This patchset adds bug fixes reported by devices using STM32 DMA and some
improvements mainly linked to dmaengine framework evolution.
M'boumba Cedric Madianga (9):
dmaengine: stm32-dma: Set correct args number for DMA request from DT
dmaengine: stm32-dma: Fix typo in Kconfig
dt-bindings: stm32-dma: Fix typo regarding DMA client binding
dmaengine: stm32-dma: Fix null pointer dereference in stm32_dma_tx_status
dmaengine: stm32-dma: Rework starting transfer management
dmaengine: stm32-dma: Fix residue computation issue in cyclic mode
dmaengine: stm32-dma: Add error messages if xlate fails
dmaengine: stm32-dma: Add synchronization support
dmaengine: stm32-dma: Add max_burst support
.../devicetree/bindings/dma/stm32-dma.txt | 5 +-
drivers/dma/Kconfig | 2 +-
drivers/dma/stm32-dma.c | 103 +++++++++++++--------
3 files changed, 66 insertions(+), 44 deletions(-)
--
1.9.1
Only four cells are required for dma client binding not five.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
Documentation/devicetree/bindings/dma/stm32-dma.txt | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt
index 70cd13f..4408af6 100644
--- a/Documentation/devicetree/bindings/dma/stm32-dma.txt
+++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt
@@ -40,8 +40,7 @@ Example:
DMA clients connected to the STM32 DMA controller must use the format
described in the dma.txt file, using a five-cell specifier for each
-channel: a phandle plus four integer cells.
-The four cells in order are:
+channel: a phandle to the DMA controller plus the following four integer cells:
1. The channel id
2. The request line number
@@ -61,7 +60,7 @@ The four cells in order are:
0x1: medium
0x2: high
0x3: very high
-5. A 32bit mask specifying the DMA FIFO threshold configuration which are device
+4. A 32bit mask specifying the DMA FIFO threshold configuration which are device
dependent:
-bit 0-1: Fifo threshold
0x0: 1/4 full FIFO
--
1.9.1
This patch adds some error messages when a slave device fails to request a
channel.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/stm32-dma.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index ba929a9..35639f6 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -975,27 +975,36 @@ static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct stm32_dma_device *dmadev = ofdma->of_dma_data;
+ struct device *dev = dmadev->ddev.dev;
struct stm32_dma_cfg cfg;
struct stm32_dma_chan *chan;
struct dma_chan *c;
- if (dma_spec->args_count < 4)
+ if (dma_spec->args_count < 4) {
+ dev_err(dev, "Bad number of cells\n");
return NULL;
+ }
cfg.channel_id = dma_spec->args[0];
cfg.request_line = dma_spec->args[1];
cfg.stream_config = dma_spec->args[2];
cfg.threshold = dma_spec->args[3];
- if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
- STM32_DMA_MAX_REQUEST_ID))
+ if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) ||
+ (cfg.request_line >= STM32_DMA_MAX_REQUEST_ID)) {
+ dev_err(dev, "Bad channel and/or request id\n");
return NULL;
+ }
chan = &dmadev->chan[cfg.channel_id];
c = dma_get_slave_channel(&chan->vchan.chan);
- if (c)
- stm32_dma_set_config(chan, &cfg);
+ if (!c) {
+ dev_err(dev, "No more channel avalaible\n");
+ return NULL;
+ }
+
+ stm32_dma_set_config(chan, &cfg);
return c;
}
--
1.9.1
This patch sets the max_burst value supported by the STM32 DMA
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
---
drivers/dma/stm32-dma.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index b7be43a..49f86ca 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -114,6 +114,7 @@
#define STM32_DMA_MAX_CHANNELS 0x08
#define STM32_DMA_MAX_REQUEST_ID 0x08
#define STM32_DMA_MAX_DATA_PARAM 0x03
+#define STM32_DMA_MAX_BURST 16
enum stm32_dma_width {
STM32_DMA_BYTE,
@@ -1084,6 +1085,7 @@ static int stm32_dma_probe(struct platform_device *pdev)
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ dd->max_burst = STM32_DMA_MAX_BURST;
dd->dev = &pdev->dev;
INIT_LIST_HEAD(&dd->channels);
--
1.9.1
Implement the new device_synchronize() callback to allow proper
synchronization when stopping a channel.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
---
drivers/dma/stm32-dma.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 35639f6..b7be43a 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -403,6 +403,13 @@ static int stm32_dma_terminate_all(struct dma_chan *c)
return 0;
}
+static void stm32_dma_synchronize(struct dma_chan *c)
+{
+ struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
+
+ vchan_synchronize(&chan->vchan);
+}
+
static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
@@ -1068,6 +1075,7 @@ static int stm32_dma_probe(struct platform_device *pdev)
dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic;
dd->device_config = stm32_dma_slave_config;
dd->device_terminate_all = stm32_dma_terminate_all;
+ dd->device_synchronize = stm32_dma_synchronize;
dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
--
1.9.1
As STM32 DMA driver is only used as buit-in driver, it couldn't be used as
module.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 263495d..96da57a 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -458,7 +458,7 @@ config STM32_DMA
help
Enable support for the on-chip DMA controller on STMicroelectronics
STM32 MCUs.
