[PATCHv2] dma40: Improve the logic of stopping logical chan
From: Narayanan G
Date: Fri Jan 06 2012 - 01:13:35 EST
>From the V2 version of the controller a logical channel
can be directly stopped by issuing a SUSPEND_REQ on the EE
bits. There is no need to suspend the physical channel and
restart it.
Also, the support for pre-V2 hw is discontinued.
EE bits for writing:
00: disable only if AS=11 or AS=00
01: enable
10: suspend_req only if AS=01 & EE=01 or EE=11
11: round / no change for writing
Signed-off-by: Narayanan G <narayanan.gopalakrishnan@xxxxxxxxxxxxxx>
---
drivers/dma/ste_dma40.c | 320 +++++++++++++++++++++++++++-----------------
drivers/dma/ste_dma40_ll.h | 2 -
2 files changed, 199 insertions(+), 123 deletions(-)
Removed some unwanted details from the commmit message.
Please ignore the first version and use the v2 version.
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index cc5ecbc..8009e8b1 100755
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -68,6 +68,22 @@ enum d40_command {
};
/*
+ * enum d40_events - The different Event Enables for the event lines.
+ *
+ * @D40_DEACTIVATE_EVENTLINE: De-activate Event line, stopping the logical chan.
+ * @D40_ACTIVATE_EVENTLINE: Activate the Event line, to start a logical chan.
+ * @D40_SUSPEND_REQ_EVENTLINE: Requesting for suspending a event line.
+ * @D40_ROUND_EVENTLINE: Status check for event line.
+ */
+
+enum d40_events {
+ D40_DEACTIVATE_EVENTLINE = 0,
+ D40_ACTIVATE_EVENTLINE = 1,
+ D40_SUSPEND_REQ_EVENTLINE = 2,
+ D40_ROUND_EVENTLINE = 3
+};
+
+/*
* These are the registers that has to be saved and later restored
* when the DMA hw is powered off.
* TODO: Add save/restore of D40_DREG_GCC on dma40 v3 or later, if that works.
@@ -873,8 +889,8 @@ static void d40_save_restore_registers(struct d40_base *base, bool save)
}
#endif
-static int d40_channel_execute_command(struct d40_chan *d40c,
- enum d40_command command)
+static int __d40_execute_command_phy(struct d40_chan *d40c,
+ enum d40_command command)
{
u32 status;
int i;
@@ -883,6 +899,12 @@ static int d40_channel_execute_command(struct d40_chan *d40c,
unsigned long flags;
u32 wmask;
+ if (command == D40_DMA_STOP) {
+ ret = __d40_execute_command_phy(d40c, D40_DMA_SUSPEND_REQ);
+ if (ret)
+ return ret;
+ }
+
spin_lock_irqsave(&d40c->base->execmd_lock, flags);
if (d40c->phy_chan->num % 2 == 0)
@@ -976,67 +998,109 @@ static void d40_term_all(struct d40_chan *d40c)
}
d40c->pending_tx = 0;
- d40c->busy = false;
}
-static void __d40_config_set_event(struct d40_chan *d40c, bool enable,
- u32 event, int reg)
+static void __d40_config_set_event(struct d40_chan *d40c,
+ enum d40_events event_type, u32 event,
+ int reg)
{
void __iomem *addr = chan_base(d40c) + reg;
int tries;
+ u32 status;
+
+ switch (event_type) {
+
+ case D40_DEACTIVATE_EVENTLINE:
- if (!enable) {
writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
| ~D40_EVENTLINE_MASK(event), addr);
- return;
- }
+ break;
+
+ case D40_SUSPEND_REQ_EVENTLINE:
+ status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+ D40_EVENTLINE_POS(event);
+
+ if (status == D40_DEACTIVATE_EVENTLINE ||
+ status == D40_SUSPEND_REQ_EVENTLINE)
+ break;
+ writel((D40_SUSPEND_REQ_EVENTLINE << D40_EVENTLINE_POS(event))
+ | ~D40_EVENTLINE_MASK(event), addr);
+
+ for (tries = 0 ; tries < D40_SUSPEND_MAX_IT; tries++) {
+
+ status = (readl(addr) & D40_EVENTLINE_MASK(event)) >>
+ D40_EVENTLINE_POS(event);
+
+ cpu_relax();
+ /*
+ * Reduce the number of bus accesses while
+ * waiting for the DMA to suspend.
