/*
 * Universal Flash Storage Host controller driver
 *
 * This code is based on drivers/scsi/ufs/ufshcd.h
 * 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.
 */

#ifndef _UFSHCD_H
#define _UFSHCD_H

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/pm_runtime.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>

#include <asm/irq.h>
#include <asm/byteorder.h>
#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_eh.h>

#include "ufs.h"
#include "ufshci.h"

#define UFSHCD "ufshcd"
#define UFSHCD_DRIVER_VERSION "0.2"

struct ufs_hba;

enum dev_cmd_type {
        DEV_CMD_TYPE_NOP                = 0x0,
        DEV_CMD_TYPE_QUERY              = 0x1,
};

/**
 * struct uic_command - UIC command structure
 * @command: UIC command
 * @argument1: UIC command argument 1
 * @argument2: UIC command argument 2
 * @argument3: UIC command argument 3
 * @cmd_active: Indicate if UIC command is outstanding
 * @result: UIC command result
 * @done: UIC command completion
 */
struct uic_command {
        u32 command;
        u32 argument1;
        u32 argument2;
        u32 argument3;
        int cmd_active;
        int result;
        struct completion done;
};

/* Used to differentiate the power management options */
enum ufs_pm_op {
        UFS_RUNTIME_PM,
        UFS_SYSTEM_PM,
        UFS_SHUTDOWN_PM,
};

#define ufshcd_is_runtime_pm(op) ((op) == UFS_RUNTIME_PM)
#define ufshcd_is_system_pm(op) ((op) == UFS_SYSTEM_PM)
#define ufshcd_is_shutdown_pm(op) ((op) == UFS_SHUTDOWN_PM)

/* Host <-> Device UniPro Link state */
enum uic_link_state {
        UIC_LINK_OFF_STATE      = 0, /* Link powered down or disabled */
        UIC_LINK_ACTIVE_STATE   = 1, /* Link is in Fast/Slow/Sleep state */
        UIC_LINK_HIBERN8_STATE  = 2, /* Link is in Hibernate state */
};

#define ufshcd_is_link_off(hba) ((hba)->uic_link_state == UIC_LINK_OFF_STATE)
#define ufshcd_is_link_active(hba) ((hba)->uic_link_state == \
                                    UIC_LINK_ACTIVE_STATE)
#define ufshcd_is_link_hibern8(hba) ((hba)->uic_link_state == \
                                    UIC_LINK_HIBERN8_STATE)
#define ufshcd_set_link_off(hba) ((hba)->uic_link_state = UIC_LINK_OFF_STATE)
#define ufshcd_set_link_active(hba) ((hba)->uic_link_state = \
                                    UIC_LINK_ACTIVE_STATE)
#define ufshcd_set_link_hibern8(hba) ((hba)->uic_link_state = \
                                    UIC_LINK_HIBERN8_STATE)

/*
 * UFS Power management levels.
 * Each level is in increasing order of power savings.
 */
enum ufs_pm_level {
        UFS_PM_LVL_0, /* UFS_ACTIVE_PWR_MODE, UIC_LINK_ACTIVE_STATE */
        UFS_PM_LVL_1, /* UFS_ACTIVE_PWR_MODE, UIC_LINK_HIBERN8_STATE */
        UFS_PM_LVL_2, /* UFS_SLEEP_PWR_MODE, UIC_LINK_ACTIVE_STATE */
        UFS_PM_LVL_3, /* UFS_SLEEP_PWR_MODE, UIC_LINK_HIBERN8_STATE */
        UFS_PM_LVL_4, /* UFS_POWERDOWN_PWR_MODE, UIC_LINK_HIBERN8_STATE */
        UFS_PM_LVL_5, /* UFS_POWERDOWN_PWR_MODE, UIC_LINK_OFF_STATE */
        UFS_PM_LVL_MAX
};

struct ufs_pm_lvl_states {
        enum ufs_dev_pwr_mode dev_state;
        enum uic_link_state link_state;
};

