LXR linux/drivers/dma/at_hdmac

   1/*
   2 * Header file for the Atmel AHB DMA Controller driver
   3 *
   4 * Copyright (C) 2008 Atmel Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 */
  11#ifndef AT_HDMAC_REGS_H
  12#define AT_HDMAC_REGS_H
  13
  14#include <mach/at_hdmac.h>
  15
  16#define AT_DMA_MAX_NR_CHANNELS  8
  17
  18
  19#define AT_DMA_GCFG     0x00    /* Global Configuration Register */
  20#define         AT_DMA_IF_BIGEND(i)     (0x1 << (i))    /* AHB-Lite Interface i in Big-endian mode */
  21#define         AT_DMA_ARB_CFG  (0x1 << 4)      /* Arbiter mode. */
  22#define                 AT_DMA_ARB_CFG_FIXED            (0x0 << 4)
  23#define                 AT_DMA_ARB_CFG_ROUND_ROBIN      (0x1 << 4)
  24
  25#define AT_DMA_EN       0x04    /* Controller Enable Register */
  26#define         AT_DMA_ENABLE   (0x1 << 0)
  27
  28#define AT_DMA_SREQ     0x08    /* Software Single Request Register */
  29#define         AT_DMA_SSREQ(x) (0x1 << ((x) << 1))             /* Request a source single transfer on channel x */
  30#define         AT_DMA_DSREQ(x) (0x1 << (1 + ((x) << 1)))       /* Request a destination single transfer on channel x */
  31
  32#define AT_DMA_CREQ     0x0C    /* Software Chunk Transfer Request Register */
  33#define         AT_DMA_SCREQ(x) (0x1 << ((x) << 1))             /* Request a source chunk transfer on channel x */
  34#define         AT_DMA_DCREQ(x) (0x1 << (1 + ((x) << 1)))       /* Request a destination chunk transfer on channel x */
  35
  36#define AT_DMA_LAST     0x10    /* Software Last Transfer Flag Register */
  37#define         AT_DMA_SLAST(x) (0x1 << ((x) << 1))             /* This src rq is last tx of buffer on channel x */
  38#define         AT_DMA_DLAST(x) (0x1 << (1 + ((x) << 1)))       /* This dst rq is last tx of buffer on channel x */
  39
  40#define AT_DMA_SYNC     0x14    /* Request Synchronization Register */
  41#define         AT_DMA_SYR(h)   (0x1 << (h))                    /* Synchronize handshake line h */
  42
  43/* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */
  44#define AT_DMA_EBCIER   0x18    /* Enable register */
  45#define AT_DMA_EBCIDR   0x1C    /* Disable register */
  46#define AT_DMA_EBCIMR   0x20    /* Mask Register */
  47#define AT_DMA_EBCISR   0x24    /* Status Register */
  48#define         AT_DMA_CBTC_OFFSET      8
  49#define         AT_DMA_ERR_OFFSET       16
  50#define         AT_DMA_BTC(x)   (0x1 << (x))
  51#define         AT_DMA_CBTC(x)  (0x1 << (AT_DMA_CBTC_OFFSET + (x)))
  52#define         AT_DMA_ERR(x)   (0x1 << (AT_DMA_ERR_OFFSET + (x)))
  53
  54#define AT_DMA_CHER     0x28    /* Channel Handler Enable Register */
  55#define         AT_DMA_ENA(x)   (0x1 << (x))
  56#define         AT_DMA_SUSP(x)  (0x1 << ( 8 + (x)))
  57#define         AT_DMA_KEEP(x)  (0x1 << (24 + (x)))
  58
  59#define AT_DMA_CHDR     0x2C    /* Channel Handler Disable Register */
  60#define         AT_DMA_DIS(x)   (0x1 << (x))
  61#define         AT_DMA_RES(x)   (0x1 << ( 8 + (x)))
  62
  63#define AT_DMA_CHSR     0x30    /* Channel Handler Status Register */
  64#define         AT_DMA_EMPT(x)  (0x1 << (16 + (x)))
  65#define         AT_DMA_STAL(x)  (0x1 << (24 + (x)))
  66
  67
  68#define AT_DMA_CH_REGS_BASE     0x3C    /* Channel registers base address */
  69#define ch_regs(x)      (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */
  70
  71/* Hardware register offset for each channel */
  72#define ATC_SADDR_OFFSET        0x00    /* Source Address Register */
  73#define ATC_DADDR_OFFSET        0x04    /* Destination Address Register */
