/*
* Driver for the Synopsys DesignWare AHB DMA Controller
*
* Copyright (C) 2005-2007 Atmel Corporation
* Copyright (C) 2010-2011 ST Microelectronics
*
* 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
/* flow controller */
enum dw_dma_fc {
DW_DMA_FC_D_M2M,
DW_DMA_FC_D_M2P,
DW_DMA_FC_D_P2M,
DW_DMA_FC_D_P2P,
DW_DMA_FC_P_P2M,
DW_DMA_FC_SP_P2P,
DW_DMA_FC_P_M2P,
DW_DMA_FC_DP_P2P,
};
/*
* 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(n) ((n) << 20)
#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_PRIOR_MASK (0x7 << 5) /* priority mask */
#define DWC_CFGL_CH_PRIOR(x) ((x) << 5) /* priority */
#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
enum dw_dmac_flags {
DW_DMA_IS_CYCLIC = 0,
};
struct dw_dma_chan {
struct dma_chan chan;
void __iomem *ch_regs;
u8 mask;
u8 priority;
bool paused;
bool initialized;
spinlock_t lock;
/* these other elements are all protected by lock */
unsigned long flags;
struct list_head active_list;
struct list_head queue;
struct list_head free_list;
struct dw_cyclic_desc *cdesc;
unsigned int descs_allocated;
/* configuration passed via DMA_SLAVE_CONFIG */
struct dma_slave_config dma_sconfig;
};
static inline struct dw_dma_chan_regs __iomem *
__dwc_regs(struct dw_dma_chan *dwc)
{
return dwc->ch_regs;
}
#define channel_readl(dwc, name) \
readl(&(__dwc_regs(dwc)->name))
#define channel_writel(dwc, name, val) \
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) \
readl(&(__dw_regs(dw)->name))
#define dma_writel(dw, name, val) \
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 list_head tx_list;
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);
}
