[ARM] tegra: Add APB DMA support

The APB DMA block handles DMA transfers to and from some peripherals
in the Tegra SOC.  It reads from sequential addresses on the memory
bus, and writes repeatedly to the same address on the APB bus.

Two transfer modes are supported, oneshot for transferring a known
size to or from a peripheral, and continuous for streaming data.
In continuous mode, a callback occurs when the buffer is half full
to allow the existing data to be handled and a new request queued.x

v2 changes:
	dma API no longer uses PTR_ERR

Signed-off-by: Erik Gilling <konkers@android.com>
Signed-off-by: Colin Cross <ccross@android.com>

arch/arm/mach-tegra/Kconfig

@@ -47,4 +47,11 @@ config TEGRA_DEBUG_UARTE
 
 endchoice
 
+config TEGRA_SYSTEM_DMA
+	bool "Enable system DMA driver for NVIDIA Tegra SoCs"
+	default y
+	help
+	  Adds system DMA functionality for NVIDIA Tegra SoCs, used by
+	  several Tegra device drivers
+
 endif

arch/arm/mach-tegra/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_ARCH_TEGRA_2x_SOC)         += tegra2_dvfs.o
 obj-$(CONFIG_ARCH_TEGRA_2x_SOC)		+= pinmux-t2-tables.o
 obj-$(CONFIG_SMP)                       += platsmp.o localtimer.o headsmp.o
 obj-$(CONFIG_HOTPLUG_CPU)               += hotplug.o
+obj-$(CONFIG_TEGRA_SYSTEM_DMA)		+= dma.o
 obj-$(CONFIG_CPU_FREQ)                  += cpu-tegra.o
 
 obj-${CONFIG_MACH_HARMONY}              += board-harmony.o

arch/arm/mach-tegra/common.c

@@ -19,10 +19,13 @@
 
 #include <linux/init.h>
 #include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
 
 #include <asm/hardware/cache-l2x0.h>
 
 #include <mach/iomap.h>
+#include <mach/dma.h>
 
 #include "board.h"
 #include "clock.h"
@@ -52,6 +55,7 @@ void __init tegra_init_cache(void)
 
 	l2x0_init(p, 0x6C080001, 0x8200c3fe);
 #endif
+
 }
 
 void __init tegra_common_init(void)
@@ -60,4 +64,7 @@ void __init tegra_common_init(void)
 	tegra_init_clock();
 	tegra_clk_init_from_table(common_clk_init_table);
 	tegra_init_cache();
+#ifdef CONFIG_TEGRA_SYSTEM_DMA
+	tegra_dma_init();
+#endif
 }