firewire: Add driver for OHCI firewire host controllers.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

4 files changed, 1558 insertions, 0 deletions

diff --git a/drivers/firewire/Kconfig b/drivers/firewire/Kconfig
index bdd6303f1a4..b3863344617 100644
--- a/drivers/firewire/Kconfig
+++ b/drivers/firewire/Kconfig
@@ -20,4 +20,15 @@ config FW
 	  To compile this driver as a module, say M here: the
 	  module will be called fw-core.
 
+config FW_OHCI
+	tristate "Support for OHCI firewire host controllers"
+	depends on PCI && FW
+	help
+	  Enable this driver if you have an firewire controller based
+	  on the OHCI specification.  For all practical purposes, this
+	  is the only chipset in use, so say Y here.
+
+	  To compile this driver as a module, say M here: the
+	  module will be called fw-ohci.
+
 endmenu
diff --git a/drivers/firewire/Makefile b/drivers/firewire/Makefile
index da77bc0501e..add3b983def 100644
--- a/drivers/firewire/Makefile
+++ b/drivers/firewire/Makefile
@@ -6,3 +6,4 @@ fw-core-objs := fw-card.o fw-topology.o fw-transaction.o fw-iso.o \
 	fw-device.o fw-device-cdev.o
 
 obj-$(CONFIG_FW) += fw-core.o
+obj-$(CONFIG_FW_OHCI) += fw-ohci.o
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
new file mode 100644
index 00000000000..5392a2b1354
--- /dev/null
+++ b/drivers/firewire/fw-ohci.c
@@ -0,0 +1,1394 @@
+/*						-*- c-basic-offset: 8 -*-
+ *
+ * fw-ohci.c - Driver for OHCI 1394 boards
+ * Copyright (C) 2003-2006 Kristian Hoegsberg <krh@bitplanet.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/poll.h>
+#include <asm/uaccess.h>
+#include <asm/semaphore.h>
+
+#include "fw-transaction.h"
+#include "fw-ohci.h"
+
+#define descriptor_output_more		0
+#define descriptor_output_last		(1 << 12)
+#define descriptor_input_more		(2 << 12)
+#define descriptor_input_last		(3 << 12)
+#define descriptor_status		(1 << 11)
+#define descriptor_key_immediate	(2 << 8)
+#define descriptor_ping			(1 << 7)
+#define descriptor_yy			(1 << 6)
+#define descriptor_no_irq		(0 << 4)
+#define descriptor_irq_error		(1 << 4)
+#define descriptor_irq_always		(3 << 4)
+#define descriptor_branch_always	(3 << 2)
+
+struct descriptor {
+	__le16 req_count;
+	__le16 control;
+	__le32 data_address;
+	__le32 branch_address;
+	__le16 res_count;
+	__le16 transfer_status;
+} __attribute__((aligned(16)));
+
+struct ar_context {
+	struct fw_ohci *ohci;
+	struct descriptor descriptor;
+	__le32 buffer[512];
+	dma_addr_t descriptor_bus;
+	dma_addr_t buffer_bus;
+
+	u32 command_ptr;
+	u32 control_set;
+	u32 control_clear;
+
+	struct tasklet_struct tasklet;
+};
+
+struct at_context {
+	struct fw_ohci *ohci;
+	dma_addr_t descriptor_bus;
+	dma_addr_t buffer_bus;
+
+	struct list_head list;
+
+	struct {
+		struct descriptor more;
+		__le32 header[4];
+		struct descriptor last;
+	} d;
+
+	u32 command_ptr;
+	u32 control_set;
+	u32 control_clear;
+
+	struct tasklet_struct tasklet;
+};
+
+#define it_header_sy(v)          ((v) <<  0)
+#define it_header_tcode(v)       ((v) <<  4)
+#define it_header_channel(v)     ((v) <<  8)
+#define it_header_tag(v)         ((v) << 14)
+#define it_header_speed(v)       ((v) << 16)
+#define it_header_data_length(v) ((v) << 16)
+
+struct iso_context {
+	struct fw_iso_context base;
+	struct tasklet_struct tasklet;
+	u32 control_set;
+	u32 control_clear;
+	u32 command_ptr;
+	u32 context_match;
+
+	struct descriptor *buffer;
+	dma_addr_t buffer_bus;
+	struct descriptor *head_descriptor;
+	struct descriptor *tail_descriptor;
+	struct descriptor *tail_descriptor_last;
+	struct descriptor *prev_descriptor;
+};
+
+#define CONFIG_ROM_SIZE 1024
+
+struct fw_ohci {
+	struct fw_card card;
+
+	__iomem char *registers;
+	dma_addr_t self_id_bus;
+	__le32 *self_id_cpu;
+	struct tasklet_struct bus_reset_tasklet;
+	int generation;
+	int request_generation;
+
+	/* Spinlock for accessing fw_ohci data.  Never call out of
+	 * this driver with this lock held. */