/**
 * struct ufshcd_lrb - local reference block
 * @utr_descriptor_ptr: UTRD address of the command
 * @ucd_req_ptr: UCD address of the command
 * @ucd_rsp_ptr: Response UPIU address for this command
 * @ucd_prdt_ptr: PRDT address of the command
 * @cmd: pointer to SCSI command
 * @sense_buffer: pointer to sense buffer address of the SCSI command
 * @sense_bufflen: Length of the sense buffer
 * @scsi_status: SCSI status of the command
 * @command_type: SCSI, UFS, Query.
 * @task_tag: Task tag of the command
 * @lun: LUN of the command
 * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
 */
struct ufshcd_lrb {
        struct utp_transfer_req_desc *utr_descriptor_ptr;
        struct utp_upiu_req *ucd_req_ptr;
        struct utp_upiu_rsp *ucd_rsp_ptr;
        struct ufshcd_sg_entry *ucd_prdt_ptr;

        struct scsi_cmnd *cmd;
        u8 *sense_buffer;
        unsigned int sense_bufflen;
        int scsi_status;

        int command_type;
        int task_tag;
        u8 lun; /* UPIU LUN id field is only 8-bit wide */
        bool intr_cmd;
};

/**
 * struct ufs_query - holds relevent data structures for query request
 * @request: request upiu and function
 * @descriptor: buffer for sending/receiving descriptor
 * @response: response upiu and response
 */
struct ufs_query {
        struct ufs_query_req request;
        u8 *descriptor;
        struct ufs_query_res response;
};

/**
 * struct ufs_dev_cmd - all assosiated fields with device management commands
 * @type: device management command type - Query, NOP OUT
 * @lock: lock to allow one command at a time
 * @complete: internal commands completion
 * @tag_wq: wait queue until free command slot is available
 */
struct ufs_dev_cmd {
        enum dev_cmd_type type;
        struct mutex lock;
        struct completion *complete;
        wait_queue_head_t tag_wq;
        struct ufs_query query;
};

/**
 * struct ufs_clk_info - UFS clock related info
 * @list: list headed by hba->clk_list_head
 * @clk: clock node
 * @name: clock name
 * @max_freq: maximum frequency supported by the clock
 * @min_freq: min frequency that can be used for clock scaling
 * @curr_freq: indicates the current frequency that it is set to
 * @enabled: variable to check against multiple enable/disable
 */
struct ufs_clk_info {
        struct list_head list;
        struct clk *clk;
        const char *name;
        u32 max_freq;
        u32 min_freq;
        u32 curr_freq;
        bool enabled;
};

#define PRE_CHANGE      0
#define POST_CHANGE     1

struct ufs_pa_layer_attr {
        u32 gear_rx;
        u32 gear_tx;
        u32 lane_rx;
        u32 lane_tx;
        u32 pwr_rx;
        u32 pwr_tx;
        u32 hs_rate;
};

struct ufs_pwr_mode_info {
        bool is_valid;
        struct ufs_pa_layer_attr info;
};

