LXR linux/drivers/dma/dw_dmac

   1/*
   2 * Driver for the Synopsys DesignWare AHB DMA Controller
   3 *
   4 * Copyright (C) 2005-2007 Atmel Corporation
   5 * Copyright (C) 2010-2011 ST Microelectronics
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 */
  11
  12#include <linux/dw_dmac.h>
  13
  14#define DW_DMA_MAX_NR_CHANNELS  8
  15
  16/* flow controller */
  17enum dw_dma_fc {
  18        DW_DMA_FC_D_M2M,
  19        DW_DMA_FC_D_M2P,
  20        DW_DMA_FC_D_P2M,
  21        DW_DMA_FC_D_P2P,
  22        DW_DMA_FC_P_P2M,
  23        DW_DMA_FC_SP_P2P,
  24        DW_DMA_FC_P_M2P,
  25        DW_DMA_FC_DP_P2P,
  26};
  27
  28/*
  29 * Redefine this macro to handle differences between 32- and 64-bit
  30 * addressing, big vs. little endian, etc.
  31 */
  32#define DW_REG(name)            u32 name; u32 __pad_##name
  33
  34/* Hardware register definitions. */
  35struct dw_dma_chan_regs {
  36        DW_REG(SAR);            /* Source Address Register */
  37        DW_REG(DAR);            /* Destination Address Register */
  38        DW_REG(LLP);            /* Linked List Pointer */
  39        u32     CTL_LO;         /* Control Register Low */
  40        u32     CTL_HI;         /* Control Register High */
  41        DW_REG(SSTAT);
  42        DW_REG(DSTAT);
  43        DW_REG(SSTATAR);
  44        DW_REG(DSTATAR);
  45        u32     CFG_LO;         /* Configuration Register Low */
  46        u32     CFG_HI;         /* Configuration Register High */
  47        DW_REG(SGR);
  48        DW_REG(DSR);
  49};
  50
  51struct dw_dma_irq_regs {
  52        DW_REG(XFER);
  53        DW_REG(BLOCK);
  54        DW_REG(SRC_TRAN);
  55        DW_REG(DST_TRAN);
  56        DW_REG(ERROR);
  57};
  58
  59struct dw_dma_regs {
  60        /* per-channel registers */
  61        struct dw_dma_chan_regs CHAN[DW_DMA_MAX_NR_CHANNELS];
  62
  63        /* irq handling */
  64        struct dw_dma_irq_regs  RAW;            /* r */
  65        struct dw_dma_irq_regs  STATUS;         /* r (raw & mask) */
  66        struct dw_dma_irq_regs  MASK;           /* rw (set = irq enabled) */
  67        struct dw_dma_irq_regs  CLEAR;          /* w (ack, affects "raw") */
  68
  69        DW_REG(STATUS_INT);                     /* r */
  70
  71        /* software handshaking */
  72        DW_REG(REQ_SRC);
  73        DW_REG(REQ_DST);
  74        DW_REG(SGL_REQ_SRC);
  75        DW_REG(SGL_REQ_DST);
  76        DW_REG(LAST_SRC);
  77        DW_REG(LAST_DST);
  78
  79        /* miscellaneous */
  80        DW_REG(CFG);
  81        DW_REG(CH_EN);
  82        DW_REG(ID);
  83        DW_REG(TEST);
  84
  85        /* reserved */
  86        DW_REG(__reserved0);
  87        DW_REG(__reserved1);
  88
  89        /* optional encoded params, 0x3c8..0x3f7 */
  90        u32     __reserved;
  91
  92        /* per-channel configuration registers */
  93        u32     DWC_PARAMS[DW_DMA_MAX_NR_CHANNELS];
  94        u32     MULTI_BLK_TYPE;
  95        u32     MAX_BLK_SIZE;
  96
  97        /* top-level parameters */
  98        u32     DW_PARAMS;
  99};
 100
 101#ifdef CONFIG_DW_DMAC_BIG_ENDIAN_IO
 102#define dma_readl_native ioread32be
 103#define dma_writel_native iowrite32be
 104#else
 105#define dma_readl_native readl
 106#define dma_writel_native writel
 107#endif
 108
 109/* To access the registers in early stage of probe */
 110#define dma_read_byaddr(addr, name) \
 111        dma_readl_native((addr) + offsetof(struct dw_dma_regs, name))
 112
 113/* Bitfields in DW_PARAMS */
 114#define DW_PARAMS_NR_CHAN       8               /* number of channels */
 115#define DW_PARAMS_NR_MASTER     11              /* number of AHB masters */
 116#define DW_PARAMS_DATA_WIDTH(n) (15 + 2 * (n))
