[PATCH RFC v7 1/6] dma: mpc512x: reorder mpc8308 specific instructions

[Alexander Popov]

Concentrate the specific code for MPC8308 in the 'if' branch
and handle MPC512x in the 'else' branch.
This modification only reorders instructions but doesn't change behaviour.

Signed-off-by: Alexander Popov 
Acked-by: Anatolij Gustschin 
Acked-by: Gerhard Sittig 
---
 drivers/dma/mpc512x_dma.c | 42 +-
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c
index 448750d..2ce248b 100644
--- a/drivers/dma/mpc512x_dma.c
+++ b/drivers/dma/mpc512x_dma.c
@@ -52,9 +52,17 @@
 #define MPC_DMA_DESCRIPTORS64
 
 /* Macro definitions */
-#define MPC_DMA_CHANNELS   64
 #define MPC_DMA_TCD_OFFSET 0x1000
 
+/*
+ * Maximum channel counts for individual hardware variants
+ * and the maximum channel count over all supported controllers,
+ * used for data structure size
+ */
+#define MPC8308_DMACHAN_MAX16
+#define MPC512x_DMACHAN_MAX64
+#define MPC_DMA_CHANNELS   64
+
 /* Arbitration mode of group and channel */
 #define MPC_DMA_DMACR_EDCG (1 << 31)
 #define MPC_DMA_DMACR_ERGA (1 << 3)
@@ -710,10 +718,10 @@ static int mpc_dma_probe(struct platform_device *op)
 
dma = &mdma->dma;
dma->dev = dev;
-   if (!mdma->is_mpc8308)
-   dma->chancnt = MPC_DMA_CHANNELS;
+   if (mdma->is_mpc8308)
+   dma->chancnt = MPC8308_DMACHAN_MAX;
else
-   dma->chancnt = 16; /* MPC8308 DMA has only 16 channels */
+   dma->chancnt = MPC512x_DMACHAN_MAX;
dma->device_alloc_chan_resources = mpc_dma_alloc_chan_resources;
dma->device_free_chan_resources = mpc_dma_free_chan_resources;
dma->device_issue_pending = mpc_dma_issue_pending;
@@ -747,7 +755,19 @@ static int mpc_dma_probe(struct platform_device *op)
 * - Round-robin group arbitration,
 * - Round-robin channel arbitration.
 */
-   if (!mdma->is_mpc8308) {
+   if (mdma->is_mpc8308) {
+   /* MPC8308 has 16 channels and lacks some registers */
+   out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
+
+   /* enable snooping */
+   out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
+   /* Disable error interrupts */
+   out_be32(&mdma->regs->dmaeeil, 0);
+
+   /* Clear interrupts status */
+   out_be32(&mdma->regs->dmaintl, 0x);
+   out_be32(&mdma->regs->dmaerrl, 0x);
+   } else {
out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_EDCG |
MPC_DMA_DMACR_ERGA | 
MPC_DMA_DMACR_ERCA);
 
@@ -768,18 +788,6 @@ static int mpc_dma_probe(struct platform_device *op)
/* Route interrupts to IPIC */
out_be32(&mdma->regs->dmaihsa, 0);
out_be32(&mdma->regs->dmailsa, 0);
-   } else {
-   /* MPC8308 has 16 channels and lacks some registers */
-   out_be32(&mdma->regs->dmacr, MPC_DMA_DMACR_ERCA);
-
-   /* enable snooping */
-   out_be32(&mdma->regs->dmagpor, MPC_DMA_DMAGPOR_SNOOP_ENABLE);
-   /* Disable error interrupts */
-   out_be32(&mdma->regs->dmaeeil, 0);
-
-   /* Clear interrupts status */
-   out_be32(&mdma->regs->dmaintl, 0x);
-   out_be32(&mdma->regs->dmaerrl, 0x);
}
 
/* Register DMA engine */
-- 
1.8.4.2

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Re: [PATCH RFC v7 1/6] dma: mpc512x: reorder mpc8308 specific instructions

[Gerhard Sittig]

[ removed DT from Cc: ]

On Wed, Feb 12, 2014 at 17:25 +0400, Alexander Popov wrote:
> 
> Concentrate the specific code for MPC8308 in the 'if' branch
> and handle MPC512x in the 'else' branch.
> This modification only reorders instructions but doesn't change behaviour.

As this one is an obvious improvement and straight forward, it
can be taken regardless of the remainder of the series.  (I guess
this formerly stated judgement is what made Alexander derive
Acked-By tags from.)


virtually yours
Gerhard Sittig
-- 
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr. 5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: off...@denx.de
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