[RFC/PATCH 19/22] W1: convert families to be proper sysfs rivers

From: Dmitry Torokhov
Date: Thu Apr 21 2005 - 03:32:54 EST

W1: convert family into proper device-model drivers:
- embed driver structure into w1_family and register with the
driver core;
- do not try to manually bind slaves to familes, leave it to
the driver core;
- fold w1_family.c into w1.c

Signed-off-by: Dmitry Torokhov <dtor@xxxxxxx>
---

drivers/w1/w1_family.c | 165 -------------------------------------------
dtor/drivers/w1/Makefile | 2
dtor/drivers/w1/w1.c | 118 +++++++++++++++++++++++-------
dtor/drivers/w1/w1.h | 16 +++-
dtor/drivers/w1/w1_family.h | 28 -------
dtor/drivers/w1/w1_sernum.c | 4 +
dtor/drivers/w1/w1_thermal.c | 6 +
7 files changed, 114 insertions(+), 225 deletions(-)

Index: dtor/drivers/w1/w1.c
===================================================================
--- dtor.orig/drivers/w1/w1.c
+++ dtor/drivers/w1/w1.c
@@ -37,7 +37,6 @@
#include "w1.h"
#include "w1_io.h"
#include "w1_log.h"
-#include "w1_family.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Evgeniy Polyakov <johnpol@xxxxxxxxxxx>");
@@ -51,14 +50,24 @@ module_param_named(scan_interval, w1_sca
module_param_named(max_slave_count, w1_max_slave_count, int, 0);
module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);

-static int w1_master_match(struct device *dev, struct device_driver *drv)
+static int w1_bus_match(struct device *dev, struct device_driver *drv)
{
- return 1;
+ /*
+ * Master devices are bound explicitely upon registration
+ * so we can only get slaves here.
+ */
+ struct w1_slave *slave = to_w1_slave(dev);
+ struct w1_family *family = to_w1_family(drv);
+
+ if (slave->reg_num.family == family->fid)
+ return 1;
+
+ return 0;
}

static struct bus_type w1_bus_type = {
.name = "w1",
- .match = w1_master_match,
+ .match = w1_bus_match,
};

struct device_driver w1_master_driver = {
@@ -102,7 +111,6 @@ static void w1_slave_release(struct devi
{
struct w1_slave *slave = to_w1_slave(dev);

- w1_family_put(slave->family);
kfree(slave);
module_put(THIS_MODULE);
}
@@ -127,28 +135,13 @@ static int w1_attach_slave_device(struct
set_bit(W1_SLAVE_ACTIVE, &slave->flags);
slave->ttl = master->slave_ttl;

- spin_lock(&w1_flock);
- slave->family = w1_family_registered(rn->family);
- if (!slave->family) {
- spin_unlock(&w1_flock);
- dev_info(&master->dev,
- "Family %x for %02x.%012llx.%02x is not registered.\n",
- rn->family, rn->family,
- (unsigned long long)rn->id, rn->crc);
- kfree(slave);
- return -ENODEV;
- }
- __w1_family_get(slave->family);
- spin_unlock(&w1_flock);
-
- slave->dev.parent = &slave->master->dev;
- slave->dev.bus = &w1_bus_type;
- slave->dev.release = &w1_slave_release;
-
snprintf(&slave->dev.bus_id[0], sizeof(slave->dev.bus_id),
"%02x-%012llx",
(unsigned int) slave->reg_num.family,
(unsigned long long) slave->reg_num.id);
+ slave->dev.parent = &slave->master->dev;
+ slave->dev.bus = &w1_bus_type;
+ slave->dev.release = &w1_slave_release;

dev_dbg(&slave->dev, "%s: registering %s.\n", __func__,
&slave->dev.bus_id[0]);
@@ -158,7 +151,6 @@ static int w1_attach_slave_device(struct
dev_err(&slave->dev,
"Device registration [%s] failed. err=%d\n",
slave->dev.bus_id, error);
- w1_family_put(slave->family);
kfree(slave);
return error;
}
@@ -174,8 +166,6 @@ static int w1_attach_slave_device(struct
return error;
}