+	spinlock_t lock;
+	u32 self_id_buffer[512];
+
+	/* Config rom buffers */
+	__be32 *config_rom;
+	dma_addr_t config_rom_bus;
+	__be32 *next_config_rom;
+	dma_addr_t next_config_rom_bus;
+	u32 next_header;
+
+	struct ar_context ar_request_ctx;
+	struct ar_context ar_response_ctx;
+	struct at_context at_request_ctx;
+	struct at_context at_response_ctx;
+
+	u32 it_context_mask;
+	struct iso_context *it_context_list;
+	u32 ir_context_mask;
+	struct iso_context *ir_context_list;
+};
+
+extern inline struct fw_ohci *fw_ohci(struct fw_card *card)
+{
+	return container_of(card, struct fw_ohci, card);
+}
+
+#define CONTEXT_CYCLE_MATCH_ENABLE	0x80000000
+
+#define CONTEXT_RUN	0x8000
+#define CONTEXT_WAKE	0x1000
+#define CONTEXT_DEAD	0x0800
+#define CONTEXT_ACTIVE	0x0400
+
+#define OHCI1394_MAX_AT_REQ_RETRIES	0x2
+#define OHCI1394_MAX_AT_RESP_RETRIES	0x2
+#define OHCI1394_MAX_PHYS_RESP_RETRIES	0x8
+
+#define FW_OHCI_MAJOR			240
+#define OHCI1394_REGISTER_SIZE		0x800
+#define OHCI_LOOP_COUNT			500
+#define OHCI1394_PCI_HCI_Control	0x40
+#define SELF_ID_BUF_SIZE		0x800
+
+/* FIXME: Move this to linux/pci_ids.h */
+#define PCI_CLASS_SERIAL_FIREWIRE_OHCI	0x0c0010
+
+static char ohci_driver_name[] = KBUILD_MODNAME;
+
+extern inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
+{
+	writel(data, ohci->registers + offset);
+}
+
+extern inline u32 reg_read(const struct fw_ohci *ohci, int offset)
+{
+	return readl(ohci->registers + offset);
+}
+
+extern inline void flush_writes(const struct fw_ohci *ohci)
+{
+	/* Do a dummy read to flush writes. */
+	reg_read(ohci, OHCI1394_Version);
+}
+
+static int
+ohci_update_phy_reg(struct fw_card *card, int addr,
+		    int clear_bits, int set_bits)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+	u32 val, old;
+
+	reg_write(ohci, OHCI1394_PhyControl, OHCI1394_PhyControl_Read(addr));
+	msleep(2);
+	val = reg_read(ohci, OHCI1394_PhyControl);
+	if ((val & OHCI1394_PhyControl_ReadDone) == 0) {
+		fw_error("failed to set phy reg bits.\n");
+		return -EBUSY;
+	}
+
+	old = OHCI1394_PhyControl_ReadData(val);
+	old = (old & ~clear_bits) | set_bits;
+	reg_write(ohci, OHCI1394_PhyControl,
+		  OHCI1394_PhyControl_Write(addr, old));
+
+	return 0;
+}
+
+static void ar_context_run(struct ar_context *ctx)
+{
+	reg_write(ctx->ohci, ctx->command_ptr, ctx->descriptor_bus | 1);
+	reg_write(ctx->ohci, ctx->control_set, CONTEXT_RUN);
+	flush_writes(ctx->ohci);
+}
+
+static void ar_context_tasklet(unsigned long data)
+{
+	struct ar_context *ctx = (struct ar_context *)data;
+	struct fw_ohci *ohci = ctx->ohci;
+	u32 status;
+	int length, speed, ack, timestamp, tcode;
+
+	/* FIXME: What to do about evt_* errors? */
+	length    = le16_to_cpu(ctx->descriptor.req_count) -
+		le16_to_cpu(ctx->descriptor.res_count) - 4;
+	status    = le32_to_cpu(ctx->buffer[length / 4]);
+	ack       = ((status >> 16) & 0x1f) - 16;
+	speed     = (status >> 21) & 0x7;
+	timestamp = status & 0xffff;
+
+	ctx->buffer[0] = le32_to_cpu(ctx->buffer[0]);
+	ctx->buffer[1] = le32_to_cpu(ctx->buffer[1]);
+	ctx->buffer[2] = le32_to_cpu(ctx->buffer[2]);
+
+	tcode = (ctx->buffer[0] >> 4) & 0x0f;
+	if (TCODE_IS_BLOCK_PACKET(tcode))
+		ctx->buffer[3] = le32_to_cpu(ctx->buffer[3]);
+
+	/* The OHCI bus reset handler synthesizes a phy packet with
+	 * the new generation number when a bus reset happens (see
+	 * section 8.4.2.3).  This helps us determine when a request
+	 * was received and make sure we send the response in the same
+	 * generation.  We only need this for requests; for responses
+	 * we use the unique tlabel for finding the matching
+	 * request. */
+
+	if (ack + 16 == 0x09)
+		ohci->request_generation = (ctx->buffer[2] >> 16) & 0xff;
+	else if (ctx == &ohci->ar_request_ctx)
+		fw_core_handle_request(&ohci->card, speed, ack, timestamp,
+				       ohci->request_generation,
+				       length, ctx->buffer);
+	else
+		fw_core_handle_response(&ohci->card, speed, ack, timestamp,
