFSHCD_INT_ENABLE);

        /* sending UIC commands to controller */
        ufshcd_send_uic_command(hba, uic_cmd);
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        return 0;
}

/**
 * ufshcd_make_hba_operational - Make UFS controller operational
 * @hba: per adapter instance
 *
 * To bring UFS host controller to operational state,
 * 1. Check if device is present
 * 2. Configure run-stop-registers
 * 3. Enable required interrupts
 * 4. Configure interrupt aggregation
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_make_hba_operational(struct ufs_hba *hba)
{
        int err = 0;
        u32 reg;

        /* check if device present */
        reg = readl((hba->mmio_base + REG_CONTROLLER_STATUS));
        if (!ufshcd_is_device_present(reg)) {
                dev_err(hba->dev, "cc: Device not present\n");
                err = -ENXIO;
                goto out;
        }

        /*
         * UCRDY, UTMRLDY and UTRLRDY bits must be 1
         * DEI, HEI bits must be 0
         */
        if (!(ufshcd_get_lists_status(reg))) {
                ufshcd_enable_run_stop_reg(hba);
        } else {
                dev_err(hba->dev,
                        "Host controller not ready to process requests");
                err = -EIO;
                goto out;
        }

        /* Enable required interrupts */
        hba->int_enable_mask |= (UTP_TRANSFER_REQ_COMPL |
                                 UIC_ERROR |
                                 UTP_TASK_REQ_COMPL |
                                 DEVICE_FATAL_ERROR |
                                 CONTROLLER_FATAL_ERROR |
                                 SYSTEM_BUS_FATAL_ERROR);
        ufshcd_int_config(hba, UFSHCD_INT_ENABLE);

        /* Configure interrupt aggregation */
        ufshcd_config_int_aggr(hba, INT_AGGR_CONFIG);

        if (hba->ufshcd_state == UFSHCD_STATE_RESET)
                scsi_unblock_requests(hba->host);

        hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
        scsi_scan_host(hba->host);
out:
        return err;
}

/**
 * ufshcd_hba_enable - initialize the controller
 * @hba: per adapter instance
 *
 * The controller resets itself and controller firmware initialization
 * sequence kicks off. When controller is ready it will set
 * the Host Controller Enable bit to 1.
 *
 * Returns 0 on success, non-zero value on failure
 */
static int ufshcd_hba_enable(struct ufs_hba *hba)
{
        int retry;

        /*
         * msleep of 1 and 5 used in this function might result in msleep(20),
         * but it was necessary to send the UFS FPGA to reset mode during
         * development and testing of this driver. msleep can be changed to
         * mdelay and retry count can be reduced based on the controller.
         */
        if (!ufshcd_is_hba_active(hba)) {

                /* change controller state to "reset state" */
                ufshcd_hba_stop(hba);

                /*
                 * This delay is based on the testing done with UFS host
                 * controller FPGA. The delay can be changed based on the
                 * host controller used.
                 */
                msleep(5);
        }

        /* start controller initialization sequence */
        ufshcd_hba_start(hba);

        /*
         * To initialize a UFS host controller HCE bit must be set to 1.
         * During initialization the HCE bit value changes from 1->0->1.
         * When the host controller completes initialization sequence
         * it sets the value of HCE bit to 1. The same HCE bit is read back
         * to check if the controller has completed initialization sequence.
         * So without this delay the value HCE = 1, set in the previous
         * instruction might be read back.
         * This delay can be changed based on the controller.
         */
        msleep(1);

        /* wait for the host controller to complete initialization */
        retry = 10;
        while (ufshcd_is_hba_active(hba)) {
                if (retry) {
                        retry--;
                } else {
                        dev_err(hba->dev,
                                "Controller enable failed\n");
                        return -EIO;
                }
                msleep(5);
        }
        return 0;
}