/**
 * struct ufs_hba_variant_ops - variant specific callbacks
 * @name: variant name
 * @init: called when the driver is initialized
 * @exit: called to cleanup everything done in init
 * @get_ufs_hci_version: called to get UFS HCI version
 * @clk_scale_notify: notifies that clks are scaled up/down
 * @setup_clocks: called before touching any of the controller registers
 * @setup_regulators: called before accessing the host controller
 * @hce_enable_notify: called before and after HCE enable bit is set to allow
 *                     variant specific Uni-Pro initialization.
 * @link_startup_notify: called before and after Link startup is carried out
 *                       to allow variant specific Uni-Pro initialization.
 * @pwr_change_notify: called before and after a power mode change
 *                      is carried out to allow vendor spesific capabilities
 *                      to be set.
 * @suspend: called during host controller PM callback
 * @resume: called during host controller PM callback
 */
struct ufs_hba_variant_ops {
        const char *name;
        int     (*init)(struct ufs_hba *);
        void    (*exit)(struct ufs_hba *);
        u32     (*get_ufs_hci_version)(struct ufs_hba *);
        void    (*clk_scale_notify)(struct ufs_hba *);
        int     (*setup_clocks)(struct ufs_hba *, bool);
        int     (*setup_regulators)(struct ufs_hba *, bool);
        int     (*hce_enable_notify)(struct ufs_hba *, bool);
        int     (*link_startup_notify)(struct ufs_hba *, bool);
        int     (*pwr_change_notify)(struct ufs_hba *,
                                        bool, struct ufs_pa_layer_attr *,
                                        struct ufs_pa_layer_attr *);
        int     (*suspend)(struct ufs_hba *, enum ufs_pm_op);
        int     (*resume)(struct ufs_hba *, enum ufs_pm_op);
};

/* clock gating state  */
enum clk_gating_state {
        CLKS_OFF,
        CLKS_ON,
        REQ_CLKS_OFF,
        REQ_CLKS_ON,
};

/**
 * struct ufs_clk_gating - UFS clock gating related info
 * @gate_work: worker to turn off clocks after some delay as specified in
 * delay_ms
 * @ungate_work: worker to turn on clocks that will be used in case of
 * interrupt context
 * @state: the current clocks state
 * @delay_ms: gating delay in ms
 * @is_suspended: clk gating is suspended when set to 1 which can be used
 * during suspend/resume
 * @delay_attr: sysfs attribute to control delay_attr
 * @active_reqs: number of requests that are pending and should be waited for
 * completion before gating clocks.
 */
struct ufs_clk_gating {
        struct delayed_work gate_work;
        struct work_struct ungate_work;
        enum clk_gating_state state;
        unsigned long delay_ms;
        bool is_suspended;
        struct device_attribute delay_attr;
        int active_reqs;
};

struct ufs_clk_scaling {
        ktime_t  busy_start_t;
        bool is_busy_started;
        unsigned long  tot_busy_t;
        unsigned long window_start_t;
};

/**
 * struct ufs_init_prefetch - contains data that is pre-fetched once during
 * initialization
 * @icc_level: icc level which was read during initialization
 */
struct ufs_init_prefetch {
        u32 icc_level;
};

/**
 * struct ufs_hba - per adapter private structure
 * @mmio_base: UFSHCI base register address
 * @ucdl_base_addr: UFS Command Descriptor base address
 * @utrdl_base_addr: UTP Transfer Request Descriptor base address
 * @utmrdl_base_addr: UTP Task Management Descriptor base address
 * @ucdl_dma_addr: UFS Command Descriptor DMA address
 * @utrdl_dma_addr: UTRDL DMA address
 * @utmrdl_dma_addr: UTMRDL DMA address
 * @host: Scsi_Host instance of the driver
 * @dev: device handle
 * @lrb: local reference block
 * @lrb_in_use: lrb in use
 * @outstanding_tasks: Bits representing outstanding task requests
 * @outstanding_reqs: Bits representing outstanding transfer requests
 * @capabilities: UFS Controller Capabilities
 * @nutrs: Transfer Request Queue depth supported by controller
 * @nutmrs: Task Management Queue depth supported by controller
 * @ufs_version: UFS Version to which controller complies
 * @vops: pointer to variant specific operations
 * @priv: pointer to variant specific private data
 * @irq: Irq number of the controller
 * @active_uic_cmd: handle of active UIC command
 * @uic_cmd_mutex: mutex for uic command
 * @tm_wq: wait queue for task management
 * @tm_tag_wq: wait queue for free task management slots
 * @tm_slots_in_use: bit map of task management request slots in use
 * @pwr_done: completion for power mode change
 * @tm_condition: condition variable for task management
 * @ufshcd_state: UFSHCD states
 * @eh_flags: Error handling flags
 * @intr_mask: Interrupt Mask Bits
 * @ee_ctrl_mask: Exception event control mask
 * @is_powered: flag to check if HBA is powered
 * @is_init_prefetch: flag to check if data was pre-fetched in initialization
 * @init_prefetch_data: data pre-fetched during initialization
 * @eh_work: Worker to handle UFS errors that require s/w attention
 * @eeh_work: Worker to handle exception events
 * @errors: HBA errors
 * @uic_error: UFS interconnect layer error status
 * @saved_err: sticky error mask
 * @saved_uic_err: sticky UIC error mask
 * @dev_cmd: ufs device management command information
 * @last_dme_cmd_tstamp: time stamp of the last completed DME command
 * @auto_bkops_enabled: to track whether bkops is enabled in device
 * @vreg_info: UFS device voltage regulator information
 * @clk_list_head: UFS host controller clocks list node head
 * @pwr_info: holds current power mode
 * @max_pwr_info: keeps the device max valid pwm
 */
struct ufs_hba {
        void __iomem *mmio_base;