+					length, ctx->buffer);
+
+	ctx->descriptor.data_address = cpu_to_le32(ctx->buffer_bus);
+	ctx->descriptor.req_count    = cpu_to_le16(sizeof ctx->buffer);
+	ctx->descriptor.res_count    = cpu_to_le16(sizeof ctx->buffer);
+
+	dma_sync_single_for_device(ohci->card.device, ctx->descriptor_bus,
+				   sizeof ctx->descriptor_bus, DMA_TO_DEVICE);
+
+	/* FIXME: We stop and restart the ar context here, what if we
+	 * stop while a receive is in progress? Maybe we could just
+	 * loop the context back to itself and use it in buffer fill
+	 * mode as intended... */
+
+	reg_write(ctx->ohci, ctx->control_clear, CONTEXT_RUN);
+	ar_context_run(ctx);
+}
+
+static int
+ar_context_init(struct ar_context *ctx, struct fw_ohci *ohci, u32 control_set)
+{
+	ctx->descriptor_bus =
+		dma_map_single(ohci->card.device, &ctx->descriptor,
+			       sizeof ctx->descriptor, DMA_TO_DEVICE);
+	if (ctx->descriptor_bus == 0)
+		return -ENOMEM;
+
+	if (ctx->descriptor_bus & 0xf)
+		fw_notify("descriptor not 16-byte aligned: 0x%08x\n",
+			  ctx->descriptor_bus);
+
+	ctx->buffer_bus =
+		dma_map_single(ohci->card.device, ctx->buffer,
+			       sizeof ctx->buffer, DMA_FROM_DEVICE);
+
+	if (ctx->buffer_bus == 0) {
+		dma_unmap_single(ohci->card.device, ctx->descriptor_bus,
+				 sizeof ctx->descriptor, DMA_TO_DEVICE);
+		return -ENOMEM;
+	}
+
+	memset(&ctx->descriptor, 0, sizeof ctx->descriptor);
+	ctx->descriptor.control      = cpu_to_le16(descriptor_input_more |
+						   descriptor_status |
+						   descriptor_branch_always);
+	ctx->descriptor.req_count    = cpu_to_le16(sizeof ctx->buffer);
+	ctx->descriptor.data_address = cpu_to_le32(ctx->buffer_bus);
+	ctx->descriptor.res_count    = cpu_to_le16(sizeof ctx->buffer);
+
+	ctx->control_set   = control_set;
+	ctx->control_clear = control_set + 4;
+	ctx->command_ptr   = control_set + 12;
+	ctx->ohci          = ohci;
+
+	tasklet_init(&ctx->tasklet, ar_context_tasklet, (unsigned long)ctx);
+
+	ar_context_run(ctx);
+
+	return 0;
+}
+
+static void
+do_packet_callbacks(struct fw_ohci *ohci, struct list_head *list)
+{
+	struct fw_packet *p, *next;
+
+	list_for_each_entry_safe(p, next, list, link)
+		p->callback(p, &ohci->card, p->status);
+}
+
+static void
+complete_transmission(struct fw_packet *packet,
+		      int status, struct list_head *list)
+{
+	list_move_tail(&packet->link, list);
+	packet->status = status;
+}
+
+/* This function prepares the first packet in the context queue for
+ * transmission.  Must always be called with the ochi->lock held to
+ * ensure proper generation handling and locking around packet queue
+ * manipulation. */
+static void
+at_context_setup_packet(struct at_context *ctx, struct list_head *list)
+{
+	struct fw_packet *packet;
+	struct fw_ohci *ohci = ctx->ohci;
+	int z, tcode;
+
+	packet = fw_packet(ctx->list.next);
+
+	memset(&ctx->d, 0, sizeof ctx->d);
+	if (packet->payload_length > 0) {
+		packet->payload_bus = dma_map_single(ohci->card.device,
+						     packet->payload,
+						     packet->payload_length,
+						     DMA_TO_DEVICE);
+		if (packet->payload_bus == 0) {
+			complete_transmission(packet, -ENOMEM, list);
+			return;
+		}
+
+		ctx->d.more.control      =
+			cpu_to_le16(descriptor_output_more |
+				    descriptor_key_immediate);
+		ctx->d.more.req_count    = cpu_to_le16(packet->header_length);
+		ctx->d.more.res_count    = cpu_to_le16(packet->timestamp);
+		ctx->d.last.control      =
+			cpu_to_le16(descriptor_output_last |
+				    descriptor_irq_always |
+				    descriptor_branch_always);
+		ctx->d.last.req_count    = cpu_to_le16(packet->payload_length);
+		ctx->d.last.data_address = cpu_to_le32(packet->payload_bus);
+		z = 3;
+	} else {
+		ctx->d.more.control   =
+			cpu_to_le16(descriptor_output_last |
+				    descriptor_key_immediate |
+				    descriptor_irq_always |
+				    descriptor_branch_always);
+		ctx->d.more.req_count = cpu_to_le16(packet->header_length);