/**
 * ufshcd_initialize_hba - start the initialization process
 * @hba: per adapter instance
 *
 * 1. Enable the controller via ufshcd_hba_enable.
 * 2. Program the Transfer Request List Address with the starting address of
 * UTRDL.
 * 3. Program the Task Management Request List Address with starting address
 * of UTMRDL.
 *
 * Returns 0 on success, non-zero value on failure.
 */
static int ufshcd_initialize_hba(struct ufs_hba *hba)
{
        if (ufshcd_hba_enable(hba))
                return -EIO;

        /* Configure UTRL and UTMRL base address registers */
        writel(lower_32_bits(hba->utrdl_dma_addr),
               (hba->mmio_base + REG_UTP_TRANSFER_REQ_LIST_BASE_L));
        writel(upper_32_bits(hba->utrdl_dma_addr),
               (hba->mmio_base + REG_UTP_TRANSFER_REQ_LIST_BASE_H));
        writel(lower_32_bits(hba->utmrdl_dma_addr),
               (hba->mmio_base + REG_UTP_TASK_REQ_LIST_BASE_L));
        writel(upper_32_bits(hba->utmrdl_dma_addr),
               (hba->mmio_base + REG_UTP_TASK_REQ_LIST_BASE_H));

        /* Initialize unipro link startup procedure */
        return ufshcd_dme_link_startup(hba);
}

/**
 * ufshcd_do_reset - reset the host controller
 * @hba: per adapter instance
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_do_reset(struct ufs_hba *hba)
{
        struct ufshcd_lrb *lrbp;
        unsigned long flags;
        int tag;

        /* block commands from midlayer */
        scsi_block_requests(hba->host);

        spin_lock_irqsave(hba->host->host_lock, flags);
        hba->ufshcd_state = UFSHCD_STATE_RESET;

        /* send controller to reset state */
        ufshcd_hba_stop(hba);
        spin_unlock_irqrestore(hba->host->host_lock, flags);

        /* abort outstanding commands */
        for (tag = 0; tag < hba->nutrs; tag++) {
                if (test_bit(tag, &hba->outstanding_reqs)) {
                        lrbp = &hba->lrb[tag];
                        scsi_dma_unmap(lrbp->cmd);
                        lrbp->cmd->result = DID_RESET << 16;
                        lrbp->cmd->scsi_done(lrbp->cmd);
                        lrbp->cmd = NULL;
                }
        }

        /* clear outstanding request/task bit maps */
        hba->outstanding_reqs = 0;
        hba->outstanding_tasks = 0;

        /* start the initialization process */
        if (ufshcd_initialize_hba(hba)) {
                dev_err(hba->dev,
                        "Reset: Controller initialization failed\n");
                return FAILED;
        }
        return SUCCESS;
}

/**
 * ufshcd_slave_alloc - handle initial SCSI device configurations
 * @sdev: pointer to SCSI device
 *
 * Returns success
 */
static int ufshcd_slave_alloc(struct scsi_device *sdev)
{
        struct ufs_hba *hba;

        hba = shost_priv(sdev->host);
        sdev->tagged_supported = 1;

        /* Mode sense(6) is not supported by UFS, so use Mode sense(10) */
        sdev->use_10_for_ms = 1;
        scsi_set_tag_type(sdev, MSG_SIMPLE_TAG);

        /*
         * Inform SCSI Midlayer that the LUN queue depth is same as the
         * controller queue depth. If a LUN queue depth is less than the
         * controller queue depth and if the LUN reports
         * SAM_STAT_TASK_SET_FULL, the LUN queue depth will be adjusted
         * with scsi_adjust_queue_depth.
         */
        scsi_activate_tcq(sdev, hba->nutrs);
        return 0;
}

/**
 * ufshcd_slave_destroy - remove SCSI device configurations
 * @sdev: pointer to SCSI device
 */
static void ufshcd_slave_destroy(struct scsi_device *sdev)
{
        struct ufs_hba *hba;

        hba = shost_priv(sdev->host);
        scsi_deactivate_tcq(sdev, hba->nutrs);
}

/**
 * ufshcd_task_req_compl - handle task management request completion
 * @hba: per adapter instance
 * @index: index of the completed request
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_task_req_compl(struct ufs_hba *hba, u32 index)
{
        struct utp_task_req_desc *task_req_descp;
        struct utp_upiu_task_rsp *task_rsp_upiup;
        unsigned long flags;
        int ocs_value;
        int task_result;

        spin_lock_irqsave(hba->host->host_lock, flags);

