[ARM] 4220/1: S3C24XX: DMA system initialised from sysdev

This patch gets the DMA system for the S3C24XX
ready for the S3C2443, which requires 6 dma channels
at a different stride, and different base IRQ.

The DMA system is now initialised from the same
drivers which apply the DMA mappings, as well
as removing the DMA sysdev intialisation out of
the main init code (which is now being called
from a sysdev probe, so cannot add a new sysdev)

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 53 insertions, 24 deletions

diff --git a/arch/arm/plat-s3c24xx/dma.c b/arch/arm/plat-s3c24xx/dma.c
index 929265aab7dd..4540a806f522 100644
--- a/arch/arm/plat-s3c24xx/dma.c
+++ b/arch/arm/plat-s3c24xx/dma.c
@@ -42,6 +42,8 @@
 static void __iomem *dma_base;
 static struct kmem_cache *dma_kmem;
 
+static int dma_channels;
+
 struct s3c24xx_dma_selection dma_sel;
 
 /* dma channel state information */
@@ -1278,7 +1280,42 @@ static void s3c2410_dma_cache_ctor(void *p, struct kmem_cache *c, unsigned long
 
 /* initialisation code */
 
-static int __init s3c2410_init_dma(void)
+int __init s3c24xx_dma_sysclass_init(void)
+{
+        int ret = sysdev_class_register(&dma_sysclass);
+
+        if (ret != 0)
+                printk(KERN_ERR "dma sysclass registration failed\n");
+
+        return ret;
+}
+
+core_initcall(s3c24xx_dma_sysclass_init);
+
+int __init s3c24xx_dma_sysdev_register(void)
+{
+        struct s3c2410_dma_chan *cp = s3c2410_chans;
+        int channel, ret;
+
+        for (channel = 0; channel < dma_channels; cp++, channel++) {
+                cp->dev.cls = &dma_sysclass;
+                cp->dev.id  = channel;
+                ret = sysdev_register(&cp->dev);
+
+                if (ret) {
+                        printk(KERN_ERR "error registering dev for dma %d\n",
+                               channel);
+                        return ret;
+                }
+        }
+
+        return 0;
+}
+
+late_initcall(s3c24xx_dma_sysdev_register);
+
+int __init s3c24xx_dma_init(unsigned int channels, unsigned int irq,
+                            unsigned int stride)
 {
         struct s3c2410_dma_chan *cp;
         int channel;
@@ -1286,21 +1323,16 @@ static int __init s3c2410_init_dma(void)
 
         printk("S3C24XX DMA Driver, (c) 2003-2004,2006 Simtec Electronics\n");
 
-        dma_base = ioremap(S3C24XX_PA_DMA, 0x200);
+        dma_channels = channels;
+
+        dma_base = ioremap(S3C24XX_PA_DMA, stride * channels);
         if (dma_base == NULL) {
                 printk(KERN_ERR "dma failed to remap register block\n");
                 return -ENOMEM;
         }
 
-        printk("Registering sysclass\n");
-
-        ret = sysdev_class_register(&dma_sysclass);
-        if (ret != 0) {
-                printk(KERN_ERR "dma sysclass registration failed\n");
-                goto err;
-        }
-
-        dma_kmem = kmem_cache_create("dma_desc", sizeof(struct s3c2410_dma_buf), 0,
+        dma_kmem = kmem_cache_create("dma_desc",
+                                     sizeof(struct s3c2410_dma_buf), 0,
                                      SLAB_HWCACHE_ALIGN,
                                      s3c2410_dma_cache_ctor, NULL);
 
@@ -1310,15 +1342,15 @@ static int __init s3c2410_init_dma(void)
                 goto err;
         }
 
-        for (channel = 0; channel < S3C2410_DMA_CHANNELS; channel++) {
+        for (channel = 0; channel < channels;  channel++) {
                 cp = &s3c2410_chans[channel];
 
                 memset(cp, 0, sizeof(struct s3c2410_dma_chan));
 
                 /* dma channel irqs are in order.. */
                 cp->number = channel;
-                cp->irq    = channel + IRQ_DMA0;
-                cp->regs   = dma_base + (channel*0x40);
+                cp->irq    = channel + irq;
+                cp->regs   = dma_base + (channel * stride);
 
                 /* point current stats somewhere */
                 cp->stats  = &cp->stats_store;
@@ -1328,12 +1360,6 @@ static int __init s3c2410_init_dma(void)
 
                 cp->load_timeout = 1<<18;
 
-                /* register system device */
-
-                cp->dev.cls = &dma_sysclass;
-                cp->dev.id  = channel;
-                ret = sysdev_register(&cp->dev);
-
                 printk("DMA channel %d at %p, irq %d\n",
                        cp->number, cp->regs, cp->irq);
         }
@@ -1347,7 +1373,10 @@ static int __init s3c2410_init_dma(void)
         return ret;
 }
 
-core_initcall(s3c2410_init_dma);
+int s3c2410_dma_init(void)
+{
+        return s3c24xx_dma_init(4, IRQ_DMA0, 0x40);
+}
 
 static inline int is_channel_valid(unsigned int channel)
 {
@@ -1384,7 +1413,7 @@ struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel)
         if (dma_order) {
                 ord = &dma_order->channels[channel];
 
-                for (ch = 0; ch < S3C2410_DMA_CHANNELS; ch++) {
+                for (ch = 0; ch < dma_channels; ch++) {
                         if (!is_channel_valid(ord->list[ch]))
                                 continue;
 
@@ -1400,7 +1429,7 @@ struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel)
 
         /* second, search the channel map for first free */
 
-        for (ch = 0; ch < S3C2410_DMA_CHANNELS; ch++) {
+        for (ch = 0; ch < dma_channels; ch++) {
                 if (!is_channel_valid(ch_map->channels[ch]))
                         continue;
 
@@ -1410,7 +1439,7 @@ struct s3c2410_dma_chan *s3c2410_dma_map_channel(int channel)
                 }
         }
 
-        if (ch >= S3C2410_DMA_CHANNELS)
+        if (ch >= dma_channels)
                 return NULL;
 
         /* update our channel mapping */