- w1_family_join(slave); /* assume it always succeeds for now */
-
list_add_tail(&slave->node, &slave->master->slist);

return 0;
@@ -186,7 +176,6 @@ static void w1_slave_detach(struct w1_sl
dev_info(&slave->dev, "%s: detaching %s.\n",
__func__, slave->dev.bus_id);

- w1_family_leave(slave);
sysfs_remove_group(&slave->dev.kobj, &w1_slave_defattr_group);
device_unregister(&slave->dev);
}
@@ -464,6 +453,79 @@ void w1_remove_master_device(struct w1_m
device_unregister(&master->dev);
}

+static int w1_family_probe(struct device *dev)
+{
+ struct w1_slave *slave = to_w1_slave(dev);
+ struct w1_family *family = to_w1_family(dev->driver);
+ int retval;
+
+ retval = down_interruptible(&slave->mutex);
+ if (retval)
+ return retval;
+
+ if (family->join)
+ retval = family->join(slave);
+
+ up(&slave->mutex);
+ return retval;
+}
+
+static int w1_family_remove(struct device *dev)
+{
+ struct w1_slave *slave = to_w1_slave(dev);
+ struct w1_family *family = to_w1_family(dev->driver);
+
+ down(&slave->mutex);
+
+ if (family->leave)
+ family->leave(slave);
+
+ up(&slave->mutex);
+ return 0;
+}
+
+static ssize_t w1_family_show_name(struct device_driver *drv, char *buf)
+{
+ struct w1_family *family = to_w1_family(drv);
+
+ return sprintf(buf, "%s\n", family->name);
+}
+
+static struct driver_attribute w1_family_attribute_name =
+ __ATTR(name, S_IRUGO, w1_family_show_name, NULL);
+
+int w1_register_family(struct w1_family *family)
+{
+ int error;
+
+ family->driver.bus = &w1_bus_type;
+ family->driver.probe = w1_family_probe;
+ family->driver.remove = w1_family_remove;
+
+ error = driver_register(&family->driver);
+ if (error) {
+ printk(KERN_ERR "w1: Failed to register family. err=%d.\n",
+ error);
+ return error;
+ }
+
+ error = driver_create_file(&family->driver, &w1_family_attribute_name);
+ if (error) {
+ printk(KERN_ERR
+ "w1: Failed to create name family attribute. err=%d.\n",
+ error);
+ driver_unregister(&family->driver);
+ return error;
+ }
+
+ return 0;
+}
+
+void w1_unregister_family(struct w1_family *family)
+{
+ driver_unregister(&family->driver);
+}
+
static int w1_init(void)
{
int error;
@@ -501,3 +563,5 @@ module_exit(w1_exit);
EXPORT_SYMBOL(w1_allocate_master_device);
EXPORT_SYMBOL(w1_add_master_device);
EXPORT_SYMBOL(w1_remove_master_device);
+EXPORT_SYMBOL(w1_register_family);
+EXPORT_SYMBOL(w1_unregister_family);
Index: dtor/drivers/w1/w1.h
===================================================================
--- dtor.orig/drivers/w1/w1.h
+++ dtor/drivers/w1/w1.h
@@ -44,8 +44,6 @@ struct w1_reg_num

#include <asm/semaphore.h>

-#include "w1_family.h"
-
#define W1_MAXNAMELEN 32

#define W1_SEARCH 0xF0
@@ -68,7 +66,6 @@ struct w1_slave
int ttl;

struct w1_master *master;
- struct w1_family *family;
struct device dev;
struct semaphore mutex;
};
@@ -119,6 +116,19 @@ struct w1_master *w1_allocate_master_dev
int w1_add_master_device(struct w1_master *);
void w1_remove_master_device(struct w1_master *);