        /* Clear completed tasks from outstanding_tasks */
        __clear_bit(index, &hba->outstanding_tasks);

        task_req_descp = hba->utmrdl_base_addr;
        ocs_value = ufshcd_get_tmr_ocs(&task_req_descp[index]);

        if (ocs_value == OCS_SUCCESS) {
                task_rsp_upiup = (struct utp_upiu_task_rsp *)
                                task_req_descp[index].task_rsp_upiu;
                task_result = be32_to_cpu(task_rsp_upiup->header.dword_1);
                task_result = ((task_result & MASK_TASK_RESPONSE) >> 8);

                if (task_result != UPIU_TASK_MANAGEMENT_FUNC_COMPL &&
                    task_result != UPIU_TASK_MANAGEMENT_FUNC_SUCCEEDED)
                        task_result = FAILED;
                else
                        task_result = SUCCESS;
        } else {
                task_result = FAILED;
                dev_err(hba->dev,
                        "trc: Invalid ocs = %x\n", ocs_value);
        }
        spin_unlock_irqrestore(hba->host->host_lock, flags);
        return task_result;
}

/**
 * ufshcd_adjust_lun_qdepth - Update LUN queue depth if device responds with
 *                            SAM_STAT_TASK_SET_FULL SCSI command status.
 * @cmd: pointer to SCSI command
 */
static void ufshcd_adjust_lun_qdepth(struct scsi_cmnd *cmd)
{
        struct ufs_hba *hba;
        int i;
        int lun_qdepth = 0;

        hba = shost_priv(cmd->device->host);

        /*
         * LUN queue depth can be obtained by counting outstanding commands
         * on the LUN.
         */
        for (i = 0; i < hba->nutrs; i++) {
                if (test_bit(i, &hba->outstanding_reqs)) {

                        /*
                         * Check if the outstanding command belongs
                         * to the LUN which reported SAM_STAT_TASK_SET_FULL.
                         */
                        if (cmd->device->lun == hba->lrb[i].lun)
                                lun_qdepth++;
                }
        }

        /*
         * LUN queue depth will be total outstanding commands, except the
         * command for which the LUN reported SAM_STAT_TASK_SET_FULL.
         */
        scsi_adjust_queue_depth(cmd->device, MSG_SIMPLE_TAG, lun_qdepth - 1);
}

/**
 * ufshcd_scsi_cmd_status - Update SCSI command result based on SCSI status
 * @lrb: pointer to local reference block of completed command
 * @scsi_status: SCSI command status
 *
 * Returns value base on SCSI command status
 */
static inline int
ufshcd_scsi_cmd_status(struct ufshcd_lrb *lrbp, int scsi_status)
{
        int result = 0;

        switch (scsi_status) {
        case SAM_STAT_GOOD:
                result |= DID_OK << 16 |
                          COMMAND_COMPLETE << 8 |
                          SAM_STAT_GOOD;
                break;
        case SAM_STAT_CHECK_CONDITION:
                result |= DID_OK << 16 |
                          COMMAND_COMPLETE << 8 |
                          SAM_STAT_CHECK_CONDITION;
                ufshcd_copy_sense_data(lrbp);
                break;
        case SAM_STAT_BUSY:
                result |= SAM_STAT_BUSY;
                break;
        case SAM_STAT_TASK_SET_FULL:

