| /* | 
 |  *  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 <asm/page.h> | 
 | #include <asm/dma.h> | 
 | #include <asm/fiq.h> | 
 | #include <asm/io.h> | 
 | #include <asm/irq.h> | 
 | #include <asm/hardware.h> | 
 | #include <asm/uaccess.h> | 
 |  | 
 | #include <asm/mach/dma.h> | 
 | #include <asm/hardware/iomd.h> | 
 |  | 
 | #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, dma_t *dma) | 
 | { | 
 | 	unsigned long end, offset, flags = 0; | 
 |  | 
 | 	if (dma->sg) { | 
 | 		sg->dma_address = dma->sg->dma_address; | 
 | 		offset = sg->dma_address & ~PAGE_MASK; | 
 |  | 
 | 		end = offset + dma->sg->length; | 
 |  | 
 | 		if (end > PAGE_SIZE) | 
 | 			end = PAGE_SIZE; | 
 |  | 
 | 		if (offset + TRANSFER_SIZE >= end) | 
 | 			flags |= DMA_END_L; | 
 |  | 
 | 		sg->length = end - TRANSFER_SIZE; | 
 |  | 
 | 		dma->sg->length -= end - offset; | 
 | 		dma->sg->dma_address += end - offset; | 
 |  | 
 | 		if (dma->sg->length == 0) { | 
 | 			if (dma->sgcount > 1) { | 
 | 				dma->sg++; | 
 | 				dma->sgcount--; | 
 | 			} else { | 
 | 				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) | 
 | { | 
 | 	dma_t *dma = (dma_t *)dev_id; | 
 | 	unsigned long base = dma->dma_base; | 
 |  | 
 | 	do { | 
 | 		unsigned int status; | 
 |  | 
 | 		status = iomd_readb(base + ST); | 
 | 		if (!(status & DMA_ST_INT)) | 
 | 			return IRQ_HANDLED; | 
 |  | 
 | 		if ((dma->state ^ status) & DMA_ST_AB) | 
 | 			iomd_get_next_sg(&dma->cur_sg, dma); | 
 |  | 
 | 		switch (status & (DMA_ST_OFL | DMA_ST_AB)) { | 
 | 		case DMA_ST_OFL:			/* OIA */ | 
 | 		case DMA_ST_AB:				/* .IB */ | 
 | 			iomd_writel(dma->cur_sg.dma_address, base + CURA); | 
 | 			iomd_writel(dma->cur_sg.length, base + ENDA); | 
 | 			dma->state = DMA_ST_AB; | 
 | 			break; | 
 |  | 
 | 		case DMA_ST_OFL | DMA_ST_AB:		/* OIB */ | 
 | 		case 0:					/* .IA */ | 
 | 			iomd_writel(dma->cur_sg.dma_address, base + CURB); | 
 | 			iomd_writel(dma->cur_sg.length, base + ENDB); | 
 | 			dma->state = 0; | 
 | 			break; | 
 | 		} | 
 |  | 
 | 		if (status & DMA_ST_OFL && | 
 | 		    dma->cur_sg.length == (DMA_END_S|DMA_END_L)) | 
 | 			break; | 
 | 	} while (1); | 
 |  | 
 | 	dma->state = ~DMA_ST_AB; | 
 | 	disable_irq(irq); | 
 |  | 
 | 	return IRQ_HANDLED; | 
 | } | 
 |  | 
 | static int iomd_request_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	return request_irq(dma->dma_irq, iomd_dma_handle, | 
 | 			   IRQF_DISABLED, dma->device_id, dma); | 
 | } | 
 |  | 
 | static void iomd_free_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	free_irq(dma->dma_irq, dma); | 
 | } | 
 |  | 
 | static void iomd_enable_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	unsigned long dma_base = dma->dma_base; | 
 | 	unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E; | 
 |  | 
 | 	if (dma->invalid) { | 
 | 		dma->invalid = 0; | 
 |  | 
 | 		/* | 
 | 		 * Cope with ISA-style drivers which expect cache | 
 | 		 * coherence. | 
 | 		 */ | 
 | 		if (!dma->sg) { | 
 | 			dma->sg = &dma->buf; | 
 | 			dma->sgcount = 1; | 
 | 			dma->buf.length = dma->count; | 
