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dma.c

/*
 * EDMA3 support for DaVinci
 *
 * Copyright (C) 2006-2009 Texas Instruments.
 *
 * 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 program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/compiler.h>
#include <linux/io.h>

#include <mach/cputype.h>
#include <mach/memory.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
#include <mach/edma.h>
#include <mach/mux.h>


/* Offsets matching "struct edmacc_param" */
#define PARM_OPT        0x00
#define PARM_SRC        0x04
#define PARM_A_B_CNT          0x08
#define PARM_DST        0x0c
#define PARM_SRC_DST_BIDX     0x10
#define PARM_LINK_BCNTRLD     0x14
#define PARM_SRC_DST_CIDX     0x18
#define PARM_CCNT       0x1c

#define PARM_SIZE       0x20

/* Offsets for EDMA CC global channel registers and their shadows */
#define SH_ER           0x00  /* 64 bits */
#define SH_ECR          0x08  /* 64 bits */
#define SH_ESR          0x10  /* 64 bits */
#define SH_CER          0x18  /* 64 bits */
#define SH_EER          0x20  /* 64 bits */
#define SH_EECR         0x28  /* 64 bits */
#define SH_EESR         0x30  /* 64 bits */
#define SH_SER          0x38  /* 64 bits */
#define SH_SECR         0x40  /* 64 bits */
#define SH_IER          0x50  /* 64 bits */
#define SH_IECR         0x58  /* 64 bits */
#define SH_IESR         0x60  /* 64 bits */
#define SH_IPR          0x68  /* 64 bits */
#define SH_ICR          0x70  /* 64 bits */
#define SH_IEVAL  0x78
#define SH_QER          0x80
#define SH_QEER         0x84
#define SH_QEECR  0x88
#define SH_QEESR  0x8c
#define SH_QSER         0x90
#define SH_QSECR  0x94
#define SH_SIZE         0x200

/* Offsets for EDMA CC global registers */
#define EDMA_REV  0x0000
#define EDMA_CCCFG      0x0004
#define EDMA_QCHMAP     0x0200      /* 8 registers */
#define EDMA_DMAQNUM    0x0240      /* 8 registers (4 on OMAP-L1xx) */
#define EDMA_QDMAQNUM   0x0260
#define EDMA_QUETCMAP   0x0280
#define EDMA_QUEPRI     0x0284
#define EDMA_EMR  0x0300      /* 64 bits */
#define EDMA_EMCR 0x0308      /* 64 bits */
#define EDMA_QEMR 0x0310
#define EDMA_QEMCR      0x0314
#define EDMA_CCERR      0x0318
#define EDMA_CCERRCLR   0x031c
#define EDMA_EEVAL      0x0320
#define EDMA_DRAE 0x0340      /* 4 x 64 bits*/
#define EDMA_QRAE 0x0380      /* 4 registers */
#define EDMA_QUEEVTENTRY      0x0400      /* 2 x 16 registers */
#define EDMA_QSTAT      0x0600      /* 2 registers */
#define EDMA_QWMTHRA    0x0620
#define EDMA_QWMTHRB    0x0624
#define EDMA_CCSTAT     0x0640

#define EDMA_M          0x1000      /* global channel registers */
#define EDMA_ECR  0x1008
#define EDMA_ECRH 0x100C
#define EDMA_SHADOW0    0x2000      /* 4 regions shadowing global channels */
#define EDMA_PARM 0x4000      /* 128 param entries */

#define DAVINCI_DMA_3PCC_BASE 0x01C00000

#define PARM_OFFSET(param_no) (EDMA_PARM + ((param_no) << 5))

#define EDMA_MAX_DMACH           64
#define EDMA_MAX_PARAMENTRY     512
#define EDMA_MAX_EVQUE            2 /* FIXME too small */


/*****************************************************************************/

static void __iomem *edmacc_regs_base;

static inline unsigned int edma_read(int offset)
{
      return (unsigned int)__raw_readl(edmacc_regs_base + offset);
}

