/*
 * Synopsys DesignWare Multimedia Card Interface driver
 *  (Based on NXP driver for lpc 31xx)
 *
 * Copyright (C) 2009 NXP Semiconductors
 * Copyright (C) 2009, 2010 Imagination Technologies Ltd.
 *
 * 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.
 */

#ifndef LINUX_MMC_DW_MMC_H
#define LINUX_MMC_DW_MMC_H

#include <linux/scatterlist.h>
#include <linux/mmc/core.h>
#include <linux/dmaengine.h>

#define MAX_MCI_SLOTS   2

enum dw_mci_state {
        STATE_IDLE = 0,
        STATE_SENDING_CMD,
        STATE_SENDING_DATA,
        STATE_DATA_BUSY,
        STATE_SENDING_STOP,
        STATE_DATA_ERROR,
        STATE_SENDING_CMD11,
        STATE_WAITING_CMD11_DONE,
};

enum {
        EVENT_CMD_COMPLETE = 0,
        EVENT_XFER_COMPLETE,
        EVENT_DATA_COMPLETE,
        EVENT_DATA_ERROR,
        EVENT_XFER_ERROR
};

struct mmc_data;

enum {
        TRANS_MODE_PIO = 0,
        TRANS_MODE_IDMAC,
        TRANS_MODE_EDMAC
};

struct dw_mci_dma_slave {
        struct dma_chan *ch;
        enum dma_transfer_direction direction;
};

/**
 * struct dw_mci - MMC controller state shared between all slots
 * @lock: Spinlock protecting the queue and associated data.
 * @regs: Pointer to MMIO registers.
 * @fifo_reg: Pointer to MMIO registers for data FIFO
 * @sg: Scatterlist entry currently being processed by PIO code, if any.
 * @sg_miter: PIO mapping scatterlist iterator.
 * @cur_slot: The slot which is currently using the controller.
 * @mrq: The request currently being processed on @cur_slot,
 *      or NULL if the controller is idle.
 * @cmd: The command currently being sent to the card, or NULL.
 * @data: The data currently being transferred, or NULL if no data
 *      transfer is in progress.
 * @use_dma: Whether DMA channel is initialized or not.
 * @using_dma: Whether DMA is in use for the current transfer.
 * @dma_64bit_address: Whether DMA supports 64-bit address mode or not.
 * @sg_dma: Bus address of DMA buffer.
 * @sg_cpu: Virtual address of DMA buffer.
 * @dma_ops: Pointer to platform-specific DMA callbacks.
 * @cmd_status: Snapshot of SR taken upon completion of the current
 *      command. Only valid when EVENT_CMD_COMPLETE is pending.
 * @data_status: Snapshot of SR taken upon completion of the current
 *      data transfer. Only valid when EVENT_DATA_COMPLETE or
 *      EVENT_DATA_ERROR is pending.
 * @stop_cmdr: Value to be loaded into CMDR when the stop command is
 *      to be sent.
 * @dir_status: Direction of current transfer.
 * @tasklet: Tasklet running the request state machine.
 * @card_tasklet: Tasklet handling card detect.
 * @pending_events: Bitmask of events flagged by the interrupt handler
 *      to be processed by the tasklet.
 * @completed_events: Bitmask of events which the state machine has
 *      processed.
 * @state: Tasklet state.
 * @queue: List of slots waiting for access to the controller.
 * @bus_hz: The rate of @mck in Hz. This forms the basis for MMC bus
 *      rate and timeout calculations.
 * @current_speed: Configured rate of the controller.
 * @num_slots: Number of slots available.
 * @verid: Denote Version ID.
 * @dev: Device associated with the MMC controller.
 * @pdata: Platform data associated with the MMC controller.
 * @drv_data: Driver specific data for identified variant of the controller
 * @priv: Implementation defined private data.
 * @biu_clk: Pointer to bus interface unit clock instance.
 * @ciu_clk: Pointer to card interface unit clock instance.
 * @slot: Slots sharing this MMC controller.
 * @fifo_depth: depth of FIFO.
 * @data_shift: log2 of FIFO item size.
 * @part_buf_start: Start index in part_buf.
 * @part_buf_count: Bytes of partial data in part_buf.
 * @part_buf: Simple buffer for partial fifo reads/writes.
 * @push_data: Pointer to FIFO push function.
 * @pull_data: Pointer to FIFO pull function.
 * @quirks: Set of quirks that apply to specific versions of the IP.
 * @irq_flags: The flags to be passed to request_irq.
 * @irq: The irq value to be passed to request_irq.
 * @sdio_id0: Number of slot0 in the SDIO interrupt registers.
 * @dto_timer: Timer for broken data transfer over scheme.
 *
 * Locking
 * =======
 *
 * @lock is a softirq-safe spinlock protecting @queue as well as
 * @cur_slot, @mrq and @state. These must always be updated
 * at the same time while holding @lock.
 *
 * @irq_lock is an irq-safe spinlock protecting the INTMASK register
 * to allow the interrupt handler to modify it directly.  Held for only long
 * enough to read-modify-write INTMASK and no other locks are grabbed when
 * holding this one.
 *
 * The @mrq field of struct dw_mci_slot is also protected by @lock,
 * and must always be written at the same time as the slot is added to
 * @queue.
 *
 * @pending_events and @completed_events are accessed using atomic bit
 * operations, so they don't need any locking.
 *
 * None of the fields touched by the interrupt handler need any
 * locking. However, ordering is important: Before EVENT_DATA_ERROR or
 * EVENT_DATA_COMPLETE is set in @pending_events, all data-related
 * interrupts must be disabled and @data_status updated with a
 * snapshot of SR. Similarly, before EVENT_CMD_COMPLETE is set, the
 * CMDRDY interrupt must be disabled and @cmd_status updated with a
 * snapshot of SR, and before EVENT_XFER_COMPLETE can be set, the
 * bytes_xfered field of @data must be written. This is ensured by
 * using barriers.
 */
struct dw_mci {
        spinlock_t              lock;
        spinlock_t              irq_lock;
        void __iomem            *regs;
        void __iomem            *fifo_reg;