+		ctx->d.more.res_count = cpu_to_le16(packet->timestamp);
+		z = 2;
+	}
+
+	/* The DMA format for asyncronous link packets is different
+	 * from the IEEE1394 layout, so shift the fields around
+	 * accordingly.  If header_length is 8, it's a PHY packet, to
+	 * which we need to prepend an extra quadlet. */
+	if (packet->header_length > 8) {
+		ctx->d.header[0] = cpu_to_le32((packet->header[0] & 0xffff) |
+					       (packet->speed << 16));
+		ctx->d.header[1] = cpu_to_le32((packet->header[1] & 0xffff) |
+					       (packet->header[0] & 0xffff0000));
+		ctx->d.header[2] = cpu_to_le32(packet->header[2]);
+
+		tcode = (packet->header[0] >> 4) & 0x0f;
+		if (TCODE_IS_BLOCK_PACKET(tcode))
+			ctx->d.header[3] = cpu_to_le32(packet->header[3]);
+		else
+			ctx->d.header[3] = packet->header[3];
+	} else {
+		ctx->d.header[0] =
+			cpu_to_le32((OHCI1394_phy_tcode << 4) |
+				    (packet->speed << 16));
+		ctx->d.header[1] = cpu_to_le32(packet->header[0]);
+		ctx->d.header[2] = cpu_to_le32(packet->header[1]);
+		ctx->d.more.req_count = cpu_to_le16(12);
+	}
+
+	/* FIXME: Document how the locking works. */
+	if (ohci->generation == packet->generation) {
+		reg_write(ctx->ohci, ctx->command_ptr,
+			  ctx->descriptor_bus | z);
+		reg_write(ctx->ohci, ctx->control_set,
+			  CONTEXT_RUN | CONTEXT_WAKE);
+	} else {
+		/* We dont return error codes from this function; all
+		 * transmission errors are reported through the
+		 * callback. */
+		complete_transmission(packet, -ESTALE, list);
+	}
+}
+
+static void at_context_stop(struct at_context *ctx)
+{
+	u32 reg;
+
+	reg_write(ctx->ohci, ctx->control_clear, CONTEXT_RUN);
+
+	reg = reg_read(ctx->ohci, ctx->control_set);
+	if (reg & CONTEXT_ACTIVE)
+		fw_notify("Tried to stop context, but it is still active "
+			  "(0x%08x).\n", reg);
+}
+
+static void at_context_tasklet(unsigned long data)
+{
+	struct at_context *ctx = (struct at_context *)data;
+	struct fw_ohci *ohci = ctx->ohci;
+	struct fw_packet *packet;
+	LIST_HEAD(list);
+	unsigned long flags;
+	int evt;
+
+	spin_lock_irqsave(&ohci->lock, flags);
+
+	packet = fw_packet(ctx->list.next);
+
+	at_context_stop(ctx);
+
+	if (packet->payload_length > 0) {
+		dma_unmap_single(ohci->card.device, packet->payload_bus,
+				 packet->payload_length, DMA_TO_DEVICE);
+		evt = le16_to_cpu(ctx->d.last.transfer_status) & 0x1f;
+		packet->timestamp = le16_to_cpu(ctx->d.last.res_count);
+	}
+	else {
+		evt = le16_to_cpu(ctx->d.more.transfer_status) & 0x1f;
+		packet->timestamp = le16_to_cpu(ctx->d.more.res_count);
+	}
+
+	if (evt < 16) {
+		switch (evt) {
+		case OHCI1394_evt_timeout:
+			/* Async response transmit timed out. */
+			complete_transmission(packet, -ETIMEDOUT, &list);
+			break;
+
+		case OHCI1394_evt_flushed:
+			/* The packet was flushed should give same
+			 * error as when we try to use a stale
+			 * generation count. */
+			complete_transmission(packet, -ESTALE, &list);
+			break;
+
+		case OHCI1394_evt_missing_ack:
+			/* This would be a higher level software
+			 * error, it is using a valid (current)
+			 * generation count, but the node is not on
+			 * the bus. */
+			complete_transmission(packet, -ENODEV, &list);
+			break;
+
+		default:
+			complete_transmission(packet, -EIO, &list);
+			break;
+		}
+	} else
+		complete_transmission(packet, evt - 16, &list);
+
+	/* If more packets are queued, set up the next one. */
+	if (!list_empty(&ctx->list))
+		at_context_setup_packet(ctx, &list);
+
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+	do_packet_callbacks(ohci, &list);
+}
+
+static int
+at_context_init(struct at_context *ctx, struct fw_ohci *ohci, u32 control_set)
+{
+	INIT_LIST_HEAD(&ctx->list);
+
+	ctx->descriptor_bus =
+		dma_map_single(ohci->card.device, &ctx->d,
+			       sizeof ctx->d, DMA_TO_DEVICE);
+	if (ctx->descriptor_bus == 0)
+		return -ENOMEM;
+
+	ctx->control_set   = control_set;
+	ctx->control_clear = control_set + 4;
+	ctx->command_ptr   = control_set + 12;