+ */
+ udelay(3);
+
+ if (status == D40_DEACTIVATE_EVENTLINE)
+ break;
+ }
+
+ if (tries == D40_SUSPEND_MAX_IT) {
+ chan_err(d40c,
+ "unable to stop the event_line chl %d (log: %d)"
+ "status %x\n", d40c->phy_chan->num,
+ d40c->log_num, status);
+ }
+ break;
+
+ case D40_ACTIVATE_EVENTLINE:
/*
* The hardware sometimes doesn't register the enable when src and dst
* event lines are active on the same logical channel. Retry to ensure
* it does. Usually only one retry is sufficient.
*/
- tries = 100;
- while (--tries) {
- writel((D40_ACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
- | ~D40_EVENTLINE_MASK(event), addr);
+ tries = 100;
+ while (--tries) {
+ writel((D40_ACTIVATE_EVENTLINE <<
+ D40_EVENTLINE_POS(event)) |
+ ~D40_EVENTLINE_MASK(event), addr);
- if (readl(addr) & D40_EVENTLINE_MASK(event))
- break;
- }
+ if (readl(addr) & D40_EVENTLINE_MASK(event))
+ break;
+ }
- if (tries != 99)
- dev_dbg(chan2dev(d40c),
- "[%s] workaround enable S%cLNK (%d tries)\n",
- __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
- 100 - tries);
+ if (tries != 99)
+ dev_dbg(chan2dev(d40c),
+ "[%s] workaround enable S%cLNK (%d tries)\n",
+ __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
+ 100 - tries);
- WARN_ON(!tries);
-}
+ WARN_ON(!tries);
+ break;
-static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
-{
- unsigned long flags;
+ case D40_ROUND_EVENTLINE:
+ BUG();
+ break;
- spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+ }
+}
+static void d40_config_set_event(struct d40_chan *d40c,
+ enum d40_events event_type)
+{
/* Enable event line connected to device (or memcpy) */
if ((d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) ||
(d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH)) {
u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
- __d40_config_set_event(d40c, do_enable, event,
+ __d40_config_set_event(d40c, event_type, event,
D40_CHAN_REG_SSLNK);
}
if (d40c->dma_cfg.dir != STEDMA40_PERIPH_TO_MEM) {
u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
- __d40_config_set_event(d40c, do_enable, event,
+ __d40_config_set_event(d40c, event_type, event,
D40_CHAN_REG_SDLNK);
}
-
- spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
}
static u32 d40_chan_has_events(struct d40_chan *d40c)
@@ -1050,6 +1114,64 @@ static u32 d40_chan_has_events(struct d40_chan *d40c)
return val;
}
+static int
+__d40_execute_command_log(struct d40_chan *d40c, enum d40_command command)
+{
+ unsigned long flags;
+ int ret = 0;
+ u32 active_status;
+ void __iomem *active_reg;
+
+ if (d40c->phy_chan->num % 2 == 0)
+ active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
+ else
+ active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;
+
+
+ spin_lock_irqsave(&d40c->phy_chan->lock, flags);
+
+ switch (command) {
+ case D40_DMA_STOP:
+ case D40_DMA_SUSPEND_REQ:
+
+ active_status = (readl(active_reg) &
+ D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
+ D40_CHAN_POS(d40c->phy_chan->num);
+
+ if (active_status == D40_DMA_RUN)
+ d40_config_set_event(d40c, D40_SUSPEND_REQ_EVENTLINE);
+ else
+ d40_config_set_event(d40c, D40_DEACTIVATE_EVENTLINE);
+
+ if (!d40_chan_has_events(d40c) && (command == D40_DMA_STOP))
+ ret = __d40_execute_command_phy(d40c, command);
+
+ break;
+
+ case D40_DMA_RUN:
+
+ d40_config_set_event(d40c, D40_ACTIVATE_EVENTLINE);
+ ret = __d40_execute_command_phy(d40c, command);
+ break;
+
+ case D40_DMA_SUSPENDED:
+ BUG();
+ break;
+ }
+
+ spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
+ return ret;
+}
+
+static int d40_channel_execute_command(struct d40_chan *d40c,
+ enum d40_command command)
+{
+ if (chan_is_logical(d40c))
+ return __d40_execute_command_log(d40c, command);
+ else