+struct w1_family {
+ struct device_driver driver;
+ u8 fid;
+ const char *name;
+
+ int (*join)(struct w1_slave *);
+ void (*leave)(struct w1_slave *);
+};
+#define to_w1_family(drv) container_of((drv), struct w1_family, driver)
+
+int w1_register_family(struct w1_family *f);
+void w1_unregister_family(struct w1_family *f);
+
#endif /* __KERNEL__ */

#endif /* __W1_H */
Index: dtor/drivers/w1/w1_thermal.c
===================================================================
--- dtor.orig/drivers/w1/w1_thermal.c
+++ dtor/drivers/w1/w1_thermal.c
@@ -51,7 +51,11 @@ static void w1_thermal_leave(struct w1_s
}

static struct w1_family w1_thermal_family = {
+ .driver = {
+ .name = "thermal",
+ },
.fid = W1_FAMILY_THERMAL,
+ .name = "Digital Thermometer Driver",
.join = w1_thermal_join,
.leave = w1_thermal_leave,
};
@@ -141,7 +145,7 @@ static ssize_t w1_thermal_show_temp(stru
if (error)
goto out;

- if (slave->family != &w1_thermal_family) {
+ if (slave->dev.driver != &w1_thermal_family.driver) {
error = -ENODEV;
goto out;
}
Index: dtor/drivers/w1/Makefile
===================================================================
--- dtor.orig/drivers/w1/Makefile
+++ dtor/drivers/w1/Makefile
@@ -7,7 +7,7 @@ EXTRA_CFLAGS += -DNETLINK_DISABLED
endif

obj-$(CONFIG_W1) += wire.o
-wire-objs := w1.o w1_family.o w1_io.o
+wire-objs := w1.o w1_io.o

obj-$(CONFIG_W1_MATROX) += matrox_w1.o
obj-$(CONFIG_W1_THERMAL) += w1_thermal.o
Index: dtor/drivers/w1/w1_sernum.c
===================================================================
--- dtor.orig/drivers/w1/w1_sernum.c
+++ dtor/drivers/w1/w1_sernum.c
@@ -41,7 +41,11 @@ MODULE_DESCRIPTION("1-Wire Silicon Seria
*/

static struct w1_family w1_serial_num_family = {
+ .driver = {
+ .name = "sernum",
+ },
.fid = W1_FAMILY_SERIAL_NUM,
+ .name = "Serial Number Driver",
};

static int __init w1_serial_num_init(void)
Index: dtor/drivers/w1/w1_family.h
===================================================================
--- dtor.orig/drivers/w1/w1_family.h
+++ dtor/drivers/w1/w1_family.h
@@ -22,35 +22,7 @@
#ifndef __W1_FAMILY_H
#define __W1_FAMILY_H

-#include <linux/types.h>
-#include <linux/device.h>
-#include <asm/atomic.h>
-
#define W1_FAMILY_SERIAL_NUM 0x01
#define W1_FAMILY_THERMAL 0x10