 117#define DW_PARAMS_DATA_WIDTH1   15              /* master 1 data width */
 118#define DW_PARAMS_DATA_WIDTH2   17              /* master 2 data width */
 119#define DW_PARAMS_DATA_WIDTH3   19              /* master 3 data width */
 120#define DW_PARAMS_DATA_WIDTH4   21              /* master 4 data width */
 121#define DW_PARAMS_EN            28              /* encoded parameters */
 122
 123/* Bitfields in DWC_PARAMS */
 124#define DWC_PARAMS_MBLK_EN      11              /* multi block transfer */
 125
 126/* Bitfields in CTL_LO */
 127#define DWC_CTLL_INT_EN         (1 << 0)        /* irqs enabled? */
 128#define DWC_CTLL_DST_WIDTH(n)   ((n)<<1)        /* bytes per element */
 129#define DWC_CTLL_SRC_WIDTH(n)   ((n)<<4)
 130#define DWC_CTLL_DST_INC        (0<<7)          /* DAR update/not */
 131#define DWC_CTLL_DST_DEC        (1<<7)
 132#define DWC_CTLL_DST_FIX        (2<<7)
 133#define DWC_CTLL_SRC_INC        (0<<7)          /* SAR update/not */
 134#define DWC_CTLL_SRC_DEC        (1<<9)
 135#define DWC_CTLL_SRC_FIX        (2<<9)
 136#define DWC_CTLL_DST_MSIZE(n)   ((n)<<11)       /* burst, #elements */
 137#define DWC_CTLL_SRC_MSIZE(n)   ((n)<<14)
 138#define DWC_CTLL_S_GATH_EN      (1 << 17)       /* src gather, !FIX */
 139#define DWC_CTLL_D_SCAT_EN      (1 << 18)       /* dst scatter, !FIX */
 140#define DWC_CTLL_FC(n)          ((n) << 20)
 141#define DWC_CTLL_FC_M2M         (0 << 20)       /* mem-to-mem */
 142#define DWC_CTLL_FC_M2P         (1 << 20)       /* mem-to-periph */
 143#define DWC_CTLL_FC_P2M         (2 << 20)       /* periph-to-mem */
 144#define DWC_CTLL_FC_P2P         (3 << 20)       /* periph-to-periph */
 145/* plus 4 transfer types for peripheral-as-flow-controller */
 146#define DWC_CTLL_DMS(n)         ((n)<<23)       /* dst master select */
 147#define DWC_CTLL_SMS(n)         ((n)<<25)       /* src master select */
 148#define DWC_CTLL_LLP_D_EN       (1 << 27)       /* dest block chain */
 149#define DWC_CTLL_LLP_S_EN       (1 << 28)       /* src block chain */
 150
 151/* Bitfields in CTL_HI */
 152#define DWC_CTLH_DONE           0x00001000
 153#define DWC_CTLH_BLOCK_TS_MASK  0x00000fff
 154
 155/* Bitfields in CFG_LO. Platform-configurable bits are in <linux/dw_dmac.h> */
 156#define DWC_CFGL_CH_PRIOR_MASK  (0x7 << 5)      /* priority mask */
 157#define DWC_CFGL_CH_PRIOR(x)    ((x) << 5)      /* priority */
 158#define DWC_CFGL_CH_SUSP        (1 << 8)        /* pause xfer */
 159#define DWC_CFGL_FIFO_EMPTY     (1 << 9)        /* pause xfer */
 160#define DWC_CFGL_HS_DST         (1 << 10)       /* handshake w/dst */
 161#define DWC_CFGL_HS_SRC         (1 << 11)       /* handshake w/src */
 162#define DWC_CFGL_MAX_BURST(x)   ((x) << 20)
 163#define DWC_CFGL_RELOAD_SAR     (1 << 30)
 164#define DWC_CFGL_RELOAD_DAR     (1 << 31)
 165
 166/* Bitfields in CFG_HI. Platform-configurable bits are in <linux/dw_dmac.h> */
 167#define DWC_CFGH_DS_UPD_EN      (1 << 5)
 168#define DWC_CFGH_SS_UPD_EN      (1 << 6)
 169
 170/* Bitfields in SGR */
 171#define DWC_SGR_SGI(x)          ((x) << 0)
 172#define DWC_SGR_SGC(x)          ((x) << 20)
 173
 174/* Bitfields in DSR */
 175#define DWC_DSR_DSI(x)          ((x) << 0)
 176#define DWC_DSR_DSC(x)          ((x) << 20)
 177
 178/* Bitfields in CFG */
 179#define DW_CFG_DMA_EN           (1 << 0)
 180
 181enum dw_dmac_flags {
 182        DW_DMA_IS_CYCLIC = 0,
 183        DW_DMA_IS_SOFT_LLP = 1,
 184};
 185
 186struct dw_dma_chan {
 187        struct dma_chan         chan;
 188        void __iomem            *ch_regs;
 189        u8                      mask;
 190        u8                      priority;
 191        bool                    paused;
 192        bool                    initialized;