        struct scatterlist      *sg;
        struct sg_mapping_iter  sg_miter;

        struct dw_mci_slot      *cur_slot;
        struct mmc_request      *mrq;
        struct mmc_command      *cmd;
        struct mmc_data         *data;
        struct mmc_command      stop_abort;
        unsigned int            prev_blksz;
        unsigned char           timing;

        /* DMA interface members*/
        int                     use_dma;
        int                     using_dma;
        int                     dma_64bit_address;

        dma_addr_t              sg_dma;
        void                    *sg_cpu;
        const struct dw_mci_dma_ops     *dma_ops;
        /* For idmac */
        unsigned int            ring_size;

        /* For edmac */
        struct dw_mci_dma_slave *dms;
        /* Registers's physical base address */
        resource_size_t         phy_regs;

        u32                     cmd_status;
        u32                     data_status;
        u32                     stop_cmdr;
        u32                     dir_status;
        struct tasklet_struct   tasklet;
        unsigned long           pending_events;
        unsigned long           completed_events;
        enum dw_mci_state       state;
        struct list_head        queue;

        u32                     bus_hz;
        u32                     current_speed;
        u32                     num_slots;
        u32                     fifoth_val;
        u16                     verid;
        struct device           *dev;
        struct dw_mci_board     *pdata;
        const struct dw_mci_drv_data    *drv_data;
        void                    *priv;
        struct clk              *biu_clk;
        struct clk              *ciu_clk;
        struct dw_mci_slot      *slot[MAX_MCI_SLOTS];

        /* FIFO push and pull */
        int                     fifo_depth;
        int                     data_shift;
        u8                      part_buf_start;
        u8                      part_buf_count;
        union {
                u16             part_buf16;
                u32             part_buf32;
                u64             part_buf;
        };
        void (*push_data)(struct dw_mci *host, void *buf, int cnt);
        void (*pull_data)(struct dw_mci *host, void *buf, int cnt);

        /* Workaround flags */
        u32                     quirks;

        bool                    vqmmc_enabled;
        unsigned long           irq_flags; /* IRQ flags */
        int                     irq;

        int                     sdio_id0;

        struct timer_list       cmd11_timer;
        struct timer_list       dto_timer;
};

/* DMA ops for Internal/External DMAC interface */
struct dw_mci_dma_ops {
        /* DMA Ops */
        int (*init)(struct dw_mci *host);
        int (*start)(struct dw_mci *host, unsigned int sg_len);
        void (*complete)(void *host);
        void (*stop)(struct dw_mci *host);
        void (*cleanup)(struct dw_mci *host);
        void (*exit)(struct dw_mci *host);
};

/* IP Quirks/flags. */
/* Timer for broken data transfer over scheme */
#define DW_MCI_QUIRK_BROKEN_DTO                 BIT(0)

struct dma_pdata;

/* Board platform data */
struct dw_mci_board {
        u32 num_slots;

        u32 quirks; /* Workaround / Quirk flags */
        unsigned int bus_hz; /* Clock speed at the cclk_in pad */

        u32 caps;       /* Capabilities */
        u32 caps2;      /* More capabilities */
        u32 pm_caps;    /* PM capabilities */
        /*
         * Override fifo depth. If 0, autodetect it from the FIFOTH register,
         * but note that this may not be reliable after a bootloader has used
         * it.
         */
        unsigned int fifo_depth;

        /* delay in mS before detecting cards after interrupt */
        u32 detect_delay_ms;

        struct dw_mci_dma_ops *dma_ops;
        struct dma_pdata *data;
};

#endif /* LINUX_MMC_DW_MMC_H */