+	ctx->ohci          = ohci;
+
+	tasklet_init(&ctx->tasklet, at_context_tasklet, (unsigned long)ctx);
+
+	return 0;
+}
+
+static void
+at_context_transmit(struct at_context *ctx, struct fw_packet *packet)
+{
+	LIST_HEAD(list);
+	unsigned long flags;
+	int was_empty;
+
+	spin_lock_irqsave(&ctx->ohci->lock, flags);
+
+	was_empty = list_empty(&ctx->list);
+	list_add_tail(&packet->link, &ctx->list);
+	if (was_empty)
+		at_context_setup_packet(ctx, &list);
+
+	spin_unlock_irqrestore(&ctx->ohci->lock, flags);
+
+	do_packet_callbacks(ctx->ohci, &list);
+}
+
+static void bus_reset_tasklet(unsigned long data)
+{
+	struct fw_ohci *ohci = (struct fw_ohci *)data;
+	int self_id_count, i, j, reg, node_id;
+	int generation, new_generation;
+	unsigned long flags;
+
+	reg = reg_read(ohci, OHCI1394_NodeID);
+	if (!(reg & OHCI1394_NodeID_idValid)) {
+		fw_error("node ID not valid, new bus reset in progress\n");
+		return;
+	}
+	node_id = reg & 0xffff;
+
+	/* The count in the SelfIDCount register is the number of
+	 * bytes in the self ID receive buffer.  Since we also receive
+	 * the inverted quadlets and a header quadlet, we shift one
+	 * bit extra to get the actual number of self IDs. */
+
+	self_id_count = (reg_read(ohci, OHCI1394_SelfIDCount) >> 3) & 0x3ff;
+	generation = (le32_to_cpu(ohci->self_id_cpu[0]) >> 16) & 0xff;
+
+	for (i = 1, j = 0; j < self_id_count; i += 2, j++) {
+		if (ohci->self_id_cpu[i] != ~ohci->self_id_cpu[i + 1])
+			fw_error("inconsistent self IDs\n");
+		ohci->self_id_buffer[j] = le32_to_cpu(ohci->self_id_cpu[i]);
+	}
+
+	/* Check the consistency of the self IDs we just read.  The
+	 * problem we face is that a new bus reset can start while we
+	 * read out the self IDs from the DMA buffer. If this happens,
+	 * the DMA buffer will be overwritten with new self IDs and we
+	 * will read out inconsistent data.  The OHCI specification
+	 * (section 11.2) recommends a technique similar to
+	 * linux/seqlock.h, where we remember the generation of the
+	 * self IDs in the buffer before reading them out and compare
+	 * it to the current generation after reading them out.  If
+	 * the two generations match we know we have a consistent set
+	 * of self IDs. */
+
+	new_generation = (reg_read(ohci, OHCI1394_SelfIDCount) >> 16) & 0xff;
+	if (new_generation != generation) {
+		fw_notify("recursive bus reset detected, "
+			  "discarding self ids\n");
+		return;
+	}
+
+	/* FIXME: Document how the locking works. */
+	spin_lock_irqsave(&ohci->lock, flags);
+
+	ohci->generation = generation;
+	at_context_stop(&ohci->at_request_ctx);
+	at_context_stop(&ohci->at_response_ctx);
+	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);
+
+	/* This next bit is unrelated to the AT context stuff but we
+	 * have to do it under the spinlock also.  If a new config rom
+	 * was set up before this reset, the old one is now no longer
+	 * in use and we can free it. Update the config rom pointers
+	 * to point to the current config rom and clear the
+	 * next_config_rom pointer so a new udpate can take place. */
+
+	if (ohci->next_config_rom != NULL) {
+		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+				  ohci->config_rom, ohci->config_rom_bus);
+		ohci->config_rom      = ohci->next_config_rom;
+		ohci->config_rom_bus  = ohci->next_config_rom_bus;
+		ohci->next_config_rom = NULL;
+
+		/* Restore config_rom image and manually update
+		 * config_rom registers.  Writing the header quadlet
+		 * will indicate that the config rom is ready, so we
+		 * do that last. */
+		reg_write(ohci, OHCI1394_BusOptions,
+			  be32_to_cpu(ohci->config_rom[2]));
+		ohci->config_rom[0] = cpu_to_be32(ohci->next_header);
+		reg_write(ohci, OHCI1394_ConfigROMhdr, ohci->next_header);
+	}
+
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+	fw_core_handle_bus_reset(&ohci->card, node_id, generation,
+				 self_id_count, ohci->self_id_buffer);
+}
+
