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