dmaengine: dw_dmac: simplify master selection

The patch to add the common DMA binding added a dummy dw_dma_slave
structure into the dw_dma_chan structure in order to configure the
masters correctly. It turns out that this can be simplified if we
pick the DMA masters in the dwc_alloc_chan_resources function instead
and save them in the dw_dma_chan structure directly.

This could be simplified further once all users that today use
dw_dma_slave for configuration get converted to device tree based
setup instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 274fd7d..951ef5b 100644 (file)
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -49,29 +49,22 @@ static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave)
        return slave ? slave->src_master : 1;
 }
 
-#define SRC_MASTER     0
-#define DST_MASTER     1
-
-static inline unsigned int dwc_get_master(struct dma_chan *chan, int master)
+static inline void dwc_set_masters(struct dw_dma_chan *dwc)
 {
-       struct dw_dma *dw = to_dw_dma(chan->device);
-       struct dw_dma_slave *dws = chan->private;
-       unsigned int m;
-
-       if (master == SRC_MASTER)
-               m = dwc_get_sms(dws);
-       else
-               m = dwc_get_dms(dws);
+       struct dw_dma *dw = to_dw_dma(dwc->chan.device);
+       struct dw_dma_slave *dws = dwc->chan.private;
+       unsigned char mmax = dw->nr_masters - 1;
 
-       return min_t(unsigned int, dw->nr_masters - 1, m);
+       if (dwc->request_line == ~0) {
+               dwc->src_master = min_t(unsigned char, mmax, dwc_get_sms(dws));
+               dwc->dst_master = min_t(unsigned char, mmax, dwc_get_dms(dws));
+       }
 }
 
 #define DWC_DEFAULT_CTLLO(_chan) ({                            \
                struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan);       \
                struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
                bool _is_slave = is_slave_direction(_dwc->direction);   \
-               int _dms = dwc_get_master(_chan, DST_MASTER);           \
-               int _sms = dwc_get_master(_chan, SRC_MASTER);           \
                u8 _smsize = _is_slave ? _sconfig->src_maxburst :       \
                        DW_DMA_MSIZE_16;                        \
                u8 _dmsize = _is_slave ? _sconfig->dst_maxburst :       \
@@ -81,8 +74,8 @@ static inline unsigned int dwc_get_master(struct dma_chan *chan, int master)
                 | DWC_CTLL_SRC_MSIZE(_smsize)                  \
                 | DWC_CTLL_LLP_D_EN                            \
                 | DWC_CTLL_LLP_S_EN                            \
-                | DWC_CTLL_DMS(_dms)                           \
-                | DWC_CTLL_SMS(_sms));                         \
+                | DWC_CTLL_DMS(_dwc->dst_master)               \
+                | DWC_CTLL_SMS(_dwc->src_master));             \
        })
 
 /*
@@ -92,13 +85,6 @@ static inline unsigned int dwc_get_master(struct dma_chan *chan, int master)
  */
 #define NR_DESCS_PER_CHANNEL   64
 
-static inline unsigned int dwc_get_data_width(struct dma_chan *chan, int master)
-{
-       struct dw_dma *dw = to_dw_dma(chan->device);
-
-       return dw->data_width[dwc_get_master(chan, master)];
-}
-
 /*----------------------------------------------------------------------*/
 
 static struct device *chan2dev(struct dma_chan *chan)
@@ -172,13 +158,7 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
        if (dwc->initialized == true)
                return;
 
-       if (dws && dws->cfg_hi == ~0 && dws->cfg_lo == ~0) {
-               /* Autoconfigure based on request line from DT */
-               if (dwc->direction == DMA_MEM_TO_DEV)
-                       cfghi = DWC_CFGH_DST_PER(dwc->request_line);
-               else if (dwc->direction == DMA_DEV_TO_MEM)
-                       cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
-       } else if (dws) {
+       if (dws) {
                /*
                 * We need controller-specific data to set up slave
                 * transfers.
@@ -189,9 +169,9 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
                cfglo |= dws->cfg_lo & ~DWC_CFGL_CH_PRIOR_MASK;
        } else {
                if (dwc->direction == DMA_MEM_TO_DEV)
-                       cfghi = DWC_CFGH_DST_PER(dwc->dma_sconfig.slave_id);
+                       cfghi = DWC_CFGH_DST_PER(dwc->request_line);
                else if (dwc->direction == DMA_DEV_TO_MEM)
-                       cfghi = DWC_CFGH_SRC_PER(dwc->dma_sconfig.slave_id);
+                       cfghi = DWC_CFGH_SRC_PER(dwc->request_line);
        }
 
        channel_writel(dwc, CFG_LO, cfglo);
@@ -745,6 +725,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
                size_t len, unsigned long flags)
 {
        struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
+       struct dw_dma           *dw = to_dw_dma(chan->device);
        struct dw_desc          *desc;
        struct dw_desc          *first;
        struct dw_desc          *prev;
@@ -767,8 +748,8 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 
        dwc->direction = DMA_MEM_TO_MEM;
 