+static irqreturn_t irq_handler(int irq, void *data)
+{
+	struct fw_ohci *ohci = data;
+	u32 event, iso_event;
+	int i;
+
+	event = reg_read(ohci, OHCI1394_IntEventClear);
+
+	if (!event)
+		return IRQ_NONE;
+
+	reg_write(ohci, OHCI1394_IntEventClear, event);
+
+	if (event & OHCI1394_selfIDComplete)
+		tasklet_schedule(&ohci->bus_reset_tasklet);
+
+	if (event & OHCI1394_RQPkt)
+		tasklet_schedule(&ohci->ar_request_ctx.tasklet);
+
+	if (event & OHCI1394_RSPkt)
+		tasklet_schedule(&ohci->ar_response_ctx.tasklet);
+
+	if (event & OHCI1394_reqTxComplete)
+		tasklet_schedule(&ohci->at_request_ctx.tasklet);
+
+	if (event & OHCI1394_respTxComplete)
+		tasklet_schedule(&ohci->at_response_ctx.tasklet);
+
+	iso_event = reg_read(ohci, OHCI1394_IsoRecvIntEventSet);
+	reg_write(ohci, OHCI1394_IsoRecvIntEventClear, iso_event);
+
+	while (iso_event) {
+		i = ffs(iso_event) - 1;
+		tasklet_schedule(&ohci->ir_context_list[i].tasklet);
+		iso_event &= ~(1 << i);
+	}
+
+	iso_event = reg_read(ohci, OHCI1394_IsoXmitIntEventSet);
+	reg_write(ohci, OHCI1394_IsoXmitIntEventClear, iso_event);
+
+	while (iso_event) {
+		i = ffs(iso_event) - 1;
+		tasklet_schedule(&ohci->it_context_list[i].tasklet);
+		iso_event &= ~(1 << i);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int ohci_enable(struct fw_card *card, u32 *config_rom, size_t length)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+	struct pci_dev *dev = to_pci_dev(card->device);
+
+	/* When the link is not yet enabled, the atomic config rom
+	 * update mechanism described below in ohci_set_config_rom()
+	 * is not active.  We have to update ConfigRomHeader and
+	 * BusOptions manually, and the write to ConfigROMmap takes
+	 * effect immediately.  We tie this to the enabling of the
+	 * link, so we have a valid config rom before enabling - the
+	 * OHCI requires that ConfigROMhdr and BusOptions have valid
+	 * values before enabling.
+	 *
+	 * However, when the ConfigROMmap is written, some controllers
+	 * always read back quadlets 0 and 2 from the config rom to
+	 * the ConfigRomHeader and BusOptions registers on bus reset.
+	 * They shouldn't do that in this initial case where the link
+	 * isn't enabled.  This means we have to use the same
+	 * workaround here, setting the bus header to 0 and then write
+	 * the right values in the bus reset tasklet.
+	 */
+
+	ohci->next_config_rom =
+		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+				   &ohci->next_config_rom_bus, GFP_KERNEL);
+	if (ohci->next_config_rom == NULL)
+		return -ENOMEM;
+
+	memset(ohci->next_config_rom, 0, CONFIG_ROM_SIZE);
+	fw_memcpy_to_be32(ohci->next_config_rom, config_rom, length * 4);
+
+	ohci->next_header = config_rom[0];
+	ohci->next_config_rom[0] = 0;
+	reg_write(ohci, OHCI1394_ConfigROMhdr, 0);
+	reg_write(ohci, OHCI1394_BusOptions, config_rom[2]);
+	reg_write(ohci, OHCI1394_ConfigROMmap, ohci->next_config_rom_bus);
+
+	reg_write(ohci, OHCI1394_AsReqFilterHiSet, 0x80000000);
+
+	if (request_irq(dev->irq, irq_handler,
+			SA_SHIRQ, ohci_driver_name, ohci)) {
+		fw_error("Failed to allocate shared interrupt %d.\n",
+			 dev->irq);
+		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+				  ohci->config_rom, ohci->config_rom_bus);
+		return -EIO;
+	}
+
+	reg_write(ohci, OHCI1394_HCControlSet,
+		  OHCI1394_HCControl_linkEnable |
+		  OHCI1394_HCControl_BIBimageValid);
+	flush_writes(ohci);
+
+	/* We are ready to go, initiate bus reset to finish the
+	 * initialization. */
+
+	fw_core_initiate_bus_reset(&ohci->card, 1);
+
+	return 0;
+}
+
+static int
+ohci_set_config_rom(struct fw_card *card, u32 *config_rom, size_t length)
+{
+	struct fw_ohci *ohci;
+	unsigned long flags;
+	int retval = 0;
+	__be32 *next_config_rom;
+	dma_addr_t next_config_rom_bus;
+
+	ohci = fw_ohci(card);
+
+	/* When the OHCI controller is enabled, the config rom update
+	 * mechanism is a bit tricky, but easy enough to use.  See
+	 * section 5.5.6 in the OHCI specification.
