|  | /* | 
|  | *  linux/arch/arm/mach-rpc/dma.c | 
|  | * | 
|  | *  Copyright (C) 1998 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. | 
|  | * | 
|  | *  DMA functions specific to RiscPC architecture | 
|  | */ | 
|  | #include <linux/slab.h> | 
|  | #include <linux/mman.h> | 
|  | #include <linux/init.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/dma-mapping.h> | 
|  | #include <linux/io.h> | 
|  |  | 
|  | #include <asm/page.h> | 
|  | #include <asm/dma.h> | 
|  | #include <asm/fiq.h> | 
|  | #include <asm/irq.h> | 
|  | #include <mach/hardware.h> | 
|  | #include <asm/uaccess.h> | 
|  |  | 
|  | #include <asm/mach/dma.h> | 
|  | #include <asm/hardware/iomd.h> | 
|  |  | 
|  | struct iomd_dma { | 
|  | struct dma_struct	dma; | 
|  | unsigned int		state; | 
|  | unsigned long		base;		/* Controller base address */ | 
|  | int			irq;		/* Controller IRQ */ | 
|  | struct scatterlist	cur_sg;		/* Current controller buffer */ | 
|  | dma_addr_t		dma_addr; | 
|  | unsigned int		dma_len; | 
|  | }; | 
|  |  | 
|  | #if 0 | 
|  | typedef enum { | 
|  | dma_size_8	= 1, | 
|  | dma_size_16	= 2, | 
|  | dma_size_32	= 4, | 
|  | dma_size_128	= 16 | 
|  | } dma_size_t; | 
|  | #endif | 
|  |  | 
|  | #define TRANSFER_SIZE	2 | 
|  |  | 
|  | #define CURA	(0) | 
|  | #define ENDA	(IOMD_IO0ENDA - IOMD_IO0CURA) | 
|  | #define CURB	(IOMD_IO0CURB - IOMD_IO0CURA) | 
|  | #define ENDB	(IOMD_IO0ENDB - IOMD_IO0CURA) | 
|  | #define CR	(IOMD_IO0CR - IOMD_IO0CURA) | 
|  | #define ST	(IOMD_IO0ST - IOMD_IO0CURA) | 
|  |  | 
|  | static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma) | 
|  | { | 
|  | unsigned long end, offset, flags = 0; | 
|  |  | 
|  | if (idma->dma.sg) { | 
|  | sg->dma_address = idma->dma_addr; | 
|  | offset = sg->dma_address & ~PAGE_MASK; | 
|  |  | 
|  | end = offset + idma->dma_len; | 
|  |  | 
|  | if (end > PAGE_SIZE) | 
|  | end = PAGE_SIZE; | 
|  |  | 
|  | if (offset + TRANSFER_SIZE >= end) | 
|  | flags |= DMA_END_L; | 
|  |  | 
|  | sg->length = end - TRANSFER_SIZE; | 
|  |  | 
|  | idma->dma_len -= end - offset; | 
|  | idma->dma_addr += end - offset; | 
|  |  | 
|  | if (idma->dma_len == 0) { | 
|  | if (idma->dma.sgcount > 1) { | 
|  | idma->dma.sg = sg_next(idma->dma.sg); | 
|  | idma->dma_addr = idma->dma.sg->dma_address; | 
|  | idma->dma_len = idma->dma.sg->length; | 
|  | idma->dma.sgcount--; | 
|  | } else { | 
|  | idma->dma.sg = NULL; | 
|  | flags |= DMA_END_S; | 
|  | } | 
|  | } | 
|  | } else { | 
|  | flags = DMA_END_S | DMA_END_L; | 
|  | sg->dma_address = 0; | 
|  | sg->length = 0; | 
|  | } | 
|  |  | 
|  | sg->length |= flags; | 
|  | } | 
|  |  | 
|  | static irqreturn_t iomd_dma_handle(int irq, void *dev_id) | 
|  | { | 
