dmaengine: mxs-dma: add dma support for i.MX23/28

This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.

* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
  instances.

* apbh-dma is different between mx23 and mx28, hardware version
  register is used to differentiate.

* mxs-dma supports pio function besides data transfer.  The driver
  uses dma_data_direction DMA_NONE to identify the pio mode, and
  steals sgl and sg_len to get pio words and numbers from clients.

* mxs dmaengine has some very specific features, like sense function
  and the special NAND support (nand_lock, nand_wait4ready).  These
  are too specific to implemented in generic dmaengine driver.

* The driver refers to imx-sdma and only a single descriptor is
  statically assigned to each channel.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/arm/mach-mxs/include/mach/dma.h b/arch/arm/mach-mxs/include/mach/dma.h
new file mode 100644
index 000000000000..7f4aeeaba8df
--- /dev/null
+++ b/arch/arm/mach-mxs/include/mach/dma.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __MACH_MXS_DMA_H__
+#define __MACH_MXS_DMA_H__
+
+struct mxs_dma_data {
+        int chan_irq;
+};
+
+static inline int mxs_dma_is_apbh(struct dma_chan *chan)
+{
+        return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbh");
+}
+
+static inline int mxs_dma_is_apbx(struct dma_chan *chan)
+{
+        return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbx");
+}
+
+#endif /* __MACH_MXS_DMA_H__ */