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Diffstat (limited to 'drivers/dma/omap-dma.c')
-rw-r--r--drivers/dma/omap-dma.c187
1 files changed, 150 insertions, 37 deletions
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 7ca27d4b1c54..ac68666cd3f4 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -166,6 +166,9 @@ enum {
CSDP_DST_BURST_16 = 1 << 14,
CSDP_DST_BURST_32 = 2 << 14,
CSDP_DST_BURST_64 = 3 << 14,
+ CSDP_WRITE_NON_POSTED = 0 << 16,
+ CSDP_WRITE_POSTED = 1 << 16,
+ CSDP_WRITE_LAST_NON_POSTED = 2 << 16,
CICR_TOUT_IE = BIT(0), /* OMAP1 only */
CICR_DROP_IE = BIT(1),
@@ -422,7 +425,30 @@ static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
c->running = true;
}
-static void omap_dma_stop(struct omap_chan *c)
+static void omap_dma_drain_chan(struct omap_chan *c)
+{
+ int i;
+ u32 val;
+
+ /* Wait for sDMA FIFO to drain */
+ for (i = 0; ; i++) {
+ val = omap_dma_chan_read(c, CCR);
+ if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
+ break;
+
+ if (i > 100)
+ break;
+
+ udelay(5);
+ }
+
+ if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
+ dev_err(c->vc.chan.device->dev,
+ "DMA drain did not complete on lch %d\n",
+ c->dma_ch);
+}
+
+static int omap_dma_stop(struct omap_chan *c)
{
struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
uint32_t val;
@@ -435,7 +461,6 @@ static void omap_dma_stop(struct omap_chan *c)
val = omap_dma_chan_read(c, CCR);
if (od->plat->errata & DMA_ERRATA_i541 && val & CCR_TRIGGER_SRC) {
uint32_t sysconfig;
- unsigned i;
sysconfig = omap_dma_glbl_read(od, OCP_SYSCONFIG);
val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
@@ -446,27 +471,19 @@ static void omap_dma_stop(struct omap_chan *c)
val &= ~CCR_ENABLE;
omap_dma_chan_write(c, CCR, val);
- /* Wait for sDMA FIFO to drain */
- for (i = 0; ; i++) {
- val = omap_dma_chan_read(c, CCR);
- if (!(val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE)))
- break;
-
- if (i > 100)
- break;
-
- udelay(5);
- }
-
- if (val & (CCR_RD_ACTIVE | CCR_WR_ACTIVE))
- dev_err(c->vc.chan.device->dev,
- "DMA drain did not complete on lch %d\n",
- c->dma_ch);
+ if (!(c->ccr & CCR_BUFFERING_DISABLE))
+ omap_dma_drain_chan(c);
omap_dma_glbl_write(od, OCP_SYSCONFIG, sysconfig);
} else {
+ if (!(val & CCR_ENABLE))
+ return -EINVAL;
+
val &= ~CCR_ENABLE;
omap_dma_chan_write(c, CCR, val);
+
+ if (!(c->ccr & CCR_BUFFERING_DISABLE))
+ omap_dma_drain_chan(c);
}
mb();
@@ -481,8 +498,8 @@ static void omap_dma_stop(struct omap_chan *c)
omap_dma_chan_write(c, CLNK_CTRL, val);
}
-
c->running = false;
+ return 0;
}
static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d)
@@ -836,6 +853,8 @@ static enum dma_status omap_dma_tx_status(struct dma_chan *chan,
} else {
txstate->residue = 0;
}
+ if (ret == DMA_IN_PROGRESS && c->paused)
+ ret = DMA_PAUSED;
spin_unlock_irqrestore(&c->vc.lock, flags);
return ret;
@@ -865,15 +884,18 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
unsigned i, es, en, frame_bytes;
bool ll_failed = false;
u32 burst;
+ u32 port_window, port_window_bytes;