  74#define ATC_DSCR_OFFSET         0x08    /* Descriptor Address Register */
  75#define ATC_CTRLA_OFFSET        0x0C    /* Control A Register */
  76#define ATC_CTRLB_OFFSET        0x10    /* Control B Register */
  77#define ATC_CFG_OFFSET          0x14    /* Configuration Register */
  78#define ATC_SPIP_OFFSET         0x18    /* Src PIP Configuration Register */
  79#define ATC_DPIP_OFFSET         0x1C    /* Dst PIP Configuration Register */
  80
  81
  82/* Bitfield definitions */
  83
  84/* Bitfields in DSCR */
  85#define ATC_DSCR_IF(i)          (0x3 & (i))     /* Dsc feched via AHB-Lite Interface i */
  86
  87/* Bitfields in CTRLA */
  88#define ATC_BTSIZE_MAX          0xFFFFUL        /* Maximum Buffer Transfer Size */
  89#define ATC_BTSIZE(x)           (ATC_BTSIZE_MAX & (x)) /* Buffer Transfer Size */
  90#define ATC_SCSIZE_MASK         (0x7 << 16)     /* Source Chunk Transfer Size */
  91#define         ATC_SCSIZE(x)           (ATC_SCSIZE_MASK & ((x) << 16))
  92#define         ATC_SCSIZE_1            (0x0 << 16)
  93#define         ATC_SCSIZE_4            (0x1 << 16)
  94#define         ATC_SCSIZE_8            (0x2 << 16)
  95#define         ATC_SCSIZE_16           (0x3 << 16)
  96#define         ATC_SCSIZE_32           (0x4 << 16)
  97#define         ATC_SCSIZE_64           (0x5 << 16)
  98#define         ATC_SCSIZE_128          (0x6 << 16)
  99#define         ATC_SCSIZE_256          (0x7 << 16)
 100#define ATC_DCSIZE_MASK         (0x7 << 20)     /* Destination Chunk Transfer Size */
 101#define         ATC_DCSIZE(x)           (ATC_DCSIZE_MASK & ((x) << 20))
 102#define         ATC_DCSIZE_1            (0x0 << 20)
 103#define         ATC_DCSIZE_4            (0x1 << 20)
 104#define         ATC_DCSIZE_8            (0x2 << 20)
 105#define         ATC_DCSIZE_16           (0x3 << 20)
 106#define         ATC_DCSIZE_32           (0x4 << 20)
 107#define         ATC_DCSIZE_64           (0x5 << 20)
 108#define         ATC_DCSIZE_128          (0x6 << 20)
 109#define         ATC_DCSIZE_256          (0x7 << 20)
 110#define ATC_SRC_WIDTH_MASK      (0x3 << 24)     /* Source Single Transfer Size */
 111#define         ATC_SRC_WIDTH(x)        ((x) << 24)
 112#define         ATC_SRC_WIDTH_BYTE      (0x0 << 24)
 113#define         ATC_SRC_WIDTH_HALFWORD  (0x1 << 24)
 114#define         ATC_SRC_WIDTH_WORD      (0x2 << 24)
 115#define ATC_DST_WIDTH_MASK      (0x3 << 28)     /* Destination Single Transfer Size */
 116#define         ATC_DST_WIDTH(x)        ((x) << 28)
 117#define         ATC_DST_WIDTH_BYTE      (0x0 << 28)
 118#define         ATC_DST_WIDTH_HALFWORD  (0x1 << 28)
 119#define         ATC_DST_WIDTH_WORD      (0x2 << 28)
 120#define ATC_DONE                (0x1 << 31)     /* Tx Done (only written back in descriptor) */
 121
 122/* Bitfields in CTRLB */
 123#define ATC_SIF(i)              (0x3 & (i))     /* Src tx done via AHB-Lite Interface i */
 124#define ATC_DIF(i)              ((0x3 & (i)) <<  4)     /* Dst tx done via AHB-Lite Interface i */
 125                                  /* Specify AHB interfaces */
 126#define AT_DMA_MEM_IF           0 /* interface 0 as memory interface */
 127#define AT_DMA_PER_IF           1 /* interface 1 as peripheral interface */
 128
 129#define ATC_SRC_PIP             (0x1 <<  8)     /* Source Picture-in-Picture enabled */
 130#define ATC_DST_PIP             (0x1 << 12)     /* Destination Picture-in-Picture enabled */
 131#define ATC_SRC_DSCR_DIS        (0x1 << 16)     /* Src Descriptor fetch disable */