- If you have a board based on such a MCU and wish to use DMA say Y or M
+ If you have a board based on such a MCU and wish to use DMA say Y
here.
config S3C24XX_DMAC
--
1.9.1
This patch resolves the residue computation issue detected in cyclic mode.
Now, in cyclic mode, we increment next_sg variable as soon as a period is
transferred instead of after pushing a new sg request.
Then, we take into account that after transferring a complete buffer,
the next_sg variable is equal to 0.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/stm32-dma.c | 39 ++++++++++++++++++++++++++-------------
1 file changed, 26 insertions(+), 13 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index adb846c..ba929a9 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -500,8 +500,6 @@ static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n",
stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
}
-
- chan->next_sg++;
}
}
@@ -510,6 +508,7 @@ static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan)
if (chan->desc) {
if (chan->desc->cyclic) {
vchan_cyclic_callback(&chan->desc->vdesc);
+ chan->next_sg++;
stm32_dma_configure_next_sg(chan);
} else {
chan->busy = false;
@@ -846,26 +845,40 @@ static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy(
return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
}
+static u32 stm32_dma_get_remaining_bytes(struct stm32_dma_chan *chan)
+{
+ u32 dma_scr, width, ndtr;
+ struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
+
+ dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
+ width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
+ ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
+
+ return ndtr << width;
+}
+
static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
struct stm32_dma_desc *desc,
u32 next_sg)
{
- struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
- u32 dma_scr, width, residue, count;
+ u32 residue = 0;
int i;
- residue = 0;
+ /*
+ * In cyclic mode, for the last period, residue = remaining bytes from
+ * NDTR
+ */
+ if (chan->desc->cyclic && next_sg == 0)
+ return stm32_dma_get_remaining_bytes(chan);
+ /*
+ * For all other periods in cyclic mode, and in sg mode,
+ * residue = remaining bytes from NDTR + remaining periods/sg to be
+ * transferred
+ */
for (i = next_sg; i < desc->num_sgs; i++)
residue += desc->sg_req[i].len;
-
- if (next_sg != 0) {
- dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id));
- width = STM32_DMA_SCR_PSIZE_GET(dma_scr);
- count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id));
-
- residue += count << width;
- }
+ residue += stm32_dma_get_remaining_bytes(chan);
return residue;
}
--
1.9.1
This patch reworks the way to manage transfer starting.
Now, starting DMA is only allowed when the channel is not busy.
Then, stm32_dma_start_transfer is declared as void.
