ARM: OMAP: dma: Clear status registers on enable/disable irq

Use omap_disable_channel_irq() function instead of directly accessing CICR
register in various functions.

The omap_disable_chanel_irq() function now clears pending interrupts
and disables interrupt on channel.

Functions omap2_enable_irq_lch()/omap2_disable_irq_lch() clear interrupt
status register.

Signed-off-by: Oleg Matcovschi <oleg.matcovschi@ti.com>
Tested-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
[tony@atomide.com: updated comments to clarify CICR access]
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 28 insertions, 31 deletions

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index cb16ade437cb..7fe626761e53 100644
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -573,22 +573,25 @@ EXPORT_SYMBOL(omap_set_dma_dest_burst_mode);
 
 static inline void omap_enable_channel_irq(int lch)
 {
-        u32 status;
-
         /* Clear CSR */
         if (cpu_class_is_omap1())
-                status = p->dma_read(CSR, lch);
-        else if (cpu_class_is_omap2())
+                p->dma_read(CSR, lch);
+        else
                 p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
 
         /* Enable some nice interrupts. */
         p->dma_write(dma_chan[lch].enabled_irqs, CICR, lch);
 }
 
-static void omap_disable_channel_irq(int lch)
+static inline void omap_disable_channel_irq(int lch)
 {
-        if (cpu_class_is_omap2())
-                p->dma_write(0, CICR, lch);
+        /* disable channel interrupts */
+        p->dma_write(0, CICR, lch);
+        /* Clear CSR */
+        if (cpu_class_is_omap1())
+                p->dma_read(CSR, lch);
+        else
+                p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
 }
 
 void omap_enable_dma_irq(int lch, u16 bits)
@@ -632,14 +635,14 @@ static inline void disable_lnk(int lch)
         l = p->dma_read(CLNK_CTRL, lch);
 
         /* Disable interrupts */
+        omap_disable_channel_irq(lch);
+
         if (cpu_class_is_omap1()) {
-                p->dma_write(0, CICR, lch);
                 /* Set the STOP_LNK bit */
                 l |= 1 << 14;
         }
 
         if (cpu_class_is_omap2()) {
-                omap_disable_channel_irq(lch);
                 /* Clear the ENABLE_LNK bit */
                 l &= ~(1 << 15);
         }
@@ -657,6 +660,9 @@ static inline void omap2_enable_irq_lch(int lch)
                 return;
 
         spin_lock_irqsave(&dma_chan_lock, flags);
+        /* clear IRQ STATUS */
+        p->dma_write(1 << lch, IRQSTATUS_L0, lch);
+        /* Enable interrupt */
         val = p->dma_read(IRQENABLE_L0, lch);
         val |= 1 << lch;
         p->dma_write(val, IRQENABLE_L0, lch);
@@ -672,9 +678,12 @@ static inline void omap2_disable_irq_lch(int lch)
                 return;
 
         spin_lock_irqsave(&dma_chan_lock, flags);
+        /* Disable interrupt */
         val = p->dma_read(IRQENABLE_L0, lch);
         val &= ~(1 << lch);
         p->dma_write(val, IRQENABLE_L0, lch);
+        /* clear IRQ STATUS */
+        p->dma_write(1 << lch, IRQSTATUS_L0, lch);
         spin_unlock_irqrestore(&dma_chan_lock, flags);
 }
 
@@ -745,11 +754,8 @@ int omap_request_dma(int dev_id, const char *dev_name,
         }
 
         if (cpu_class_is_omap2()) {
-                omap2_enable_irq_lch(free_ch);
                 omap_enable_channel_irq(free_ch);
-                /* Clear the CSR register and IRQ status register */
-                p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, free_ch);
-                p->dma_write(1 << free_ch, IRQSTATUS_L0, 0);
+                omap2_enable_irq_lch(free_ch);
         }
 
         *dma_ch_out = free_ch;
@@ -768,27 +774,19 @@ void omap_free_dma(int lch)
                 return;
         }
 
-        if (cpu_class_is_omap1()) {
-                /* Disable all DMA interrupts for the channel. */
-                p->dma_write(0, CICR, lch);
-                /* Make sure the DMA transfer is stopped. */
-                p->dma_write(0, CCR, lch);
-        }
-
-        if (cpu_class_is_omap2()) {
+        /* Disable interrupt for logical channel */
+        if (cpu_class_is_omap2())
                 omap2_disable_irq_lch(lch);
 
-                /* Clear the CSR register and IRQ status register */
-                p->dma_write(OMAP2_DMA_CSR_CLEAR_MASK, CSR, lch);
-                p->dma_write(1 << lch, IRQSTATUS_L0, lch);
+        /* Disable all DMA interrupts for the channel. */
+        omap_disable_channel_irq(lch);
 
-                /* Disable all DMA interrupts for the channel. */
-                p->dma_write(0, CICR, lch);
+        /* Make sure the DMA transfer is stopped. */
+        p->dma_write(0, CCR, lch);
 
-                /* Make sure the DMA transfer is stopped. */
-                p->dma_write(0, CCR, lch);
+        /* Clear registers */
+        if (cpu_class_is_omap2())
                 omap_clear_dma(lch);
-        }
 
         spin_lock_irqsave(&dma_chan_lock, flags);
         dma_chan[lch].dev_id = -1;
@@ -943,8 +941,7 @@ void omap_stop_dma(int lch)
         u32 l;
 
         /* Disable all interrupts on the channel */
-        if (cpu_class_is_omap1())
-                p->dma_write(0, CICR, lch);
+        omap_disable_channel_irq(lch);
 
         l = p->dma_read(CCR, lch);
         if (IS_DMA_ERRATA(DMA_ERRATA_i541) &&