-struct w1_slave;
-
-struct w1_family
-{
- struct list_head family_entry;
- u8 fid;
- atomic_t refcnt;
- u8 need_exit;
-
- int (*join)(struct w1_slave *);
- void (*leave)(struct w1_slave *);
-};
-
-extern spinlock_t w1_flock;
-
-void w1_family_get(struct w1_family *);
-void w1_family_put(struct w1_family *);
-void __w1_family_get(struct w1_family *);
-void __w1_family_put(struct w1_family *);
-struct w1_family * w1_family_registered(u8);
-int w1_family_join(struct w1_slave *);
-void w1_family_leave(struct w1_slave *);
-void w1_unregister_family(struct w1_family *);
-int w1_register_family(struct w1_family *);
#endif /* __W1_FAMILY_H */
Index: dtor/drivers/w1/w1_family.c
===================================================================
--- dtor.orig/drivers/w1/w1_family.c
+++ /dev/null
@@ -1,165 +0,0 @@
-/*
- * w1_family.c
- *
- * Copyright (c) 2004 Evgeniy Polyakov <johnpol@xxxxxxxxxxx>
- *
- *
- * 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/spinlock.h>
-#include <linux/list.h>
-#include <linux/delay.h>
-
-#include "w1.h"
-#include "w1_family.h"
-
-DEFINE_SPINLOCK(w1_flock);
-static LIST_HEAD(w1_families);
-
-int w1_register_family(struct w1_family *newf)
-{
- struct list_head *ent, *n;
- struct w1_family *f;
- int ret = 0;
-
- spin_lock(&w1_flock);
- list_for_each_safe(ent, n, &w1_families) {
- f = list_entry(ent, struct w1_family, family_entry);
-
- if (f->fid == newf->fid) {
- ret = -EEXIST;
- break;
- }
- }
-
- if (!ret) {
- atomic_set(&newf->refcnt, 0);
- newf->need_exit = 0;
- list_add_tail(&newf->family_entry, &w1_families);
- }
-
- spin_unlock(&w1_flock);
-
- return ret;
-}
-
-void w1_unregister_family(struct w1_family *fent)
-{
- struct list_head *ent, *n;
- struct w1_family *f;
-
- spin_lock(&w1_flock);
- list_for_each_safe(ent, n, &w1_families) {
- f = list_entry(ent, struct w1_family, family_entry);
-
- if (f->fid == fent->fid) {
- list_del(&fent->family_entry);
- break;
- }
- }
-
- fent->need_exit = 1;
-
- spin_unlock(&w1_flock);
-
- while (atomic_read(&fent->refcnt)) {
- printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n",
- fent->fid, atomic_read(&fent->refcnt));
-
- if (msleep_interruptible(1000))
- flush_signals(current);
- }
-}
-
-/*
- * Should be called under w1_flock held.
- */
-struct w1_family * w1_family_registered(u8 fid)
-{
- struct list_head *ent, *n;
- struct w1_family *f = NULL;
- int ret = 0;
-
- list_for_each_safe(ent, n, &w1_families) {
- f = list_entry(ent, struct w1_family, family_entry);
-
- if (f->fid == fid) {
- ret = 1;
- break;
- }
- }
-
- return (ret) ? f : NULL;
-}
-
-int w1_family_join(struct w1_slave *slave)
-{
- int retval;
-
- retval = down_interruptible(&slave->mutex);
- if (retval)
- return retval;
-
- if (slave->family->join)
- retval = slave->family->join(slave);
-
- up(&slave->mutex);
- return retval;
-}
-
-void w1_family_leave(struct w1_slave *slave)
-{
- down(&slave->mutex);
-
- if (slave->family->leave)
- slave->family->leave(slave);
-
- up(&slave->mutex);
-}
-
-void w1_family_put(struct w1_family *f)
-{
- spin_lock(&w1_flock);
- __w1_family_put(f);
- spin_unlock(&w1_flock);
-}
-
-void __w1_family_put(struct w1_family *f)
-{
- if (atomic_dec_and_test(&f->refcnt))
- f->need_exit = 1;
-}
-
-void w1_family_get(struct w1_family *f)
-{
- spin_lock(&w1_flock);
- __w1_family_get(f);
- spin_unlock(&w1_flock);
-
-}
-
-void __w1_family_get(struct w1_family *f)
-{
- smp_mb__before_atomic_inc();
- atomic_inc(&f->refcnt);
- smp_mb__after_atomic_inc();
-}
-
-EXPORT_SYMBOL(w1_family_get);
-EXPORT_SYMBOL(w1_family_put);
-EXPORT_SYMBOL(w1_family_registered);
-EXPORT_SYMBOL(w1_unregister_family);
-EXPORT_SYMBOL(w1_register_family);
-
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