+ return __d40_execute_command_phy(d40c, command);
+}
+
static u32 d40_get_prmo(struct d40_chan *d40c)
{
static const unsigned int phy_map[] = {
@@ -1152,15 +1274,7 @@ static int d40_pause(struct d40_chan *d40c)
spin_lock_irqsave(&d40c->lock, flags);
res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
- if (res == 0) {
- if (chan_is_logical(d40c)) {
- d40_config_set_event(d40c, false);
- /* Resume the other logical channels if any */
- if (d40_chan_has_events(d40c))
- res = d40_channel_execute_command(d40c,
- D40_DMA_RUN);
- }
- }
+
pm_runtime_mark_last_busy(d40c->base->dev);
pm_runtime_put_autosuspend(d40c->base->dev);
spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1177,45 +1291,17 @@ static int d40_resume(struct d40_chan *d40c)
spin_lock_irqsave(&d40c->lock, flags);
pm_runtime_get_sync(d40c->base->dev);
- if (d40c->base->rev == 0)
- if (chan_is_logical(d40c)) {
- res = d40_channel_execute_command(d40c,
- D40_DMA_SUSPEND_REQ);
- goto no_suspend;
- }
/* If bytes left to transfer or linked tx resume job */
- if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {
-
- if (chan_is_logical(d40c))
- d40_config_set_event(d40c, true);
-
+ if (d40_residue(d40c) || d40_tx_is_linked(d40c))
res = d40_channel_execute_command(d40c, D40_DMA_RUN);
- }
-no_suspend:
pm_runtime_mark_last_busy(d40c->base->dev);
pm_runtime_put_autosuspend(d40c->base->dev);
spin_unlock_irqrestore(&d40c->lock, flags);
return res;
}
-static int d40_terminate_all(struct d40_chan *chan)
-{
- unsigned long flags;
- int ret = 0;
-
- ret = d40_pause(chan);
- if (!ret && chan_is_physical(chan))
- ret = d40_channel_execute_command(chan, D40_DMA_STOP);
-
- spin_lock_irqsave(&chan->lock, flags);
- d40_term_all(chan);
- spin_unlock_irqrestore(&chan->lock, flags);
-
- return ret;
-}
-
static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct d40_chan *d40c = container_of(tx->chan,
@@ -1242,20 +1328,6 @@ static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
static int d40_start(struct d40_chan *d40c)
{
- if (d40c->base->rev == 0) {
- int err;
-
- if (chan_is_logical(d40c)) {
- err = d40_channel_execute_command(d40c,
- D40_DMA_SUSPEND_REQ);
- if (err)
- return err;
- }
- }
-
- if (chan_is_logical(d40c))
- d40_config_set_event(d40c, true);
-
return d40_channel_execute_command(d40c, D40_DMA_RUN);
}
@@ -1268,10 +1340,10 @@ static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
d40d = d40_first_queued(d40c);
if (d40d != NULL) {
- if (!d40c->busy)
+ if (!d40c->busy) {
d40c->busy = true;
-
- pm_runtime_get_sync(d40c->base->dev);
+ pm_runtime_get_sync(d40c->base->dev);
+ }
/* Remove from queue */
d40_desc_remove(d40d);
@@ -1398,8 +1470,8 @@ static void dma_tasklet(unsigned long data)
return;
- err:
- /* Rescue manoeuvre if receiving double interrupts */
+err:
+ /* Rescue manouver if receiving double interrupts */
if (d40c->pending_tx > 0)
d40c->pending_tx--;
spin_unlock_irqrestore(&d40c->lock, flags);
@@ -1780,7 +1852,6 @@ static int d40_config_memcpy(struct d40_chan *d40c)
return 0;
}
-
static int d40_free_dma(struct d40_chan *d40c)
{
@@ -1816,43 +1887,18 @@ static int d40_free_dma(struct d40_chan *d40c)
}
pm_runtime_get_sync(d40c->base->dev);
- res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
+ res = d40_channel_execute_command(d40c, D40_DMA_STOP);
if (res) {
- chan_err(d40c, "suspend failed\n");
+ chan_err(d40c, "stop failed\n");
goto out;
}
- if (chan_is_logical(d40c)) {
- /* Release logical channel, deactivate the event line */
+ d40_alloc_mask_free(phy, is_src, chan_is_logical(d40c) ? event : 0);
- d40_config_set_event(d40c, false);
+ if (chan_is_logical(d40c))
d40c->base->lookup_log_chans[d40c->log_num] = NULL;
-
- /*
- * Check if there are more logical allocation
- * on this phy channel.
