patch-2.1.132 linux/arch/arm/kernel/dma-isa.c

• Lines: 108
• Date: Thu Dec 17 09:05:42 1998
• Orig file: v2.1.131/linux/arch/arm/kernel/dma-isa.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.131/linux/arch/arm/kernel/dma-isa.c linux/arch/arm/kernel/dma-isa.c
@@ -0,0 +1,107 @@
+/*
+ * arch/arm/kernel/dma-isa.c: ISA DMA primitives
+ *
+ * Copyright (C) Russell King
+ *
+ * Taken from various sources, including:
+ *  linux/include/asm/dma.h: Defines for using and allocating dma channels.
+ *    Written by Hennus Bergman, 1992.
+ *    High DMA channel support & info by Hannu Savolainen and John Boyd, Nov. 1992.
+ *  arch/arm/kernel/dma-ebsa285.c
+ *  Copyright (C) 1998 Phil Blundell
+ */
+#include <linux/sched.h>
+
+#include <asm/dma.h>
+#include <asm/io.h>
+
+#include "dma.h"
+#include "dma-isa.h"
+
+#define ISA_DMA_MASK		0
+#define ISA_DMA_MODE		1
+#define ISA_DMA_CLRFF		2
+#define ISA_DMA_PGHI		3
+#define ISA_DMA_PGLO		4
+#define ISA_DMA_ADDR		5
+#define ISA_DMA_COUNT		6
+
+static unsigned int isa_dma_port[8][7] = {
+	/* MASK   MODE   CLRFF  PAGE_HI PAGE_LO ADDR COUNT */
+	{  0x0a,  0x0b,  0x0c,  0x487,  0x087,  0x00, 0x01 },
+	{  0x0a,  0x0b,  0x0c,  0x483,  0x083,  0x02, 0x03 },
+	{  0x0a,  0x0b,  0x0c,  0x481,  0x081,  0x04, 0x05 },
+	{  0x0a,  0x0b,  0x0c,  0x482,  0x082,  0x06, 0x07 },
+	{  0xd4,  0xd6,  0xd8,  0x000,  0x000,  0xc0, 0xc2 },
+	{  0xd4,  0xd6,  0xd8,  0x48b,  0x08b,  0xc4, 0xc6 },
+	{  0xd4,  0xd6,  0xd8,  0x489,  0x089,  0xc8, 0xca },
+	{  0xd4,  0xd6,  0xd8,  0x48a,  0x08a,  0xcc, 0xce }
+};
+
+int isa_request_dma(int channel, dma_t *dma, const char *dev_name)
+{
+	if (channel != 4)
+		return 0;
+
+	return -EINVAL;
+}
+
+void isa_free_dma(int channel, dma_t *dma)
+{
+	/* nothing to do */
+}
+
+int isa_get_dma_residue(int channel, dma_t *dma)
+{
+	unsigned int io_port = isa_dma_port[channel][ISA_DMA_COUNT];
+	int count;
+
+	count = 1 + inb(io_port) + (inb(io_port) << 8);
+
+	return channel < 4 ? count : (count << 1);
+}
+
+void isa_enable_dma(int channel, dma_t *dma)
+{
+	unsigned long address, length;
+
+	if (dma->invalid) {
+		address = dma->buf.address;
+		length  = dma->buf.length - 1;
+
+		outb(address >> 24, isa_dma_port[channel][ISA_DMA_PGHI]);
+		outb(address >> 16, isa_dma_port[channel][ISA_DMA_PGLO]);
+
+		if (channel >= 4) {
+			address >>= 1;
+			length = (length >> 1) & 0xfe; /* why &0xfe? */
+		}
+
+		outb(0, isa_dma_port[channel][ISA_DMA_CLRFF]);
+
+		outb(address, isa_dma_port[channel][ISA_DMA_ADDR]);
+		outb(address >> 8, isa_dma_port[channel][ISA_DMA_ADDR]);
+
+		outb(length, isa_dma_port[channel][ISA_DMA_COUNT]);
+		outb(length >> 8, isa_dma_port[channel][ISA_DMA_COUNT]);
+
+		outb(dma->dma_mode | (channel & 3), isa_dma_port[channel][ISA_DMA_MODE]);
+
+		switch (dma->dma_mode) {
+		case DMA_MODE_READ:
+			dma_cache_inv(__bus_to_virt(dma->buf.address), dma->buf.length);
+			break;
+
+		case DMA_MODE_WRITE:
+			dma_cache_wback(__bus_to_virt(dma->buf.address), dma->buf.length);
+			break;
+		}
+		dma->invalid = 0;
+	}
+	outb(channel & 3, isa_dma_port[channel][ISA_DMA_MASK]);
+}
+
+void isa_disable_dma(int channel, dma_t *dma)
+{
+	outb(channel | 4, isa_dma_port[channel][ISA_DMA_MASK]);
+}