firewire: Add device probing and sysfs integration.

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

1 files changed, 613 insertions, 0 deletions

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
new file mode 100644
index 00000000000..ec1cb7fc8e9
--- /dev/null
+++ b/drivers/firewire/fw-device.c
@@ -0,0 +1,613 @@
+/*						-*- c-basic-offset: 8 -*-
+ *
+ * fw-device.c - Device probing and sysfs code.
+ *
+ * Copyright (C) 2005-2006  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/module.h>
+#include <linux/wait.h>
+#include <linux/errno.h>
+#include <linux/kthread.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include "fw-transaction.h"
+#include "fw-topology.h"
+#include "fw-device.h"
+
+void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
+{
+	ci->p = p + 1;
+	ci->end = ci->p + (p[0] >> 16);
+}
+
+EXPORT_SYMBOL(fw_csr_iterator_init);
+
+int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
+{
+	*key = *ci->p >> 24;
+	*value = *ci->p & 0xffffff;
+
+	return ci->p++ < ci->end;
+}
+
+EXPORT_SYMBOL(fw_csr_iterator_next);
+
+static int is_fw_unit(struct device *dev);
+
+static int match_unit_directory(u32 * directory, struct fw_device_id *id)
+{
+	struct fw_csr_iterator ci;
+	int key, value, match;
+
+	match = 0;
+	fw_csr_iterator_init(&ci, directory);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		if (key == CSR_VENDOR && value == id->vendor)
+			match |= FW_MATCH_VENDOR;
+		if (key == CSR_MODEL && value == id->model)
+			match |= FW_MATCH_MODEL;
+		if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
+			match |= FW_MATCH_SPECIFIER_ID;
+		if (key == CSR_VERSION && value == id->version)
+			match |= FW_MATCH_VERSION;
+	}
+
+	return (match & id->match_flags) == id->match_flags;
+}
+
+static int fw_unit_match(struct device *dev, struct device_driver *drv)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	struct fw_driver *driver = fw_driver(drv);
+	int i;
+
+	/* We only allow binding to fw_units. */
+	if (!is_fw_unit(dev))
+		return 0;
+
+	for (i = 0; driver->id_table[i].match_flags != 0; i++) {
+		if (match_unit_directory(unit->directory, &driver->id_table[i]))
+			return 1;
+	}
+
+	return 0;
+}
+
+static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
+{
+	struct fw_device *device = fw_device(unit->device.parent);
+	struct fw_csr_iterator ci;
+
+	int key, value;
+	int vendor = 0;
+	int model = 0;
+	int specifier_id = 0;
+	int version = 0;
+
+	fw_csr_iterator_init(&ci, &device->config_rom[5]);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		switch (key) {
+		case CSR_VENDOR:
+			vendor = value;
+			break;
+		case CSR_MODEL:
+			model = value;
+			break;
+		}
+	}
+
+	fw_csr_iterator_init(&ci, unit->directory);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		switch (key) {
+		case CSR_SPECIFIER_ID:
+			specifier_id = value;
+			break;
+		case CSR_VERSION:
+			version = value;
+			break;
+		}
+	}
+
+	return snprintf(buffer, buffer_size,
+			"ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
+			vendor, model, specifier_id, version);
+}
+
+static int
+fw_unit_uevent(struct device *dev, char **envp, int num_envp,
+	       char *buffer, int buffer_size)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	char modalias[64];
+	int length = 0;
+	int i = 0;
+
+	if (!is_fw_unit(dev))
+		goto out;
+
+	get_modalias(unit, modalias, sizeof modalias);
+
+	if (add_uevent_var(envp, num_envp, &i,
+			   buffer, buffer_size, &length,
+			   "MODALIAS=%s", modalias))
+		return -ENOMEM;
+
+      out:
+	envp[i] = NULL;
+
+	return 0;
+}
+
+struct bus_type fw_bus_type = {
+	.name = "fw",
+	.match = fw_unit_match,
+	.uevent = fw_unit_uevent
+};
+
+EXPORT_SYMBOL(fw_bus_type);
+
+extern struct fw_device *fw_device_get(struct fw_device *device)
+{
+	get_device(&device->device);
+
+	return device;
+}
+
+extern void fw_device_put(struct fw_device *device)
+{
+	put_device(&device->device);
+}
+
+static void fw_device_release(struct device *dev)
+{
+	struct fw_device *device = fw_device(dev);
+	unsigned long flags;
+
+	/* Take the card lock so we don't set this to NULL while a
+	 * FW_NODE_UPDATED callback is being handled. */
+	spin_lock_irqsave(&device->card->lock, flags);
+	device->node->data = NULL;
