/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include 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 */ }; #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.sg->dma_address; offset = sg->dma_address & ~PAGE_MASK; end = offset + idma->dma.sg->length; if (end > PAGE_SIZE) end = PAGE_SIZE; if (offset + TRANSFER_SIZE >= end) flags |= DMA_END_L; sg->length = end - TRANSFER_SIZE; idma->dma.sg->length -= end - offset; idma->dma.sg->dma_address += end - offset; if (idma->dma.sg->length == 0) { if (idma->dma.sgcount > 1) { idma->dma.sg = sg_next(idma->dma.sg); 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);