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 <[e-mail]>
Tested-by: Marc Zyngier <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>

arch/arm/Kconfig

···
 	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
 	  newer boards don't support it.  If you have ISA, say Y, otherwise N.
 
-# Select ISA DMA controller support
-config ISA_DMA
-	bool
-	select ISA_DMA_API
-
 # Select ISA DMA interface
 config ISA_DMA_API
 	bool

arch/arm/include/asm/mach/dma.h

···
  * isa_dma_add - add an ISA-style DMA channel
  */
 extern int isa_dma_add(unsigned int, dma_t *dma);
-
-/*
- * Add the ISA DMA controller.  Always takes channels 0-7.
- */
-extern void isa_init_dma(void);

arch/arm/kernel/Makefile

···
 obj-$(CONFIG_FIQ)		+= fiq.o fiqasm.o
 obj-$(CONFIG_MODULES)		+= armksyms.o module.o
 obj-$(CONFIG_ARM_MODULE_PLTS)	+= module-plts.o
-obj-$(CONFIG_ISA_DMA)		+= dma-isa.o
 obj-$(CONFIG_PCI)		+= bios32.o isa.o
 obj-$(CONFIG_ARM_CPU_SUSPEND)	+= sleep.o suspend.o
 obj-$(CONFIG_HIBERNATION)	+= hibernate.o

arch/arm/kernel/dma-isa.c arch/arm/mach-footbridge/dma-isa.c

···
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- *  linux/arch/arm/kernel/dma-isa.c
- *
  *  Copyright (C) 1999-2000 Russell King
  *
  *  ISA DMA primitives
···
 /*
  * ISA DMA always starts at channel 0
  */
-void __init isa_init_dma(void)
+static int __init isa_dma_init(void)
 {
 	/*
 	 * Try to autodetect presence of an ISA DMA controller.
···
 
 		request_dma(DMA_ISA_CASCADE, "cascade");
 	}
+
+	return 0;
 }
+core_initcall(isa_dma_init);

arch/arm/mach-footbridge/Kconfig

···
 	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

arch/arm/mach-footbridge/Makefile

···
 
 # 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
···
 
 obj-$(CONFIG_PCI)	+=$(pci-y)
 
-obj-$(CONFIG_ISA)	+= isa.o isa-rtc.o

arch/arm/mach-footbridge/dma.c

···
-// 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);

arch/arm/mach-footbridge/include/mach/isa-dma.h

···
 #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	8
 
-#define MAX_DMA_CHANNELS	10
-
-#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 */