|  | struct iomd_dma *idma = dev_id; | 
|  | unsigned long base = idma->base; | 
|  |  | 
|  | do { | 
|  | unsigned int status; | 
|  |  | 
|  | status = iomd_readb(base + ST); | 
|  | if (!(status & DMA_ST_INT)) | 
|  | return IRQ_HANDLED; | 
|  |  | 
|  | if ((idma->state ^ status) & DMA_ST_AB) | 
|  | iomd_get_next_sg(&idma->cur_sg, idma); | 
|  |  | 
|  | switch (status & (DMA_ST_OFL | DMA_ST_AB)) { | 
|  | case DMA_ST_OFL:			/* OIA */ | 
|  | case DMA_ST_AB:				/* .IB */ | 
|  | iomd_writel(idma->cur_sg.dma_address, base + CURA); | 
|  | iomd_writel(idma->cur_sg.length, base + ENDA); | 
|  | idma->state = DMA_ST_AB; | 
|  | break; | 
|  |  | 
|  | case DMA_ST_OFL | DMA_ST_AB:		/* OIB */ | 
|  | case 0:					/* .IA */ | 
|  | iomd_writel(idma->cur_sg.dma_address, base + CURB); | 
|  | iomd_writel(idma->cur_sg.length, base + ENDB); | 
|  | idma->state = 0; | 
|  | break; | 
|  | } | 
|  |  | 
|  | if (status & DMA_ST_OFL && | 
|  | idma->cur_sg.length == (DMA_END_S|DMA_END_L)) | 
|  | break; | 
|  | } while (1); | 
|  |  | 
|  | idma->state = ~DMA_ST_AB; | 
|  | disable_irq(irq); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | static int iomd_request_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); | 
|  |  | 
|  | return request_irq(idma->irq, iomd_dma_handle, | 
|  | IRQF_DISABLED, idma->dma.device_id, idma); | 
|  | } | 
|  |  | 
|  | static void iomd_free_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); | 
|  |  | 
|  | free_irq(idma->irq, idma); | 
|  | } | 
|  |  | 
|  | static void iomd_enable_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); | 
|  | unsigned long dma_base = idma->base; | 
|  | unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E; | 
|  |  | 
|  | if (idma->dma.invalid) { | 
|  | idma->dma.invalid = 0; | 
|  |  | 
|  | /* | 
|  | * Cope with ISA-style drivers which expect cache | 
|  | * coherence. | 
|  | */ | 
|  | if (!idma->dma.sg) { | 
|  | idma->dma.sg = &idma->dma.buf; | 
|  | idma->dma.sgcount = 1; | 
|  | idma->dma.buf.length = idma->dma.count; | 
|  | idma->dma.buf.dma_address = dma_map_single(NULL, | 
|  | idma->dma.addr, idma->dma.count, | 
|  | idma->dma.dma_mode == DMA_MODE_READ ? | 
|  | DMA_FROM_DEVICE : DMA_TO_DEVICE); | 
|  | } | 
|  |  | 
|  | iomd_writeb(DMA_CR_C, dma_base + CR); | 
|  | idma->state = DMA_ST_AB; | 
|  | } | 
|  |  | 
|  | if (idma->dma.dma_mode == DMA_MODE_READ) | 
|  | ctrl |= DMA_CR_D; | 
|  |  | 
|  | iomd_writeb(ctrl, dma_base + CR); | 
|  | enable_irq(idma->irq); | 
|  | } | 
|  |  | 
|  | static void iomd_disable_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); | 
|  | unsigned long dma_base = idma->base; | 
|  | unsigned long flags; | 
|  |  | 
|  | local_irq_save(flags); | 
|  | if (idma->state != ~DMA_ST_AB) | 
