Endpoint controller drivers may need to expose or consume eDMA-related
resources (e.g. for remote programming or doorbell/self-tests). For
that, consumers need a stable way to discover the Linux IRQ used by a
given eDMA channel/vector and a register offset suitable for interrupt
emulation.
Record each channel's IRQ-vector index and store the requested Linux IRQ
number. Add a core callback .ch_info() to provide core-specific metadata
and implement it for v0.
Export dw_edma_chan_info() so that platform drivers can retrieve:
- per-channel device name
- Linux IRQ number for the channel's interrupt vector
- offset of the register used as an emulated-interrupt doorbell within
the eDMA register window.
Signed-off-by: Koichiro Den <[email protected]>
---
drivers/dma/dw-edma/dw-edma-core.c | 31 +++++++++++++++++++++++++++
drivers/dma/dw-edma/dw-edma-core.h | 14 ++++++++++++
drivers/dma/dw-edma/dw-edma-v0-core.c | 7 ++++++
include/linux/dma/edma.h | 20 +++++++++++++++++
4 files changed, 72 insertions(+)
diff --git a/drivers/dma/dw-edma/dw-edma-core.c
b/drivers/dma/dw-edma/dw-edma-core.c
index dd01a9aa8ad8..147a5466e4e7 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -842,6 +842,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32
wr_alloc, u32 rd_alloc)
else
pos = wr_alloc + chan->id % rd_alloc;
+ chan->irq_idx = pos;
irq = &dw->irq[pos];
if (chan->dir == EDMA_DIR_WRITE)
@@ -947,6 +948,7 @@ static int dw_edma_irq_request(struct dw_edma *dw,
if (irq_get_msi_desc(irq))
get_cached_msi_msg(irq, &dw->irq[0].msi);
+ dw->irq[0].irq = irq;
dw->nr_irqs = 1;
} else {
/* Distribute IRQs equally among all channels */
@@ -973,6 +975,7 @@ static int dw_edma_irq_request(struct dw_edma *dw,
if (irq_get_msi_desc(irq))
get_cached_msi_msg(irq, &dw->irq[i].msi);
+ dw->irq[i].irq = irq;
}
dw->nr_irqs = i;
@@ -1098,6 +1101,34 @@ int dw_edma_remove(struct dw_edma_chip *chip)
}
EXPORT_SYMBOL_GPL(dw_edma_remove);
+int dw_edma_chan_info(struct dw_edma_chip *chip, unsigned int ch_idx,
+ struct dw_edma_chan_info *info)
+{
+ struct dw_edma *dw = chip->dw;
+ struct dw_edma_chan *chan;
+ struct dma_chan *dchan;
+ u32 ch_cnt;
+ int ret;
+
+ if (!chip || !info || !dw)
+ return -EINVAL;
+
+ ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
+ if (ch_idx >= ch_cnt)
+ return -EINVAL;
+
+ chan = &dw->chan[ch_idx];
+ dchan = &chan->vc.chan;
+
+ ret = dw_edma_core_ch_info(dw, chan, info);
+ if (ret)
+ return ret;
+
+ info->irq = dw->irq[chan->irq_idx].irq;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dw_edma_chan_info);
+
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Synopsys DesignWare eDMA controller core driver");
MODULE_AUTHOR("Gustavo Pimentel <[email protected]>");
diff --git a/drivers/dma/dw-edma/dw-edma-core.h
b/drivers/dma/dw-edma/dw-edma-core.h
index abc97e375484..e92891ed5536 100644
--- a/drivers/dma/dw-edma/dw-edma-core.h
+++ b/drivers/dma/dw-edma/dw-edma-core.h
@@ -82,6 +82,7 @@ struct dw_edma_chan {
struct msi_msg msi;
enum dw_edma_ch_irq_mode irq_mode;