if (dir == DMA_DEV_TO_MEM) {
dev_addr = c->cfg.src_addr;
dev_width = c->cfg.src_addr_width;
burst = c->cfg.src_maxburst;
+ port_window = c->cfg.src_port_window_size;
} else if (dir == DMA_MEM_TO_DEV) {
dev_addr = c->cfg.dst_addr;
dev_width = c->cfg.dst_addr_width;
burst = c->cfg.dst_maxburst;
+ port_window = c->cfg.dst_port_window_size;
} else {
dev_err(chan->device->dev, "%s: bad direction?\n", __func__);
return NULL;
@@ -894,6 +916,12 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
return NULL;
}
+ /* When the port_window is used, one frame must cover the window */
+ if (port_window) {
+ burst = port_window;
+ port_window_bytes = port_window * es_bytes[es];
+ }
+
/* Now allocate and setup the descriptor. */
d = kzalloc(sizeof(*d) + sglen * sizeof(d->sg[0]), GFP_ATOMIC);
if (!d)
@@ -905,11 +933,45 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
d->ccr = c->ccr | CCR_SYNC_FRAME;
if (dir == DMA_DEV_TO_MEM) {
- d->ccr |= CCR_DST_AMODE_POSTINC | CCR_SRC_AMODE_CONSTANT;
d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
+
+ d->ccr |= CCR_DST_AMODE_POSTINC;
+ if (port_window) {
+ d->ccr |= CCR_SRC_AMODE_DBLIDX;
+ d->ei = 1;
+ /*
+ * One frame covers the port_window and by configure
+ * the source frame index to be -1 * (port_window - 1)
+ * we instruct the sDMA that after a frame is processed
+ * it should move back to the start of the window.
+ */
+ d->fi = -(port_window_bytes - 1);
+
+ if (port_window_bytes >= 64)
+ d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
+ else if (port_window_bytes >= 32)
+ d->csdp = CSDP_SRC_BURST_32 | CSDP_SRC_PACKED;
+ else if (port_window_bytes >= 16)
+ d->csdp = CSDP_SRC_BURST_16 | CSDP_SRC_PACKED;
+ } else {
+ d->ccr |= CCR_SRC_AMODE_CONSTANT;
+ }
} else {
- d->ccr |= CCR_DST_AMODE_CONSTANT | CCR_SRC_AMODE_POSTINC;
d->csdp = CSDP_SRC_BURST_64 | CSDP_SRC_PACKED;
+
+ d->ccr |= CCR_SRC_AMODE_POSTINC;
+ if (port_window) {
+ d->ccr |= CCR_DST_AMODE_DBLIDX;
+
+ if (port_window_bytes >= 64)
+ d->csdp = CSDP_DST_BURST_64 | CSDP_DST_PACKED;
+ else if (port_window_bytes >= 32)
+ d->csdp = CSDP_DST_BURST_32 | CSDP_DST_PACKED;
+ else if (port_window_bytes >= 16)
+ d->csdp = CSDP_DST_BURST_16 | CSDP_DST_PACKED;
+ } else {
+ d->ccr |= CCR_DST_AMODE_CONSTANT;
+ }
}
d->cicr = CICR_DROP_IE | CICR_BLOCK_IE;
@@ -927,6 +989,9 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
d->ccr |= CCR_TRIGGER_SRC;
d->cicr |= CICR_MISALIGNED_ERR_IE | CICR_TRANS_ERR_IE;
+
+ if (port_window)
+ d->csdp |= CSDP_WRITE_LAST_NON_POSTED;
}
if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
d->clnk_ctrl = c->dma_ch;
@@ -952,6 +1017,16 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
osg->addr = sg_dma_address(sgent);
osg->en = en;
osg->fn = sg_dma_len(sgent) / frame_bytes;
+ if (port_window && dir == DMA_MEM_TO_DEV) {
+ osg->ei = 1;
+ /*
+ * One frame covers the port_window and by configure
+ * the source frame index to be -1 * (port_window - 1)
+ * we instruct the sDMA that after a frame is processed
+ * it should move back to the start of the window.
