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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/arm/kernel/dma-isa.c
Initial import
Diffstat (limited to 'arch/arm/kernel/dma-isa.c')
-rw-r--r--arch/arm/kernel/dma-isa.c222
1 files changed, 222 insertions, 0 deletions
diff --git a/arch/arm/kernel/dma-isa.c b/arch/arm/kernel/dma-isa.c
new file mode 100644
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+++ b/arch/arm/kernel/dma-isa.c
@@ -0,0 +1,222 @@
+/*
+ * linux/arch/arm/kernel/dma-isa.c
+ *
+ * Copyright (C) 1999-2000 Russell King
+ *
+ * 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.
+ *
+ * ISA DMA primitives
+ * 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/ioport.h>
+#include <linux/init.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+#include <asm/dma.h>
+#include <asm/mach/dma.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 }
+};
+
+static int isa_get_dma_residue(unsigned int chan, dma_t *dma)
+{
+ unsigned int io_port = isa_dma_port[chan][ISA_DMA_COUNT];
+ int count;
+
+ count = 1 + inb(io_port);
+ count |= inb(io_port) << 8;
+
+ return chan < 4 ? count : (count << 1);
+}
+
+static void isa_enable_dma(unsigned int chan, dma_t *dma)
+{
+ if (dma->invalid) {
+ unsigned long address, length;
+ unsigned int mode;
+ enum dma_data_direction direction;
+
+ mode = (chan & 3) | dma->dma_mode;
+ switch (dma->dma_mode & DMA_MODE_MASK) {
+ case DMA_MODE_READ:
+ direction = DMA_FROM_DEVICE;
+ break;
+
+ case DMA_MODE_WRITE:
+ direction = DMA_TO_DEVICE;
+ break;
+
+ case DMA_MODE_CASCADE:
+ direction = DMA_BIDIRECTIONAL;
+ break;
+
+ default:
+ direction = DMA_NONE;
+ break;
+ }
+
+ if (!dma->sg) {
+ /*
+ * Cope with ISA-style drivers which expect cache
+ * coherence.
+ */
+ dma->sg = &dma->buf;
+ dma->sgcount = 1;
+ dma->buf.length = dma->count;
+ dma->buf.dma_address = dma_map_single(NULL,
+ dma->addr, dma->count,
+ direction);
+ }
+
+ address = dma->buf.dma_address;
+ length = dma->buf.length - 1;
+
+ outb(address >> 16, isa_dma_port[chan][ISA_DMA_PGLO]);
+ outb(address >> 24, isa_dma_port[chan][ISA_DMA_PGHI]);
+
+ if (chan >= 4) {
+ address >>= 1;
+ length >>= 1;
+ }
+
+ outb(0, isa_dma_port[chan][ISA_DMA_CLRFF]);
+
+ outb(address, isa_dma_port[chan][ISA_DMA_ADDR]);
+ outb(address >> 8, isa_dma_port[chan][ISA_DMA_ADDR]);
+
+ outb(length, isa_dma_port[chan][ISA_DMA_COUNT]);
+ outb(length >> 8, isa_dma_port[chan][ISA_DMA_COUNT]);
+
+ outb(mode, isa_dma_port[chan][ISA_DMA_MODE]);
+ dma->invalid = 0;
+ }
+ outb(chan & 3, isa_dma_port[chan][ISA_DMA_MASK]);
+}
+
+static void isa_disable_dma(unsigned int chan, dma_t *dma)
+{
+ outb(chan | 4, isa_dma_port[chan][ISA_DMA_MASK]);
+}
+
+static struct dma_ops isa_dma_ops = {
+ .type = "ISA",
+ .enable = isa_enable_dma,
+ .disable = isa_disable_dma,
+ .residue = isa_get_dma_residue,
+};
+
+static struct resource dma_resources[] = { {
+ .name = "dma1",
+ .start = 0x0000,
+ .end = 0x000f
+}, {
+ .name = "dma low page",
+ .start = 0x0080,
+ .end = 0x008f
+}, {
+ .name = "dma2",
+ .start = 0x00c0,
+ .end = 0x00df
+}, {
+ .name = "dma high page",
+ .start = 0x0480,
+ .end = 0x048f
+} };
+
+static dma_t isa_dma[8];
+
+/*
+ * ISA DMA always starts at channel 0
+ */
+void __init isa_init_dma(void)
+{
+ /*
+ * Try to autodetect presence of an ISA DMA controller.
+ * We do some minimal initialisation, and check that
+ * channel 0's DMA address registers are writeable.
+ */
+ outb(0xff, 0x0d);
+ outb(0xff, 0xda);
+
+ /*
+ * Write high and low address, and then read them back
+ * in the same order.
+ */
+ outb(0x55, 0x00);
+ outb(0xaa, 0x00);
+
+ if (inb(0) == 0x55 && inb(0) == 0xaa) {
+ unsigned int chan, i;
+
+ for (chan = 0; chan < 8; chan++) {
+ isa_dma[chan].d_ops = &isa_dma_ops;
+ isa_disable_dma(chan, NULL);
+ }
+
+ outb(0x40, 0x0b);
+ outb(0x41, 0x0b);
+ outb(0x42, 0x0b);
+ outb(0x43, 0x0b);
+
+ outb(0xc0, 0xd6);
+ outb(0x41, 0xd6);
+ outb(0x42, 0xd6);
+ outb(0x43, 0xd6);
+
+ outb(0, 0xd4);
+
+ outb(0x10, 0x08);
+ outb(0x10, 0xd0);
+
+ /*
+ * Is this correct? According to my documentation, it
+ * doesn't appear to be. It should be:
+ * outb(0x3f, 0x40b); outb(0x3f, 0x4d6);
+ */
+ outb(0x30, 0x40b);
+ outb(0x31, 0x40b);
+ outb(0x32, 0x40b);
+ outb(0x33, 0x40b);
+ outb(0x31, 0x4d6);
+ outb(0x32, 0x4d6);
+ outb(0x33, 0x4d6);
+
+ for (i = 0; i < ARRAY_SIZE(dma_resources); i++)
+ request_resource(&ioport_resource, dma_resources + i);
+
+ for (chan = 0; chan < 8; chan++) {
+ int ret = isa_dma_add(chan, &isa_dma[chan]);
+ if (ret)
+ pr_err("ISADMA%u: unable to register: %d\n",
+ chan, ret);
+ }
+
+ request_dma(DMA_ISA_CASCADE, "cascade");
+ }
+}