[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
 }

arch/arm/mach-tegra/include/mach/dma.h

+/*
+ * arch/arm/mach-tegra/include/mach/dma.h
+ *
+ * Copyright (c) 2008-2009, NVIDIA Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+#ifndef __MACH_TEGRA_DMA_H
+#define __MACH_TEGRA_DMA_H
+
+#include <linux/list.h>
+
+#if defined(CONFIG_TEGRA_SYSTEM_DMA)
+
+struct tegra_dma_req;
+struct tegra_dma_channel;
+
+#define TEGRA_DMA_REQ_SEL_CNTR			0
+#define TEGRA_DMA_REQ_SEL_I2S_2			1
+#define TEGRA_DMA_REQ_SEL_I2S_1			2
+#define TEGRA_DMA_REQ_SEL_SPD_I			3
+#define TEGRA_DMA_REQ_SEL_UI_I			4
+#define TEGRA_DMA_REQ_SEL_MIPI			5
+#define TEGRA_DMA_REQ_SEL_I2S2_2		6
+#define TEGRA_DMA_REQ_SEL_I2S2_1		7
+#define TEGRA_DMA_REQ_SEL_UARTA			8
+#define TEGRA_DMA_REQ_SEL_UARTB			9
+#define TEGRA_DMA_REQ_SEL_UARTC			10
+#define TEGRA_DMA_REQ_SEL_SPI			11
+#define TEGRA_DMA_REQ_SEL_AC97			12
+#define TEGRA_DMA_REQ_SEL_ACMODEM		13
+#define TEGRA_DMA_REQ_SEL_SL4B			14
+#define TEGRA_DMA_REQ_SEL_SL2B1			15
+#define TEGRA_DMA_REQ_SEL_SL2B2			16
+#define TEGRA_DMA_REQ_SEL_SL2B3			17
+#define TEGRA_DMA_REQ_SEL_SL2B4			18
+#define TEGRA_DMA_REQ_SEL_UARTD			19
+#define TEGRA_DMA_REQ_SEL_UARTE			20
+#define TEGRA_DMA_REQ_SEL_I2C			21
+#define TEGRA_DMA_REQ_SEL_I2C2			22
+#define TEGRA_DMA_REQ_SEL_I2C3			23
+#define TEGRA_DMA_REQ_SEL_DVC_I2C		24
+#define TEGRA_DMA_REQ_SEL_OWR			25
+#define TEGRA_DMA_REQ_SEL_INVALID		31
+
+enum tegra_dma_mode {
+	TEGRA_DMA_SHARED = 1,
+	TEGRA_DMA_MODE_CONTINOUS = 2,
+	TEGRA_DMA_MODE_ONESHOT = 4,
+};
+
+enum tegra_dma_req_error {
+	TEGRA_DMA_REQ_SUCCESS = 0,
+	TEGRA_DMA_REQ_ERROR_ABORTED,
+	TEGRA_DMA_REQ_INFLIGHT,
+};
+
+enum tegra_dma_req_buff_status {
+	TEGRA_DMA_REQ_BUF_STATUS_EMPTY = 0,
+	TEGRA_DMA_REQ_BUF_STATUS_HALF_FULL,
+	TEGRA_DMA_REQ_BUF_STATUS_FULL,
+};
+
+struct tegra_dma_req {
+	struct list_head node;
+	unsigned int modid;
+	int instance;
+
+	/* Called when the req is complete and from the DMA ISR context.
+	 * When this is called the req structure is no longer queued by
+	 * the DMA channel.
+	 *
+	 * State of the DMA depends on the number of req it has. If there are
+	 * no DMA requests queued up, then it will STOP the DMA. It there are
+	 * more requests in the DMA, then it will queue the next request.
+	 */
+	void (*complete)(struct tegra_dma_req *req);
+
+	/*  This is a called from the DMA ISR context when the DMA is still in
+	 *  progress and is actively filling same buffer.
+	 *
+	 *  In case of continous mode receive, this threshold is 1/2 the buffer
+	 *  size. In other cases, this will not even be called as there is no
+	 *  hardware support for it.
+	 *
+	 * In the case of continous mode receive, if there is next req already
+	 * queued, DMA programs the HW to use that req when this req is
+	 * completed. If there is no "next req" queued, then DMA ISR doesn't do
+	 * anything before calling this callback.
+	 *
+	 *	This is mainly used by the cases, where the clients has queued
+	 *	only one req and want to get some sort of DMA threshold
+	 *	callback to program the next buffer.
+	 *
+	 */
+	void (*threshold)(struct tegra_dma_req *req);
+
+	/* 1 to copy to memory.
+	 * 0 to copy from the memory to device FIFO */
+	int to_memory;
+
+	void *virt_addr;
+
+	unsigned long source_addr;
+	unsigned long dest_addr;
+	unsigned long dest_wrap;
+	unsigned long source_wrap;
+	unsigned long source_bus_width;
+	unsigned long dest_bus_width;
+	unsigned long req_sel;
+	unsigned int size;
+
+	/* Updated by the DMA driver on the conpletion of the request. */
+	int bytes_transferred;
+	int status;
+
+	/* DMA completion tracking information */
+	int buffer_status;
+
+	/* Client specific data */
+	void *dev;
+};
+
+int tegra_dma_enqueue_req(struct tegra_dma_channel *ch,
+	struct tegra_dma_req *req);
+int tegra_dma_dequeue_req(struct tegra_dma_channel *ch,
+	struct tegra_dma_req *req);
+void tegra_dma_dequeue(struct tegra_dma_channel *ch);
+void tegra_dma_flush(struct tegra_dma_channel *ch);
+
+bool tegra_dma_is_req_inflight(struct tegra_dma_channel *ch,
+	struct tegra_dma_req *req);
+bool tegra_dma_is_empty(struct tegra_dma_channel *ch);
+
+struct tegra_dma_channel *tegra_dma_allocate_channel(int mode);
+void tegra_dma_free_channel(struct tegra_dma_channel *ch);
+
+int __init tegra_dma_init(void);
+
+#endif
+
+#endif