+	 *
+	 * The OHCI controller caches the new config rom address in a
+	 * shadow register (ConfigROMmapNext) and needs a bus reset
+	 * for the changes to take place.  When the bus reset is
+	 * detected, the controller loads the new values for the
+	 * ConfigRomHeader and BusOptions registers from the specified
+	 * config rom and loads ConfigROMmap from the ConfigROMmapNext
+	 * shadow register. All automatically and atomically.
+	 *
+	 * Now, there's a twist to this story.  The automatic load of
+	 * ConfigRomHeader and BusOptions doesn't honor the
+	 * noByteSwapData bit, so with a be32 config rom, the
+	 * controller will load be32 values in to these registers
+	 * during the atomic update, even on litte endian
+	 * architectures.  The workaround we use is to put a 0 in the
+	 * header quadlet; 0 is endian agnostic and means that the
+	 * config rom isn't ready yet.  In the bus reset tasklet we
+	 * then set up the real values for the two registers.
+	 *
+	 * We use ohci->lock to avoid racing with the code that sets
+	 * ohci->next_config_rom to NULL (see bus_reset_tasklet).
+	 */
+
+	next_config_rom =
+		dma_alloc_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+				   &next_config_rom_bus, GFP_KERNEL);
+	if (next_config_rom == NULL)
+		return -ENOMEM;
+
+	spin_lock_irqsave(&ohci->lock, flags);
+
+	if (ohci->next_config_rom == NULL) {
+		ohci->next_config_rom = next_config_rom;
+		ohci->next_config_rom_bus = next_config_rom_bus;
+
+		memset(ohci->next_config_rom, 0, CONFIG_ROM_SIZE);
+		fw_memcpy_to_be32(ohci->next_config_rom, config_rom,
+				  length * 4);
+
+		ohci->next_header = config_rom[0];
+		ohci->next_config_rom[0] = 0;
+
+		reg_write(ohci, OHCI1394_ConfigROMmap,
+			  ohci->next_config_rom_bus);
+	} else {
+		dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
+				  next_config_rom, next_config_rom_bus);
+		retval = -EBUSY;
+	}
+
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+	/* Now initiate a bus reset to have the changes take
+	 * effect. We clean up the old config rom memory and DMA
+	 * mappings in the bus reset tasklet, since the OHCI
+	 * controller could need to access it before the bus reset
+	 * takes effect. */
+	if (retval == 0)
+		fw_core_initiate_bus_reset(&ohci->card, 1);
+
+	return retval;
+}
+
+static void ohci_send_request(struct fw_card *card, struct fw_packet *packet)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+
+	at_context_transmit(&ohci->at_request_ctx, packet);
+}
+
+static void ohci_send_response(struct fw_card *card, struct fw_packet *packet)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+
+	at_context_transmit(&ohci->at_response_ctx, packet);
+}
+
+static int
+ohci_enable_phys_dma(struct fw_card *card, int node_id, int generation)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+	unsigned long flags;
+	int retval = 0;
+
+	/* FIXME: make sure this bitmask is cleared when we clear the
+	 * busReset interrupt bit. */
+
+	spin_lock_irqsave(&ohci->lock, flags);
+
+	if (ohci->generation != generation) {
+		retval = -ESTALE;
+		goto out;
+	}
+
+	if (node_id < 32) {
+		reg_write(ohci, OHCI1394_PhyReqFilterLoSet, 1 << node_id);
+	} else {
+		reg_write(ohci, OHCI1394_PhyReqFilterHiSet,
+			  1 << (node_id - 32));
+	}
+	flush_writes(ohci);
+
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+ out:
+	return retval;
+}
+
+static void ir_context_tasklet(unsigned long data)
+{
+	struct iso_context *ctx = (struct iso_context *)data;
+
+	(void)ctx;
+}
+
+#define ISO_BUFFER_SIZE (64 * 1024)
+
+static void flush_iso_context(struct iso_context *ctx)
+{
+	struct fw_ohci *ohci = fw_ohci(ctx->base.card);
+	struct descriptor *d, *last;
+	u32 address;
+	int z;
+
+	dma_sync_single_for_cpu(ohci->card.device, ctx->buffer_bus,
+				ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+
+	d    = ctx->tail_descriptor;
+	last = ctx->tail_descriptor_last;
+
+	while (last->branch_address != 0 && last->transfer_status != 0) {
+		address = le32_to_cpu(last->branch_address);
+		z = address & 0xf;
+		d = ctx->buffer + (address - ctx->buffer_bus) / sizeof *d;
+
+		if (z == 2)
+			last = d;
+		else
+			last = d + z - 1;