 | 			dma->buf.dma_address = dma_map_single(NULL, | 
 | 				dma->addr, dma->count, | 
 | 				dma->dma_mode == DMA_MODE_READ ? | 
 | 				DMA_FROM_DEVICE : DMA_TO_DEVICE); | 
 | 		} | 
 |  | 
 | 		iomd_writeb(DMA_CR_C, dma_base + CR); | 
 | 		dma->state = DMA_ST_AB; | 
 | 	} | 
 | 		 | 
 | 	if (dma->dma_mode == DMA_MODE_READ) | 
 | 		ctrl |= DMA_CR_D; | 
 |  | 
 | 	iomd_writeb(ctrl, dma_base + CR); | 
 | 	enable_irq(dma->dma_irq); | 
 | } | 
 |  | 
 | static void iomd_disable_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	unsigned long dma_base = dma->dma_base; | 
 | 	unsigned long flags; | 
 |  | 
 | 	local_irq_save(flags); | 
 | 	if (dma->state != ~DMA_ST_AB) | 
 | 		disable_irq(dma->dma_irq); | 
 | 	iomd_writeb(0, dma_base + CR); | 
 | 	local_irq_restore(flags); | 
 | } | 
 |  | 
 | static int iomd_set_dma_speed(dmach_t channel, 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 (channel) { | 
 | 	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" | 
 | }; | 
 |  | 
 | static void floppy_enable_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	void *fiqhandler_start; | 
 | 	unsigned int fiqhandler_length; | 
 | 	struct pt_regs regs; | 
 |  | 
 | 	if (dma->sg) | 
 | 		BUG(); | 
 |  | 
 | 	if (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  = dma->count; | 
 | 	regs.ARM_r10 = (unsigned long)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(dma->dma_irq); | 
 | } | 
 |  | 
 | static void floppy_disable_dma(dmach_t channel, dma_t *dma) | 
 | { | 
 | 	disable_fiq(dma->dma_irq); | 
 | 	release_fiq(&fh); | 
 | } | 
 |  | 
 | static int floppy_get_residue(dmach_t channel, 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(dmach_t channel, dma_t *dma) | 
 | { | 
 | } | 
 |  | 
 | static struct dma_ops sound_dma_ops = { | 
 | 	.type		= "VIRTUAL", | 
 | 	.enable		= sound_enable_disable_dma, | 
 | 	.disable	= sound_enable_disable_dma, | 
 | }; | 
 |  | 
 | void __init arch_dma_init(dma_t *dma) | 
 | { | 
 | 	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); | 
 |  | 
 | 	dma[DMA_0].dma_base		= IOMD_IO0CURA; | 
 | 	dma[DMA_0].dma_irq		= IRQ_DMA0; | 
 | 	dma[DMA_0].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_1].dma_base		= IOMD_IO1CURA; | 
 | 	dma[DMA_1].dma_irq		= IRQ_DMA1; | 
 | 	dma[DMA_1].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_2].dma_base		= IOMD_IO2CURA; | 
 | 	dma[DMA_2].dma_irq		= IRQ_DMA2; | 
 | 	dma[DMA_2].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_3].dma_base		= IOMD_IO3CURA; | 
 | 	dma[DMA_3].dma_irq		= IRQ_DMA3; | 
 | 	dma[DMA_3].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_S0].dma_base		= IOMD_SD0CURA; | 
 | 	dma[DMA_S0].dma_irq		= IRQ_DMAS0; | 
 | 	dma[DMA_S0].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_S1].dma_base		= IOMD_SD1CURA; | 
 | 	dma[DMA_S1].dma_irq		= IRQ_DMAS1; | 
 | 	dma[DMA_S1].d_ops		= &iomd_dma_ops; | 
 | 	dma[DMA_VIRTUAL_FLOPPY].dma_irq	= FIQ_FLOPPYDATA; | 
 | 	dma[DMA_VIRTUAL_FLOPPY].d_ops	= &floppy_dma_ops; | 
 | 	dma[DMA_VIRTUAL_SOUND].d_ops	= &sound_dma_ops; | 
 |  | 
 | 	/* | 
 | 	 * 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); | 
 | } |