 132#define ATC_DST_DSCR_DIS        (0x1 << 20)     /* Dst Descriptor fetch disable */
 133#define ATC_FC_MASK             (0x7 << 21)     /* Choose Flow Controller */
 134#define         ATC_FC_MEM2MEM          (0x0 << 21)     /* Mem-to-Mem (DMA) */
 135#define         ATC_FC_MEM2PER          (0x1 << 21)     /* Mem-to-Periph (DMA) */
 136#define         ATC_FC_PER2MEM          (0x2 << 21)     /* Periph-to-Mem (DMA) */
 137#define         ATC_FC_PER2PER          (0x3 << 21)     /* Periph-to-Periph (DMA) */
 138#define         ATC_FC_PER2MEM_PER      (0x4 << 21)     /* Periph-to-Mem (Peripheral) */
 139#define         ATC_FC_MEM2PER_PER      (0x5 << 21)     /* Mem-to-Periph (Peripheral) */
 140#define         ATC_FC_PER2PER_SRCPER   (0x6 << 21)     /* Periph-to-Periph (Src Peripheral) */
 141#define         ATC_FC_PER2PER_DSTPER   (0x7 << 21)     /* Periph-to-Periph (Dst Peripheral) */
 142#define ATC_SRC_ADDR_MODE_MASK  (0x3 << 24)
 143#define         ATC_SRC_ADDR_MODE_INCR  (0x0 << 24)     /* Incrementing Mode */
 144#define         ATC_SRC_ADDR_MODE_DECR  (0x1 << 24)     /* Decrementing Mode */
 145#define         ATC_SRC_ADDR_MODE_FIXED (0x2 << 24)     /* Fixed Mode */
 146#define ATC_DST_ADDR_MODE_MASK  (0x3 << 28)
 147#define         ATC_DST_ADDR_MODE_INCR  (0x0 << 28)     /* Incrementing Mode */
 148#define         ATC_DST_ADDR_MODE_DECR  (0x1 << 28)     /* Decrementing Mode */
 149#define         ATC_DST_ADDR_MODE_FIXED (0x2 << 28)     /* Fixed Mode */
 150#define ATC_IEN                 (0x1 << 30)     /* BTC interrupt enable (active low) */
 151#define ATC_AUTO                (0x1 << 31)     /* Auto multiple buffer tx enable */
 152
 153/* Bitfields in CFG */
 154/* are in at_hdmac.h */
 155
 156/* Bitfields in SPIP */
 157#define ATC_SPIP_HOLE(x)        (0xFFFFU & (x))
 158#define ATC_SPIP_BOUNDARY(x)    ((0x3FF & (x)) << 16)
 159
 160/* Bitfields in DPIP */
 161#define ATC_DPIP_HOLE(x)        (0xFFFFU & (x))
 162#define ATC_DPIP_BOUNDARY(x)    ((0x3FF & (x)) << 16)
 163
 164
 165/*--  descriptors  -----------------------------------------------------*/
 166
 167/* LLI == Linked List Item; aka DMA buffer descriptor */
 168struct at_lli {
 169        /* values that are not changed by hardware */
 170        dma_addr_t      saddr;
 171        dma_addr_t      daddr;
 172        /* value that may get written back: */
 173        u32             ctrla;
 174        /* more values that are not changed by hardware */
 175        u32             ctrlb;
 176        dma_addr_t      dscr;   /* chain to next lli */
 177};
 178
 179/**
 180 * struct at_desc - software descriptor
 181 * @at_lli: hardware lli structure
 182 * @txd: support for the async_tx api
 183 * @desc_node: node on the channed descriptors list
 184 * @len: total transaction bytecount
 185 */
 186struct at_desc {
 187        /* FIRST values the hardware uses */
 188        struct at_lli                   lli;
 189
 190        /* THEN values for driver housekeeping */
 191        struct list_head                tx_list;
 192        struct dma_async_tx_descriptor  txd;
 193        struct list_head                desc_node;
 194        size_t                          len;
 195};
 196
 197static inline struct at_desc *
 198txd_to_at_desc(struct dma_async_tx_descriptor *txd)
 199{
 200        return container_of(txd, struct at_desc, txd);
 201}
 202
 203
 204/*--  Channels  --------------------------------------------------------*/
 205
 206/**
 207 * atc_status - information bits stored in channel status flag
 208 *
 209 * Manipulated with atomic operations.
