/*
 * BRIEF MODULE DESCRIPTION
 *      Defines for using and allocating DMA channels on the Alchemy
 *      Au1x00 MIPS processors.
 *
 * Copyright 2000, 2008 MontaVista Software Inc.
 * Author: MontaVista Software, Inc. <source@mvista.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.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``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 AUTHOR  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.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#ifndef __ASM_AU1000_DMA_H
#define __ASM_AU1000_DMA_H

#include <linux/io.h>           /* need byte IO */
#include <linux/spinlock.h>     /* And spinlocks */
#include <linux/delay.h>

#define NUM_AU1000_DMA_CHANNELS 8

/* DMA Channel Register Offsets */
#define DMA_MODE_SET            0x00000000
#define DMA_MODE_READ           DMA_MODE_SET
#define DMA_MODE_CLEAR          0x00000004
/* DMA Mode register bits follow */
#define DMA_DAH_MASK            (0x0f << 20)
#define DMA_DID_BIT             16
#define DMA_DID_MASK            (0x0f << DMA_DID_BIT)
#define DMA_DS                  (1 << 15)
#define DMA_BE                  (1 << 13)
#define DMA_DR                  (1 << 12)
#define DMA_TS8                 (1 << 11)
#define DMA_DW_BIT              9
#define DMA_DW_MASK             (0x03 << DMA_DW_BIT)
#define DMA_DW8                 (0 << DMA_DW_BIT)
#define DMA_DW16                (1 << DMA_DW_BIT)
#define DMA_DW32                (2 << DMA_DW_BIT)
#define DMA_NC                  (1 << 8)
#define DMA_IE                  (1 << 7)
#define DMA_HALT                (1 << 6)
#define DMA_GO                  (1 << 5)
#define DMA_AB                  (1 << 4)
#define DMA_D1                  (1 << 3)
#define DMA_BE1                 (1 << 2)
#define DMA_D0                  (1 << 1)
#define DMA_BE0                 (1 << 0)

#define DMA_PERIPHERAL_ADDR     0x00000008
#define DMA_BUFFER0_START       0x0000000C
#define DMA_BUFFER1_START       0x00000014
#define DMA_BUFFER0_COUNT       0x00000010
#define DMA_BUFFER1_COUNT       0x00000018
#define DMA_BAH_BIT     16
#define DMA_BAH_MASK    (0x0f << DMA_BAH_BIT)
#define DMA_COUNT_BIT   0
#define DMA_COUNT_MASK  (0xffff << DMA_COUNT_BIT)

/* DMA Device IDs follow */
enum {
        DMA_ID_UART0_TX = 0,
        DMA_ID_UART0_RX,
        DMA_ID_GP04,
        DMA_ID_GP05,
        DMA_ID_AC97C_TX,
        DMA_ID_AC97C_RX,
        DMA_ID_UART3_TX,
        DMA_ID_UART3_RX,
        DMA_ID_USBDEV_EP0_RX,
        DMA_ID_USBDEV_EP0_TX,
        DMA_ID_USBDEV_EP2_TX,
        DMA_ID_USBDEV_EP3_TX,
        DMA_ID_USBDEV_EP4_RX,
        DMA_ID_USBDEV_EP5_RX,
        DMA_ID_I2S_TX,
        DMA_ID_I2S_RX,
        DMA_NUM_DEV
};

/* DMA Device ID's for 2nd bank (AU1100) follow */
enum {
        DMA_ID_SD0_TX = 0,
        DMA_ID_SD0_RX,
        DMA_ID_SD1_TX,
        DMA_ID_SD1_RX,
        DMA_NUM_DEV_BANK2
};

struct dma_chan {
        int dev_id;             /* this channel is allocated if >= 0, */
                                /* free otherwise */
        void __iomem *io;
        const char *dev_str;
        int irq;
        void *irq_dev;
        unsigned int fifo_addr;
        unsigned int mode;
};