+	spin_unlock_irqrestore(&device->card->lock, flags);
+
+	fw_node_put(device->node);
+	fw_card_put(device->card);
+	kfree(device->config_rom);
+	kfree(device);
+}
+
+int fw_device_enable_phys_dma(struct fw_device *device)
+{
+	return device->card->driver->enable_phys_dma(device->card,
+						     device->node_id,
+						     device->generation);
+}
+
+EXPORT_SYMBOL(fw_device_enable_phys_dma);
+
+static ssize_t
+show_modalias_attribute(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	int length;
+
+	length = get_modalias(unit, buf, PAGE_SIZE);
+	strcpy(buf + length, "\n");
+
+	return length + 1;
+}
+
+static struct device_attribute modalias_attribute = {
+	.attr = {.name = "modalias",.mode = S_IRUGO},
+	.show = show_modalias_attribute
+};
+
+static ssize_t
+show_config_rom_attribute(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	struct fw_device *device = fw_device(dev);
+
+	memcpy(buf, device->config_rom, device->config_rom_length * 4);
+
+	return device->config_rom_length * 4;
+}
+
+static struct device_attribute config_rom_attribute = {
+	.attr = {.name = "config_rom",.mode = S_IRUGO},
+	.show = show_config_rom_attribute,
+};
+
+struct read_quadlet_callback_data {
+	struct completion done;
+	int rcode;
+	u32 data;
+};
+
+static void
+complete_transaction(struct fw_card *card, int rcode,
+		     void *payload, size_t length, void *data)
+{
+	struct read_quadlet_callback_data *callback_data = data;
+
+	if (rcode == RCODE_COMPLETE)
+		callback_data->data = be32_to_cpu(*(__be32 *)payload);
+	callback_data->rcode = rcode;
+	complete(&callback_data->done);
+}
+
+static int read_rom(struct fw_device *device, int index, u32 * data)
+{
+	struct read_quadlet_callback_data callback_data;
+	struct fw_transaction t;
+	u64 offset;
+
+	init_completion(&callback_data.done);
+
+	offset = 0xfffff0000400ULL + index * 4;
+	fw_send_request(device->card, &t, TCODE_READ_QUADLET_REQUEST,
+			device->node_id | LOCAL_BUS,
+			device->generation, SCODE_100,
+			offset, NULL, 4, complete_transaction, &callback_data);
+
+	wait_for_completion(&callback_data.done);
+
+	*data = callback_data.data;
+
+	return callback_data.rcode;
+}
+
+static int read_bus_info_block(struct fw_device *device)
+{
+	static u32 rom[256];
+	u32 stack[16], sp, key;
+	int i, end, length;
+
+	/* First read the bus info block. */
+	for (i = 0; i < 5; i++) {
+		if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+			return -1;
+		/* As per IEEE1212 7.2, during power-up, devices can
+		 * reply with a 0 for the first quadlet of the config
+		 * rom to indicate that they are booting (for example,
+		 * if the firmware is on the disk of a external
+		 * harddisk).  In that case we just fail, and the
+		 * retry mechanism will try again later. */
+		if (i == 0 && rom[i] == 0)
+			return -1;
+	}
+
+	/* Now parse the config rom.  The config rom is a recursive
+	 * directory structure so we parse it using a stack of
+	 * references to the blocks that make up the structure.  We
+	 * push a reference to the root directory on the stack to
+	 * start things off. */
+	length = i;
+	sp = 0;
+	stack[sp++] = 0xc0000005;
+	while (sp > 0) {
+		/* Pop the next block reference of the stack.  The
+		 * lower 24 bits is the offset into the config rom,
+		 * the upper 8 bits are the type of the reference the
+		 * block. */
+		key = stack[--sp];
+		i = key & 0xffffff;
+		if (i >= ARRAY_SIZE(rom))
+			/* The reference points outside the standard
+			 * config rom area, something's fishy. */
+			return -1;
+
+		/* Read header quadlet for the block to get the length. */
+		if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+			return -1;
+		end = i + (rom[i] >> 16) + 1;
+		i++;
+		if (end > ARRAY_SIZE(rom))
+			/* This block extends outside standard config
+			 * area (and the array we're reading it
+			 * into).  That's broken, so ignore this
+			 * device. */
+			return -1;
+
+		/* Now read in the block.  If this is a directory
+		 * block, check the entries as we read them to see if
+		 * it references another block, and push it in that case. */
+		while (i < end) {
+			if (read_rom(device, i, &rom[i]) != RCODE_COMPLETE)
+				return -1;
+			if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