 210 */
 211enum atc_status {
 212        ATC_IS_ERROR = 0,
 213        ATC_IS_PAUSED = 1,
 214        ATC_IS_CYCLIC = 24,
 215};
 216
 217/**
 218 * struct at_dma_chan - internal representation of an Atmel HDMAC channel
 219 * @chan_common: common dmaengine channel object members
 220 * @device: parent device
 221 * @ch_regs: memory mapped register base
 222 * @mask: channel index in a mask
 223 * @status: transmit status information from irq/prep* functions
 224 *                to tasklet (use atomic operations)
 225 * @tasklet: bottom half to finish transaction work
 226 * @save_cfg: configuration register that is saved on suspend/resume cycle
 227 * @save_dscr: for cyclic operations, preserve next descriptor address in
 228 *             the cyclic list on suspend/resume cycle
 229 * @dma_sconfig: configuration for slave transfers, passed via DMA_SLAVE_CONFIG
 230 * @lock: serializes enqueue/dequeue operations to descriptors lists
 231 * @active_list: list of descriptors dmaengine is being running on
 232 * @queue: list of descriptors ready to be submitted to engine
 233 * @free_list: list of descriptors usable by the channel
 234 * @descs_allocated: records the actual size of the descriptor pool
 235 */
 236struct at_dma_chan {
 237        struct dma_chan         chan_common;
 238        struct at_dma           *device;
 239        void __iomem            *ch_regs;
 240        u8                      mask;
 241        unsigned long           status;
 242        struct tasklet_struct   tasklet;
 243        u32                     save_cfg;
 244        u32                     save_dscr;
 245        struct dma_slave_config dma_sconfig;
 246
 247        spinlock_t              lock;
 248
 249        /* these other elements are all protected by lock */
 250        struct list_head        active_list;
 251        struct list_head        queue;
 252        struct list_head        free_list;
 253        unsigned int            descs_allocated;
 254};
 255
 256#define channel_readl(atchan, name) \
 257        __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET)
 258
 259#define channel_writel(atchan, name, val) \
 260        __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET)
 261
 262static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
 263{
 264        return container_of(dchan, struct at_dma_chan, chan_common);
 265}
 266
 267/*
 268 * Fix sconfig's burst size according to at_hdmac. We need to convert them as:
 269 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
 270 *
 271 * This can be done by finding most significant bit set.
 272 */
 273static inline void convert_burst(u32 *maxburst)
 274{
 275        if (*maxburst > 1)
 276                *maxburst = fls(*maxburst) - 2;
 277        else
 278                *maxburst = 0;
 279}
 280
 281/*
 282 * Fix sconfig's bus width according to at_hdmac.
 283 * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2.
 284 */
 285static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
 286{
 287        switch (addr_width) {
 288        case DMA_SLAVE_BUSWIDTH_2_BYTES:
 289                return 1;
 290        case DMA_SLAVE_BUSWIDTH_4_BYTES:
 291                return 2;
 292        default:
 293                /* For 1 byte width or fallback */
 294                return 0;
 295        }
 296}
 297
 298/*--  Controller  ------------------------------------------------------*/
 299
 300/**
 301 * struct at_dma - internal representation of an Atmel HDMA Controller
 302 * @chan_common: common dmaengine dma_device object members
 303 * @atdma_devtype: identifier of DMA controller compatibility
 304 * @ch_regs: memory mapped register base
 305 * @clk: dma controller clock
 306 * @save_imr: interrupt mask register that is saved on suspend/resume cycle
 307 * @all_chan_mask: all channels availlable in a mask
 308 * @dma_desc_pool: base of DMA descriptor region (DMA address)
 309 * @chan: channels table to store at_dma_chan structures
 310 */
 311struct at_dma {
 312        struct dma_device       dma_common;
 313        void __iomem            *regs;
 314        struct clk              *clk;
 315        u32                     save_imr;
 316
 317        u8                      all_chan_mask;
