Re: [PATCH 4/4] dmaengine: stm32-dma3: introduce ddata2dev helper
From: Amelie Delaunay
Date: Fri Nov 21 2025 - 07:17:03 EST
On 11/21/25 10:25, Eugen Hristev wrote:
On 11/3/25 12:15, Amelie Delaunay wrote:
ddata2dev helper returns the device pointer from struct dma_device stored
in stm32_dma3_ddata structure.
Device pointer from struct dma_device has been initialized with &pdev->dev,
so the ddata2dev helper returns &pdev->dev.
Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxxxxxxx>
---
drivers/dma/stm32/stm32-dma3.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/dma/stm32/stm32-dma3.c b/drivers/dma/stm32/stm32-dma3.c
index 29ea510fa539..9f49ef8e2972 100644
--- a/drivers/dma/stm32/stm32-dma3.c
+++ b/drivers/dma/stm32/stm32-dma3.c
@@ -333,6 +333,11 @@ static struct device *chan2dev(struct stm32_dma3_chan *chan)
return &chan->vchan.chan.dev->device;
}
+static struct device *ddata2dev(struct stm32_dma3_ddata *ddata)
+{
+ return ddata->dma_dev.dev;
+}
Not really sure how much this helper actually simplifies the code. To me
it appears as if there is no improvement, but this is a personal
preference.> +
Hi Eugen, thanks for your review.
Saving two characters cannot be considered an improvement, but the purpose of this helper is to 'standardize' device pointer retrieval, similar to the chan2dev() helper above.
static void stm32_dma3_chan_dump_reg(struct stm32_dma3_chan *chan)This newline here appears to be unintended > }
{
struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
@@ -392,6 +397,7 @@ static void stm32_dma3_chan_dump_hwdesc(struct stm32_dma3_chan *chan,
} else {
dev_dbg(chan2dev(chan), "X\n");
}
+
Indeed! I'll fix it in v2 Thanks for catching that.
Regards,
Amelie
static struct stm32_dma3_swdesc *stm32_dma3_chan_desc_alloc(struct stm32_dma3_chan *chan, u32 count)
@@ -1110,7 +1116,7 @@ static int stm32_dma3_alloc_chan_resources(struct dma_chan *c)
struct stm32_dma3_ddata *ddata = to_stm32_dma3_ddata(chan);
int ret;
- ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
+ ret = pm_runtime_resume_and_get(ddata2dev(ddata));
if (ret < 0)
return ret;
@@ -1144,7 +1150,7 @@ static int stm32_dma3_alloc_chan_resources(struct dma_chan *c)
chan->lli_pool = NULL;
err_put_sync:
- pm_runtime_put_sync(ddata->dma_dev.dev);
+ pm_runtime_put_sync(ddata2dev(ddata));
return ret;
}
@@ -1170,7 +1176,7 @@ static void stm32_dma3_free_chan_resources(struct dma_chan *c)
if (chan->semaphore_mode)
stm32_dma3_put_chan_sem(chan);
- pm_runtime_put_sync(ddata->dma_dev.dev);
+ pm_runtime_put_sync(ddata2dev(ddata));
/* Reset configuration */
memset(&chan->dt_config, 0, sizeof(chan->dt_config));
@@ -1610,11 +1616,11 @@ static bool stm32_dma3_filter_fn(struct dma_chan *c, void *fn_param)
if (!(mask & BIT(chan->id)))
return false;
- ret = pm_runtime_resume_and_get(ddata->dma_dev.dev);
+ ret = pm_runtime_resume_and_get(ddata2dev(ddata));
if (ret < 0)
return false;
semcr = readl_relaxed(ddata->base + STM32_DMA3_CSEMCR(chan->id));
- pm_runtime_put_sync(ddata->dma_dev.dev);
+ pm_runtime_put_sync(ddata2dev(ddata));
/* Check if chan is free */
if (semcr & CSEMCR_SEM_MUTEX)
@@ -1636,7 +1642,7 @@ static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args *dma_spec, st
struct dma_chan *c;
if (dma_spec->args_count < 3) {
- dev_err(ddata->dma_dev.dev, "Invalid args count\n");
+ dev_err(ddata2dev(ddata), "Invalid args count\n");
return NULL;
}
@@ -1645,14 +1651,14 @@ static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args *dma_spec, st
conf.tr_conf = dma_spec->args[2];
if (conf.req_line >= ddata->dma_requests) {
- dev_err(ddata->dma_dev.dev, "Invalid request line\n");
+ dev_err(ddata2dev(ddata), "Invalid request line\n");
return NULL;
}
/* Request dma channel among the generic dma controller list */
c = dma_request_channel(mask, stm32_dma3_filter_fn, &conf);
if (!c) {
- dev_err(ddata->dma_dev.dev, "No suitable channel found\n");
+ dev_err(ddata2dev(ddata), "No suitable channel found\n");
return NULL;
}
@@ -1665,6 +1671,7 @@ static struct dma_chan *stm32_dma3_of_xlate(struct of_phandle_args *dma_spec, st
static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
{
+ struct device *dev = ddata2dev(ddata);
u32 chan_reserved, mask = 0, i, ccidcfgr, invalid_cid = 0;
/* Reserve Secure channels */
@@ -1676,7 +1683,7 @@ static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
* In case CID filtering is not configured, dma-channel-mask property can be used to
* specify available DMA channels to the kernel.
*/
- of_property_read_u32(ddata->dma_dev.dev->of_node, "dma-channel-mask", &mask);
+ of_property_read_u32(dev->of_node, "dma-channel-mask", &mask);
/* Reserve !CID-filtered not in dma-channel-mask, static CID != CID1, CID1 not allowed */
for (i = 0; i < ddata->dma_channels; i++) {
@@ -1696,7 +1703,7 @@ static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
ddata->chans[i].semaphore_mode = true;
}
}
- dev_dbg(ddata->dma_dev.dev, "chan%d: %s mode, %s\n", i,
+ dev_dbg(dev, "chan%d: %s mode, %s\n", i,
!(ccidcfgr & CCIDCFGR_CFEN) ? "!CID-filtered" :
ddata->chans[i].semaphore_mode ? "Semaphore" : "Static CID",
(chan_reserved & BIT(i)) ? "denied" :
@@ -1704,7 +1711,7 @@ static u32 stm32_dma3_check_rif(struct stm32_dma3_ddata *ddata)
}
if (invalid_cid)
- dev_warn(ddata->dma_dev.dev, "chan%*pbl have invalid CID configuration\n",
+ dev_warn(dev, "chan%*pbl have invalid CID configuration\n",
ddata->dma_channels, &invalid_cid);
return chan_reserved;