EDMA: require explicit alloc for DSP

More EDMA misfeature removal:

 - Static bitmask for channels allocated for DSP.  There may be
   no DSP, and different DSP firmware may use different channels.
   To allocate a channel for a DSP, davinci_request_dma() works.

 - A similar bit mask of PARAM slots, which oddly enough had
   four times as many entries as PARAM slots.

 - Unused fields in the dma_chan[] data structure:
     * "dma_running" was completely unused
     * "dev_id" was only written, never read
     * "link_lch" was only (sometimes!) written, never read

In the future it might be worth providing some init mechanism to
preallocate channels for the DSP firmware that's used, so master
channels can't be modified from the shadow region used by the ARM.
(That is, *after* there's DSP support in DaVinci GIT kernels...)

Saves about 1.7 KBytes, mostly data from the unused fields.
(Each field wasted 512 bytes.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/dma.c

@@ -246,10 +246,7 @@ static struct platform_device edma_dev = {
 
 /* Structure containing the dma channel parameters */
 static struct davinci_dma_lch {
-	int dev_id;
 	int in_use;		/* 1-used 0-unused */
-	int link_lch;
-	int dma_running;
 	int param_no;
 	int tcc;
 } dma_chan[DAVINCI_EDMA_NUM_PARAMENTRY];
@@ -259,26 +256,6 @@ static struct dma_interrupt_data {
 	void *data;
 } intr_data[DAVINCI_EDMA_NUM_DMACH];
 
-/*
-  Each bit field of the elements below indicates corresponding EDMA channel
-  availability  on arm side events
-*/
-static const unsigned long edma_channels_arm[] = {
-	0xffffffff,
-	0xffffffff
-};
-
-/*
-   Each bit field of the elements below indicates corresponding PARAM entry
-   availability on arm side events
-*/
-static const unsigned long param_entry_arm[] = {
-	0xffffffff, 0xffffffff, 0x0000ffff, 0xffffffff,
-	0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
-	0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
-	0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff
-};
-
 /*
    Each bit field of the elements below indicates whether a PARAM entry
    is free or in use
@@ -383,8 +360,7 @@ static int request_param(int lch, int dev_id)
 
 		LOCK;
 		while (i < DAVINCI_EDMA_NUM_PARAMENTRY) {
-			if ((param_entry_arm[i / 32] & (1 << (i % 32))) &&
-			    (param_entry_use_status[i / 32] &
+			if ((param_entry_use_status[i / 32] &
 						(1 << (i % 32)))) {
 				if (dev_id == DAVINCI_DMA_CHANNEL_ANY) {
 					if (i >= DAVINCI_EDMA_NUM_DMACH)
@@ -754,16 +730,6 @@ int davinci_request_dma(int dev_id, const char *name,
 
 	int ret_val = 0, i = 0;
 
-	/* checking the ARM side events */
-	if (dev_id >= 0 && (dev_id < DAVINCI_EDMA_NUM_DMACH)) {
-		if (!(edma_channels_arm[dev_id / 32] & (1 << (dev_id % 32)))) {
-			dev_dbg(&edma_dev.dev,
-				"dev_id = %d not supported on ARM side\r\n",
-				dev_id);
-			return -EINVAL;
-		}
-	}
-
 	if ((dev_id != DAVINCI_DMA_CHANNEL_ANY) &&
 	    (dev_id != DAVINCI_EDMA_PARAM_ANY)) {
 		edma_or_array2(EDMA_DRAE, 0, dev_id >> 5,
@@ -861,7 +827,6 @@ int davinci_request_dma(int dev_id, const char *name,
 		   available or not */
 		dma_chan[*lch].in_use = 1;
 		UNLOCK;
-		dma_chan[*lch].dev_id = *lch;
 		j = dma_chan[*lch].param_no;
 		if (dma_chan[*lch].tcc != -1) {
 			edma_parm_modify(PARM_OPT, j, ~TCC,
@@ -1204,7 +1169,6 @@ void davinci_dma_link_lch(int lch, int lch_que)
 		edma_parm_modify(PARM_LINK_BCNTRLD, dma_chan[lch].param_no,
 				0xffff0000,
 				PARM_OFFSET(dma_chan[lch_que].param_no));
-		dma_chan[lch].link_lch = lch_que;
 	}
 }
 EXPORT_SYMBOL(davinci_dma_link_lch);
@@ -1225,7 +1189,6 @@ void davinci_dma_unlink_lch(int lch, int lch_que)
 	    (lch_que >= 0) && (lch_que < DAVINCI_EDMA_NUM_PARAMENTRY)) {
 		edma_parm_or(PARM_LINK_BCNTRLD, dma_chan[lch].param_no,
 				0xffff);
-		dma_chan[lch].link_lch = -1;
 	}
 }
 EXPORT_SYMBOL(davinci_dma_unlink_lch);