 318
 319        struct dma_pool         *dma_desc_pool;
 320        /* AT THE END channels table */
 321        struct at_dma_chan      chan[0];
 322};
 323
 324#define dma_readl(atdma, name) \
 325        __raw_readl((atdma)->regs + AT_DMA_##name)
 326#define dma_writel(atdma, name, val) \
 327        __raw_writel((val), (atdma)->regs + AT_DMA_##name)
 328
 329static inline struct at_dma *to_at_dma(struct dma_device *ddev)
 330{
 331        return container_of(ddev, struct at_dma, dma_common);
 332}
 333
 334
 335/*--  Helper functions  ------------------------------------------------*/
 336
 337static struct device *chan2dev(struct dma_chan *chan)
 338{
 339        return &chan->dev->device;
 340}
 341static struct device *chan2parent(struct dma_chan *chan)
 342{
 343        return chan->dev->device.parent;
 344}
 345
 346#if defined(VERBOSE_DEBUG)
 347static void vdbg_dump_regs(struct at_dma_chan *atchan)
 348{
 349        struct at_dma   *atdma = to_at_dma(atchan->chan_common.device);
 350
 351        dev_err(chan2dev(&atchan->chan_common),
 352                "  channel %d : imr = 0x%x, chsr = 0x%x\n",
 353                atchan->chan_common.chan_id,
 354                dma_readl(atdma, EBCIMR),
 355                dma_readl(atdma, CHSR));
 356
 357        dev_err(chan2dev(&atchan->chan_common),
 358                "  channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n",
 359                channel_readl(atchan, SADDR),
 360                channel_readl(atchan, DADDR),
 361                channel_readl(atchan, CTRLA),
 362                channel_readl(atchan, CTRLB),
 363                channel_readl(atchan, CFG),
 364                channel_readl(atchan, DSCR));
 365}
 366#else
 367static void vdbg_dump_regs(struct at_dma_chan *atchan) {}
 368#endif
 369
 370static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli)
 371{
 372        dev_printk(KERN_CRIT, chan2dev(&atchan->chan_common),
 373                        "  desc: s0x%x d0x%x ctrl0x%x:0x%x l0x%x\n",
 374                        lli->saddr, lli->daddr,
 375                        lli->ctrla, lli->ctrlb, lli->dscr);
 376}
 377
 378
 379static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on)
 380{
 381        u32 ebci;
 382
 383        /* enable interrupts on buffer transfer completion & error */
 384        ebci =    AT_DMA_BTC(chan_id)
 385                | AT_DMA_ERR(chan_id);
 386        if (on)
 387                dma_writel(atdma, EBCIER, ebci);
 388        else
 389                dma_writel(atdma, EBCIDR, ebci);
 390}
 391
 392static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id)
 393{
 394        atc_setup_irq(atdma, chan_id, 1);
 395}
 396
 397static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id)
 398{
 399        atc_setup_irq(atdma, chan_id, 0);
 400}
 401
 402
 403/**
 404 * atc_chan_is_enabled - test if given channel is enabled
 405 * @atchan: channel we want to test status
 406 */
 407static inline int atc_chan_is_enabled(struct at_dma_chan *atchan)
 408{
 409        struct at_dma   *atdma = to_at_dma(atchan->chan_common.device);
 410
 411        return !!(dma_readl(atdma, CHSR) & atchan->mask);
 412}
 413
 414/**
 415 * atc_chan_is_paused - test channel pause/resume status
 416 * @atchan: channel we want to test status
 417 */
 418static inline int atc_chan_is_paused(struct at_dma_chan *atchan)
 419{
 420        return test_bit(ATC_IS_PAUSED, &atchan->status);
 421}
 422
 423/**
 424 * atc_chan_is_cyclic - test if given channel has cyclic property set
 425 * @atchan: channel we want to test status
 426 */
 427static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan)
 428{
 429        return test_bit(ATC_IS_CYCLIC, &atchan->status);
 430}
 431
 432/**
 433 * set_desc_eol - set end-of-link to descriptor so it will end transfer
 434 * @desc: descriptor, signle or at the end of a chain, to end chain on
 435 */
 436static void set_desc_eol(struct at_desc *desc)
 437{
 438        u32 ctrlb = desc->lli.ctrlb;
 439
 440        ctrlb &= ~ATC_IEN;
 441        ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS;
 442
 443        desc->lli.ctrlb = ctrlb;
 444        desc->lli.dscr = 0;
 445}
 446
 447#endif /* AT_HDMAC_REGS_H */
 448