                /*
                 * If a LUN reports SAM_STAT_TASK_SET_FULL, then the LUN queue
                 * depth needs to be adjusted to the exact number of
                 * outstanding commands the LUN can handle at any given time.
                 */
                ufshcd_adjust_lun_qdepth(lrbp->cmd);
                result |= SAM_STAT_TASK_SET_FULL;
                break;
        case SAM_STAT_TASK_ABORTED:
                result |= SAM_STAT_TASK_ABORTED;
                break;
        default:
                result |= DID_ERROR << 16;
                break;
        } /* end of switch */

        return result;
}

/**
 * ufshcd_transfer_rsp_status - Get overall status of the response
 * @hba: per adapter instance
 * @lrb: pointer to local reference block of completed command
 *
 * Returns result of the command to notify SCSI midlayer
 */
static inline int
ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
{
        int result = 0;
        int scsi_status;
        int ocs;

        /* overall command status of utrd */
        ocs = ufshcd_get_tr_ocs(lrbp);

        switch (ocs) {
        case OCS_SUCCESS:

                /* check if the returned transfer response is valid */
                result = ufshcd_is_valid_req_rsp(lrbp->ucd_rsp_ptr);
                if (result) {
                        dev_err(hba->dev,
                                "Invalid response = %x\n", result);
                        break;
                }

                /*
                 * get the response UPIU result to extract
                 * the SCSI command status
                 */
                result = ufshcd_get_rsp_upiu_result(lrbp->ucd_rsp_ptr);

                /*
                 * get the result based on SCSI status response
                 * to notify the SCSI midlayer of the command status
                 */
                scsi_status = result & MASK_SCSI_STATUS;
                result = ufshcd_scsi_cmd_status(lrbp, scsi_status);
                break;
        case OCS_ABORTED:
                result |= DID_ABORT << 16;
                break;
        case OCS_INVALID_CMD_TABLE_ATTR:
        case OCS_INVALID_PRDT_ATTR:
        case OCS_MISMATCH_DATA_BUF_SIZE:
        case OCS_MISMATCH_RESP_UPIU_SIZE:
        case OCS_PEER_COMM_FAILURE:
        case OCS_FATAL_ERROR:
        default:
                result |= DID_ERROR << 16;
                dev_err(hba->dev,
                "OCS error from controller = %x\n", ocs);
                break;
        } /* end of switch */

        return result;
}

/**
 * ufshcd_transfer_req_compl - handle SCSI and query command completion
 * @hba: per adapter instance
 */
static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
{
        struct ufshcd_lrb *lrb;
        unsigned long completed_reqs;
        u32 tr_doorbell;
        int result;
        int index;

        lrb = hba->lrb;
        tr_doorbell =
                readl(hba->mmio_base + REG_UTP_TRANSFER_REQ_DOOR_BELL);
        completed_reqs = tr_doorbell ^ hba->outstanding_reqs;

        for (index = 0; index < hba->nutrs; index++) {
                if (test_bit(index, &completed_reqs)) {

                        result = ufshcd_transfer_rsp_status(hba, &lrb[index]);

                        if (lrb[index].cmd) {
                                scsi_dma_unmap(lrb[index].cmd);
                                lrb[index].cmd->result = result;
                                lrb[index].cmd->scsi_done(lrb[index].cmd);

                                /* Mark completed command as NULL in LRB */
                                lrb[index].cmd = NULL;
                        }
                } /* end of if */
        } /* end of for */

        /* clear corresponding bits of completed commands */
        hba->outstanding_reqs ^= completed_reqs;

        /* Reset interrupt aggregation counters */
        ufshcd_config_int_aggr(hba, INT_AGGR_RESET);
}

/**
 * ufshcd_uic_cc_handler - handle UIC command completion
 * @work: pointer to a work queue structure
 *
 * Returns 0 on success, non-zero value on failure
 */
static void ufshcd_uic_cc_handler (struct work_struct *work)
{
        struct ufs_hba *hba;

        hba = container_of(work, struct ufs_hba, uic_workq);

        if ((hba->active_uic_cmd.command == UIC_CMD_DME_LINK_STARTUP) &&
            !(ufshcd_get_uic_cmd_result(hba))) {

                if (ufshcd_make_hba_operational(hba))
                        dev_err(hba->dev,
                                "cc: hba not operational state\n");
                return;
        }
}

