ARM: footbridge: move isa-dma support into footbridge

The dma-isa.c was shared between footbridge and shark a long time ago,
but as shark was removed, it can be made footbridge specific again.

The fb_dma bits in turn are not used at all and can be removed.

All the ISA related files are now built into the platform regardless
of CONFIG_ISA, as they just refer to on-chip devices rather than actual
ISA cards.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

5 files changed, 231 insertions, 71 deletions

diff --git a/arch/arm/mach-footbridge/Kconfig b/arch/arm/mach-footbridge/Kconfig
index 3497ea8e91e3..1a3676109654 100644
--- a/arch/arm/mach-footbridge/Kconfig
+++ b/arch/arm/mach-footbridge/Kconfig
@@ -48,7 +48,7 @@ config FOOTBRIDGE
 	def_bool y
 	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_MIGHT_HAVE_PC_SERIO
-	select ISA_DMA
+	select ISA_DMA_API
 
 config ARCH_EBSA285
 	bool
diff --git a/arch/arm/mach-footbridge/Makefile b/arch/arm/mach-footbridge/Makefile
index 30bae6684dce..55d570739f19 100644
--- a/arch/arm/mach-footbridge/Makefile
+++ b/arch/arm/mach-footbridge/Makefile
@@ -5,7 +5,7 @@
 
 # Object file lists.
 
-obj-y			:= common.o dma.o isa-irq.o
+obj-y			:= common.o isa-irq.o isa.o isa-rtc.o dma-isa.o
 
 pci-y			+= dc21285.o
 pci-$(CONFIG_ARCH_CATS) += cats-pci.o
@@ -18,4 +18,3 @@ obj-$(CONFIG_ARCH_NETWINDER) += netwinder-hw.o isa-timer.o
 
 obj-$(CONFIG_PCI)	+=$(pci-y)
 
-obj-$(CONFIG_ISA)	+= isa.o isa-rtc.o
diff --git a/arch/arm/mach-footbridge/dma-isa.c b/arch/arm/mach-footbridge/dma-isa.c
new file mode 100644
index 000000000000..0fc0705fd58b
--- /dev/null
+++ b/arch/arm/mach-footbridge/dma-isa.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright (C) 1999-2000 Russell King
+ *
+ *  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 struct device isa_dma_dev = {
+	.init_name		= "fallback device",
+	.coherent_dma_mask	= ~(dma_addr_t)0,
+	.dma_mask		= &isa_dma_dev.coherent_dma_mask,
+};
+
+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(&isa_dma_dev,
+				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
+ */
+static int __init isa_dma_init(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");
+	}
+
+	return 0;
+}
+core_initcall(isa_dma_init);
diff --git a/arch/arm/mach-footbridge/dma.c b/arch/arm/mach-footbridge/dma.c
deleted file mode 100644
index 228757c8e06f..000000000000
--- a/arch/arm/mach-footbridge/dma.c
+++ /dev/null
@@ -1,57 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- *  linux/arch/arm/kernel/dma-ebsa285.c
- *
- *  Copyright (C) 1998 Phil Blundell
- *
- * DMA functions specific to EBSA-285/CATS architectures
- *
- *  Changelog:
- *   09-Nov-1998 RMK	Split out ISA DMA functions to dma-isa.c
- *   17-Mar-1999 RMK	Allow any EBSA285-like architecture to have
- *			ISA DMA controllers.
- */
-#include <linux/init.h>
-#include <linux/io.h>
-#include <linux/spinlock.h>
-#include <linux/scatterlist.h>
-
-#include <asm/dma.h>
-
-#include <asm/mach/dma.h>
-#include <asm/hardware/dec21285.h>
-
-#if 0
-static int fb_dma_request(unsigned int chan, dma_t *dma)
-{
-	return -EINVAL;
-}
-
-static void fb_dma_enable(unsigned int chan, dma_t *dma)
-{
-}
-
-static void fb_dma_disable(unsigned int chan, dma_t *dma)
-{
-}
-
-static struct dma_ops fb_dma_ops = {
-	.type		= "fb",
-	.request	= fb_dma_request,
-	.enable		= fb_dma_enable,
-	.disable	= fb_dma_disable,
-};
-#endif
-
-static int __init fb_dma_init(void)
-{
-#if 0
-	dma[_DC21285_DMA(0)].d_ops = &fb_dma_ops;
-	dma[_DC21285_DMA(1)].d_ops = &fb_dma_ops;
-#endif
-#ifdef CONFIG_ISA_DMA
-	isa_init_dma();
-#endif
-	return 0;
-}
-core_initcall(fb_dma_init);
diff --git a/arch/arm/mach-footbridge/include/mach/isa-dma.h b/arch/arm/mach-footbridge/include/mach/isa-dma.h
index 8a1b991076e1..b10731a1f66a 100644
--- a/arch/arm/mach-footbridge/include/mach/isa-dma.h
+++ b/arch/arm/mach-footbridge/include/mach/isa-dma.h
@@ -10,17 +10,9 @@
 #ifndef __ASM_ARCH_DMA_H
 #define __ASM_ARCH_DMA_H
 
-/*
- * The 21285 has two internal DMA channels; we call these 8 and 9.
- * On CATS hardware we have an additional eight ISA dma channels
- * numbered 0..7.
- */
-#define _ISA_DMA(x)		(0+(x))
-#define _DC21285_DMA(x)		(8+(x))
-
-#define MAX_DMA_CHANNELS	10
+#define MAX_DMA_CHANNELS	8
 
-#define DMA_FLOPPY		_ISA_DMA(2)
-#define DMA_ISA_CASCADE		_ISA_DMA(4)
+#define DMA_FLOPPY		(2)
+#define DMA_ISA_CASCADE		(4)
 
 #endif /* _ASM_ARCH_DMA_H */