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linux/drivers/dma/dw_dmac_regs.h
Viresh Kumar 61e183f830 dmaengine/dw_dmac: Reconfigure interrupt and chan_cfg register on resume 
In S2R all DMA registers are reset by hardware and thus they are required to be
reprogrammed. The channels which aren't reprogrammed are channel configuration
and interrupt enable registers, which are currently programmed at chan_alloc
time.

This patch creates another routine to initialize a channel. It will try to
initialize channel on every dwc_dostart() call. If channel is already
initialised then it simply returns, otherwise it configures registers.

This routine will also initialize registers on wakeup from S2R, as we mark
channels as uninitialized on suspend.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2011-11-28 08:48:02 +05:30

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/*
* 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
/*
* 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;
dma_cookie_t completed;
struct list_head active_list;
struct list_head queue;
struct list_head free_list;
struct dw_cyclic_desc *cdesc;
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) \
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);
}
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