firewire: Add sysfs attributes for config rom directory values.

We export the entire config rom, so this is technically redundant,
but should make udev rules and HAL integration easier.

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

1 files changed, 147 insertions, 4 deletions

diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index 59451f524fc3..71bb9d1e8196 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -28,6 +28,7 @@
 #include <linux/idr.h>
 #include <linux/rwsem.h>
 #include <asm/semaphore.h>
+#include <linux/ctype.h>
 #include "fw-transaction.h"
 #include "fw-topology.h"
 #include "fw-device.h"
@@ -193,6 +194,129 @@ int fw_device_enable_phys_dma(struct fw_device *device)
 }
 EXPORT_SYMBOL(fw_device_enable_phys_dma);
 
+struct config_rom_attribute {
+        struct device_attribute attr;
+        u32 key;
+};
+
+static ssize_t
+show_immediate(struct device *dev, struct device_attribute *dattr, char *buf)
+{
+        struct config_rom_attribute *attr =
+                container_of(dattr, struct config_rom_attribute, attr);
+        struct fw_csr_iterator ci;
+        u32 *dir;
+        int key, value;
+
+        if (is_fw_unit(dev))
+                dir = fw_unit(dev)->directory;
+        else
+                dir = fw_device(dev)->config_rom + 5;
+
+        fw_csr_iterator_init(&ci, dir);
+        while (fw_csr_iterator_next(&ci, &key, &value))
+                if (attr->key == key)
+                        return snprintf(buf, buf ? PAGE_SIZE : 0,
+                                        "0x%06x\n", value);
+
+        return -ENOENT;
+}
+
+#define IMMEDIATE_ATTR(name, key)                               \
+        { __ATTR(name, S_IRUGO, show_immediate, NULL), key }
+
+static ssize_t
+show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf)
+{
+        struct config_rom_attribute *attr =
+                container_of(dattr, struct config_rom_attribute, attr);
+        struct fw_csr_iterator ci;
+        u32 *dir, *block = NULL, *p, *end;
+        int length, key, value, last_key = 0;
+        char *b;
+
+        if (is_fw_unit(dev))
+                dir = fw_unit(dev)->directory;
+        else
+                dir = fw_device(dev)->config_rom + 5;
+
+        fw_csr_iterator_init(&ci, dir);
+        while (fw_csr_iterator_next(&ci, &key, &value)) {
+                if (attr->key == last_key &&
+                    key == (CSR_DESCRIPTOR | CSR_LEAF))
+                        block = ci.p - 1 + value;
+                last_key = key;
+        }
+
+        if (block == NULL)
+                return -ENOENT;
+
+        length = min(block[0] >> 16, 256U);
+        if (length < 3)
+                return -ENOENT;
+
+        if (block[1] != 0 || block[2] != 0)
+                /* Unknown encoding. */
+                return -ENOENT;
+
+        if (buf == NULL)
+                return length * 4;
+
+        b = buf;
+        end = &block[length + 1];
+        for (p = &block[3]; p < end; p++, b += 4)
+                * (u32 *) b = (__force u32) __cpu_to_be32(*p);
+
+        /* Strip trailing whitespace and add newline. */
+        while (b--, (isspace(*b) || *b == '\0') && b > buf);
+        strcpy(b + 1, "\n");
+
+        return b + 2 - buf;
+}
+
+#define TEXT_LEAF_ATTR(name, key)                               \
+        { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
+
+static struct config_rom_attribute config_rom_attributes[] = {
+        IMMEDIATE_ATTR(vendor, CSR_VENDOR),
+        IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
+        IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
+        IMMEDIATE_ATTR(version, CSR_VERSION),
+        IMMEDIATE_ATTR(model, CSR_MODEL),
+        TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
+        TEXT_LEAF_ATTR(model_name, CSR_MODEL),
+        TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
+};
+
+static void
+remove_config_rom_attributes(struct device *dev)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++)
+                device_remove_file(dev, &config_rom_attributes[i].attr);
+}
+
+static int
+add_config_rom_attributes(struct device *dev)
+{
+        struct device_attribute *attr;
+        int i, err = 0;
+
+        for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
+                attr = &config_rom_attributes[i].attr;
+                if (attr->show(dev, attr, NULL) < 0)
+                        continue;
+                err = device_create_file(dev, attr);
+                if (err < 0) {
+                        remove_config_rom_attributes(dev);
+                        break;
+                }
+        }
+
+        return err;
+}
+
 static ssize_t
 modalias_show(struct device *dev,
               struct device_attribute *attr, char *buf)
@@ -399,15 +523,26 @@ static void create_units(struct fw_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_register(&unit->device) < 0)
+                        goto skip_unit;
+
+                if (add_config_rom_attributes(&unit->device) < 0)
+                        goto skip_unregister;
+
+                continue;
+
+        skip_unregister:
+                device_unregister(&unit->device);
+        skip_unit:
+                kfree(unit);
         }
 }
 
 static int shutdown_unit(struct device *device, void *data)
 {
+        struct fw_unit *unit = fw_unit(device);
+
+        remove_config_rom_attributes(&unit->device);
         device_unregister(device);
 
         return 0;
@@ -437,6 +572,8 @@ static void fw_device_shutdown(struct work_struct *work)
         idr_remove(&fw_device_idr, minor);
         up_write(&fw_bus_type.subsys.rwsem);
 
+        remove_config_rom_attributes(&device->device);
+
         fw_device_cdev_remove(device);
         device_for_each_child(&device->device, NULL, shutdown_unit);
         device_unregister(&device->device);
@@ -504,6 +641,10 @@ static void fw_device_init(struct work_struct *work)
                 goto error_with_cdev;
         }
 
+        err = add_config_rom_attributes(&device->device);
+        if (err < 0)
+                goto error_with_register;
+
         create_units(device);
 
         /* Transition the device to running state.  If it got pulled
@@ -530,6 +671,8 @@ static void fw_device_init(struct work_struct *work)
 
         return;
 
+ error_with_register:
+        device_unregister(&device->device);
  error_with_cdev:
         down_write(&fw_bus_type.subsys.rwsem);
         idr_remove(&fw_device_idr, minor);