-       data_width = min_t(unsigned int, dwc_get_data_width(chan, SRC_MASTER),
-                          dwc_get_data_width(chan, DST_MASTER));
+       data_width = min_t(unsigned int, dw->data_width[dwc->src_master],
+                          dw->data_width[dwc->dst_master]);
 
        src_width = dst_width = min_t(unsigned int, data_width,
                                      dwc_fast_fls(src | dest | len));
@@ -826,6 +807,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                unsigned long flags, void *context)
 {
        struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
+       struct dw_dma           *dw = to_dw_dma(chan->device);
        struct dma_slave_config *sconfig = &dwc->dma_sconfig;
        struct dw_desc          *prev;
        struct dw_desc          *first;
@@ -859,7 +841,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
                ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
                        DWC_CTLL_FC(DW_DMA_FC_D_M2P);
 
-               data_width = dwc_get_data_width(chan, SRC_MASTER);
+               data_width = dw->data_width[dwc->src_master];
 
                for_each_sg(sgl, sg, sg_len, i) {
                        struct dw_desc  *desc;
@@ -919,7 +901,7 @@ slave_sg_todev_fill_desc:
                ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
                        DWC_CTLL_FC(DW_DMA_FC_D_P2M);
 
-               data_width = dwc_get_data_width(chan, DST_MASTER);
+               data_width = dw->data_width[dwc->dst_master];
 
                for_each_sg(sgl, sg, sg_len, i) {
                        struct dw_desc  *desc;
@@ -1020,6 +1002,10 @@ set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
        memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
        dwc->direction = sconfig->direction;
 
+       /* Take the request line from slave_id member */
+       if (dwc->request_line == ~0)
+               dwc->request_line = sconfig->slave_id;
+
        convert_burst(&dwc->dma_sconfig.src_maxburst);
        convert_burst(&dwc->dma_sconfig.dst_maxburst);
        convert_slave_id(dwc);
@@ -1170,6 +1156,8 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
         * doesn't mean what you think it means), and status writeback.
         */
 
+       dwc_set_masters(dwc);
+
        spin_lock_irqsave(&dwc->lock, flags);
        i = dwc->descs_allocated;
        while (dwc->descs_allocated < NR_DESCS_PER_CHANNEL) {
@@ -1227,6 +1215,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
        list_splice_init(&dwc->free_list, &list);
        dwc->descs_allocated = 0;
        dwc->initialized = false;
+       dwc->request_line = ~0;
 
        /* Disable interrupts */
        channel_clear_bit(dw, MASK.XFER, dwc->mask);
@@ -1254,23 +1243,15 @@ struct dw_dma_of_filter_args {
 static bool dw_dma_of_filter(struct dma_chan *chan, void *param)
 {
        struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
-       struct dw_dma *dw = to_dw_dma(chan->device);
        struct dw_dma_of_filter_args *fargs = param;
-       struct dw_dma_slave *dws = &dwc->slave;
 
        /* Ensure the device matches our channel */
         if (chan->device != &fargs->dw->dma)
                 return false;
 
-       dws->dma_dev    = dw->dma.dev;
-       dws->cfg_hi     = ~0;
-       dws->cfg_lo     = ~0;
-       dws->src_master = fargs->src;
-       dws->dst_master = fargs->dst;
-
        dwc->request_line = fargs->req;
-
-       chan->private = dws;
+       dwc->src_master = fargs->src;
+       dwc->dst_master = fargs->dst;
 
        return true;
 }
@@ -1784,6 +1765,7 @@ static int dw_probe(struct platform_device *pdev)
                channel_clear_bit(dw, CH_EN, dwc->mask);
 
                dwc->direction = DMA_TRANS_NONE;
+               dwc->request_line = ~0;
 
                /* Hardware configuration */
                if (autocfg) {

diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index 4d02c36..9b0e12e 100644 (file)
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -212,8 +212,11 @@ struct dw_dma_chan {
        /* hardware configuration */
        unsigned int            block_size;
        bool                    nollp;
+
+       /* custom slave configuration */
        unsigned int            request_line;
-       struct dw_dma_slave     slave;
+       unsigned char           src_master;
+       unsigned char           dst_master;
 
        /* configuration passed via DMA_SLAVE_CONFIG */
        struct dma_slave_config dma_sconfig;