static inline void edma_write(int offset, int val)
{
      __raw_writel(val, edmacc_regs_base + offset);
}
static inline void edma_modify(int offset, unsigned and, unsigned or)
{
      unsigned val = edma_read(offset);
      val &= and;
      val |= or;
      edma_write(offset, val);
}
static inline void edma_and(int offset, unsigned and)
{
      unsigned val = edma_read(offset);
      val &= and;
      edma_write(offset, val);
}
static inline void edma_or(int offset, unsigned or)
{
      unsigned val = edma_read(offset);
      val |= or;
      edma_write(offset, val);
}
static inline unsigned int edma_read_array(int offset, int i)
{
      return edma_read(offset + (i << 2));
}
static inline void edma_write_array(int offset, int i, unsigned val)
{
      edma_write(offset + (i << 2), val);
}
static inline void edma_modify_array(int offset, int i,
            unsigned and, unsigned or)
{
      edma_modify(offset + (i << 2), and, or);
}
static inline void edma_or_array(int offset, int i, unsigned or)
{
      edma_or(offset + (i << 2), or);
}
static inline void edma_or_array2(int offset, int i, int j, unsigned or)
{
      edma_or(offset + ((i*2 + j) << 2), or);
}
static inline void edma_write_array2(int offset, int i, int j, unsigned val)
{
      edma_write(offset + ((i*2 + j) << 2), val);
}
static inline unsigned int edma_shadow0_read(int offset)
{
      return edma_read(EDMA_SHADOW0 + offset);
}
static inline unsigned int edma_shadow0_read_array(int offset, int i)
{
      return edma_read(EDMA_SHADOW0 + offset + (i << 2));
}
static inline void edma_shadow0_write(int offset, unsigned val)
{
      edma_write(EDMA_SHADOW0 + offset, val);
}
static inline void edma_shadow0_write_array(int offset, int i, unsigned val)
{
      edma_write(EDMA_SHADOW0 + offset + (i << 2), val);
}
static inline unsigned int edma_parm_read(int offset, int param_no)
{
      return edma_read(EDMA_PARM + offset + (param_no << 5));
}
static inline void edma_parm_write(int offset, int param_no, unsigned val)
{
      edma_write(EDMA_PARM + offset + (param_no << 5), val);
}
static inline void edma_parm_modify(int offset, int param_no,
            unsigned and, unsigned or)
{
      edma_modify(EDMA_PARM + offset + (param_no << 5), and, or);
}
static inline void edma_parm_and(int offset, int param_no, unsigned and)
{
      edma_and(EDMA_PARM + offset + (param_no << 5), and);
}
static inline void edma_parm_or(int offset, int param_no, unsigned or)
{
      edma_or(EDMA_PARM + offset + (param_no << 5), or);
}

/*****************************************************************************/

/* actual number of DMA channels and slots on this silicon */
static unsigned num_channels;
static unsigned num_slots;

00213 static struct dma_interrupt_data {
      void (*callback)(unsigned channel, unsigned short ch_status,
                   void *data);
      void *data;
} intr_data[EDMA_MAX_DMACH];

/* The edma_inuse bit for each PaRAM slot is clear unless the
 * channel is in use ... by ARM or DSP, for QDMA, or whatever.
 */
static DECLARE_BITMAP(edma_inuse, EDMA_MAX_PARAMENTRY);

/* The edma_noevent bit for each channel is clear unless
 * it doesn't trigger DMA events on this platform.  It uses a
 * bit of SOC-specific initialization code.
 */
static DECLARE_BITMAP(edma_noevent, EDMA_MAX_DMACH);

/* dummy param set used to (re)initialize parameter RAM slots */
static const struct edmacc_param dummy_paramset = {
      .link_bcntrld = 0xffff,
      .ccnt = 1,
};

static const int __initconst
queue_tc_mapping[EDMA_MAX_EVQUE + 1][2] = {
/* {event queue no, TC no} */
      {0, 0},
      {1, 1},
      {-1, -1}
};

static const int __initconst
queue_priority_mapping[EDMA_MAX_EVQUE + 1][2] = {
      /* {event queue no, Priority} */
      {0, 3},
      {1, 7},
      {-1, -1}
};

/*****************************************************************************/

static void map_dmach_queue(unsigned ch_no, enum dma_event_q queue_no)
{
      int bit = (ch_no & 0x7) * 4;

      /* default to low priority queue */
      if (queue_no == EVENTQ_DEFAULT)
            queue_no = EVENTQ_1;

      queue_no &= 7;
      edma_modify_array(EDMA_DMAQNUM, (ch_no >> 3),
                  ~(0x7 << bit), queue_no << bit);
}

static void __init map_queue_tc(int queue_no, int tc_no)
{
      int bit = queue_no * 4;
      edma_modify(EDMA_QUETCMAP, ~(0x7 << bit), ((tc_no & 0x7) << bit));
}

static void __init assign_priority_to_queue(int queue_no, int priority)
{
      int bit = queue_no * 4;
      edma_modify(EDMA_QUEPRI, ~(0x7 << bit), ((priority & 0x7) << bit));
}

static inline void
setup_dma_interrupt(unsigned lch,
      void (*callback)(unsigned channel, u16 ch_status, void *data),
      void *data)
{
      if (!callback) {
            edma_shadow0_write_array(SH_IECR, lch >> 5,
                        (1 << (lch & 0x1f)));
      }

      intr_data[lch].callback = callback;
      intr_data[lch].data = data;

      if (callback) {
            edma_shadow0_write_array(SH_ICR, lch >> 5,
                        (1 << (lch & 0x1f)));
            edma_shadow0_write_array(SH_IESR, lch >> 5,
                        (1 << (lch & 0x1f)));
      }
}

