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>

diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c
index 56eb90f..78f45de 100644 (file)
--- a/arch/arm/plat-omap/dma.c
+++ b/arch/arm/plat-omap/dma.c
@@ -563,22 +563,25 @@ 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)
@@ -622,14 +625,14 @@ 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);
        }
@@ -647,6 +650,9 @@ 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);
@@ -662,9 +668,12 @@ 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);
 }
 
@@ -735,11 +744,8 @@ 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;
@@ -758,27 +764,19 @@ 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;
@@ -933,8 +931,7 @@ 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) &&