/**
 * ufshcd_fatal_err_handler - handle fatal errors
 * @hba: per adapter instance
 */
static void ufshcd_fatal_err_handler(struct work_struct *work)
{
        struct ufs_hba *hba;
        hba = container_of(work, struct ufs_hba, feh_workq);

        /* check if reset is already in progress */
        if (hba->ufshcd_state != UFSHCD_STATE_RESET)
                ufshcd_do_reset(hba);
}

/**
 * ufshcd_err_handler - Check for fatal errors
 * @work: pointer to a work queue structure
 */
static void ufshcd_err_handler(struct ufs_hba *hba)
{
        u32 reg;

        if (hba->errors & INT_FATAL_ERRORS)
                goto fatal_eh;

        if (hba->errors & UIC_ERROR) {

                reg = readl(hba->mmio_base +
                            REG_UIC_ERROR_CODE_PHY_ADAPTER_LAYER);
                if (reg & UIC_DATA_LINK_LAYER_ERROR_PA_INIT)
                        goto fatal_eh;
        }
        return;
fatal_eh:
        hba->ufshcd_state = UFSHCD_STATE_ERROR;
        schedule_work(&hba->feh_workq);
}

/**
 * ufshcd_tmc_handler - handle task management function completion
 * @hba: per adapter instance
 */
static void ufshcd_tmc_handler(struct ufs_hba *hba)
{
        u32 tm_doorbell;

        tm_doorbell = readl(hba->mmio_base + REG_UTP_TASK_REQ_DOOR_BELL);
        hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
        wake_up_interruptible(&hba->ufshcd_tm_wait_queue);
}

/**
 * ufshcd_sl_intr - Interrupt service routine
 * @hba: per adapter instance
 * @intr_status: contains interrupts generated by the controller
 */
static void ufshcd_sl_intr(struct ufs_hba *hba, u32 intr_status)
{
        hba->errors = UFSHCD_ERROR_MASK & intr_status;
        if (hba->errors)
                ufshcd_err_handler(hba);

        if (intr_status & UIC_COMMAND_COMPL)
                schedule_work(&hba->uic_workq);

        if (intr_status & UTP_TASK_REQ_COMPL)
                ufshcd_tmc_handler(hba);

        if (intr_status & UTP_TRANSFER_REQ_COMPL)
                ufshcd_transfer_req_compl(hba);
}

/**
 * ufshcd_intr - Main interrupt service routine
 * @irq: irq number
 * @__hba: pointer to adapter instance
 *
 * Returns IRQ_HANDLED - If interrupt is valid
 *              IRQ_NONE - If invalid interrupt
 */
static irqreturn_t ufshcd_intr(int irq, void *__hba)
{
        u32 intr_status;
        irqreturn_t retval = IRQ_NONE;
        struct ufs_hba *hba = __hba;

        spin_lock(hba->host->host_lock);
        intr_status = readl(hba->mmio_base + REG_INTERRUPT_STATUS);

        if (intr_status) {
                ufshcd_sl_intr(hba, intr_status);

                /* If UFSHCI 1.0 then clear interrupt status register */
                if (hba->ufs_version == UFSHCI_VERSION_10)
                        writel(intr_status,
                               (hba->mmio_base + REG_INTERRUPT_STATUS));
                retval = IRQ_HANDLED;
        }
        spin_unlock(hba->host->host_lock);
        return retval;
}

/**
 * ufshcd_issue_tm_cmd - issues task management commands to controller
 * @hba: per adapter instance
 * @lrbp: pointer to local reference block
 *
 * Returns SUCCESS/FAILED
 */
static int
ufshcd_issue_tm_cmd(struct ufs_hba *hba,
                    struct ufshcd_lrb *lrbp,
                    u8 tm_function)
{
        struct utp_task_req_desc *task_req_descp;
        struct utp_upiu_task_req *task_req_upiup;
        struct Scsi_Host *host;
        unsigned long flags;
        int free_slot = 0;
        int err;

        host = hba->host;

        spin_lock_irqsave(host->host_lock, flags);

