| /* |
| * 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/pci.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, struct pt_regs *regs) |
| { |
| 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, |
| SA_INTERRUPT, 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->using_sg) { |
| dma->buf.dma_address = pci_map_single(NULL, |
| dma->buf.__address, dma->buf.length, |
| dma->dma_mode == DMA_MODE_READ ? |
| PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE); |
| } |
| |
| 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->using_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->buf.length; |
| regs.ARM_r10 = (unsigned long)dma->buf.__address; |
| 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); |
| } |