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Subject[PATCH V3 10/12] dmaengine/dw_dmac: Add support for DMA_SLAVE_CONFIG
Date
This patch adds support for DMA_SLAVE_CONFIG in dwc DMAC controller. Fields in
struct dw_dma_slave for passing similar data are preserved in this patch untill
all existing users are fixed.

That will be handled later in this patchset.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
drivers/dma/dw_dmac.c | 119 +++++++++++++++++++++++++++++++++-----------
drivers/dma/dw_dmac_regs.h | 3 +
2 files changed, 93 insertions(+), 29 deletions(-)

diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 44d8069..ccfb03b 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -9,6 +9,7 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
@@ -33,19 +34,23 @@
* which does not support descriptor writeback.
*/

-#define DWC_DEFAULT_CTLLO(private) ({ \
- struct dw_dma_slave *__slave = (private); \
- int dms = __slave ? __slave->dst_master : 0; \
- int sms = __slave ? __slave->src_master : 1; \
- u8 smsize = __slave ? __slave->src_msize : DW_DMA_MSIZE_16; \
- u8 dmsize = __slave ? __slave->dst_msize : DW_DMA_MSIZE_16; \
+#define DWC_DEFAULT_CTLLO(_chan) ({ \
+ struct dw_dma_slave *__slave = (_chan->private); \
+ struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan); \
+ struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \
+ int _dms = __slave ? __slave->dst_master : 0; \
+ int _sms = __slave ? __slave->src_master : 1; \
+ u8 _smsize = __slave ? _sconfig->src_maxburst : \
+ DW_DMA_MSIZE_16; \
+ u8 _dmsize = __slave ? _sconfig->dst_maxburst : \
+ DW_DMA_MSIZE_16; \
\
- (DWC_CTLL_DST_MSIZE(dmsize) \
- | DWC_CTLL_SRC_MSIZE(smsize) \
+ (DWC_CTLL_DST_MSIZE(_dmsize) \
+ | 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(_dms) \
+ | DWC_CTLL_SMS(_sms)); \
})

/*
@@ -664,7 +669,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
else
src_width = dst_width = 0;

- ctllo = DWC_DEFAULT_CTLLO(chan->private)
+ ctllo = DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_DST_WIDTH(dst_width)
| DWC_CTLL_SRC_WIDTH(src_width)
| DWC_CTLL_DST_INC
@@ -725,6 +730,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
struct dw_dma_slave *dws = chan->private;
+ struct dma_slave_config *sconfig = &dwc->dma_sconfig;
struct dw_desc *prev;
struct dw_desc *first;
u32 ctllo;
@@ -739,17 +745,20 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (unlikely(!dws || !sg_len))
return NULL;

- reg_width = dws->reg_width;
prev = first = NULL;

switch (direction) {
case DMA_MEM_TO_DEV:
- ctllo = (DWC_DEFAULT_CTLLO(chan->private)
+ reg_width = __fls(sconfig->dst_addr_width);
+ reg = sconfig->dst_addr;
+ ctllo = (DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_DST_FIX
- | DWC_CTLL_SRC_INC
- | DWC_CTLL_FC(dws->fc));
- reg = dws->tx_reg;
+ | DWC_CTLL_SRC_INC);
+
+ ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
+ DWC_CTLL_FC(DW_DMA_FC_D_M2P);
+
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len, dlen, mem;
@@ -807,13 +816,16 @@ slave_sg_todev_fill_desc:
}
break;
case DMA_DEV_TO_MEM:
- ctllo = (DWC_DEFAULT_CTLLO(chan->private)
+ reg_width = __fls(sconfig->src_addr_width);
+ reg = sconfig->src_addr;
+ ctllo = (DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_INC
- | DWC_CTLL_SRC_FIX
- | DWC_CTLL_FC(dws->fc));
+ | DWC_CTLL_SRC_FIX);
+
+ ctllo |= sconfig->device_fc ? DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
+ DWC_CTLL_FC(DW_DMA_FC_D_P2M);

- reg = dws->rx_reg;
for_each_sg(sgl, sg, sg_len, i) {
struct dw_desc *desc;
u32 len, dlen, mem;
@@ -889,6 +901,39 @@ err_desc_get:
return NULL;
}