 193
 194        /* software emulation of the LLP transfers */
 195        struct list_head        *tx_list;
 196        struct list_head        *tx_node_active;
 197
 198        spinlock_t              lock;
 199
 200        /* these other elements are all protected by lock */
 201        unsigned long           flags;
 202        struct list_head        active_list;
 203        struct list_head        queue;
 204        struct list_head        free_list;
 205        struct dw_cyclic_desc   *cdesc;
 206
 207        unsigned int            descs_allocated;
 208
 209        /* hardware configuration */
 210        unsigned int            block_size;
 211        bool                    nollp;
 212
 213        /* configuration passed via DMA_SLAVE_CONFIG */
 214        struct dma_slave_config dma_sconfig;
 215
 216        /* backlink to dw_dma */
 217        struct dw_dma           *dw;
 218};
 219
 220static inline struct dw_dma_chan_regs __iomem *
 221__dwc_regs(struct dw_dma_chan *dwc)
 222{
 223        return dwc->ch_regs;
 224}
 225
 226#define channel_readl(dwc, name) \
 227        dma_readl_native(&(__dwc_regs(dwc)->name))
 228#define channel_writel(dwc, name, val) \
 229        dma_writel_native((val), &(__dwc_regs(dwc)->name))
 230
 231static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
 232{
 233        return container_of(chan, struct dw_dma_chan, chan);
 234}
 235
 236struct dw_dma {
 237        struct dma_device       dma;
 238        void __iomem            *regs;
 239        struct tasklet_struct   tasklet;
 240        struct clk              *clk;
 241
 242        u8                      all_chan_mask;
 243
 244        /* hardware configuration */
 245        unsigned char           nr_masters;
 246        unsigned char           data_width[4];
 247
 248        struct dw_dma_chan      chan[0];
 249};
 250
 251static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
 252{
 253        return dw->regs;
 254}
 255
 256#define dma_readl(dw, name) \
 257        dma_readl_native(&(__dw_regs(dw)->name))
 258#define dma_writel(dw, name, val) \
 259        dma_writel_native((val), &(__dw_regs(dw)->name))
 260
 261#define channel_set_bit(dw, reg, mask) \
 262        dma_writel(dw, reg, ((mask) << 8) | (mask))
 263#define channel_clear_bit(dw, reg, mask) \
 264        dma_writel(dw, reg, ((mask) << 8) | 0)
 265
 266static inline struct dw_dma *to_dw_dma(struct dma_device *ddev)
 267{
 268        return container_of(ddev, struct dw_dma, dma);
 269}
 270
 271/* LLI == Linked List Item; a.k.a. DMA block descriptor */
 272struct dw_lli {
 273        /* values that are not changed by hardware */
 274        u32             sar;
 275        u32             dar;
 276        u32             llp;            /* chain to next lli */
 277        u32             ctllo;
 278        /* values that may get written back: */
 279        u32             ctlhi;
 280        /* sstat and dstat can snapshot peripheral register state.
 281         * silicon config may discard either or both...
 282         */
 283        u32             sstat;
 284        u32             dstat;
 285};
 286
 287struct dw_desc {
 288        /* FIRST values the hardware uses */
 289        struct dw_lli                   lli;
 290
 291        /* THEN values for driver housekeeping */
 292        struct list_head                desc_node;
 293        struct list_head                tx_list;
 294        struct dma_async_tx_descriptor  txd;
 295        size_t                          len;
 296};
 297
 298static inline struct dw_desc *
 299txd_to_dw_desc(struct dma_async_tx_descriptor *txd)
 300{
 301        return container_of(txd, struct dw_desc, txd);
 302}
 303