/* These are in arch/mips/au1000/common/dma.c */
extern struct dma_chan au1000_dma_table[];
extern int request_au1000_dma(int dev_id,
                              const char *dev_str,
                              irq_handler_t irqhandler,
                              unsigned long irqflags,
                              void *irq_dev_id);
extern void free_au1000_dma(unsigned int dmanr);
extern int au1000_dma_read_proc(char *buf, char **start, off_t fpos,
                                int length, int *eof, void *data);
extern spinlock_t au1000_dma_spin_lock;

static inline struct dma_chan *get_dma_chan(unsigned int dmanr)
{
        if (dmanr >= NUM_AU1000_DMA_CHANNELS ||
            au1000_dma_table[dmanr].dev_id < 0)
                return NULL;
        return &au1000_dma_table[dmanr];
}

static inline unsigned long claim_dma_lock(void)
{
        unsigned long flags;

        spin_lock_irqsave(&au1000_dma_spin_lock, flags);
        return flags;
}

static inline void release_dma_lock(unsigned long flags)
{
        spin_unlock_irqrestore(&au1000_dma_spin_lock, flags);
}

/*
 * Set the DMA buffer enable bits in the mode register.
 */
static inline void enable_dma_buffer0(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_BE0, chan->io + DMA_MODE_SET);
}

static inline void enable_dma_buffer1(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_BE1, chan->io + DMA_MODE_SET);
}
static inline void enable_dma_buffers(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_BE0 | DMA_BE1, chan->io + DMA_MODE_SET);
}

static inline void start_dma(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_GO, chan->io + DMA_MODE_SET);
}

#define DMA_HALT_POLL 0x5000

static inline void halt_dma(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);
        int i;

        if (!chan)
                return;
        __raw_writel(DMA_GO, chan->io + DMA_MODE_CLEAR);

        /* Poll the halt bit */
        for (i = 0; i < DMA_HALT_POLL; i++)
                if (__raw_readl(chan->io + DMA_MODE_READ) & DMA_HALT)
                        break;
        if (i == DMA_HALT_POLL)
                printk(KERN_INFO "halt_dma: HALT poll expired!\n");
}

static inline void disable_dma(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;

        halt_dma(dmanr);

        /* Now we can disable the buffers */
        __raw_writel(~DMA_GO, chan->io + DMA_MODE_CLEAR);
}

static inline int dma_halted(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return 1;
        return (__raw_readl(chan->io + DMA_MODE_READ) & DMA_HALT) ? 1 : 0;
}

/* Initialize a DMA channel. */
static inline void init_dma(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);
        u32 mode;

        if (!chan)
                return;

        disable_dma(dmanr);

        /* Set device FIFO address */
        __raw_writel(CPHYSADDR(chan->fifo_addr), chan->io + DMA_PERIPHERAL_ADDR);

        mode = chan->mode | (chan->dev_id << DMA_DID_BIT);
        if (chan->irq)
                mode |= DMA_IE;

        __raw_writel(~mode, chan->io + DMA_MODE_CLEAR);
        __raw_writel(mode,       chan->io + DMA_MODE_SET);
}

/*
 * Set mode for a specific DMA channel
 */
static inline void set_dma_mode(unsigned int dmanr, unsigned int mode)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        /*
         * set_dma_mode is only allowed to change endianness, direction,
         * transfer size, device FIFO width, and coherency settings.
         * Make sure anything else is masked off.
         */
        mode &= (DMA_BE | DMA_DR | DMA_TS8 | DMA_DW_MASK | DMA_NC);
        chan->mode &= ~(DMA_BE | DMA_DR | DMA_TS8 | DMA_DW_MASK | DMA_NC);
        chan->mode |= mode;
}

static inline unsigned int get_dma_mode(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return 0;
        return chan->mode;
}

static inline int get_dma_active_buffer(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return -1;
        return (__raw_readl(chan->io + DMA_MODE_READ) & DMA_AB) ? 1 : 0;
}