/******************************************************************************
 *
 * DMA interrupt handler
 *
 *****************************************************************************/
static irqreturn_t dma_irq_handler(int irq, void *data)
{
      int i;
      unsigned int cnt = 0;

      dev_dbg(data, "dma_irq_handler\n");

      if ((edma_shadow0_read_array(SH_IPR, 0) == 0)
          && (edma_shadow0_read_array(SH_IPR, 1) == 0))
            return IRQ_NONE;

      while (1) {
            int j;
            if (edma_shadow0_read_array(SH_IPR, 0))
                  j = 0;
            else if (edma_shadow0_read_array(SH_IPR, 1))
                  j = 1;
            else
                  break;
            dev_dbg(data, "IPR%d %08x\n", j,
                        edma_shadow0_read_array(SH_IPR, j));
            for (i = 0; i < 32; i++) {
                  int k = (j << 5) + i;
                  if (edma_shadow0_read_array(SH_IPR, j) & (1 << i)) {
                        /* Clear the corresponding IPR bits */
                        edma_shadow0_write_array(SH_ICR, j, (1 << i));
                        if (intr_data[k].callback) {
                              intr_data[k].callback(k, DMA_COMPLETE,
                                    intr_data[k].data);
                        }
                  }
            }
            cnt++;
            if (cnt > 10)
                  break;
      }
      edma_shadow0_write(SH_IEVAL, 1);
      return IRQ_HANDLED;
}

/******************************************************************************
 *
 * DMA error interrupt handler
 *
 *****************************************************************************/
static irqreturn_t dma_ccerr_handler(int irq, void *data)
{
      int i;
      unsigned int cnt = 0;

      dev_dbg(data, "dma_ccerr_handler\n");

      if ((edma_read_array(EDMA_EMR, 0) == 0) &&
          (edma_read_array(EDMA_EMR, 1) == 0) &&
          (edma_read(EDMA_QEMR) == 0) && (edma_read(EDMA_CCERR) == 0))
            return IRQ_NONE;

      while (1) {
            int j = -1;
            if (edma_read_array(EDMA_EMR, 0))
                  j = 0;
            else if (edma_read_array(EDMA_EMR, 1))
                  j = 1;
            if (j >= 0) {
                  dev_dbg(data, "EMR%d %08x\n", j,
                              edma_read_array(EDMA_EMR, j));
                  for (i = 0; i < 32; i++) {
                        int k = (j << 5) + i;
                        if (edma_read_array(EDMA_EMR, j) & (1 << i)) {
                              /* Clear the corresponding EMR bits */
                              edma_write_array(EDMA_EMCR, j, 1 << i);
                              /* Clear any SER */
                              edma_shadow0_write_array(SH_SECR, j,
                                          (1 << i));
                              if (intr_data[k].callback) {
                                    intr_data[k].callback(k,
                                                DMA_CC_ERROR,
                                                intr_data
                                                [k].data);
                              }
                        }
                  }
            } else if (edma_read(EDMA_QEMR)) {
                  dev_dbg(data, "QEMR %02x\n",
                        edma_read(EDMA_QEMR));
                  for (i = 0; i < 8; i++) {
                        if (edma_read(EDMA_QEMR) & (1 << i)) {
                              /* Clear the corresponding IPR bits */
                              edma_write(EDMA_QEMCR, 1 << i);
                              edma_shadow0_write(SH_QSECR, (1 << i));

                              /* NOTE:  not reported!! */
                        }
                  }
            } else if (edma_read(EDMA_CCERR)) {
                  dev_dbg(data, "CCERR %08x\n",
                        edma_read(EDMA_CCERR));
                  /* FIXME:  CCERR.BIT(16) ignored!  much better
                   * to just write CCERRCLR with CCERR value...
                   */
                  for (i = 0; i < 8; i++) {
                        if (edma_read(EDMA_CCERR) & (1 << i)) {
                              /* Clear the corresponding IPR bits */
                              edma_write(EDMA_CCERRCLR, 1 << i);

                              /* NOTE:  not reported!! */
                        }
                  }
            }
            if ((edma_read_array(EDMA_EMR, 0) == 0)
                && (edma_read_array(EDMA_EMR, 1) == 0)
                && (edma_read(EDMA_QEMR) == 0)
                && (edma_read(EDMA_CCERR) == 0)) {
                  break;
            }
            cnt++;
            if (cnt > 10)
                  break;
      }
      edma_write(EDMA_EEVAL, 1);
      return IRQ_HANDLED;
}

/******************************************************************************
 *
 * Transfer controller error interrupt handlers
 *
 *****************************************************************************/

#define tc_errs_handled false /* disabled as long as they're NOPs */

static irqreturn_t dma_tc0err_handler(int irq, void *data)
{
      dev_dbg(data, "dma_tc0err_handler\n");
      return IRQ_HANDLED;
}

static irqreturn_t dma_tc1err_handler(int irq, void *data)
{
      dev_dbg(data, "dma_tc1err_handler\n");
      return IRQ_HANDLED;
}

