| /* |
| * 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/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); |