/*
 * Set the device FIFO address for a specific DMA channel - only
 * applicable to GPO4 and GPO5. All the other devices have fixed
 * FIFO addresses.
 */
static inline void set_dma_fifo_addr(unsigned int dmanr, unsigned int a)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;

        if (chan->mode & DMA_DS)        /* second bank of device IDs */
                return;

        if (chan->dev_id != DMA_ID_GP04 && chan->dev_id != DMA_ID_GP05)
                return;

        __raw_writel(CPHYSADDR(a), chan->io + DMA_PERIPHERAL_ADDR);
}

/*
 * Clear the DMA buffer done bits in the mode register.
 */
static inline void clear_dma_done0(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_D0, chan->io + DMA_MODE_CLEAR);
}

static inline void clear_dma_done1(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(DMA_D1, chan->io + DMA_MODE_CLEAR);
}

/*
 * This does nothing - not applicable to Au1000 DMA.
 */
static inline void set_dma_page(unsigned int dmanr, char pagenr)
{
}

/*
 * Set Buffer 0 transfer address for specific DMA channel.
 */
static inline void set_dma_addr0(unsigned int dmanr, unsigned int a)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(a, chan->io + DMA_BUFFER0_START);
}

/*
 * Set Buffer 1 transfer address for specific DMA channel.
 */
static inline void set_dma_addr1(unsigned int dmanr, unsigned int a)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        __raw_writel(a, chan->io + DMA_BUFFER1_START);
}


/*
 * Set Buffer 0 transfer size (max 64k) for a specific DMA channel.
 */
static inline void set_dma_count0(unsigned int dmanr, unsigned int count)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        count &= DMA_COUNT_MASK;
        __raw_writel(count, chan->io + DMA_BUFFER0_COUNT);
}

/*
 * Set Buffer 1 transfer size (max 64k) for a specific DMA channel.
 */
static inline void set_dma_count1(unsigned int dmanr, unsigned int count)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        count &= DMA_COUNT_MASK;
        __raw_writel(count, chan->io + DMA_BUFFER1_COUNT);
}

/*
 * Set both buffer transfer sizes (max 64k) for a specific DMA channel.
 */
static inline void set_dma_count(unsigned int dmanr, unsigned int count)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return;
        count &= DMA_COUNT_MASK;
        __raw_writel(count, chan->io + DMA_BUFFER0_COUNT);
        __raw_writel(count, chan->io + DMA_BUFFER1_COUNT);
}

/*
 * Returns which buffer has its done bit set in the mode register.
 * Returns -1 if neither or both done bits set.
 */
static inline unsigned int get_dma_buffer_done(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return 0;
        return __raw_readl(chan->io + DMA_MODE_READ) & (DMA_D0 | DMA_D1);
}


/*
 * Returns the DMA channel's Buffer Done IRQ number.
 */
static inline int get_dma_done_irq(unsigned int dmanr)
{
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return -1;
        return chan->irq;
}

/*
 * Get DMA residue count. Returns the number of _bytes_ left to transfer.
 */
static inline int get_dma_residue(unsigned int dmanr)
{
        int curBufCntReg, count;
        struct dma_chan *chan = get_dma_chan(dmanr);

        if (!chan)
                return 0;

        curBufCntReg = (__raw_readl(chan->io + DMA_MODE_READ) & DMA_AB) ?
            DMA_BUFFER1_COUNT : DMA_BUFFER0_COUNT;

        count = __raw_readl(chan->io + curBufCntReg) & DMA_COUNT_MASK;

        if ((chan->mode & DMA_DW_MASK) == DMA_DW16)
                count <<= 1;
        else if ((chan->mode & DMA_DW_MASK) == DMA_DW32)
                count <<= 2;

        return count;
}

#endif /* __ASM_AU1000_DMA_H */