[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>

arch/arm/mach-s3c2410/dma.c

@@ -19,9 +19,9 @@
 
 #include <asm/dma.h>
 #include <asm/arch/dma.h>
-#include <asm/plat-s3c24xx/dma.h>
 
 #include <asm/plat-s3c24xx/cpu.h>
+#include <asm/plat-s3c24xx/dma.h>
 
 #include <asm/arch/regs-serial.h>
 #include <asm/arch/regs-gpio.h>
@@ -147,6 +147,7 @@ static struct s3c24xx_dma_order __initdata s3c2410_dma_order = {
 
 static int s3c2410_dma_add(struct sys_device *sysdev)
 {
+	s3c2410_dma_init();
 	s3c24xx_dma_order_set(&s3c2410_dma_order);
 	return s3c24xx_dma_init_map(&s3c2410_dma_sel);
 }
@@ -156,12 +157,12 @@ static struct sysdev_driver s3c2410_dma_driver = {
 	.add	= s3c2410_dma_add,
 };
 
-static int __init s3c2410_dma_init(void)
+static int __init s3c2410_dma_drvinit(void)
 {
 	return sysdev_driver_register(&s3c2410_sysclass, &s3c2410_dma_driver);
 }
 
-arch_initcall(s3c2410_dma_init);
+arch_initcall(s3c2410_dma_drvinit);
 #endif
 
 #if defined(CONFIG_CPU_S3C2442)
@@ -170,11 +171,11 @@ static struct sysdev_driver s3c2442_dma_driver = {
 	.add	= s3c2410_dma_add,
 };
 
-static int __init s3c2442_dma_init(void)
+static int __init s3c2442_dma_drvinit(void)
 {
 	return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_dma_driver);
 }
 
-arch_initcall(s3c2442_dma_init);
+arch_initcall(s3c2442_dma_drvinit);
 #endif
 

arch/arm/mach-s3c2412/dma.c

@@ -146,6 +146,7 @@ static struct s3c24xx_dma_selection __initdata s3c2412_dma_sel = {
 
 static int s3c2412_dma_add(struct sys_device *sysdev)
 {
+	s3c2410_dma_init();
 	return s3c24xx_dma_init_map(&s3c2412_dma_sel);
 }
 

arch/arm/mach-s3c2440/dma.c

@@ -19,8 +19,8 @@
 
 #include <asm/dma.h>
 #include <asm/arch/dma.h>
-#include <asm/plat-s3c24xx/dma.h>
 
+#include <asm/plat-s3c24xx/dma.h>
 #include <asm/plat-s3c24xx/cpu.h>
 
 #include <asm/arch/regs-serial.h>
@@ -192,6 +192,7 @@ static struct s3c24xx_dma_order __initdata s3c2440_dma_order = {
 
 static int s3c2440_dma_add(struct sys_device *sysdev)
 {
+	s3c2410_dma_init();
 	s3c24xx_dma_order_set(&s3c2440_dma_order);
 	return s3c24xx_dma_init_map(&s3c2440_dma_sel);
 }

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 */

include/asm-arm/plat-s3c24xx/dma.h

@@ -68,3 +68,10 @@ struct s3c24xx_dma_order {
 };
 
 extern int s3c24xx_dma_order_set(struct s3c24xx_dma_order *map);
+
+/* DMA init code, called from the cpu support code */
+
+extern int s3c2410_dma_init(void);
+
+extern int s3c24xx_dma_init(unsigned int channels, unsigned int irq,
+			    unsigned int stride);