|  | disable_irq(idma->irq); | 
|  | iomd_writeb(0, dma_base + CR); | 
|  | local_irq_restore(flags); | 
|  | } | 
|  |  | 
|  | static int iomd_set_dma_speed(unsigned int chan, dma_t *dma, int cycle) | 
|  | { | 
|  | int tcr, speed; | 
|  |  | 
|  | if (cycle < 188) | 
|  | speed = 3; | 
|  | else if (cycle <= 250) | 
|  | speed = 2; | 
|  | else if (cycle < 438) | 
|  | speed = 1; | 
|  | else | 
|  | speed = 0; | 
|  |  | 
|  | tcr = iomd_readb(IOMD_DMATCR); | 
|  | speed &= 3; | 
|  |  | 
|  | switch (chan) { | 
|  | case DMA_0: | 
|  | tcr = (tcr & ~0x03) | speed; | 
|  | break; | 
|  |  | 
|  | case DMA_1: | 
|  | tcr = (tcr & ~0x0c) | (speed << 2); | 
|  | break; | 
|  |  | 
|  | case DMA_2: | 
|  | tcr = (tcr & ~0x30) | (speed << 4); | 
|  | break; | 
|  |  | 
|  | case DMA_3: | 
|  | tcr = (tcr & ~0xc0) | (speed << 6); | 
|  | break; | 
|  |  | 
|  | default: | 
|  | break; | 
|  | } | 
|  |  | 
|  | iomd_writeb(tcr, IOMD_DMATCR); | 
|  |  | 
|  | return speed; | 
|  | } | 
|  |  | 
|  | static struct dma_ops iomd_dma_ops = { | 
|  | .type		= "IOMD", | 
|  | .request	= iomd_request_dma, | 
|  | .free		= iomd_free_dma, | 
|  | .enable		= iomd_enable_dma, | 
|  | .disable	= iomd_disable_dma, | 
|  | .setspeed	= iomd_set_dma_speed, | 
|  | }; | 
|  |  | 
|  | static struct fiq_handler fh = { | 
|  | .name	= "floppydma" | 
|  | }; | 
|  |  | 
|  | struct floppy_dma { | 
|  | struct dma_struct	dma; | 
|  | unsigned int		fiq; | 
|  | }; | 
|  |  | 
|  | static void floppy_enable_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); | 
|  | void *fiqhandler_start; | 
|  | unsigned int fiqhandler_length; | 
|  | struct pt_regs regs; | 
|  |  | 
|  | if (fdma->dma.sg) | 
|  | BUG(); | 
|  |  | 
|  | if (fdma->dma.dma_mode == DMA_MODE_READ) { | 
|  | extern unsigned char floppy_fiqin_start, floppy_fiqin_end; | 
|  | fiqhandler_start = &floppy_fiqin_start; | 
|  | fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start; | 
|  | } else { | 
|  | extern unsigned char floppy_fiqout_start, floppy_fiqout_end; | 
|  | fiqhandler_start = &floppy_fiqout_start; | 
|  | fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start; | 
|  | } | 
|  |  | 
|  | regs.ARM_r9  = fdma->dma.count; | 
|  | regs.ARM_r10 = (unsigned long)fdma->dma.addr; | 
|  | regs.ARM_fp  = (unsigned long)FLOPPYDMA_BASE; | 
|  |  | 
|  | if (claim_fiq(&fh)) { | 
|  | printk("floppydma: couldn't claim FIQ.\n"); | 
|  | return; | 
|  | } | 
|  |  | 
|  | set_fiq_handler(fiqhandler_start, fiqhandler_length); | 
|  | set_fiq_regs(®s); | 
|  | enable_fiq(fdma->fiq); | 
|  | } | 
|  |  | 
|  | static void floppy_disable_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); | 
|  | disable_fiq(fdma->fiq); | 