        /* Virtual memory reference */
        struct utp_transfer_cmd_desc *ucdl_base_addr;
        struct utp_transfer_req_desc *utrdl_base_addr;
        struct utp_task_req_desc *utmrdl_base_addr;

        /* DMA memory reference */
        dma_addr_t ucdl_dma_addr;
        dma_addr_t utrdl_dma_addr;
        dma_addr_t utmrdl_dma_addr;

        struct Scsi_Host *host;
        struct device *dev;
        /*
         * This field is to keep a reference to "scsi_device" corresponding to
         * "UFS device" W-LU.
         */
        struct scsi_device *sdev_ufs_device;

        enum ufs_dev_pwr_mode curr_dev_pwr_mode;
        enum uic_link_state uic_link_state;
        /* Desired UFS power management level during runtime PM */
        enum ufs_pm_level rpm_lvl;
        /* Desired UFS power management level during system PM */
        enum ufs_pm_level spm_lvl;
        int pm_op_in_progress;

        struct ufshcd_lrb *lrb;
        unsigned long lrb_in_use;

        unsigned long outstanding_tasks;
        unsigned long outstanding_reqs;

        u32 capabilities;
        int nutrs;
        int nutmrs;
        u32 ufs_version;
        struct ufs_hba_variant_ops *vops;
        void *priv;
        unsigned int irq;
        bool is_irq_enabled;

        /* Interrupt aggregation support is broken */
        #define UFSHCD_QUIRK_BROKEN_INTR_AGGR                   UFS_BIT(0)

        /*
         * delay before each dme command is required as the unipro
         * layer has shown instabilities
         */
        #define UFSHCD_QUIRK_DELAY_BEFORE_DME_CMDS              UFS_BIT(1)

        /*
         * If UFS host controller is having issue in processing LCC (Line
         * Control Command) coming from device then enable this quirk.
         * When this quirk is enabled, host controller driver should disable
         * the LCC transmission on UFS device (by clearing TX_LCC_ENABLE
         * attribute of device to 0).
         */
        #define UFSHCD_QUIRK_BROKEN_LCC                         UFS_BIT(2)

        /*
         * The attribute PA_RXHSUNTERMCAP specifies whether or not the
         * inbound Link supports unterminated line in HS mode. Setting this
         * attribute to 1 fixes moving to HS gear.
         */
        #define UFSHCD_QUIRK_BROKEN_PA_RXHSUNTERMCAP            UFS_BIT(3)

        /*
         * This quirk needs to be enabled if the host contoller only allows
         * accessing the peer dme attributes in AUTO mode (FAST AUTO or
         * SLOW AUTO).
         */
        #define UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE          UFS_BIT(4)

