summaryrefslogtreecommitdiff
path: root/arch/arm/mach-rpc/dma.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-rpc/dma.c')
-rw-r--r--arch/arm/mach-rpc/dma.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c
new file mode 100644
index 000000000000..bc0747439fb3
--- /dev/null
+++ b/arch/arm/mach-rpc/dma.c
@@ -0,0 +1,338 @@
+/*
+ * 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(&regs);
+ 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(&regs);
+ 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);
+}