diff options
| author | Viresh Kumar <viresh.kumar@st.com> | 2011-03-03 15:47:22 +0530 |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2011-03-07 01:12:28 +0530 |
| commit | 93317e8e35b77633d589fe0e132291195757d785 (patch) | |
| tree | c3419c1a02e3952506ca0af281f9f9c5bc52888d | |
| parent | b0c3130d69bda5cd91aa3b3f08e7878df49fde69 (diff) | |
| download | linux-93317e8e35b77633d589fe0e132291195757d785.tar.bz2 | |
dw_dmac: Pass Channel Priority from platform_data
In Synopsys designware, channel priority is programmable. This patch adds
support for passing channel priority through platform data. By default Ascending
channel priority will be followed, i.e. channel 0 will get highest priority and
channel 7 will get lowest.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
| -rw-r--r-- | drivers/dma/dw_dmac.c | 11 | ||||
| -rw-r--r-- | drivers/dma/dw_dmac_regs.h | 3 | ||||
| -rw-r--r-- | include/linux/dw_dmac.h | 4 |
3 files changed, 16 insertions, 2 deletions
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index f413e123405a..318a342fc7ec 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -901,8 +901,11 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan) BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev); cfghi = dws->cfg_hi; - cfglo = dws->cfg_lo; + cfglo = dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK; } + + cfglo |= DWC_CFGL_CH_PRIOR(dwc->priority); + channel_writel(dwc, CFG_LO, cfglo); channel_writel(dwc, CFG_HI, cfghi); @@ -1325,6 +1328,12 @@ static int __init dw_probe(struct platform_device *pdev) else list_add(&dwc->chan.device_node, &dw->dma.channels); + /* 7 is highest priority & 0 is lowest. */ + if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING) + dwc->priority = 7 - i; + else + dwc->priority = i; + dwc->ch_regs = &__dw_regs(dw)->CHAN[i]; spin_lock_init(&dwc->lock); dwc->mask = 1 << i; diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h index d9a939f67f46..6a8e6d35f359 100644 --- a/drivers/dma/dw_dmac_regs.h +++ b/drivers/dma/dw_dmac_regs.h @@ -101,6 +101,8 @@ struct dw_dma_regs { #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 */ @@ -134,6 +136,7 @@ struct dw_dma_chan { struct dma_chan chan; void __iomem *ch_regs; u8 mask; + u8 priority; spinlock_t lock; diff --git a/include/linux/dw_dmac.h b/include/linux/dw_dmac.h index a18c498984d9..64c76da571ef 100644 --- a/include/linux/dw_dmac.h +++ b/include/linux/dw_dmac.h @@ -25,6 +25,9 @@ struct dw_dma_platform_data { #define CHAN_ALLOCATION_ASCENDING 0 /* zero to seven */ #define CHAN_ALLOCATION_DESCENDING 1 /* seven to zero */ unsigned char chan_allocation_order; +#define CHAN_PRIORITY_ASCENDING 0 /* chan0 highest */ +#define CHAN_PRIORITY_DESCENDING 1 /* chan7 highest */ + unsigned char chan_priority; }; /** @@ -70,7 +73,6 @@ struct dw_dma_slave { #define DWC_CFGH_DST_PER(x) ((x) << 11) /* Platform-configurable bits in CFG_LO */ -#define DWC_CFGL_PRIO(x) ((x) << 5) /* priority */ #define DWC_CFGL_LOCK_CH_XFER (0 << 12) /* scope of LOCK_CH */ #define DWC_CFGL_LOCK_CH_BLOCK (1 << 12) #define DWC_CFGL_LOCK_CH_XACT (2 << 12) |