+			    sp < ARRAY_SIZE(stack))
+				stack[sp++] = i + rom[i];
+			i++;
+		}
+		if (length < i)
+			length = i;
+	}
+
+	device->config_rom = kmalloc(length * 4, GFP_KERNEL);
+	if (device->config_rom == NULL)
+		return -1;
+	memcpy(device->config_rom, rom, length * 4);
+	device->config_rom_length = length;
+
+	return 0;
+}
+
+static void fw_unit_release(struct device *dev)
+{
+	struct fw_unit *unit = fw_unit(dev);
+
+	kfree(unit);
+}
+
+static int is_fw_unit(struct device *dev)
+{
+	return dev->release == fw_unit_release;
+}
+
+static void create_units(struct fw_device *device)
+{
+	struct fw_csr_iterator ci;
+	struct fw_unit *unit;
+	int key, value, i;
+
+	i = 0;
+	fw_csr_iterator_init(&ci, &device->config_rom[5]);
+	while (fw_csr_iterator_next(&ci, &key, &value)) {
+		if (key != (CSR_UNIT | CSR_DIRECTORY))
+			continue;
+
+		/* Get the address of the unit directory and try to
+		 * match the drivers id_tables against it. */
+		unit = kzalloc(sizeof *unit, GFP_KERNEL);
+		if (unit == NULL) {
+			fw_error("failed to allocate memory for unit\n");
+			continue;
+		}
+
+		unit->directory = ci.p + value - 1;
+		unit->device.bus = &fw_bus_type;
+		unit->device.release = fw_unit_release;
+		unit->device.parent = &device->device;
+		snprintf(unit->device.bus_id, sizeof unit->device.bus_id,
+			 "%s.%d", device->device.bus_id, i++);
+
+		if (device_register(&unit->device) < 0) {
+			kfree(unit);
+			continue;
+		}
+
+		if (device_create_file(&unit->device, &modalias_attribute) < 0) {
+			device_unregister(&unit->device);
+			kfree(unit);
+		}
+	}
+}
+
+static int shutdown_unit(struct device *device, void *data)
+{
+	struct fw_unit *unit = fw_unit(device);
+
+	if (is_fw_unit(device)) {
+		device_remove_file(&unit->device, &modalias_attribute);
+		device_unregister(&unit->device);
+	}
+
+	return 0;
+}
+
+static void fw_device_shutdown(struct work_struct *work)
+{
+	struct fw_device *device =
+		container_of(work, struct fw_device, work.work);
+
+	device_remove_file(&device->device, &config_rom_attribute);
+	cdev_del(&device->cdev);
+	unregister_chrdev_region(device->device.devt, 1);
+	device_for_each_child(&device->device, NULL, shutdown_unit);
+	device_unregister(&device->device);
+}
+
+/* These defines control the retry behavior for reading the config
+ * rom.  It shouldn't be necessary to tweak these; if the device
+ * doesn't respond to a config rom read within 10 seconds, it's not
+ * going to respond at all.  As for the initial delay, a lot of
+ * devices will be able to respond within half a second after bus
+ * reset.  On the other hand, it's not really worth being more
+ * aggressive than that, since it scales pretty well; if 10 devices
+ * are plugged in, they're all getting read within one second. */
+
+#define MAX_RETRIES	5
+#define RETRY_DELAY	(2 * HZ)
+#define INITIAL_DELAY	(HZ / 2)
+
+static void fw_device_init(struct work_struct *work)
+{
+	static int serial;
+	struct fw_device *device =
+		container_of(work, struct fw_device, work.work);
+
+	/* All failure paths here set node->data to NULL, so that we
+	 * don't try to do device_for_each_child() on a kfree()'d
+	 * device. */
+
+	if (read_bus_info_block(device) < 0) {
+		if (device->config_rom_retries < MAX_RETRIES) {
+			device->config_rom_retries++;
+			schedule_delayed_work(&device->work, RETRY_DELAY);
+		} else {
+			fw_notify("giving up on config rom for node id %d\n",
+				  device->node_id);
+			fw_device_release(&device->device);
+		}
+		return;
+	}
+
+	device->device.bus = &fw_bus_type;
+	device->device.release = fw_device_release;
+	device->device.parent = device->card->device;
+	snprintf(device->device.bus_id, sizeof device->device.bus_id,
+		 "fw%d", serial++);
+
+	if (alloc_chrdev_region(&device->device.devt, 0, 1, "fw")) {
+		fw_error("Failed to register char device region.\n");
+		goto error;
+	}
+
+	cdev_init(&device->cdev, &fw_device_ops);
+	device->cdev.owner = THIS_MODULE;
+	kobject_set_name(&device->cdev.kobj, device->device.bus_id);
+	if (cdev_add(&device->cdev, device->device.devt, 1)) {
+		fw_error("Failed to register char device.\n");
+		goto error;
+	}
+
+	if (device_add(&device->device)) {
+		fw_error("Failed to add device.\n");
+		goto error;
+	}
+