/*-----------------------------------------------------------------------*/

/* Resource alloc/free:  dma channels, parameter RAM slots */

/**
 * edma_alloc_channel - allocate DMA channel and paired parameter RAM
 * @channel: specific channel to allocate; negative for "any unmapped channel"
 * @callback: optional; to be issued on DMA completion or errors
 * @data: passed to callback
 * @eventq_no: an EVENTQ_* constant, used to choose which Transfer
 *    Controller (TC) executes requests using this channel.  Use
 *    EVENTQ_DEFAULT unless you really need a high priority queue.
 *
 * This allocates a DMA channel and its associated parameter RAM slot.
 * The parameter RAM is initialized to hold a dummy transfer.
 *
 * Normal use is to pass a specific channel number as @channel, to make
 * use of hardware events mapped to that channel.  When the channel will
 * be used only for software triggering or event chaining, channels not
 * mapped to hardware events (or mapped to unused events) are preferable.
 *
 * DMA transfers start from a channel using edma_start(), or by
 * chaining.  When the transfer described in that channel's parameter RAM
 * slot completes, that slot's data may be reloaded through a link.
 *
 * DMA errors are only reported to the @callback associated with the
 * channel driving that transfer, but transfer completion callbacks can
 * be sent to another channel under control of the TCC field in
 * the option word of the transfer's parameter RAM set.  Drivers must not
 * use DMA transfer completion callbacks for channels they did not allocate.
 * (The same applies to TCC codes used in transfer chaining.)
 *
 * Returns the number of the channel, else negative errno.
 */
int edma_alloc_channel(int channel,
            void (*callback)(unsigned channel, u16 ch_status, void *data),
            void *data,
            enum dma_event_q eventq_no)
{
      if (channel < 0) {
            channel = 0;
            for (;;) {
                  channel = find_next_bit(edma_noevent,
                              num_channels, channel);
                  if (channel == num_channels)
                        return -ENOMEM;
                  if (!test_and_set_bit(channel, edma_inuse))
                        break;
                  channel++;
            }
      } else if (channel >= num_channels) {
            return -EINVAL;
      } else if (test_and_set_bit(channel, edma_inuse)) {
            return -EBUSY;
      }

      /* ensure access through shadow region 0 */
      edma_or_array2(EDMA_DRAE, 0, channel >> 5, 1 << (channel & 0x1f));

      /* ensure no events are pending */
      edma_stop(channel);
      memcpy_toio(edmacc_regs_base + PARM_OFFSET(channel),
                  &dummy_paramset, PARM_SIZE);

      if (callback)
            setup_dma_interrupt(channel, callback, data);

      map_dmach_queue(channel, eventq_no);

      return channel;
}
EXPORT_SYMBOL(edma_alloc_channel);


/**
 * edma_free_channel - deallocate DMA channel
 * @channel: dma channel returned from edma_alloc_channel()
 *
 * This deallocates the DMA channel and associated parameter RAM slot
 * allocated by edma_alloc_channel().
 *
 * Callers are responsible for ensuring the channel is inactive, and
 * will not be reactivated by linking, chaining, or software calls to
 * edma_start().
 */
void edma_free_channel(unsigned channel)
{
      if (channel >= num_channels)
            return;

      setup_dma_interrupt(channel, NULL, NULL);
      /* REVISIT should probably take out of shadow region 0 */

      memcpy_toio(edmacc_regs_base + PARM_OFFSET(channel),
                  &dummy_paramset, PARM_SIZE);
      clear_bit(channel, edma_inuse);
}
EXPORT_SYMBOL(edma_free_channel);

/**
 * edma_alloc_slot - allocate DMA parameter RAM
 * @slot: specific slot to allocate; negative for "any unused slot"
 *
 * This allocates a parameter RAM slot, initializing it to hold a
 * dummy transfer.  Slots allocated using this routine have not been
 * mapped to a hardware DMA channel, and will normally be used by
 * linking to them from a slot associated with a DMA channel.
 *
 * Normal use is to pass EDMA_SLOT_ANY as the @slot, but specific
 * slots may be allocated on behalf of DSP firmware.
 *
 * Returns the number of the slot, else negative errno.
 */
int edma_alloc_slot(int slot)
{
      if (slot < 0) {
            slot = num_channels;
            for (;;) {
                  slot = find_next_zero_bit(edma_inuse,
                              num_slots, slot);
                  if (slot == num_slots)
                        return -ENOMEM;
                  if (!test_and_set_bit(slot, edma_inuse))
                        break;
            }
      } else if (slot < num_channels || slot >= num_slots) {
            return -EINVAL;
      } else if (test_and_set_bit(slot, edma_inuse)) {
            return -EBUSY;
      }

      memcpy_toio(edmacc_regs_base + PARM_OFFSET(slot),
                  &dummy_paramset, PARM_SIZE);

      return slot;
}
EXPORT_SYMBOL(edma_alloc_slot);