|  | release_fiq(&fh); | 
|  | } | 
|  |  | 
|  | static int floppy_get_residue(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | struct pt_regs regs; | 
|  | get_fiq_regs(®s); | 
|  | return regs.ARM_r9; | 
|  | } | 
|  |  | 
|  | static struct dma_ops floppy_dma_ops = { | 
|  | .type		= "FIQDMA", | 
|  | .enable		= floppy_enable_dma, | 
|  | .disable	= floppy_disable_dma, | 
|  | .residue	= floppy_get_residue, | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * This is virtual DMA - we don't need anything here. | 
|  | */ | 
|  | static void sound_enable_disable_dma(unsigned int chan, dma_t *dma) | 
|  | { | 
|  | } | 
|  |  | 
|  | static struct dma_ops sound_dma_ops = { | 
|  | .type		= "VIRTUAL", | 
|  | .enable		= sound_enable_disable_dma, | 
|  | .disable	= sound_enable_disable_dma, | 
|  | }; | 
|  |  | 
|  | static struct iomd_dma iomd_dma[6]; | 
|  |  | 
|  | static struct floppy_dma floppy_dma = { | 
|  | .dma		= { | 
|  | .d_ops	= &floppy_dma_ops, | 
|  | }, | 
|  | .fiq		= FIQ_FLOPPYDATA, | 
|  | }; | 
|  |  | 
|  | static dma_t sound_dma = { | 
|  | .d_ops		= &sound_dma_ops, | 
|  | }; | 
|  |  | 
|  | static int __init rpc_dma_init(void) | 
|  | { | 
|  | unsigned int i; | 
|  | int ret; | 
|  |  | 
|  | iomd_writeb(0, IOMD_IO0CR); | 
|  | iomd_writeb(0, IOMD_IO1CR); | 
|  | iomd_writeb(0, IOMD_IO2CR); | 
|  | iomd_writeb(0, IOMD_IO3CR); | 
|  |  | 
|  | iomd_writeb(0xa0, IOMD_DMATCR); | 
|  |  | 
|  | /* | 
|  | * Setup DMA channels 2,3 to be for podules | 
|  | * and channels 0,1 for internal devices | 
|  | */ | 
|  | iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT); | 
|  |  | 
|  | iomd_dma[DMA_0].base	= IOMD_IO0CURA; | 
|  | iomd_dma[DMA_0].irq	= IRQ_DMA0; | 
|  | iomd_dma[DMA_1].base	= IOMD_IO1CURA; | 
|  | iomd_dma[DMA_1].irq	= IRQ_DMA1; | 
|  | iomd_dma[DMA_2].base	= IOMD_IO2CURA; | 
|  | iomd_dma[DMA_2].irq	= IRQ_DMA2; | 
|  | iomd_dma[DMA_3].base	= IOMD_IO3CURA; | 
|  | iomd_dma[DMA_3].irq	= IRQ_DMA3; | 
|  | iomd_dma[DMA_S0].base	= IOMD_SD0CURA; | 
|  | iomd_dma[DMA_S0].irq	= IRQ_DMAS0; | 
|  | iomd_dma[DMA_S1].base	= IOMD_SD1CURA; | 
|  | iomd_dma[DMA_S1].irq	= IRQ_DMAS1; | 
|  |  | 
|  | for (i = DMA_0; i <= DMA_S1; i++) { | 
|  | iomd_dma[i].dma.d_ops = &iomd_dma_ops; | 
|  |  | 
|  | ret = isa_dma_add(i, &iomd_dma[i].dma); | 
|  | if (ret) | 
|  | printk("IOMDDMA%u: unable to register: %d\n", i, ret); | 
|  | } | 
|  |  | 
|  | ret = isa_dma_add(DMA_VIRTUAL_FLOPPY, &floppy_dma.dma); | 
|  | if (ret) | 
|  | printk("IOMDFLOPPY: unable to register: %d\n", ret); | 
|  | ret = isa_dma_add(DMA_VIRTUAL_SOUND, &sound_dma); | 
|  | if (ret) | 
|  | printk("IOMDSOUND: unable to register: %d\n", ret); | 
|  | return 0; | 
|  | } | 
|  | core_initcall(rpc_dma_init); |