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authorNicolas Ferre <nicolas.ferre@atmel.com>2012-03-14 15:41:43 +0400
committerVinod Koul <vinod.koul@linux.intel.com>2012-03-21 19:42:29 +0400
commitbeeaa103eecc7a132682c40867f0ef70655383a5 (patch)
treec1cc34c65347a04d859eae78076322668d2f636d /drivers
parent185ecb5f4fd43911c35956d4cc7d94a1da30417f (diff)
downloadlinux-beeaa103eecc7a132682c40867f0ef70655383a5.tar.xz
dmaengine: at_hdmac: add slave config operation
This patch introduces DMA_SLAVE_CONFIG to at_hdmac Atmel DMA driver. It is needed to fix a regression in the use of atmel-mci.c driver on Atmel AT91 platforms brouth by e2b35f3: "dmaengine/dw_dmac: Fix dw_dmac user drivers to adapt to slave_config changes" We remove some parts of the private structure "at_dma_slave" and use the information provided by "struct dma_slave_config": source/destination peripheral registers and access width. AT_DMA_SLAVE_WIDTH_* values used previously are not needed anymore as we now use the standard ones. Although some conversion functions are needed to match register expected values. Some AT91 sub-architecture specific files are slightly touched by this patch but it cannot be split because it can break compilation. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma/at_hdmac.c56
-rw-r--r--drivers/dma/at_hdmac_regs.h32
2 files changed, 75 insertions, 13 deletions
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index f24b16e455fd..7aa58d204892 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -648,6 +648,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
struct at_desc *first = NULL;
struct at_desc *prev = NULL;
u32 ctrla;
@@ -669,19 +670,18 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
return NULL;
}
- reg_width = atslave->reg_width;
-
ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla;
ctrlb = ATC_IEN;
switch (direction) {
case DMA_MEM_TO_DEV:
+ reg_width = convert_buswidth(sconfig->dst_addr_width);
ctrla |= ATC_DST_WIDTH(reg_width);
ctrlb |= ATC_DST_ADDR_MODE_FIXED
| ATC_SRC_ADDR_MODE_INCR
| ATC_FC_MEM2PER
| ATC_SIF(AT_DMA_MEM_IF) | ATC_DIF(AT_DMA_PER_IF);
- reg = atslave->tx_reg;
+ reg = sconfig->dst_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct at_desc *desc;
u32 len;
@@ -709,13 +709,14 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
}
break;
case DMA_DEV_TO_MEM:
+ reg_width = convert_buswidth(sconfig->src_addr_width);
ctrla |= ATC_SRC_WIDTH(reg_width);
ctrlb |= ATC_DST_ADDR_MODE_INCR
| ATC_SRC_ADDR_MODE_FIXED
| ATC_FC_PER2MEM
| ATC_SIF(AT_DMA_PER_IF) | ATC_DIF(AT_DMA_MEM_IF);
- reg = atslave->rx_reg;
+ reg = sconfig->src_addr;
for_each_sg(sgl, sg, sg_len, i) {
struct at_desc *desc;
u32 len;
@@ -791,12 +792,15 @@ err_out:
* atc_dma_cyclic_fill_desc - Fill one period decriptor
*/
static int
-atc_dma_cyclic_fill_desc(struct at_dma_slave *atslave, struct at_desc *desc,
+atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
unsigned int period_index, dma_addr_t buf_addr,
- size_t period_len, enum dma_transfer_direction direction)
+ unsigned int reg_width, size_t period_len,
+ enum dma_transfer_direction direction)
{
- u32 ctrla;
- unsigned int reg_width = atslave->reg_width;
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+ struct at_dma_slave *atslave = chan->private;
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
+ u32 ctrla;
/* prepare common CRTLA value */
ctrla = ATC_DEFAULT_CTRLA | atslave->ctrla
@@ -807,7 +811,7 @@ atc_dma_cyclic_fill_desc(struct at_dma_slave *atslave, struct at_desc *desc,
switch (direction) {
case DMA_MEM_TO_DEV:
desc->lli.saddr = buf_addr + (period_len * period_index);
- desc->lli.daddr = atslave->tx_reg;
+ desc->lli.daddr = sconfig->dst_addr;
desc->lli.ctrla = ctrla;
desc->lli.ctrlb = ATC_DST_ADDR_MODE_FIXED
| ATC_SRC_ADDR_MODE_INCR
@@ -817,7 +821,7 @@ atc_dma_cyclic_fill_desc(struct at_dma_slave *atslave, struct at_desc *desc,
break;
case DMA_DEV_TO_MEM:
- desc->lli.saddr = atslave->rx_reg;
+ desc->lli.saddr = sconfig->src_addr;
