[PATCH RFC 05/26] dmaengine: omap-dma: control start/stop directly
Russell King
rmk+kernel at arm.linux.org.uk
Thu Jan 2 10:09:40 EST 2014
Program the non-cyclic mode DMA start/stop directly, rather than via
arch/arm/plat-omap/dma.c.
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
---
drivers/dma/omap-dma.c | 152 ++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 142 insertions(+), 10 deletions(-)
diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 602c98aebca8..8e2dd4f658d5 100644
--- a/drivers/dma/omap-dma.c
+++ b/drivers/dma/omap-dma.c
@@ -5,6 +5,7 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
@@ -60,6 +61,7 @@ struct omap_desc {
uint8_t sync_mode; /* OMAP_DMA_SYNC_xxx */
uint8_t sync_type; /* OMAP_DMA_xxx_SYNC* */
uint8_t periph_port; /* Peripheral port */
+ uint16_t cicr; /* CICR value */
unsigned sglen;
struct omap_sg sg[0];
@@ -95,6 +97,112 @@ static void omap_dma_desc_free(struct virt_dma_desc *vd)
kfree(container_of(vd, struct omap_desc, vd));
}
+static void omap_dma_start(struct omap_chan *c, struct omap_desc *d)
+{
+ struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
+ uint32_t val;
+
+ if (__dma_omap15xx(od->plat->dma_attr))
+ c->plat->dma_write(0, CPC, c->dma_ch);
+ else
+ c->plat->dma_write(0, CDAC, c->dma_ch);
+
+ if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
+ val = c->plat->dma_read(CLNK_CTRL, c->dma_ch);
+
+ if (dma_omap1())
+ val &= ~(1 << 14);
+
+ val |= c->dma_ch | 1 << 15;
+
+ c->plat->dma_write(val, CLNK_CTRL, c->dma_ch);
+ } else if (od->plat->errata & DMA_ERRATA_PARALLEL_CHANNELS)
+ c->plat->dma_write(c->dma_ch, CLNK_CTRL, c->dma_ch);
+
+ /* Clear CSR */
+ if (dma_omap1())
+ c->plat->dma_read(CSR, c->dma_ch);
+ else
+ c->plat->dma_write(~0, CSR, c->dma_ch);
+
+ /* Enable interrupts */
+ c->plat->dma_write(d->cicr, CICR, c->dma_ch);
+
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ if (od->plat->errata & DMA_ERRATA_IFRAME_BUFFERING)
+ val |= OMAP_DMA_CCR_BUFFERING_DISABLE;
+ val |= OMAP_DMA_CCR_EN;
+ mb();
+ c->plat->dma_write(val, CCR, c->dma_ch);
+}
+
+static void omap_dma_stop(struct omap_chan *c)
+{
+ struct omap_dmadev *od = to_omap_dma_dev(c->vc.chan.device);
+ uint32_t val;
+
+ /* disable irq */
+ c->plat->dma_write(0, CICR, c->dma_ch);
+
+ /* Clear CSR */
+ if (dma_omap1())
+ c->plat->dma_read(CSR, c->dma_ch);
+ else
+ c->plat->dma_write(~0, CSR, c->dma_ch);
+
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ if (od->plat->errata & DMA_ERRATA_i541 &&
+ val & OMAP_DMA_CCR_SEL_SRC_DST_SYNC) {
+ uint32_t sysconfig;
+ unsigned i;
+
+ sysconfig = c->plat->dma_read(OCP_SYSCONFIG, c->dma_ch);
+ val = sysconfig & ~DMA_SYSCONFIG_MIDLEMODE_MASK;
+ val |= DMA_SYSCONFIG_MIDLEMODE(DMA_IDLEMODE_NO_IDLE);
+ c->plat->dma_write(val, OCP_SYSCONFIG, c->dma_ch);
+
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ val &= ~OMAP_DMA_CCR_EN;
+ c->plat->dma_write(val, CCR, c->dma_ch);
+
+ /* Wait for sDMA FIFO to drain */
+ for (i = 0; ; i++) {
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ if (!(val & (OMAP_DMA_CCR_RD_ACTIVE | OMAP_DMA_CCR_WR_ACTIVE)))
+ break;
+
+ if (i > 100)
+ break;
+
+ udelay(5);
+ }
+
+ if (val & (OMAP_DMA_CCR_RD_ACTIVE | OMAP_DMA_CCR_WR_ACTIVE))
+ dev_err(c->vc.chan.device->dev,
+ "DMA drain did not complete on lch %d\n",
+ c->dma_ch);
+
+ c->plat->dma_write(sysconfig, OCP_SYSCONFIG, c->dma_ch);
+ } else {
+ val &= ~OMAP_DMA_CCR_EN;
+ c->plat->dma_write(val, CCR, c->dma_ch);
+ }
+
+ mb();
+