        /* If task management queue is full */
        free_slot = ufshcd_get_tm_free_slot(hba);
        if (free_slot >= hba->nutmrs) {
                spin_unlock_irqrestore(host->host_lock, flags);
                dev_err(hba->dev, "Task management queue full\n");
                err = FAILED;
                goto out;
        }

        task_req_descp = hba->utmrdl_base_addr;
        task_req_descp += free_slot;

        /* Configure task request descriptor */
        task_req_descp->header.dword_0 = cpu_to_le32(UTP_REQ_DESC_INT_CMD);
        task_req_descp->header.dword_2 =
                        cpu_to_le32(OCS_INVALID_COMMAND_STATUS);

        /* Configure task request UPIU */
        task_req_upiup =
                (struct utp_upiu_task_req *) task_req_descp->task_req_upiu;
        task_req_upiup->header.dword_0 =
                cpu_to_be32(UPIU_HEADER_DWORD(UPIU_TRANSACTION_TASK_REQ, 0,
                                              lrbp->lun, lrbp->task_tag));
        task_req_upiup->header.dword_1 =
        cpu_to_be32(UPIU_HEADER_DWORD(0, tm_function, 0, 0));

        task_req_upiup->input_param1 = lrbp->lun;
        task_req_upiup->input_param1 =
                cpu_to_be32(task_req_upiup->input_param1);
        task_req_upiup->input_param2 = lrbp->task_tag;
        task_req_upiup->input_param2 =
                cpu_to_be32(task_req_upiup->input_param2);

        /* send command to the controller */
        __set_bit(free_slot, &hba->outstanding_tasks);
        writel((1 << free_slot),
               (hba->mmio_base + REG_UTP_TASK_REQ_DOOR_BELL));

        spin_unlock_irqrestore(host->host_lock, flags);

        /* wait until the task management command is completed */
        err =
        wait_event_interruptible_timeout(hba->ufshcd_tm_wait_queue,
                                         (test_bit(free_slot,
                                         &hba->tm_condition) != 0),
                                         60 * HZ);
        if (!err) {
                dev_err(hba->dev,
                        "Task management command timed-out\n");
                err = FAILED;
                goto out;
        }
        clear_bit(free_slot, &hba->tm_condition);
        err = ufshcd_task_req_compl(hba, free_slot);
out:
        return err;
}

/**
 * ufshcd_device_reset - reset device and abort all the pending commands
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_device_reset(struct scsi_cmnd *cmd)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        unsigned int tag;
        u32 pos;
        int err;

        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;

        err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_LOGICAL_RESET);
        if (err == FAILED)
                goto out;

        for (pos = 0; pos < hba->nutrs; pos++) {
                if (test_bit(pos, &hba->outstanding_reqs) &&
                    (hba->lrb[tag].lun == hba->lrb[pos].lun)) {

                        /* clear the respective UTRLCLR register bit */
                        ufshcd_utrl_clear(hba, pos);

                        clear_bit(pos, &hba->outstanding_reqs);

                        if (hba->lrb[pos].cmd) {
                                scsi_dma_unmap(hba->lrb[pos].cmd);
                                hba->lrb[pos].cmd->result =
                                                DID_ABORT << 16;
                                hba->lrb[pos].cmd->scsi_done(cmd);
                                hba->lrb[pos].cmd = NULL;
                        }
                }
        } /* end of for */
out:
        return err;
}

/**
 * ufshcd_host_reset - Main reset function registered with scsi layer
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_host_reset(struct scsi_cmnd *cmd)
{
        struct ufs_hba *hba;

        hba = shost_priv(cmd->device->host);

        if (hba->ufshcd_state == UFSHCD_STATE_RESET)
                return SUCCESS;

        return ufshcd_do_reset(hba);
}

/**
 * ufshcd_abort - abort a specific command
 * @cmd: SCSI command pointer
 *
 * Returns SUCCESS/FAILED
 */
static int ufshcd_abort(struct scsi_cmnd *cmd)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        unsigned long flags;
        unsigned int tag;
        int err;

        host = cmd->device->host;
        hba = shost_priv(host);
        tag = cmd->request->tag;

        spin_lock_irqsave(host->host_lock, flags);

