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 000000000000..ec1cb7fc8e96
--- /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;
+        }
+}