+ u32 irq_idx;
enum dw_edma_request request;
enum dw_edma_status status;
@@ -95,6 +96,7 @@ struct dw_edma_irq {
u32 wr_mask;
u32 rd_mask;
struct dw_edma *dw;
+ int irq;
};
struct dw_edma {
@@ -129,6 +131,7 @@ struct dw_edma_core_ops {
void (*ch_config)(struct dw_edma_chan *chan);
void (*debugfs_on)(struct dw_edma *dw);
void (*ack_selfirq)(struct dw_edma *dw);
+ void (*ch_info)(struct dw_edma_chan *chan, struct dw_edma_chan_info
*info);
};
struct dw_edma_sg {
@@ -219,6 +222,17 @@ int dw_edma_core_ack_selfirq(struct dw_edma *dw)
return 0;
}
+static inline
+int dw_edma_core_ch_info(struct dw_edma *dw, struct dw_edma_chan *chan,
+ struct dw_edma_chan_info *info)
+{
+ if (!dw->core->ch_info)
+ return -EOPNOTSUPP;
+
+ dw->core->ch_info(chan, info);
+ return 0;
+}
+
static inline
bool dw_edma_core_ch_ignore_irq(struct dw_edma_chan *chan)
{
diff --git a/drivers/dma/dw-edma/dw-edma-v0-core.c
b/drivers/dma/dw-edma/dw-edma-v0-core.c
index 68e0d088570d..9c7908a76fff 100644
--- a/drivers/dma/dw-edma/dw-edma-v0-core.c
+++ b/drivers/dma/dw-edma/dw-edma-v0-core.c
@@ -529,6 +529,12 @@ static void dw_edma_v0_core_ack_selfirq(struct dw_edma *dw)
SET_BOTH_32(dw, int_clear, 0);
}
+static void dw_edma_v0_core_ch_info(struct dw_edma_chan *chan,
+ struct dw_edma_chan_info *info)
+{
+ info->db_offset = offsetof(struct dw_edma_v0_regs, rd_int_status);
+}
+
static const struct dw_edma_core_ops dw_edma_v0_core = {
.off = dw_edma_v0_core_off,
.ch_count = dw_edma_v0_core_ch_count,
@@ -538,6 +544,7 @@ static const struct dw_edma_core_ops dw_edma_v0_core = {
.ch_config = dw_edma_v0_core_ch_config,
.debugfs_on = dw_edma_v0_core_debugfs_on,
.ack_selfirq = dw_edma_v0_core_ack_selfirq,
+ .ch_info = dw_edma_v0_core_ch_info,
};
void dw_edma_v0_core_register(struct dw_edma *dw)
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
index 53b31a974331..9fd78dc313e5 100644
--- a/include/linux/dma/edma.h
+++ b/include/linux/dma/edma.h
@@ -129,10 +129,23 @@ struct dw_edma_chip {
struct dw_edma *dw;
};
+/**
+ * struct dw_edma_chan_info - DW eDMA channel metadata
+ * @irq: Linux IRQ number used by this channel's interrupt vector
+ * @db_offset: offset within the eDMA register window that can be used as
+ * an interrupt-emulation doorbell for this channel
+ */
+struct dw_edma_chan_info {
+ int irq;
+ resource_size_t db_offset;
+};
+
/* Export to the platform drivers */
#if IS_REACHABLE(CONFIG_DW_EDMA)
int dw_edma_probe(struct dw_edma_chip *chip);
int dw_edma_remove(struct dw_edma_chip *chip);
+int dw_edma_chan_info(struct dw_edma_chip *chip, unsigned int ch_idx,
+ struct dw_edma_chan_info *info);
#else
static inline int dw_edma_probe(struct dw_edma_chip *chip)
{
@@ -143,6 +156,13 @@ static inline int dw_edma_remove(struct dw_edma_chip *chip)
{
return 0;
}
+
+static inline int dw_edma_chan_info(struct dw_edma_chip *chip,
+ unsigned int ch_idx,
+ struct dw_edma_chan_info *info)
+{
+ return -ENODEV;
+}
#endif /* CONFIG_DW_EDMA */
#endif /* _DW_EDMA_H */
--
2.51.0