        /* check if command is still pending */
        if (!(test_bit(tag, &hba->outstanding_reqs))) {
                err = FAILED;
                spin_unlock_irqrestore(host->host_lock, flags);
                goto out;
        }
        spin_unlock_irqrestore(host->host_lock, flags);

        err = ufshcd_issue_tm_cmd(hba, &hba->lrb[tag], UFS_ABORT_TASK);
        if (err == FAILED)
                goto out;

        scsi_dma_unmap(cmd);

        spin_lock_irqsave(host->host_lock, flags);

        /* clear the respective UTRLCLR register bit */
        ufshcd_utrl_clear(hba, tag);

        __clear_bit(tag, &hba->outstanding_reqs);
        hba->lrb[tag].cmd = NULL;
        spin_unlock_irqrestore(host->host_lock, flags);
out:
        return err;
}

static struct scsi_host_template ufshcd_driver_template = {
        .module                 = THIS_MODULE,
        .name                   = UFSHCD,
        .proc_name              = UFSHCD,
        .queuecommand           = ufshcd_queuecommand,
        .slave_alloc            = ufshcd_slave_alloc,
        .slave_destroy          = ufshcd_slave_destroy,
        .eh_abort_handler       = ufshcd_abort,
        .eh_device_reset_handler = ufshcd_device_reset,
        .eh_host_reset_handler  = ufshcd_host_reset,
        .this_id                = -1,
        .sg_tablesize           = SG_ALL,
        .cmd_per_lun            = UFSHCD_CMD_PER_LUN,
        .can_queue              = UFSHCD_CAN_QUEUE,
};

/**
 * ufshcd_suspend - suspend power management function
 * @hba: per adapter instance
 * @state: power state
 *
 * Returns -ENOSYS
 */
int ufshcd_suspend(struct ufs_hba *hba, pm_message_t state)
{
        /*
         * TODO:
         * 1. Block SCSI requests from SCSI midlayer
         * 2. Change the internal driver state to non operational
         * 3. Set UTRLRSR and UTMRLRSR bits to zero
         * 4. Wait until outstanding commands are completed
         * 5. Set HCE to zero to send the UFS host controller to reset state
         */

        return -ENOSYS;
}
EXPORT_SYMBOL_GPL(ufshcd_suspend);

/**
 * ufshcd_resume - resume power management function
 * @hba: per adapter instance
 *
 * Returns -ENOSYS
 */
int ufshcd_resume(struct ufs_hba *hba)
{
        /*
         * TODO:
         * 1. Set HCE to 1, to start the UFS host controller
         * initialization process
         * 2. Set UTRLRSR and UTMRLRSR bits to 1
         * 3. Change the internal driver state to operational
         * 4. Unblock SCSI requests from SCSI midlayer
         */

        return -ENOSYS;
}
EXPORT_SYMBOL_GPL(ufshcd_resume);

/**
 * ufshcd_hba_free - free allocated memory for
 *                      host memory space data structures
 * @hba: per adapter instance
 */
static void ufshcd_hba_free(struct ufs_hba *hba)
{
        iounmap(hba->mmio_base);
        ufshcd_free_hba_memory(hba);
}

/**
 * ufshcd_remove - de-allocate SCSI host and host memory space
 *              data structure memory
 * @hba - per adapter instance
 */
void ufshcd_remove(struct ufs_hba *hba)
{
        /* disable interrupts */
        ufshcd_int_config(hba, UFSHCD_INT_DISABLE);

        ufshcd_hba_stop(hba);
        ufshcd_hba_free(hba);

        scsi_remove_host(hba->host);
        scsi_host_put(hba->host);
}
EXPORT_SYMBOL_GPL(ufshcd_remove);