/**
 * edma_free_slot - deallocate DMA parameter RAM
 * @slot: parameter RAM slot returned from edma_alloc_slot()
 *
 * This deallocates the parameter RAM slot allocated by edma_alloc_slot().
 * Callers are responsible for ensuring the slot is inactive, and will
 * not be activated.
 */
void edma_free_slot(unsigned slot)
{
      if (slot < num_channels || slot >= num_slots)
            return;

      memcpy_toio(edmacc_regs_base + PARM_OFFSET(slot),
                  &dummy_paramset, PARM_SIZE);
      clear_bit(slot, edma_inuse);
}
EXPORT_SYMBOL(edma_free_slot);

/*-----------------------------------------------------------------------*/

/* Parameter RAM operations (i) -- read/write partial slots */

/**
 * edma_set_src - set initial DMA source address in parameter RAM slot
 * @slot: parameter RAM slot being configured
 * @src_port: physical address of source (memory, controller FIFO, etc)
 * @addressMode: INCR, except in very rare cases
 * @fifoWidth: ignored unless @addressMode is FIFO, else specifies the
 *    width to use when addressing the fifo (e.g. W8BIT, W32BIT)
 *
 * Note that the source address is modified during the DMA transfer
 * according to edma_set_src_index().
 */
void edma_set_src(unsigned slot, dma_addr_t src_port,
                        enum address_mode mode, enum fifo_width width)
{
      if (slot < num_slots) {
            unsigned int i = edma_parm_read(PARM_OPT, slot);

            if (mode) {
                  /* set SAM and program FWID */
                  i = (i & ~(EDMA_FWID)) | (SAM | ((width & 0x7) << 8));
            } else {
                  /* clear SAM */
                  i &= ~SAM;
            }
            edma_parm_write(PARM_OPT, slot, i);

            /* set the source port address
               in source register of param structure */
            edma_parm_write(PARM_SRC, slot, src_port);
      }
}
EXPORT_SYMBOL(edma_set_src);

/**
 * edma_set_dest - set initial DMA destination address in parameter RAM slot
 * @slot: parameter RAM slot being configured
 * @dest_port: physical address of destination (memory, controller FIFO, etc)
 * @addressMode: INCR, except in very rare cases
 * @fifoWidth: ignored unless @addressMode is FIFO, else specifies the
 *    width to use when addressing the fifo (e.g. W8BIT, W32BIT)
 *
 * Note that the destination address is modified during the DMA transfer
 * according to edma_set_dest_index().
 */
void edma_set_dest(unsigned slot, dma_addr_t dest_port,
                         enum address_mode mode, enum fifo_width width)
{
      if (slot < num_slots) {
            unsigned int i = edma_parm_read(PARM_OPT, slot);

            if (mode) {
                  /* set DAM and program FWID */
                  i = (i & ~(EDMA_FWID)) | (DAM | ((width & 0x7) << 8));
            } else {
                  /* clear DAM */
                  i &= ~DAM;
            }
            edma_parm_write(PARM_OPT, slot, i);
            /* set the destination port address
               in dest register of param structure */
            edma_parm_write(PARM_DST, slot, dest_port);
      }
}
EXPORT_SYMBOL(edma_set_dest);

/**
 * edma_get_position - returns the current transfer points
 * @slot: parameter RAM slot being examined
 * @src: pointer to source port position
 * @dst: pointer to destination port position
 *
 * Returns current source and destination addresses for a particular
 * parameter RAM slot.  Its channel should not be active when this is called.
 */
void edma_get_position(unsigned slot, dma_addr_t *src, dma_addr_t *dst)
{
      struct edmacc_param temp;

      edma_read_slot(slot, &temp);
      if (src != NULL)
            *src = temp.src;
      if (dst != NULL)
            *dst = temp.dst;
}
EXPORT_SYMBOL(edma_get_position);

/**
 * edma_set_src_index - configure DMA source address indexing
 * @slot: parameter RAM slot being configured
 * @src_bidx: byte offset between source arrays in a frame
 * @src_cidx: byte offset between source frames in a block
 *
 * Offsets are specified to support either contiguous or discontiguous
 * memory transfers, or repeated access to a hardware register, as needed.
 * When accessing hardware registers, both offsets are normally zero.
 */
void edma_set_src_index(unsigned slot, s16 src_bidx, s16 src_cidx)
{
      if (slot < num_slots) {
            edma_parm_modify(PARM_SRC_DST_BIDX, slot,
                        0xffff0000, src_bidx);
            edma_parm_modify(PARM_SRC_DST_CIDX, slot,
                        0xffff0000, src_cidx);
      }
}
EXPORT_SYMBOL(edma_set_src_index);