+/*
+ * Fix sconfig's burst size according to dw_dmac. We need to convert them as:
+ * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3.
+ *
+ * NOTE: burst size 2 is not supported by controller.
+ *
+ * This can be done by finding least significant bit set: n & (n - 1)
+ */
+static inline void convert_burst(u32 *maxburst)
+{
+ if (*maxburst > 1)
+ *maxburst = fls(*maxburst) - 2;
+ else
+ *maxburst = 0;
+}
+
+static int
+set_runtime_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
+{
+ struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+
+ /* Check if it is chan is configured for slave transfers */
+ if (!chan->private)
+ return -EINVAL;
+
+ memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
+
+ convert_burst(&dwc->dma_sconfig.src_maxburst);
+ convert_burst(&dwc->dma_sconfig.dst_maxburst);
+
+ return 0;
+}
+
static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
{
@@ -938,8 +983,11 @@ static int dwc_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
/* Flush all pending and queued descriptors */
list_for_each_entry_safe(desc, _desc, &list, desc_node)
dwc_descriptor_complete(dwc, desc, false);
- } else
+ } else if (cmd == DMA_SLAVE_CONFIG) {
+ return set_runtime_config(chan, (struct dma_slave_config *)arg);
+ } else {
return -ENXIO;
+ }

return 0;
}
@@ -1180,11 +1228,11 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
enum dma_transfer_direction direction)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+ struct dma_slave_config *sconfig = &dwc->dma_sconfig;
struct dw_cyclic_desc *cdesc;
struct dw_cyclic_desc *retval = NULL;
struct dw_desc *desc;
struct dw_desc *last = NULL;
- struct dw_dma_slave *dws = chan->private;
unsigned long was_cyclic;
unsigned int reg_width;
unsigned int periods;
@@ -1208,7 +1256,12 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
}

retval = ERR_PTR(-EINVAL);
- reg_width = dws->reg_width;
+
+ if (direction == DMA_MEM_TO_DEV)
+ reg_width = __ffs(sconfig->dst_addr_width);
+ else
+ reg_width = __ffs(sconfig->src_addr_width);
+
periods = buf_len / period_len;

/* Check for too big/unaligned periods and unaligned DMA buffer. */
@@ -1241,26 +1294,34 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,

switch (direction) {
case DMA_MEM_TO_DEV:
- desc->lli.dar = dws->tx_reg;
+ desc->lli.dar = sconfig->dst_addr;
desc->lli.sar = buf_addr + (period_len * i);
- desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
+ desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_FIX
| DWC_CTLL_SRC_INC
- | DWC_CTLL_FC(dws->fc)
| DWC_CTLL_INT_EN);
+
+ desc->lli.ctllo |= sconfig->device_fc ?
+ DWC_CTLL_FC(DW_DMA_FC_P_M2P) :
+ DWC_CTLL_FC(DW_DMA_FC_D_M2P);
+
break;
case DMA_DEV_TO_MEM:
desc->lli.dar = buf_addr + (period_len * i);
- desc->lli.sar = dws->rx_reg;
- desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan->private)
+ desc->lli.sar = sconfig->src_addr;
+ desc->lli.ctllo = (DWC_DEFAULT_CTLLO(chan)
| DWC_CTLL_SRC_WIDTH(reg_width)
| DWC_CTLL_DST_WIDTH(reg_width)
| DWC_CTLL_DST_INC
| DWC_CTLL_SRC_FIX
- | DWC_CTLL_FC(dws->fc)
| DWC_CTLL_INT_EN);
+
+ desc->lli.ctllo |= sconfig->device_fc ?
+ DWC_CTLL_FC(DW_DMA_FC_P_P2M) :
+ DWC_CTLL_FC(DW_DMA_FC_D_P2M);
+
break;
default:
break;
diff --git a/drivers/dma/dw_dmac_regs.h b/drivers/dma/dw_dmac_regs.h
index 5eef694..2005d30 100644
--- a/drivers/dma/dw_dmac_regs.h
+++ b/drivers/dma/dw_dmac_regs.h
@@ -153,6 +153,9 @@ struct dw_dma_chan {
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 *
--
1.7.8.110.g4cb5d


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