desc->lli.daddr = buf_addr + (period_len * period_index);
desc->lli.ctrla = ctrla;
desc->lli.ctrlb = ATC_DST_ADDR_MODE_INCR
@@ -850,9 +854,11 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
{
struct at_dma_chan *atchan = to_at_dma_chan(chan);
struct at_dma_slave *atslave = chan->private;
+ struct dma_slave_config *sconfig = &atchan->dma_sconfig;
struct at_desc *first = NULL;
struct at_desc *prev = NULL;
unsigned long was_cyclic;
+ unsigned int reg_width;
unsigned int periods = buf_len / period_len;
unsigned int i;
@@ -872,8 +878,13 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
return NULL;
}
+ if (sconfig->direction == DMA_MEM_TO_DEV)
+ reg_width = convert_buswidth(sconfig->dst_addr_width);
+ else
+ reg_width = convert_buswidth(sconfig->src_addr_width);
+
/* Check for too big/unaligned periods and unaligned DMA buffer */
- if (atc_dma_cyclic_check_values(atslave->reg_width, buf_addr,
+ if (atc_dma_cyclic_check_values(reg_width, buf_addr,
period_len, direction))
goto err_out;
@@ -885,8 +896,8 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
if (!desc)
goto err_desc_get;
- if (atc_dma_cyclic_fill_desc(atslave, desc, i, buf_addr,
- period_len, direction))
+ if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr,
+ reg_width, period_len, direction))
goto err_desc_get;
atc_desc_chain(&first, &prev, desc);
@@ -909,6 +920,23 @@ err_out:
return NULL;
}
+static int set_runtime_config(struct dma_chan *chan,
+ struct dma_slave_config *sconfig)
+{
+ struct at_dma_chan *atchan = to_at_dma_chan(chan);
+
+ /* Check if it is chan is configured for slave transfers */
+ if (!chan->private)
+ return -EINVAL;
+
+ memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig));
+
+ convert_burst(&atchan->dma_sconfig.src_maxburst);
+ convert_burst(&atchan->dma_sconfig.dst_maxburst);
+
+ return 0;
+}
+
static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
@@ -969,6 +997,8 @@ static int atc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
clear_bit(ATC_IS_CYCLIC, &atchan->status);
spin_unlock_irqrestore(&atchan->lock, flags);
+ } else if (cmd == DMA_SLAVE_CONFIG) {
+ return set_runtime_config(chan, (struct dma_slave_config *)arg);
} else {
return -ENXIO;
}
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index 08fd8a0ae797..897a8bcaec90 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -207,6 +207,7 @@ enum atc_status {
* @save_cfg: configuration register that is saved on suspend/resume cycle
* @save_dscr: for cyclic operations, preserve next descriptor address in
* the cyclic list on suspend/resume cycle
+ * @dma_sconfig: configuration for slave transfers, passed via DMA_SLAVE_CONFIG
* @lock: serializes enqueue/dequeue operations to descriptors lists
* @active_list: list of descriptors dmaengine is being running on
* @queue: list of descriptors ready to be submitted to engine
@@ -222,6 +223,7 @@ struct at_dma_chan {
struct tasklet_struct tasklet;
u32 save_cfg;
u32 save_dscr;
+ struct dma_slave_config dma_sconfig;
spinlock_t lock;
@@ -243,6 +245,36 @@ static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *dchan)
return container_of(dchan, struct at_dma_chan, chan_common);
}
+/*
+ * Fix sconfig's burst size according to at_hdmac. We need to convert them as:
+ * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7.
+ *
+ * This can be done by finding most significant bit set.
+ */
+static inline void convert_burst(u32 *maxburst)
+{
+ if (*maxburst > 1)
+ *maxburst = fls(*maxburst) - 2;
+ else
+ *maxburst = 0;
+}
+
+/*
+ * Fix sconfig's bus width according to at_hdmac.
+ * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2.
+ */
+static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width)
+{
+ switch (addr_width) {
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ return 1;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ return 2;
+ default:
+ /* For 1 byte width or fallback */
+ return 0;
+ }
+}
/*-- Controller ------------------------------------------------------*/