229 lines
6.0 KiB
C
229 lines
6.0 KiB
C
/*
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* Driver for the Synopsys DesignWare AHB DMA Controller
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*
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* Copyright (C) 2005-2007 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/dw_dmac.h>
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#define DW_DMA_MAX_NR_CHANNELS 8
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/*
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* Redefine this macro to handle differences between 32- and 64-bit
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* addressing, big vs. little endian, etc.
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*/
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#define DW_REG(name) u32 name; u32 __pad_##name
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/* Hardware register definitions. */
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struct dw_dma_chan_regs {
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DW_REG(SAR); /* Source Address Register */
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DW_REG(DAR); /* Destination Address Register */
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DW_REG(LLP); /* Linked List Pointer */
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u32 CTL_LO; /* Control Register Low */
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u32 CTL_HI; /* Control Register High */
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DW_REG(SSTAT);
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DW_REG(DSTAT);
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DW_REG(SSTATAR);
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DW_REG(DSTATAR);
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u32 CFG_LO; /* Configuration Register Low */
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u32 CFG_HI; /* Configuration Register High */
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DW_REG(SGR);
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DW_REG(DSR);
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};
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struct dw_dma_irq_regs {
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DW_REG(XFER);
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DW_REG(BLOCK);
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DW_REG(SRC_TRAN);
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DW_REG(DST_TRAN);
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DW_REG(ERROR);
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};
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struct dw_dma_regs {
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/* per-channel registers */
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struct dw_dma_chan_regs CHAN[DW_DMA_MAX_NR_CHANNELS];
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/* irq handling */
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struct dw_dma_irq_regs RAW; /* r */
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struct dw_dma_irq_regs STATUS; /* r (raw & mask) */
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struct dw_dma_irq_regs MASK; /* rw (set = irq enabled) */
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struct dw_dma_irq_regs CLEAR; /* w (ack, affects "raw") */
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DW_REG(STATUS_INT); /* r */
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/* software handshaking */
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DW_REG(REQ_SRC);
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DW_REG(REQ_DST);
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DW_REG(SGL_REQ_SRC);
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DW_REG(SGL_REQ_DST);
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DW_REG(LAST_SRC);
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DW_REG(LAST_DST);
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/* miscellaneous */
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DW_REG(CFG);
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DW_REG(CH_EN);
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DW_REG(ID);
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DW_REG(TEST);
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/* optional encoded params, 0x3c8..0x3 */
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};
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/* Bitfields in CTL_LO */
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#define DWC_CTLL_INT_EN (1 << 0) /* irqs enabled? */
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#define DWC_CTLL_DST_WIDTH(n) ((n)<<1) /* bytes per element */
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#define DWC_CTLL_SRC_WIDTH(n) ((n)<<4)
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#define DWC_CTLL_DST_INC (0<<7) /* DAR update/not */
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#define DWC_CTLL_DST_DEC (1<<7)
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#define DWC_CTLL_DST_FIX (2<<7)
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#define DWC_CTLL_SRC_INC (0<<7) /* SAR update/not */
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#define DWC_CTLL_SRC_DEC (1<<9)
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#define DWC_CTLL_SRC_FIX (2<<9)
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#define DWC_CTLL_DST_MSIZE(n) ((n)<<11) /* burst, #elements */
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#define DWC_CTLL_SRC_MSIZE(n) ((n)<<14)
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#define DWC_CTLL_S_GATH_EN (1 << 17) /* src gather, !FIX */
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#define DWC_CTLL_D_SCAT_EN (1 << 18) /* dst scatter, !FIX */
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#define DWC_CTLL_FC_M2M (0 << 20) /* mem-to-mem */
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#define DWC_CTLL_FC_M2P (1 << 20) /* mem-to-periph */
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#define DWC_CTLL_FC_P2M (2 << 20) /* periph-to-mem */
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#define DWC_CTLL_FC_P2P (3 << 20) /* periph-to-periph */
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/* plus 4 transfer types for peripheral-as-flow-controller */
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#define DWC_CTLL_DMS(n) ((n)<<23) /* dst master select */
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#define DWC_CTLL_SMS(n) ((n)<<25) /* src master select */
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#define DWC_CTLL_LLP_D_EN (1 << 27) /* dest block chain */
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#define DWC_CTLL_LLP_S_EN (1 << 28) /* src block chain */
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/* Bitfields in CTL_HI */
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#define DWC_CTLH_DONE 0x00001000
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#define DWC_CTLH_BLOCK_TS_MASK 0x00000fff
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/* Bitfields in CFG_LO. Platform-configurable bits are in <linux/dw_dmac.h> */
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#define DWC_CFGL_CH_SUSP (1 << 8) /* pause xfer */
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#define DWC_CFGL_FIFO_EMPTY (1 << 9) /* pause xfer */
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#define DWC_CFGL_HS_DST (1 << 10) /* handshake w/dst */
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#define DWC_CFGL_HS_SRC (1 << 11) /* handshake w/src */
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#define DWC_CFGL_MAX_BURST(x) ((x) << 20)