+ */
+ osg->fi = -(port_window_bytes - 1);
+ }
if (d->using_ll) {
osg->t2_desc = dma_pool_alloc(od->desc_pool, GFP_ATOMIC,
@@ -1247,10 +1322,8 @@ static int omap_dma_terminate_all(struct dma_chan *chan)
omap_dma_stop(c);
}
- if (c->cyclic) {
- c->cyclic = false;
- c->paused = false;
- }
+ c->cyclic = false;
+ c->paused = false;
vchan_get_all_descriptors(&c->vc, &head);
spin_unlock_irqrestore(&c->vc.lock, flags);
@@ -1269,28 +1342,66 @@ static void omap_dma_synchronize(struct dma_chan *chan)
static int omap_dma_pause(struct dma_chan *chan)
{
struct omap_chan *c = to_omap_dma_chan(chan);
+ struct omap_dmadev *od = to_omap_dma_dev(chan->device);
+ unsigned long flags;
+ int ret = -EINVAL;
+ bool can_pause = false;
- /* Pause/Resume only allowed with cyclic mode */
- if (!c->cyclic)
- return -EINVAL;
+ spin_lock_irqsave(&od->irq_lock, flags);
- if (!c->paused) {
- omap_dma_stop(c);
- c->paused = true;
+ if (!c->desc)
+ goto out;
+
+ if (c->cyclic)
+ can_pause = true;
+
+ /*
+ * We do not allow DMA_MEM_TO_DEV transfers to be paused.
+ * From the AM572x TRM, 16.1.4.18 Disabling a Channel During Transfer:
+ * "When a channel is disabled during a transfer, the channel undergoes
+ * an abort, unless it is hardware-source-synchronized …".
+ * A source-synchronised channel is one where the fetching of data is
+ * under control of the device. In other words, a device-to-memory
+ * transfer. So, a destination-synchronised channel (which would be a
+ * memory-to-device transfer) undergoes an abort if the the CCR_ENABLE
+ * bit is cleared.
+ * From 16.1.4.20.4.6.2 Abort: "If an abort trigger occurs, the channel
+ * aborts immediately after completion of current read/write
+ * transactions and then the FIFO is cleaned up." The term "cleaned up"
+ * is not defined. TI recommends to check that RD_ACTIVE and WR_ACTIVE
+ * are both clear _before_ disabling the channel, otherwise data loss
+ * will occur.
+ * The problem is that if the channel is active, then device activity
+ * can result in DMA activity starting between reading those as both
+ * clear and the write to DMA_CCR to clear the enable bit hitting the
+ * hardware. If the DMA hardware can't drain the data in its FIFO to the
+ * destination, then data loss "might" occur (say if we write to an UART
+ * and the UART is not accepting any further data).
+ */
+ else if (c->desc->dir == DMA_DEV_TO_MEM)
+ can_pause = true;
+
+ if (can_pause && !c->paused) {
+ ret = omap_dma_stop(c);
+ if (!ret)
+ c->paused = true;
}
+out:
+ spin_unlock_irqrestore(&od->irq_lock, flags);
- return 0;
+ return ret;
}
static int omap_dma_resume(struct dma_chan *chan)
{
struct omap_chan *c = to_omap_dma_chan(chan);
+ struct omap_dmadev *od = to_omap_dma_dev(chan->device);
+ unsigned long flags;
+ int ret = -EINVAL;
- /* Pause/Resume only allowed with cyclic mode */
- if (!c->cyclic)
- return -EINVAL;
+ spin_lock_irqsave(&od->irq_lock, flags);
- if (c->paused) {
+ if (c->paused && c->desc) {
mb();
/* Restore channel link register */
@@ -1298,9 +1409,11 @@ static int omap_dma_resume(struct dma_chan *chan)
omap_dma_start(c, c->desc);
c->paused = false;
+ ret = 0;
}
+ spin_unlock_irqrestore(&od->irq_lock, flags);
- return 0;
+ return ret;
}
static int omap_dma_chan_init(struct omap_dmadev *od)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 21:54:14 +0000