        /*
         * This quirk needs to be enabled if the host contoller doesn't
         * advertise the correct version in UFS_VER register. If this quirk
         * is enabled, standard UFS host driver will call the vendor specific
         * ops (get_ufs_hci_version) to get the correct version.
         */
        #define UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION             UFS_BIT(5)

        unsigned int quirks;    /* Deviations from standard UFSHCI spec. */

        wait_queue_head_t tm_wq;
        wait_queue_head_t tm_tag_wq;
        unsigned long tm_condition;
        unsigned long tm_slots_in_use;

        struct uic_command *active_uic_cmd;
        struct mutex uic_cmd_mutex;
        struct completion *uic_async_done;

        u32 ufshcd_state;
        u32 eh_flags;
        u32 intr_mask;
        u16 ee_ctrl_mask;
        bool is_powered;
        bool is_init_prefetch;
        struct ufs_init_prefetch init_prefetch_data;

        /* Work Queues */
        struct work_struct eh_work;
        struct work_struct eeh_work;

        /* HBA Errors */
        u32 errors;
        u32 uic_error;
        u32 saved_err;
        u32 saved_uic_err;

        /* Device management request data */
        struct ufs_dev_cmd dev_cmd;
        ktime_t last_dme_cmd_tstamp;

        /* Keeps information of the UFS device connected to this host */
        struct ufs_dev_info dev_info;
        bool auto_bkops_enabled;
        struct ufs_vreg_info vreg_info;
        struct list_head clk_list_head;

        bool wlun_dev_clr_ua;

        struct ufs_pa_layer_attr pwr_info;
        struct ufs_pwr_mode_info max_pwr_info;

        struct ufs_clk_gating clk_gating;
        /* Control to enable/disable host capabilities */
        u32 caps;
        /* Allow dynamic clk gating */
#define UFSHCD_CAP_CLK_GATING   (1 << 0)
        /* Allow hiberb8 with clk gating */
#define UFSHCD_CAP_HIBERN8_WITH_CLK_GATING (1 << 1)
        /* Allow dynamic clk scaling */
#define UFSHCD_CAP_CLK_SCALING  (1 << 2)
        /* Allow auto bkops to enabled during runtime suspend */
#define UFSHCD_CAP_AUTO_BKOPS_SUSPEND (1 << 3)
        /*
         * This capability allows host controller driver to use the UFS HCI's
         * interrupt aggregation capability.
         * CAUTION: Enabling this might reduce overall UFS throughput.
         */
#define UFSHCD_CAP_INTR_AGGR (1 << 4)

        struct devfreq *devfreq;
        struct ufs_clk_scaling clk_scaling;
        bool is_sys_suspended;
};

/* Returns true if clocks can be gated. Otherwise false */
static inline bool ufshcd_is_clkgating_allowed(struct ufs_hba *hba)
{
        return hba->caps & UFSHCD_CAP_CLK_GATING;
}
static inline bool ufshcd_can_hibern8_during_gating(struct ufs_hba *hba)
{
        return hba->caps & UFSHCD_CAP_HIBERN8_WITH_CLK_GATING;
}
static inline int ufshcd_is_clkscaling_enabled(struct ufs_hba *hba)
{
        return hba->caps & UFSHCD_CAP_CLK_SCALING;
}
static inline bool ufshcd_can_autobkops_during_suspend(struct ufs_hba *hba)
{
        return hba->caps & UFSHCD_CAP_AUTO_BKOPS_SUSPEND;
}

static inline bool ufshcd_is_intr_aggr_allowed(struct ufs_hba *hba)
{
        if ((hba->caps & UFSHCD_CAP_INTR_AGGR) &&
            !(hba->quirks & UFSHCD_QUIRK_BROKEN_INTR_AGGR))
                return true;
        else
                return false;
}

#define ufshcd_writel(hba, val, reg)    \
        writel((val), (hba)->mmio_base + (reg))
#define ufshcd_readl(hba, reg)  \
        readl((hba)->mmio_base + (reg))

