1 files changed, 201 insertions, 0 deletions

diff --git a/arch/x86/include/asm/mca_dma.h b/arch/x86/include/asm/mca_dma.h
new file mode 100644
index 000000000000..49f22be237d2
--- /dev/null
+++ b/arch/x86/include/asm/mca_dma.h
@@ -0,0 +1,201 @@
+#ifndef ASM_X86__MCA_DMA_H
+#define ASM_X86__MCA_DMA_H
+
+#include <asm/io.h>
+#include <linux/ioport.h>
+
+/*
+ * Microchannel specific DMA stuff.  DMA on an MCA machine is fairly similar to
+ *   standard PC dma, but it certainly has its quirks.  DMA register addresses
+ *   are in a different place and there are some added functions.  Most of this
+ *   should be pretty obvious on inspection.  Note that the user must divide
+ *   count by 2 when using 16-bit dma; that is not handled by these functions.
+ *
+ * Ramen Noodles are yummy.
+ *
+ *  1998 Tymm Twillman <tymm@computer.org>
+ */
+
+/*
+ * Registers that are used by the DMA controller; FN is the function register
+ *   (tell the controller what to do) and EXE is the execution register (how
+ *   to do it)
+ */
+
+#define MCA_DMA_REG_FN  0x18
+#define MCA_DMA_REG_EXE 0x1A
+
+/*
+ * Functions that the DMA controller can do
+ */
+
+#define MCA_DMA_FN_SET_IO       0x00
+#define MCA_DMA_FN_SET_ADDR     0x20
+#define MCA_DMA_FN_GET_ADDR     0x30
+#define MCA_DMA_FN_SET_COUNT    0x40
+#define MCA_DMA_FN_GET_COUNT    0x50
+#define MCA_DMA_FN_GET_STATUS   0x60
+#define MCA_DMA_FN_SET_MODE     0x70
+#define MCA_DMA_FN_SET_ARBUS    0x80
+#define MCA_DMA_FN_MASK         0x90
+#define MCA_DMA_FN_RESET_MASK   0xA0
+#define MCA_DMA_FN_MASTER_CLEAR 0xD0
+
+/*
+ * Modes (used by setting MCA_DMA_FN_MODE in the function register)
+ *
+ * Note that the MODE_READ is read from memory (write to device), and
+ *   MODE_WRITE is vice-versa.
+ */
+
+#define MCA_DMA_MODE_XFER  0x04  /* read by default */
+#define MCA_DMA_MODE_READ  0x04  /* same as XFER */
+#define MCA_DMA_MODE_WRITE 0x08  /* OR with MODE_XFER to use */
+#define MCA_DMA_MODE_IO    0x01  /* DMA from IO register */
+#define MCA_DMA_MODE_16    0x40  /* 16 bit xfers */
+
+
+/**
+ *      mca_enable_dma  -       channel to enable DMA on
+ *      @dmanr: DMA channel
+ *
+ *      Enable the MCA bus DMA on a channel. This can be called from
+ *      IRQ context.
+ */
+
+static inline void mca_enable_dma(unsigned int dmanr)
+{
+        outb(MCA_DMA_FN_RESET_MASK | dmanr, MCA_DMA_REG_FN);
+}
+
+/**
+ *      mca_disble_dma  -       channel to disable DMA on
+ *      @dmanr: DMA channel
+ *
+ *      Enable the MCA bus DMA on a channel. This can be called from
+ *      IRQ context.
+ */
+
+static inline void mca_disable_dma(unsigned int dmanr)
+{
+        outb(MCA_DMA_FN_MASK | dmanr, MCA_DMA_REG_FN);
+}
+
+/**
+ *      mca_set_dma_addr -      load a 24bit DMA address
+ *      @dmanr: DMA channel
+ *      @a: 24bit bus address
+ *
+ *      Load the address register in the DMA controller. This has a 24bit
+ *      limitation (16Mb).
