77 lines
2.4 KiB
Diff
77 lines
2.4 KiB
Diff
|
From 6077fbf31d4263222eb1815f1c4edf67e90a3434 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Matt Porter <mporter@ti.com>
|
||
|
|
Date: Wed, 6 Mar 2013 19:56:06 +0000
|
||
|
|
Subject: [PATCH 02/13] dma: edma: add device_slave_sg_limits() support
|
||
|
|
|
||
|
|
Implement device_slave_sg_limits().
|
||
|
|
|
||
|
|
EDMA has a finite set of PaRAM slots available for linking a
|
||
|
|
multi-segment SG transfer. In order to prevent any one channel
|
||
|
|
from consuming all PaRAM slots to fulfill a large SG transfer,
|
||
|
|
the driver reports a static per-channel max number of SG segments
|
||
|
|
it will handle.
|
||
|
|
|
||
|
|
The maximum size of an SG segment is limited by the addr_width
|
||
|
|
and maxburst of a given transfer request. These values are
|
||
|
|
provided by the client driver and used to calculate and return
|
||
|
|
the maximum segment length.
|
||
|
|
|
||
|
|
Signed-off-by: Matt Porter <mporter@ti.com>
|
||
|
|
Signed-off-by: Joel A Fernandes <joelagnel@ti.com>
|
||
|
|
---
|
||
|
|
drivers/dma/edma.c | 17 +++++++++++++++++
|
||
|
|
1 file changed, 17 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
|
||
|
|
index 5f3e532..e008ed2 100644
|
||
|
|
--- a/drivers/dma/edma.c
|
||
|
|
+++ b/drivers/dma/edma.c
|
||
|
|
@@ -70,6 +70,7 @@ struct edma_chan {
|
||
|
|
bool alloced;
|
||
|
|
int slot[EDMA_MAX_SLOTS];
|
||
|
|
struct dma_slave_config cfg;
|
||
|
|
+ struct dma_slave_sg_limits sg_limits;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct edma_cc {
|
||
|
|
@@ -462,6 +463,20 @@ static void edma_issue_pending(struct dma_chan *chan)
|
||
|
|
spin_unlock_irqrestore(&echan->vchan.lock, flags);
|
||
|
|
}
|
||
|
|
|
||
|
|
+static struct dma_slave_sg_limits
|
||
|
|
+*edma_get_slave_sg_limits(struct dma_chan *chan,
|
||
|
|
+ enum dma_slave_buswidth addr_width,
|
||
|
|
+ u32 maxburst)
|
||
|
|
+{
|
||
|
|
+ struct edma_chan *echan;
|
||
|
|
+
|
||
|
|
+ echan = to_edma_chan(chan);
|
||
|
|
+ echan->sg_limits.max_seg_len =
|
||
|
|
+ (SZ_64K - 1) * addr_width * maxburst;
|
||
|
|
+
|
||
|
|
+ return &echan->sg_limits;
|
||
|
|
+}
|
||
|
|
+
|
||
|
|
static size_t edma_desc_size(struct edma_desc *edesc)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
@@ -521,6 +536,7 @@ static void __init edma_chan_init(struct edma_cc *ecc,
|
||
|
|
echan->ch_num = EDMA_CTLR_CHAN(ecc->ctlr, i);
|
||
|
|
echan->ecc = ecc;
|
||
|
|
echan->vchan.desc_free = edma_desc_free;
|
||
|
|
+ echan->sg_limits.max_seg_nr = MAX_NR_SG;
|
||
|
|
|
||
|
|
vchan_init(&echan->vchan, dma);
|
||
|
|
|
||
|
|
@@ -537,6 +553,7 @@ static void edma_dma_init(struct edma_cc *ecc, struct dma_device *dma,
|
||
|
|
dma->device_alloc_chan_resources = edma_alloc_chan_resources;
|
||
|
|
dma->device_free_chan_resources = edma_free_chan_resources;
|
||
|
|
dma->device_issue_pending = edma_issue_pending;
|
||
|
|
+ dma->device_slave_sg_limits = edma_get_slave_sg_limits;
|
||
|
|
dma->device_tx_status = edma_tx_status;
|
||
|
|
dma->device_control = edma_control;
|
||
|
|
dma->dev = dev;
|
||
|
|
--
|
||
|
|
1.8.2.1
|
||
|
|
|