dmaengine: omap-dma: control start/stop directly

Program the non-cyclic mode DMA start/stop directly, rather than via
arch/arm/plat-omap/dma.c.

Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 141 insertions, 10 deletions

diff --git a/drivers/dma/omap-dma.c b/drivers/dma/omap-dma.c
index 8c5c862f01ed..7aa5ff7ab935 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 +97,111 @@ 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 */
+                else
+                        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 +220,7 @@ 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)
@@ -434,6 +541,12 @@ 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
+                d->cicr |= OMAP2_DMA_MISALIGNED_ERR_IRQ | OMAP2_DMA_TRANS_ERR_IRQ;
 
         /*
          * Build our scatterlist entries: each contains the address,
@@ -463,6 +576,7 @@ 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;
@@ -519,15 +633,25 @@ 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
+                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()) {
@@ -568,20 +692,27 @@ 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);
@@ -598,7 +729,7 @@ 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;
         }
 
@@ -612,7 +743,7 @@ 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;
         }