+ */
+
+static inline void mca_set_dma_addr(unsigned int dmanr, unsigned int a)
+{
+        outb(MCA_DMA_FN_SET_ADDR | dmanr, MCA_DMA_REG_FN);
+        outb(a & 0xff, MCA_DMA_REG_EXE);
+        outb((a >> 8) & 0xff, MCA_DMA_REG_EXE);
+        outb((a >> 16) & 0xff, MCA_DMA_REG_EXE);
+}
+
+/**
+ *      mca_get_dma_addr -      load a 24bit DMA address
+ *      @dmanr: DMA channel
+ *
+ *      Read the address register in the DMA controller. This has a 24bit
+ *      limitation (16Mb). The return is a bus address.
+ */
+
+static inline unsigned int mca_get_dma_addr(unsigned int dmanr)
+{
+        unsigned int addr;
+
+        outb(MCA_DMA_FN_GET_ADDR | dmanr, MCA_DMA_REG_FN);
+        addr = inb(MCA_DMA_REG_EXE);
+        addr |= inb(MCA_DMA_REG_EXE) << 8;
+        addr |= inb(MCA_DMA_REG_EXE) << 16;
+
+        return addr;
+}
+
+/**
+ *      mca_set_dma_count -     load a 16bit transfer count
+ *      @dmanr: DMA channel
+ *      @count: count
+ *
+ *      Set the DMA count for this channel. This can be up to 64Kbytes.
+ *      Setting a count of zero will not do what you expect.
+ */
+
+static inline void mca_set_dma_count(unsigned int dmanr, unsigned int count)
+{
+        count--;  /* transfers one more than count -- correct for this */
+
+        outb(MCA_DMA_FN_SET_COUNT | dmanr, MCA_DMA_REG_FN);
+        outb(count & 0xff, MCA_DMA_REG_EXE);
+        outb((count >> 8) & 0xff, MCA_DMA_REG_EXE);
+}
+
+/**
+ *      mca_get_dma_residue -   get the remaining bytes to transfer
+ *      @dmanr: DMA channel
+ *
+ *      This function returns the number of bytes left to transfer
+ *      on this DMA channel.
+ */
+
+static inline unsigned int mca_get_dma_residue(unsigned int dmanr)
+{
+        unsigned short count;
+
+        outb(MCA_DMA_FN_GET_COUNT | dmanr, MCA_DMA_REG_FN);
+        count = 1 + inb(MCA_DMA_REG_EXE);
+        count += inb(MCA_DMA_REG_EXE) << 8;
+
+        return count;
+}
+
+/**
+ *      mca_set_dma_io -        set the port for an I/O transfer
+ *      @dmanr: DMA channel
+ *      @io_addr: an I/O port number
+ *
+ *      Unlike the ISA bus DMA controllers the DMA on MCA bus can transfer
+ *      with an I/O port target.
+ */
+
+static inline void mca_set_dma_io(unsigned int dmanr, unsigned int io_addr)
+{
+        /*
+         * DMA from a port address -- set the io address
+         */
+
+        outb(MCA_DMA_FN_SET_IO | dmanr, MCA_DMA_REG_FN);
+        outb(io_addr & 0xff, MCA_DMA_REG_EXE);
+        outb((io_addr >>  8) & 0xff, MCA_DMA_REG_EXE);
+}
+
+/**
+ *      mca_set_dma_mode -      set the DMA mode
+ *      @dmanr: DMA channel
+ *      @mode: mode to set
+ *
+ *      The DMA controller supports several modes. The mode values you can
+ *      set are-
+ *
+ *      %MCA_DMA_MODE_READ when reading from the DMA device.
+ *
+ *      %MCA_DMA_MODE_WRITE to writing to the DMA device.
+ *
+ *      %MCA_DMA_MODE_IO to do DMA to or from an I/O port.
+ *
+ *      %MCA_DMA_MODE_16 to do 16bit transfers.
+ */
+
+static inline void mca_set_dma_mode(unsigned int dmanr, unsigned int mode)
+{
+        outb(MCA_DMA_FN_SET_MODE | dmanr, MCA_DMA_REG_FN);
+        outb(mode, MCA_DMA_REG_EXE);
+}
+
+#endif /* ASM_X86__MCA_DMA_H */