- */
- if (!d40_alloc_mask_free(phy, is_src, event)) {
- /* Resume the other logical channels if any */
- if (d40_chan_has_events(d40c)) {
- res = d40_channel_execute_command(d40c,
- D40_DMA_RUN);
- if (res)
- chan_err(d40c,
- "Executing RUN command\n");
- }
- goto out;
- }
- } else {
- (void) d40_alloc_mask_free(phy, is_src, 0);
- }
-
- /* Release physical channel */
- res = d40_channel_execute_command(d40c, D40_DMA_STOP);
- if (res) {
- chan_err(d40c, "Failed to stop channel\n");
- goto out;
- }
+ else
+ d40c->base->lookup_phy_chans[phy->num] = NULL;
if (d40c->busy) {
pm_runtime_mark_last_busy(d40c->base->dev);
@@ -1862,7 +1908,6 @@ static int d40_free_dma(struct d40_chan *d40c)
d40c->busy = false;
d40c->phy_chan = NULL;
d40c->configured = false;
- d40c->base->lookup_phy_chans[phy->num] = NULL;
out:
pm_runtime_mark_last_busy(d40c->base->dev);
@@ -2386,6 +2431,31 @@ static void d40_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&d40c->lock, flags);
}
+static void d40_terminate_all(struct dma_chan *chan)
+{
+ unsigned long flags;
+ struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
+ int ret;
+
+ spin_lock_irqsave(&d40c->lock, flags);
+
+ pm_runtime_get_sync(d40c->base->dev);
+ ret = d40_channel_execute_command(d40c, D40_DMA_STOP);
+ if (ret)
+ chan_err(d40c, "Failed to stop channel\n");
+
+ d40_term_all(d40c);
+ pm_runtime_mark_last_busy(d40c->base->dev);
+ pm_runtime_put_autosuspend(d40c->base->dev);
+ if (d40c->busy) {
+ pm_runtime_mark_last_busy(d40c->base->dev);
+ pm_runtime_put_autosuspend(d40c->base->dev);
+ }
+ d40c->busy = false;
+
+ spin_unlock_irqrestore(&d40c->lock, flags);
+}
+
static int
dma40_config_to_halfchannel(struct d40_chan *d40c,
struct stedma40_half_channel_info *info,
@@ -2566,7 +2636,8 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
switch (cmd) {
case DMA_TERMINATE_ALL:
- return d40_terminate_all(d40c);
+ d40_terminate_all(chan);
+ return 0;
case DMA_PAUSE:
return d40_pause(d40c);
case DMA_RESUME:
@@ -2923,6 +2994,12 @@ static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
rev, res->start);
+ if (rev < 2) {
+ d40_err(&pdev->dev, "hardware revision: %d is not supported",
+ rev);
+ goto failure;
+ }
+
plat_data = pdev->dev.platform_data;
/* Count the number of logical channels in use */
@@ -3013,6 +3090,7 @@ failure:
if (base) {
kfree(base->lcla_pool.alloc_map);
+ kfree(base->reg_val_backup_chan);
kfree(base->lookup_log_chans);
kfree(base->lookup_phy_chans);
kfree(base->phy_res);
diff --git a/drivers/dma/ste_dma40_ll.h b/drivers/dma/ste_dma40_ll.h
index 8d3d490..51e8e53 100644
--- a/drivers/dma/ste_dma40_ll.h
+++ b/drivers/dma/ste_dma40_ll.h
@@ -62,8 +62,6 @@
#define D40_SREG_ELEM_LOG_LIDX_MASK (0xFF << D40_SREG_ELEM_LOG_LIDX_POS)
/* Link register */
-#define D40_DEACTIVATE_EVENTLINE 0x0
-#define D40_ACTIVATE_EVENTLINE 0x1
#define D40_EVENTLINE_POS(i) (2 * i)
#define D40_EVENTLINE_MASK(i) (0x3 << D40_EVENTLINE_POS(i))
--
1.7.4.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/