+	if (device_create_file(&device->device, &config_rom_attribute) < 0) {
+		fw_error("Failed to create config rom file.\n");
+		goto error_with_device;
+	}
+
+	create_units(device);
+
+	/* Transition the device to running state.  If it got pulled
+	 * out from under us while we did the intialization work, we
+	 * have to shut down the device again here.  Normally, though,
+	 * fw_node_event will be responsible for shutting it down when
+	 * necessary.  We have to use the atomic cmpxchg here to avoid
+	 * racing with the FW_NODE_DESTROYED case in
+	 * fw_node_event(). */
+	if (cmpxchg(&device->state,
+		    FW_DEVICE_INITIALIZING,
+		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)
+		fw_device_shutdown(&device->work.work);
+	else
+		fw_notify("created new fw device %s (%d config rom retries)\n",
+			  device->device.bus_id, device->config_rom_retries);
+
+	/* Reschedule the IRM work if we just finished reading the
+	 * root node config rom.  If this races with a bus reset we
+	 * just end up running the IRM work a couple of extra times -
+	 * pretty harmless. */
+	if (device->node == device->card->root_node)
+		schedule_delayed_work(&device->card->work, 0);
+
+	return;
+
+      error_with_device:
+	device_del(&device->device);
+      error:
+	cdev_del(&device->cdev);
+	unregister_chrdev_region(device->device.devt, 1);
+	put_device(&device->device);
+}
+
+static int update_unit(struct device *dev, void *data)
+{
+	struct fw_unit *unit = fw_unit(dev);
+	struct fw_driver *driver = (struct fw_driver *)dev->driver;
+
+	if (is_fw_unit(dev) && driver != NULL && driver->update != NULL)
+		driver->update(unit);
+
+	return 0;
+}
+
+void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
+{
+	struct fw_device *device;
+
+	/* Ignore events for the local node (i.e. the node that
+	 * corresponds to the ieee1394 controller in this linux box). */
+	if (node == card->local_node)
+		return;
+
+	switch (event) {
+	case FW_NODE_CREATED:
+	case FW_NODE_LINK_ON:
+		if (!node->link_on)
+			break;
+
+		device = kzalloc(sizeof(*device), GFP_ATOMIC);
+		if (device == NULL)
+			break;
+
+		/* Do minimal intialization of the device here, the
+		 * rest will happen in fw_device_init().  We need the
+		 * card and node so we can read the config rom and we
+		 * need to do device_initialize() now so
+		 * device_for_each_child() in FW_NODE_UPDATED is
+		 * doesn't freak out. */
+		device_initialize(&device->device);
+		device->state = FW_DEVICE_INITIALIZING;
+		device->card = fw_card_get(card);
+		device->node = fw_node_get(node);
+		device->node_id = node->node_id;
+		device->generation = card->generation;
+
+		/* Set the node data to point back to this device so
+		 * FW_NODE_UPDATED callbacks can update the node_id
+		 * and generation for the device. */
+		node->data = device;
+
+		/* Many devices are slow to respond after bus resets,
+		 * especially if they are bus powered and go through
+		 * power-up after getting plugged in.  We schedule the
+		 * first config rom scan half a second after bus reset. */
+		INIT_DELAYED_WORK(&device->work, fw_device_init);
+		schedule_delayed_work(&device->work, INITIAL_DELAY);
+		break;
+
+	case FW_NODE_UPDATED:
+		if (!node->link_on || node->data == NULL)
+			break;
+
+		device = node->data;
+		device->node_id = node->node_id;
+		device->generation = card->generation;
+		device_for_each_child(&device->device, NULL, update_unit);
+		break;
+
+	case FW_NODE_DESTROYED:
+	case FW_NODE_LINK_OFF:
+		if (!node->data)
+			break;
+
+		/* Destroy the device associated with the node.  There
+		 * are two cases here: either the device is fully
+		 * initialized (FW_DEVICE_RUNNING) or we're in the
+		 * process of reading its config rom
+		 * (FW_DEVICE_INITIALIZING).  If it is fully
+		 * initialized we can reuse device->work to schedule a
+		 * full fw_device_shutdown().  If not, there's work
+		 * scheduled to read it's config rom, and we just put
+		 * the device in shutdown state to have that code fail
+		 * to create the device. */
+		device = node->data;
+		if (xchg(&device->state,
+			 FW_DEVICE_SHUTDOWN) == FW_DEVICE_RUNNING) {
+			INIT_DELAYED_WORK(&device->work, fw_device_shutdown);
+			schedule_delayed_work(&device->work, 0);
+		}
+		break;
+	}
+}