/**
 * ufshcd_rmwl - read modify write into a register
 * @hba - per adapter instance
 * @mask - mask to apply on read value
 * @val - actual value to write
 * @reg - register address
 */
static inline void ufshcd_rmwl(struct ufs_hba *hba, u32 mask, u32 val, u32 reg)
{
        u32 tmp;

        tmp = ufshcd_readl(hba, reg);
        tmp &= ~mask;
        tmp |= (val & mask);
        ufshcd_writel(hba, tmp, reg);
}

int ufshcd_alloc_host(struct device *, struct ufs_hba **);
int ufshcd_init(struct ufs_hba * , void __iomem * , unsigned int);
void ufshcd_remove(struct ufs_hba *);

/**
 * ufshcd_hba_stop - Send controller to reset state
 * @hba: per adapter instance
 */
static inline void ufshcd_hba_stop(struct ufs_hba *hba)
{
        ufshcd_writel(hba, CONTROLLER_DISABLE,  REG_CONTROLLER_ENABLE);
}

static inline void check_upiu_size(void)
{
        BUILD_BUG_ON(ALIGNED_UPIU_SIZE <
                GENERAL_UPIU_REQUEST_SIZE + QUERY_DESC_MAX_SIZE);
}

extern int ufshcd_runtime_suspend(struct ufs_hba *hba);
extern int ufshcd_runtime_resume(struct ufs_hba *hba);
extern int ufshcd_runtime_idle(struct ufs_hba *hba);
extern int ufshcd_system_suspend(struct ufs_hba *hba);
extern int ufshcd_system_resume(struct ufs_hba *hba);
extern int ufshcd_shutdown(struct ufs_hba *hba);
extern int ufshcd_dme_set_attr(struct ufs_hba *hba, u32 attr_sel,
                               u8 attr_set, u32 mib_val, u8 peer);
extern int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel,
                               u32 *mib_val, u8 peer);

/* UIC command interfaces for DME primitives */
#define DME_LOCAL       0
#define DME_PEER        1
#define ATTR_SET_NOR    0       /* NORMAL */
#define ATTR_SET_ST     1       /* STATIC */

static inline int ufshcd_dme_set(struct ufs_hba *hba, u32 attr_sel,
                                 u32 mib_val)
{
        return ufshcd_dme_set_attr(hba, attr_sel, ATTR_SET_NOR,
                                   mib_val, DME_LOCAL);
}

static inline int ufshcd_dme_st_set(struct ufs_hba *hba, u32 attr_sel,
                                    u32 mib_val)
{
        return ufshcd_dme_set_attr(hba, attr_sel, ATTR_SET_ST,
                                   mib_val, DME_LOCAL);
}

static inline int ufshcd_dme_peer_set(struct ufs_hba *hba, u32 attr_sel,
                                      u32 mib_val)
{
        return ufshcd_dme_set_attr(hba, attr_sel, ATTR_SET_NOR,
                                   mib_val, DME_PEER);
}

static inline int ufshcd_dme_peer_st_set(struct ufs_hba *hba, u32 attr_sel,
                                         u32 mib_val)
{
        return ufshcd_dme_set_attr(hba, attr_sel, ATTR_SET_ST,
                                   mib_val, DME_PEER);
}

static inline int ufshcd_dme_get(struct ufs_hba *hba,
                                 u32 attr_sel, u32 *mib_val)
{
        return ufshcd_dme_get_attr(hba, attr_sel, mib_val, DME_LOCAL);
}

static inline int ufshcd_dme_peer_get(struct ufs_hba *hba,
                                      u32 attr_sel, u32 *mib_val)
{
        return ufshcd_dme_get_attr(hba, attr_sel, mib_val, DME_PEER);
}

int ufshcd_hold(struct ufs_hba *hba, bool async);
void ufshcd_release(struct ufs_hba *hba);
#endif /* End of Header */