At least, after each transfer completion, we start the next transfer if a
new descriptor as been queued in the issued list during an ongoing
transfer.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/stm32-dma.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 3056ce7..adb846c 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -421,7 +421,7 @@ static void stm32_dma_dump_reg(struct stm32_dma_chan *chan)
dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr);
}
-static int stm32_dma_start_transfer(struct stm32_dma_chan *chan)
+static void stm32_dma_start_transfer(struct stm32_dma_chan *chan)
{
struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan);
struct virt_dma_desc *vdesc;
@@ -432,12 +432,12 @@ static int stm32_dma_start_transfer(struct stm32_dma_chan *chan)
ret = stm32_dma_disable_chan(chan);
if (ret < 0)
- return ret;
+ return;
if (!chan->desc) {
vdesc = vchan_next_desc(&chan->vchan);
if (!vdesc)
- return -EPERM;
+ return;
chan->desc = to_stm32_dma_desc(vdesc);
chan->next_sg = 0;
@@ -471,7 +471,7 @@ static int stm32_dma_start_transfer(struct stm32_dma_chan *chan)
chan->busy = true;
- return 0;
+ dev_dbg(chan2dev(chan), "vchan %p: started\n", &chan->vchan);
}
static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan)
@@ -552,15 +552,13 @@ static void stm32_dma_issue_pending(struct dma_chan *c)
{
struct stm32_dma_chan *chan = to_stm32_dma_chan(c);
unsigned long flags;
- int ret;
spin_lock_irqsave(&chan->vchan.lock, flags);
- if (!chan->busy) {
- if (vchan_issue_pending(&chan->vchan) && !chan->desc) {
- ret = stm32_dma_start_transfer(chan);
- if ((!ret) && (chan->desc->cyclic))
- stm32_dma_configure_next_sg(chan);
- }
+ if (vchan_issue_pending(&chan->vchan) && !chan->desc && !chan->busy) {
+ dev_dbg(chan2dev(chan), "vchan %p: issued\n", &chan->vchan);
+ stm32_dma_start_transfer(chan);
+ if (chan->desc->cyclic)
+ stm32_dma_configure_next_sg(chan);
}
spin_unlock_irqrestore(&chan->vchan.lock, flags);
}
--
1.9.1
chan->desc is always set to NULL when a DMA transfer is complete.
As a DMA transfer could be complete during the call of stm32_dma_tx_status,
we need to be sure that chan->desc is not NULL before using this variable
to avoid a null pointer deference issue.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/stm32-dma.c | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index a884b85..3056ce7 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -880,7 +880,7 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
struct virt_dma_desc *vdesc;
enum dma_status status;
unsigned long flags;
- u32 residue;
+ u32 residue = 0;
status = dma_cookie_status(c, cookie, state);
if ((status == DMA_COMPLETE) || (!state))
@@ -888,16 +888,12 @@ static enum dma_status stm32_dma_tx_status(struct dma_chan *c,
spin_lock_irqsave(&chan->vchan.lock, flags);
vdesc = vchan_find_desc(&chan->vchan, cookie);
- if (cookie == chan->desc->vdesc.tx.cookie) {
+ if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
residue = stm32_dma_desc_residue(chan, chan->desc,
chan->next_sg);
- } else if (vdesc) {
+ else if (vdesc)
residue = stm32_dma_desc_residue(chan,
to_stm32_dma_desc(vdesc), 0);
- } else {
- residue = 0;
- }
-
dma_set_residue(state, residue);
spin_unlock_irqrestore(&chan->vchan.lock, flags);
--
1.9.1
This patch sets the right number of arguments to be used for DMA clients
which request channels from DT.
Signed-off-by: M'boumba Cedric Madianga <[email protected]>
Reviewed-by: Ludovic BARRE <[email protected]>
---
drivers/dma/stm32-dma.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 3688d08..a884b85 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -972,21 +972,18 @@ static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec,
struct stm32_dma_chan *chan;
struct dma_chan *c;
- if (dma_spec->args_count < 3)
+ if (dma_spec->args_count < 4)
return NULL;
cfg.channel_id = dma_spec->args[0];
cfg.request_line = dma_spec->args[1];
cfg.stream_config = dma_spec->args[2];
- cfg.threshold = 0;
+ cfg.threshold = dma_spec->args[3];
if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >=
STM32_DMA_MAX_REQUEST_ID))
return NULL;
- if (dma_spec->args_count > 3)
- cfg.threshold = dma_spec->args[3];
-
chan = &dmadev->chan[cfg.channel_id];
c = dma_get_slave_channel(&chan->vchan.chan);
--
1.9.1
On Tue, Dec 13, 2016 at 02:40:45PM +0100, M'boumba Cedric Madianga wrote:
> Only four cells are required for dma client binding not five.
>
> Signed-off-by: M'boumba Cedric Madianga <[email protected]>
> Reviewed-by: Ludovic BARRE <[email protected]>
> ---
> Documentation/devicetree/bindings/dma/stm32-dma.txt | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
Acked-by: Rob Herring <[email protected]>