[V2] dmaengine: fsl-edma: Add eDMA support for QorIQ LS1028A platform

[Peng Ma]

Our platforms(such as LS1021A, LS1012A, LS1043A, LS1046A, LS1028A) with below
registers(CHCFG0 - CHCFG15) of eDMA as follows:
*-----------------------------------------------------------*
|     Offset   |	OTHERS      |		LS1028A	    |
|--------------|--------------------|-----------------------|
|     0x0      |        CHCFG0      |           CHCFG3      |
|--------------|--------------------|-----------------------|
|     0x1      |        CHCFG1      |           CHCFG2      |
|--------------|--------------------|-----------------------|
|     0x2      |        CHCFG2      |           CHCFG1      |
|--------------|--------------------|-----------------------|
|     0x3      |        CHCFG3      |           CHCFG0      |
|--------------|--------------------|-----------------------|
|     ...      |        ......      |           ......      |
|--------------|--------------------|-----------------------|
|     0xC      |        CHCFG12     |           CHCFG15     |
|--------------|--------------------|-----------------------|
|     0xD      |        CHCFG13     |           CHCFG14     |
|--------------|--------------------|-----------------------|
|     0xE      |        CHCFG14     |           CHCFG13     |
|--------------|--------------------|-----------------------|
|     0xF      |        CHCFG15     |           CHCFG12     |
*-----------------------------------------------------------*

This patch is to improve edma driver to fit LS1028A platform.

Signed-off-by: Peng Ma <peng.ma@xxxxxxx>
---
Changed for V2:
	- Explaining what's the "Our platforms"

 drivers/dma/fsl-edma-common.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c
index b1a7ca9..611186b 100644
--- a/drivers/dma/fsl-edma-common.c
+++ b/drivers/dma/fsl-edma-common.c
@@ -7,6 +7,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/dma-mapping.h>
+#include <linux/sys_soc.h>
 
 #include "fsl-edma-common.h"
 
@@ -42,6 +43,11 @@
 
 #define EDMA_TCD		0x1000
 
+static struct soc_device_attribute soc_fixup_tuning[] = {
+	{ .family = "QorIQ LS1028A"},
+	{ },
+};
+
 static void fsl_edma_enable_request(struct fsl_edma_chan *fsl_chan)
 {
 	struct edma_regs *regs = &fsl_chan->edma->regs;
@@ -109,10 +115,16 @@ void fsl_edma_chan_mux(struct fsl_edma_chan *fsl_chan,
 	u32 ch = fsl_chan->vchan.chan.chan_id;
 	void __iomem *muxaddr;
 	unsigned int chans_per_mux, ch_off;
+	int endian_diff[4] = {3, 1, -1, -3};
 	u32 dmamux_nr = fsl_chan->edma->drvdata->dmamuxs;
 
 	chans_per_mux = fsl_chan->edma->n_chans / dmamux_nr;
 	ch_off = fsl_chan->vchan.chan.chan_id % chans_per_mux;
+
+	if (!fsl_chan->edma->big_endian &&
+	    soc_device_match(soc_fixup_tuning))
+		ch_off += endian_diff[ch_off % 4];
+
 	muxaddr = fsl_chan->edma->muxbase[ch / chans_per_mux];
 	slot = EDMAMUX_CHCFG_SOURCE(slot);
 
-- 
2.9.5