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#define DWC_CFGL_RELOAD_SAR (1 << 30)
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#define DWC_CFGL_RELOAD_DAR (1 << 31)
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/* Bitfields in CFG_HI. Platform-configurable bits are in <linux/dw_dmac.h> */
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#define DWC_CFGH_DS_UPD_EN (1 << 5)
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#define DWC_CFGH_SS_UPD_EN (1 << 6)
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/* Bitfields in SGR */
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#define DWC_SGR_SGI(x) ((x) << 0)
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#define DWC_SGR_SGC(x) ((x) << 20)
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/* Bitfields in DSR */
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#define DWC_DSR_DSI(x) ((x) << 0)
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#define DWC_DSR_DSC(x) ((x) << 20)
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/* Bitfields in CFG */
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#define DW_CFG_DMA_EN (1 << 0)
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#define DW_REGLEN 0x400
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enum dw_dmac_flags {
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DW_DMA_IS_CYCLIC = 0,
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};
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struct dw_dma_chan {
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struct dma_chan chan;
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void __iomem *ch_regs;
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u8 mask;
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spinlock_t lock;
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/* these other elements are all protected by lock */
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unsigned long flags;
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dma_cookie_t completed;
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struct list_head active_list;
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struct list_head queue;
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struct list_head free_list;
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struct dw_cyclic_desc *cdesc;
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unsigned int descs_allocated;
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};
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static inline struct dw_dma_chan_regs __iomem *
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__dwc_regs(struct dw_dma_chan *dwc)
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{
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return dwc->ch_regs;
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}
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#define channel_readl(dwc, name) \
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__raw_readl(&(__dwc_regs(dwc)->name))
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#define channel_writel(dwc, name, val) \
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__raw_writel((val), &(__dwc_regs(dwc)->name))
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static inline struct dw_dma_chan *to_dw_dma_chan(struct dma_chan *chan)
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{
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return container_of(chan, struct dw_dma_chan, chan);
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}
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struct dw_dma {
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struct dma_device dma;
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void __iomem *regs;
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struct tasklet_struct tasklet;
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struct clk *clk;
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u8 all_chan_mask;
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struct dw_dma_chan chan[0];
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};
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static inline struct dw_dma_regs __iomem *__dw_regs(struct dw_dma *dw)
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{
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return dw->regs;
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}
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#define dma_readl(dw, name) \
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__raw_readl(&(__dw_regs(dw)->name))
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#define dma_writel(dw, name, val) \
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__raw_writel((val), &(__dw_regs(dw)->name))
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#define channel_set_bit(dw, reg, mask) \
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dma_writel(dw, reg, ((mask) << 8) | (mask))
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#define channel_clear_bit(dw, reg, mask) \
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dma_writel(dw, reg, ((mask) << 8) | 0)
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static inline struct dw_dma *to_dw_dma(struct dma_device *ddev)
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{
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return container_of(ddev, struct dw_dma, dma);
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}
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/* LLI == Linked List Item; a.k.a. DMA block descriptor */
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struct dw_lli {
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/* values that are not changed by hardware */
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dma_addr_t sar;
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dma_addr_t dar;
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dma_addr_t llp; /* chain to next lli */
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u32 ctllo;
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/* values that may get written back: */
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u32 ctlhi;
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/* sstat and dstat can snapshot peripheral register state.
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* silicon config may discard either or both...
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*/
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u32 sstat;
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u32 dstat;
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};
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struct dw_desc {
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/* FIRST values the hardware uses */
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struct dw_lli lli;
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/* THEN values for driver housekeeping */
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struct list_head desc_node;
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struct dma_async_tx_descriptor txd;
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size_t len;
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};
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static inline struct dw_desc *
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txd_to_dw_desc(struct dma_async_tx_descriptor *txd)
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{
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return container_of(txd, struct dw_desc, txd);
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}
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