Enable runtime pm and use pm_runtime_get_sync and pm_runtime_put
for OMAP DMA driver.

Since DMA driver callback will happen from interrupt context and
DMA client driver will release all DMA resources from interrupt
context itself, pm_runtime_put_sync() cannot be used in DMA driver.
Instead, pm_runtime_put() is used which is asynchronous call and
gets executed in work queue.

Signed-off-by: G, Manjunath Kondaiah <manj...@ti.com>
Cc: linux-arm-ker...@lists.infradead.org
Cc: Kevin Hilman <khil...@deeprootsystems.com>
Cc: Tony Lindgren <t...@atomide.com>
Cc: Santosh Shilimkar <santosh.shilim...@ti.com>
Cc: Benoit Cousson <b-cous...@ti.com>
---
 arch/arm/plat-omap/dma.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index a859c70..527ebfc 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -32,6 +32,7 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/pm_runtime.h>
 
 #include <plat/dma.h>
 #include <plat/tc.h>
@@ -302,6 +303,7 @@ int omap_request_dma(int dev_id, const char *dev_name,
        unsigned long flags;
        struct omap_dma_lch *chan;
 
+       pm_runtime_get_sync(&pd->dev);
        spin_lock_irqsave(&dma_chan_lock, flags);
        for (ch = 0; ch < dma_chan_count; ch++) {
                if (free_ch == -1 && dma_chan[ch].dev_id == -1) {
@@ -312,6 +314,7 @@ int omap_request_dma(int dev_id, const char *dev_name,
        }
        if (free_ch == -1) {
                spin_unlock_irqrestore(&dma_chan_lock, flags);
+               pm_runtime_put(&pd->dev);
                return -EBUSY;
        }
        chan = dma_chan + free_ch;
@@ -403,6 +406,7 @@ void omap_free_dma(int lch)
                omap_clear_dma(lch);
                p->clear_sglist_mode(lch);
        }
+       pm_runtime_put(&pd->dev);
        spin_lock_irqsave(&dma_chan_lock, flags);
        dma_chan[lch].dev_id = -1;
        dma_chan[lch].next_lch = -1;
@@ -734,6 +738,9 @@ static int __devinit omap_system_dma_probe(struct 
platform_device *pdev)
        dma_chan                = d->chan;
        enable_1510_mode        = d->dev_caps & ENABLE_1510_MODE;
 
+       pm_runtime_enable(&pd->dev);
+       pm_runtime_get_sync(&pd->dev);
+
        spin_lock_init(&dma_chan_lock);
        for (ch = 0; ch < dma_chan_count; ch++) {
                unsigned long flags;
@@ -760,6 +767,14 @@ static int __devinit omap_system_dma_probe(struct 
platform_device *pdev)
                dma_chan[1].dev_id = 1;
        }
        p->show_dma_caps();
+
+       /*
+        * Note: If dma channels are reserved through boot paramters,
+        * then dma device is always enabled.
+        */
+       if (!omap_dma_reserve_channels)
+               pm_runtime_put(&pd->dev);
+
        return 0;
 }
 
-- 
1.7.1

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