/**
 * edma_set_dest_index - configure DMA destination address indexing
 * @slot: parameter RAM slot being configured
 * @dest_bidx: byte offset between destination arrays in a frame
 * @dest_cidx: byte offset between destination frames in a block
 *
 * Offsets are specified to support either contiguous or discontiguous
 * memory transfers, or repeated access to a hardware register, as needed.
 * When accessing hardware registers, both offsets are normally zero.
 */
void edma_set_dest_index(unsigned slot, s16 dest_bidx, s16 dest_cidx)
{
      if (slot < num_slots) {
            edma_parm_modify(PARM_SRC_DST_BIDX, slot,
                        0x0000ffff, dest_bidx << 16);
            edma_parm_modify(PARM_SRC_DST_CIDX, slot,
                        0x0000ffff, dest_cidx << 16);
      }
}
EXPORT_SYMBOL(edma_set_dest_index);

/**
 * edma_set_transfer_params - configure DMA transfer parameters
 * @slot: parameter RAM slot being configured
 * @acnt: how many bytes per array (at least one)
 * @bcnt: how many arrays per frame (at least one)
 * @ccnt: how many frames per block (at least one)
 * @bcnt_rld: used only for A-Synchronized transfers; this specifies
 *    the value to reload into bcnt when it decrements to zero
 * @sync_mode: ASYNC or ABSYNC
 *
 * See the EDMA3 documentation to understand how to configure and link
 * transfers using the fields in PaRAM slots.  If you are not doing it
 * all at once with edma_write_slot(), you will use this routine
 * plus two calls each for source and destination, setting the initial
 * address and saying how to index that address.
 *
 * An example of an A-Synchronized transfer is a serial link using a
 * single word shift register.  In that case, @acnt would be equal to
 * that word size; the serial controller issues a DMA synchronization
 * event to transfer each word, and memory access by the DMA transfer
 * controller will be word-at-a-time.
 *
 * An example of an AB-Synchronized transfer is a device using a FIFO.
 * In that case, @acnt equals the FIFO width and @bcnt equals its depth.
 * The controller with the FIFO issues DMA synchronization events when
 * the FIFO threshold is reached, and the DMA transfer controller will
 * transfer one frame to (or from) the FIFO.  It will probably use
 * efficient burst modes to access memory.
 */
void edma_set_transfer_params(unsigned slot,
            u16 acnt, u16 bcnt, u16 ccnt,
            u16 bcnt_rld, enum sync_dimension sync_mode)
{
      if (slot < num_slots) {
            edma_parm_modify(PARM_LINK_BCNTRLD, slot,
                        0x0000ffff, bcnt_rld << 16);
            if (sync_mode == ASYNC)
                  edma_parm_and(PARM_OPT, slot, ~SYNCDIM);
            else
                  edma_parm_or(PARM_OPT, slot, SYNCDIM);
            /* Set the acount, bcount, ccount registers */
            edma_parm_write(PARM_A_B_CNT, slot, (bcnt << 16) | acnt);
            edma_parm_write(PARM_CCNT, slot, ccnt);
      }
}
EXPORT_SYMBOL(edma_set_transfer_params);

/**
 * edma_link - link one parameter RAM slot to another
 * @from: parameter RAM slot originating the link
 * @to: parameter RAM slot which is the link target
 *
 * The originating slot should not be part of any active DMA transfer.
 */
void edma_link(unsigned from, unsigned to)
{
      if (from >= num_slots)
            return;
      if (to >= num_slots)
            return;
      edma_parm_modify(PARM_LINK_BCNTRLD, from, 0xffff0000, PARM_OFFSET(to));
}
EXPORT_SYMBOL(edma_link);

/**
 * edma_unlink - cut link from one parameter RAM slot
 * @from: parameter RAM slot originating the link
 *
 * The originating slot should not be part of any active DMA transfer.
 * Its link is set to 0xffff.
 */
void edma_unlink(unsigned from)
{
      if (from >= num_slots)
            return;
      edma_parm_or(PARM_LINK_BCNTRLD, from, 0xffff);
}
EXPORT_SYMBOL(edma_unlink);

/*-----------------------------------------------------------------------*/

/* Parameter RAM operations (ii) -- read/write whole parameter sets */

/**
 * edma_write_slot - write parameter RAM data for slot
 * @slot: number of parameter RAM slot being modified
 * @param: data to be written into parameter RAM slot
 *
 * Use this to assign all parameters of a transfer at once.  This
 * allows more efficient setup of transfers than issuing multiple
 * calls to set up those parameters in small pieces, and provides
 * complete control over all transfer options.
 */
void edma_write_slot(unsigned slot, const struct edmacc_param *param)
{
      if (slot >= num_slots)
            return;
      memcpy_toio(edmacc_regs_base + PARM_OFFSET(slot), param, PARM_SIZE);
}
EXPORT_SYMBOL(edma_write_slot);

