--- /dev/null
+/*
+ * 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,
+ 0, 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);
Code Review / kvmfornfv.git / blobdiff