+ if (!__dma_omap15xx(od->plat->dma_attr) && c->cyclic) {
+ val = c->plat->dma_read(CLNK_CTRL, c->dma_ch);
+
+ if (dma_omap1())
+ val |= 1 << 14; /* set the STOP_LNK bit */
+
+ if (dma_omap2plus())
+ val &= ~(1 << 15); /* Clear the ENABLE_LNK bit */
+
+ c->plat->dma_write(val, CLNK_CTRL, c->dma_ch);
+ }
+}
+
static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
unsigned idx)
{
@@ -113,7 +221,7 @@ static void omap_dma_start_sg(struct omap_chan *c, struct omap_desc *d,
c->plat->dma_write(sg->en, CEN, c->dma_ch);
c->plat->dma_write(sg->fn, CFN, c->dma_ch);
- omap_start_dma(c->dma_ch);
+ omap_dma_start(c, d);
}
static void omap_dma_start_desc(struct omap_chan *c)
@@ -436,6 +544,12 @@ static struct dma_async_tx_descriptor *omap_dma_prep_slave_sg(
d->sync_mode = OMAP_DMA_SYNC_FRAME;
d->sync_type = sync_type;
d->periph_port = OMAP_DMA_PORT_TIPB;
+ d->cicr = OMAP_DMA_DROP_IRQ | OMAP_DMA_BLOCK_IRQ;
+
+ if (dma_omap1())
+ d->cicr |= OMAP1_DMA_TOUT_IRQ;
+ else if (dma_omap2plus())
+ d->cicr |= OMAP2_DMA_MISALIGNED_ERR_IRQ | OMAP2_DMA_TRANS_ERR_IRQ;
/*
* Build our scatterlist entries: each contains the address,
@@ -465,6 +579,7 @@ static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
size_t period_len, enum dma_transfer_direction dir, unsigned long flags,
void *context)
{
+ struct omap_dmadev *od = to_omap_dma_dev(chan->device);
struct omap_chan *c = to_omap_dma_chan(chan);
enum dma_slave_buswidth dev_width;
struct omap_desc *d;
@@ -521,15 +636,25 @@ static struct dma_async_tx_descriptor *omap_dma_prep_dma_cyclic(
d->sg[0].en = period_len / es_bytes[es];
d->sg[0].fn = buf_len / period_len;
d->sglen = 1;
+ d->cicr = OMAP_DMA_DROP_IRQ;
+ if (flags & DMA_PREP_INTERRUPT)
+ d->cicr |= OMAP_DMA_FRAME_IRQ;
+
+ if (dma_omap1())
+ d->cicr |= OMAP1_DMA_TOUT_IRQ;
+ else if (dma_omap2plus())
+ d->cicr |= OMAP2_DMA_MISALIGNED_ERR_IRQ | OMAP2_DMA_TRANS_ERR_IRQ;
if (!c->cyclic) {
c->cyclic = true;
- omap_dma_link_lch(c->dma_ch, c->dma_ch);
- if (flags & DMA_PREP_INTERRUPT)
- omap_enable_dma_irq(c->dma_ch, OMAP_DMA_FRAME_IRQ);
+ if (__dma_omap15xx(od->plat->dma_attr)) {
+ uint32_t val;
- omap_disable_dma_irq(c->dma_ch, OMAP_DMA_BLOCK_IRQ);
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ val |= 3 << 8;
+ c->plat->dma_write(val, CCR, c->dma_ch);
+ }
}
if (dma_omap2plus()) {
@@ -570,20 +695,27 @@ static int omap_dma_terminate_all(struct omap_chan *c)
/*
* Stop DMA activity: we assume the callback will not be called
- * after omap_stop_dma() returns (even if it does, it will see
+ * after omap_dma_stop() returns (even if it does, it will see
* c->desc is NULL and exit.)
*/
if (c->desc) {
c->desc = NULL;
/* Avoid stopping the dma twice */
if (!c->paused)
- omap_stop_dma(c->dma_ch);
+ omap_dma_stop(c);
}
if (c->cyclic) {
c->cyclic = false;
c->paused = false;
- omap_dma_unlink_lch(c->dma_ch, c->dma_ch);
+
+ if (__dma_omap15xx(od->plat->dma_attr)) {
+ uint32_t val;
+
+ val = c->plat->dma_read(CCR, c->dma_ch);
+ val &= ~(3 << 8);
+ c->plat->dma_write(val, CCR, c->dma_ch);
+ }
}
vchan_get_all_descriptors(&c->vc, &head);
@@ -600,7 +732,7 @@ static int omap_dma_pause(struct omap_chan *c)
return -EINVAL;
if (!c->paused) {
- omap_stop_dma(c->dma_ch);
+ omap_dma_stop(c);
c->paused = true;
}
@@ -614,7 +746,7 @@ static int omap_dma_resume(struct omap_chan *c)
return -EINVAL;
if (c->paused) {
- omap_start_dma(c->dma_ch);
+ omap_dma_start(c, c->desc);
c->paused = false;
}
--
1.7.4.4
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