/**
 * edma_read_slot - read parameter RAM data from slot
 * @slot: number of parameter RAM slot being copied
 * @param: where to store copy of parameter RAM data
 *
 * Use this to read data from a parameter RAM slot, perhaps to
 * save them as a template for later reuse.
 */
void edma_read_slot(unsigned slot, struct edmacc_param *param)
{
      if (slot >= num_slots)
            return;
      memcpy_fromio(param, edmacc_regs_base + PARM_OFFSET(slot), PARM_SIZE);
}
EXPORT_SYMBOL(edma_read_slot);

/*-----------------------------------------------------------------------*/

/* Various EDMA channel control operations */

/**
 * edma_pause - pause dma on a channel
 * @channel: on which edma_start() has been called
 *
 * This temporarily disables EDMA hardware events on the specified channel,
 * preventing them from triggering new transfers on its behalf
 */
void edma_pause(unsigned channel)
{
      if (channel < num_channels) {
            unsigned int mask = (1 << (channel & 0x1f));

            edma_shadow0_write_array(SH_EECR, channel >> 5, mask);
      }
}
EXPORT_SYMBOL(edma_pause);

/**
 * edma_resume - resumes dma on a paused channel
 * @channel: on which edma_pause() has been called
 *
 * This re-enables EDMA hardware events on the specified channel.
 */
void edma_resume(unsigned channel)
{
      if (channel < num_channels) {
            unsigned int mask = (1 << (channel & 0x1f));

            edma_shadow0_write_array(SH_EESR, channel >> 5, mask);
      }
}
EXPORT_SYMBOL(edma_resume);

/**
 * edma_start - start dma on a channel
 * @channel: channel being activated
 *
 * Channels with event associations will be triggered by their hardware
 * events, and channels without such associations will be triggered by
 * software.  (At this writing there is no interface for using software
 * triggers except with channels that don't support hardware triggers.)
 *
 * Returns zero on success, else negative errno.
 */
int edma_start(unsigned channel)
{
      if (channel < num_channels) {
            int j = channel >> 5;
            unsigned int mask = (1 << (channel & 0x1f));

            /* EDMA channels without event association */
            if (test_bit(channel, edma_noevent)) {
                  pr_debug("EDMA: ESR%d %08x\n", j,
                        edma_shadow0_read_array(SH_ESR, j));
                  edma_shadow0_write_array(SH_ESR, j, mask);
                  return 0;
            }

            /* EDMA channel with event association */
            pr_debug("EDMA: ER%d %08x\n", j,
                  edma_shadow0_read_array(SH_ER, j));
            /* Clear any pending error */
            edma_write_array(EDMA_EMCR, j, mask);
            /* Clear any SER */
            edma_shadow0_write_array(SH_SECR, j, mask);
            edma_shadow0_write_array(SH_EESR, j, mask);
            pr_debug("EDMA: EER%d %08x\n", j,
                  edma_shadow0_read_array(SH_EER, j));
            return 0;
      }

      return -EINVAL;
}
EXPORT_SYMBOL(edma_start);

/**
 * edma_stop - stops dma on the channel passed
 * @channel: channel being deactivated
 *
 * When @lch is a channel, any active transfer is paused and
 * all pending hardware events are cleared.  The current transfer
 * may not be resumed, and the channel's Parameter RAM should be
 * reinitialized before being reused.
 */
void edma_stop(unsigned channel)
{
      if (channel < num_channels) {
            int j = channel >> 5;
            unsigned int mask = (1 << (channel & 0x1f));

            edma_shadow0_write_array(SH_EECR, j, mask);
            edma_shadow0_write_array(SH_ECR, j, mask);
            edma_shadow0_write_array(SH_SECR, j, mask);
            edma_write_array(EDMA_EMCR, j, mask);

            pr_debug("EDMA: EER%d %08x\n", j,
                        edma_shadow0_read_array(SH_EER, j));

            /* REVISIT:  consider guarding against inappropriate event
             * chaining by overwriting with dummy_paramset.
             */
      }
}
EXPORT_SYMBOL(edma_stop);

/******************************************************************************
 *
 * It cleans ParamEntry qand bring back EDMA to initial state if media has
 * been removed before EDMA has finished.It is usedful for removable media.
 * Arguments:
 *      ch_no     - channel no
 *
 * Return: zero on success, or corresponding error no on failure
 *
 * FIXME this should not be needed ... edma_stop() should suffice.
 *
 *****************************************************************************/

void edma_clean_channel(unsigned channel)
{
      if (channel < num_channels) {
            int j = (channel >> 5);
            unsigned int mask = 1 << (channel & 0x1f);

            pr_debug("EDMA: EMR%d %08x\n", j,
                        edma_read_array(EDMA_EMR, j));
            edma_shadow0_write_array(SH_ECR, j, mask);
            /* Clear the corresponding EMR bits */
            edma_write_array(EDMA_EMCR, j, mask);
            /* Clear any SER */
            edma_shadow0_write_array(SH_SECR, j, mask);
            edma_write(EDMA_CCERRCLR, (1 << 16) | 0x3);
      }
}
EXPORT_SYMBOL(edma_clean_channel);