/**
 * ufshcd_init - Driver initialization routine
 * @dev: pointer to device handle
 * @hba_handle: driver private handle
 * @mmio_base: base register address
 * @irq: Interrupt line of device
 * Returns 0 on success, non-zero value on failure
 */
int ufshcd_init(struct device *dev, struct ufs_hba **hba_handle,
                 void __iomem *mmio_base, unsigned int irq)
{
        struct Scsi_Host *host;
        struct ufs_hba *hba;
        int err;

        if (!dev) {
                dev_err(dev,
                "Invalid memory reference for dev is NULL\n");
                err = -ENODEV;
                goto out_error;
        }

        if (!mmio_base) {
                dev_err(dev,
                "Invalid memory reference for mmio_base is NULL\n");
                err = -ENODEV;
                goto out_error;
        }

        host = scsi_host_alloc(&ufshcd_driver_template,
                                sizeof(struct ufs_hba));
        if (!host) {
                dev_err(dev, "scsi_host_alloc failed\n");
                err = -ENOMEM;
                goto out_error;
        }
        hba = shost_priv(host);
        hba->host = host;
        hba->dev = dev;
        hba->mmio_base = mmio_base;
        hba->irq = irq;

        /* Read capabilities registers */
        ufshcd_hba_capabilities(hba);

        /* Get UFS version supported by the controller */
        hba->ufs_version = ufshcd_get_ufs_version(hba);

        /* Allocate memory for host memory space */
        err = ufshcd_memory_alloc(hba);
        if (err) {
                dev_err(hba->dev, "Memory allocation failed\n");
                goto out_disable;
        }

        /* Configure LRB */
        ufshcd_host_memory_configure(hba);

        host->can_queue = hba->nutrs;
        host->cmd_per_lun = hba->nutrs;
        host->max_id = UFSHCD_MAX_ID;
        host->max_lun = UFSHCD_MAX_LUNS;
        host->max_channel = UFSHCD_MAX_CHANNEL;
        host->unique_id = host->host_no;
        host->max_cmd_len = MAX_CDB_SIZE;

        /* Initailize wait queue for task management */
        init_waitqueue_head(&hba->ufshcd_tm_wait_queue);

        /* Initialize work queues */
        INIT_WORK(&hba->uic_workq, ufshcd_uic_cc_handler);
        INIT_WORK(&hba->feh_workq, ufshcd_fatal_err_handler);

        /* IRQ registration */
        err = request_irq(irq, ufshcd_intr, IRQF_SHARED, UFSHCD, hba);
        if (err) {
                dev_err(hba->dev, "request irq failed\n");
                goto out_lrb_free;
        }

        /* Enable SCSI tag mapping */
        err = scsi_init_shared_tag_map(host, host->can_queue);
        if (err) {
                dev_err(hba->dev, "init shared queue failed\n");
                goto out_free_irq;
        }

        err = scsi_add_host(host, hba->dev);
        if (err) {
                dev_err(hba->dev, "scsi_add_host failed\n");
                goto out_free_irq;
        }

        /* Initialization routine */
        err = ufshcd_initialize_hba(hba);
        if (err) {
                dev_err(hba->dev, "Initialization failed\n");
                goto out_remove_scsi_host;
        }
        *hba_handle = hba;

        return 0;

out_remove_scsi_host:
        scsi_remove_host(hba->host);
out_free_irq:
        free_irq(irq, hba);
out_lrb_free:
        ufshcd_free_hba_memory(hba);
out_disable:
        scsi_host_put(host);
out_error:
        return err;
}
EXPORT_SYMBOL_GPL(ufshcd_init);

MODULE_AUTHOR("Santosh Yaragnavi <santosh.sy@samsung.com>");
MODULE_AUTHOR("Vinayak Holikatti <h.vinayak@samsung.com>");
MODULE_DESCRIPTION("Generic UFS host controller driver Core");
MODULE_LICENSE("GPL");
MODULE_VERSION(UFSHCD_DRIVER_VERSION);