+
+		if (le16_to_cpu(last->control) & descriptor_irq_always)
+			ctx->base.callback(&ctx->base,
+					   0, le16_to_cpu(last->res_count),
+					   ctx->base.callback_data);
+	}
+
+	ctx->tail_descriptor      = d;
+	ctx->tail_descriptor_last = last;
+}
+
+static void it_context_tasklet(unsigned long data)
+{
+	struct iso_context *ctx = (struct iso_context *)data;
+
+	flush_iso_context(ctx);
+}
+
+static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
+							int type)
+{
+	struct fw_ohci *ohci = fw_ohci(card);
+	struct iso_context *ctx, *list;
+	void (*tasklet) (unsigned long data);
+	u32 *mask;
+	unsigned long flags;
+	int index;
+
+	if (type == FW_ISO_CONTEXT_TRANSMIT) {
+		mask = &ohci->it_context_mask;
+		list = ohci->it_context_list;
+		tasklet = it_context_tasklet;
+	} else {
+		mask = &ohci->ir_context_mask;
+		list = ohci->ir_context_list;
+		tasklet = ir_context_tasklet;
+	}
+
+	spin_lock_irqsave(&ohci->lock, flags);
+	index = ffs(*mask) - 1;
+	if (index >= 0)
+		*mask &= ~(1 << index);
+	spin_unlock_irqrestore(&ohci->lock, flags);
+
+	if (index < 0)
+		return ERR_PTR(-EBUSY);
+
+	ctx = &list[index];
+	memset(ctx, 0, sizeof *ctx);
+	tasklet_init(&ctx->tasklet, tasklet, (unsigned long)ctx);
+
+	ctx->buffer = kmalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
+	if (ctx->buffer == NULL) {
+		spin_lock_irqsave(&ohci->lock, flags);
+		*mask |= 1 << index;
+		spin_unlock_irqrestore(&ohci->lock, flags);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	ctx->buffer_bus =
+	    dma_map_single(card->device, ctx->buffer,
+			   ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+
+	ctx->head_descriptor      = ctx->buffer;
+	ctx->prev_descriptor      = ctx->buffer;
+	ctx->tail_descriptor      = ctx->buffer;
+	ctx->tail_descriptor_last = ctx->buffer;
+
+	/* We put a dummy descriptor in the buffer that has a NULL
+	 * branch address and looks like it's been sent.  That way we
+	 * have a descriptor to append DMA programs to.  Also, the
+	 * ring buffer invariant is that it always has at least one
+	 * element so that head == tail means buffer full. */
+
+	memset(ctx->head_descriptor, 0, sizeof *ctx->head_descriptor);
+	ctx->head_descriptor->control          =
+		cpu_to_le16(descriptor_output_last);
+	ctx->head_descriptor->transfer_status  = cpu_to_le16(0x8011);
+	ctx->head_descriptor++;
+
+	return &ctx->base;
+}
+
+static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)
+{
+	struct iso_context *ctx = (struct iso_context *)base;
+	struct fw_ohci *ohci = fw_ohci(ctx->base.card);
+	u32 cycle_match = 0;
+	int index;
+
+	index = ctx - ohci->it_context_list;
+	if (cycle > 0)
+		cycle_match = CONTEXT_CYCLE_MATCH_ENABLE |
+			(cycle & 0x7fff) << 16;
+
+	reg_write(ohci, OHCI1394_IsoXmitIntMaskSet, 1 << index);
+	reg_write(ohci, OHCI1394_IsoXmitCommandPtr(index),
+		  le32_to_cpu(ctx->tail_descriptor_last->branch_address));
+	reg_write(ohci, OHCI1394_IsoXmitContextControlClear(index), ~0);
+	reg_write(ohci, OHCI1394_IsoXmitContextControlSet(index),
+		  CONTEXT_RUN | cycle_match);
+	flush_writes(ohci);
+
+	return 0;
+}
+
+static void ohci_free_iso_context(struct fw_iso_context *base)
+{
+	struct fw_ohci *ohci = fw_ohci(base->card);
+	struct iso_context *ctx = (struct iso_context *)base;
+	unsigned long flags;
+	int index;
+
+	flush_iso_context(ctx);
+
+	spin_lock_irqsave(&ohci->lock, flags);
+
+	if (ctx->base.type == FW_ISO_CONTEXT_TRANSMIT) {
+		index = ctx - ohci->it_context_list;
+		reg_write(ohci, OHCI1394_IsoXmitContextControlClear(index), ~0);
+		reg_write(ohci, OHCI1394_IsoXmitIntMaskClear, 1 << index);
+		ohci->it_context_mask |= 1 << index;
+	} else {
+		index = ctx - ohci->ir_context_list;
+		reg_write(ohci, OHCI1394_IsoRcvContextControlClear(index), ~0);
+		reg_write(ohci, OHCI1394_IsoRecvIntMaskClear, 1 << index);
+		ohci->ir_context_mask |= 1 << index;
+	}
+	flush_writes(ohci);
+
+	dma_unmap_single(ohci->card.device, ctx->buffer_bus,
+			 ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+
+	spin_unlock_irqrestore(&ohci->lock, flags);
+}
+
+static int
+ohci_queue_iso(struct fw_iso_context *base,
+	       struct fw_iso_packet *packe