/*
 * edma_clear_event - clear an outstanding event on the DMA channel
 * Arguments:
 *    channel - channel number
 */
void edma_clear_event(unsigned channel)
{
      if (channel >= num_channels)
            return;
      if (channel < 32)
            edma_write(EDMA_ECR, 1 << channel);
      else
            edma_write(EDMA_ECRH, 1 << (channel - 32));
}
EXPORT_SYMBOL(edma_clear_event);

/*-----------------------------------------------------------------------*/

static int __init edma_probe(struct platform_device *pdev)
{
      struct edma_soc_info    *info = pdev->dev.platform_data;
      int               i;
      int               status;
      const s8          *noevent;
      int               irq = 0, err_irq = 0;
      struct resource         *r;
      resource_size_t         len;

      if (!info)
            return -ENODEV;

      r = platform_get_resource_byname(pdev, IORESOURCE_MEM, "edma_cc");
      if (!r)
            return -ENODEV;

      len = r->end - r->start + 1;

      r = request_mem_region(r->start, len, r->name);
      if (!r)
            return -EBUSY;

      edmacc_regs_base = ioremap(r->start, len);
      if (!edmacc_regs_base) {
            status = -EBUSY;
            goto fail1;
      }

      num_channels = min_t(unsigned, info->n_channel, EDMA_MAX_DMACH);
      num_slots = min_t(unsigned, info->n_slot, EDMA_MAX_PARAMENTRY);

      dev_dbg(&pdev->dev, "DMA REG BASE ADDR=%p\n", edmacc_regs_base);

      for (i = 0; i < num_slots; i++)
            memcpy_toio(edmacc_regs_base + PARM_OFFSET(i),
                        &dummy_paramset, PARM_SIZE);

      noevent = info->noevent;
      if (noevent) {
            while (*noevent != -1)
                  set_bit(*noevent++, edma_noevent);
      }

      irq = platform_get_irq(pdev, 0);
      status = request_irq(irq, dma_irq_handler, 0, "edma", &pdev->dev);
      if (status < 0) {
            dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
                  irq, status);
            goto fail;
      }

      err_irq = platform_get_irq(pdev, 1);
      status = request_irq(err_irq, dma_ccerr_handler, 0,
                        "edma_error", &pdev->dev);
      if (status < 0) {
            dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
                  err_irq, status);
            goto fail;
      }

      if (tc_errs_handled) {
            status = request_irq(IRQ_TCERRINT0, dma_tc0err_handler, 0,
                              "edma_tc0", &pdev->dev);
            if (status < 0) {
                  dev_dbg(&pdev->dev, "request_irq %d failed --> %d\n",
                        IRQ_TCERRINT0, status);
                  return status;
            }
            status = request_irq(IRQ_TCERRINT, dma_tc1err_handler, 0,
                              "edma_tc1", &pdev->dev);
            if (status < 0) {
                  dev_dbg(&pdev->dev, "request_irq %d --> %d\n",
                        IRQ_TCERRINT, status);
                  return status;
            }
      }

      /* Everything lives on transfer controller 1 until otherwise specified.
       * This way, long transfers on the low priority queue
       * started by the codec engine will not cause audio defects.
       */
      for (i = 0; i < num_channels; i++)
            map_dmach_queue(i, EVENTQ_1);

      /* Event queue to TC mapping */
      for (i = 0; queue_tc_mapping[i][0] != -1; i++)
            map_queue_tc(queue_tc_mapping[i][0], queue_tc_mapping[i][1]);

      /* Event queue priority mapping */
      for (i = 0; queue_priority_mapping[i][0] != -1; i++)
            assign_priority_to_queue(queue_priority_mapping[i][0],
                               queue_priority_mapping[i][1]);

      for (i = 0; i < info->n_region; i++) {
            edma_write_array2(EDMA_DRAE, i, 0, 0x0);
            edma_write_array2(EDMA_DRAE, i, 1, 0x0);
            edma_write_array(EDMA_QRAE, i, 0x0);
      }

      return 0;

fail:
      if (err_irq)
            free_irq(err_irq, NULL);
      if (irq)
            free_irq(irq, NULL);
      iounmap(edmacc_regs_base);
fail1:
      release_mem_region(r->start, len);
      return status;
}


static struct platform_driver edma_driver = {
      .driver.name      = "edma",
};

static int __init edma_init(void)
{
      return platform_driver_probe(&edma_driver, edma_probe);
}
arch_initcall(edma_init);


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