--- /dev/null
+/*
+ * w1.c
+ *
+ * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
+ *
+ *
+ * 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 <asm/atomic.h>
+#include <asm/delay.h>
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/suspend.h>
+
+#include "w1.h"
+#include "w1_io.h"
+#include "w1_log.h"
+#include "w1_int.h"
+#include "w1_family.h"
+#include "w1_netlink.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
+MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
+
+static int w1_timeout = 5 * HZ;
+int w1_max_slave_count = 10;
+
+module_param_named(timeout, w1_timeout, int, 0);
+module_param_named(max_slave_count, w1_max_slave_count, int, 0);
+
+spinlock_t w1_mlock = SPIN_LOCK_UNLOCKED;
+LIST_HEAD(w1_masters);
+
+static pid_t control_thread;
+static int control_needs_exit;
+static DECLARE_COMPLETION(w1_control_complete);
+static DECLARE_WAIT_QUEUE_HEAD(w1_control_wait);
+
+static int w1_master_match(struct device *dev, struct device_driver *drv)
+{
+ return 1;
+}
+
+static int w1_master_probe(struct device *dev)
+{
+ return -ENODEV;
+}
+
+static int w1_master_remove(struct device *dev)
+{
+ return 0;
+}
+
+static void w1_master_release(struct device *dev)
+{
+ struct w1_master *md = container_of(dev, struct w1_master, dev);
+
+ complete(&md->dev_released);
+}
+
+static void w1_slave_release(struct device *dev)
+{
+ struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+ complete(&sl->dev_released);
+}
+
+static ssize_t w1_default_read_name(struct device *dev, char *buf)
+{
+ return sprintf(buf, "No family registered.\n");
+}
+
+static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
+ size_t count)
+{
+ return sprintf(buf, "No family registered.\n");
+}
+
+struct bus_type w1_bus_type = {
+ .name = "w1",
+ .match = w1_master_match,
+};
+
+struct device_driver w1_driver = {
+ .name = "w1_driver",
+ .bus = &w1_bus_type,
+ .probe = w1_master_probe,
+ .remove = w1_master_remove,
+};
+
+struct device w1_device = {
+ .parent = NULL,
+ .bus = &w1_bus_type,
+ .bus_id = "w1 bus master",
+ .driver = &w1_driver,
+ .release = &w1_master_release
+};
+
+static struct device_attribute w1_slave_attribute = {
+ .attr = {
+ .name = "name",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE
+ },
+ .show = &w1_default_read_name,
+};
+
+static struct device_attribute w1_slave_attribute_val = {
+ .attr = {
+ .name = "value",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE
+ },
+ .show = &w1_default_read_name,
+};
+
+static ssize_t w1_master_attribute_show(struct device *dev, char *buf)
+{
+ return sprintf(buf, "please fix me\n");
+#if 0
+ struct w1_master *md = container_of(dev, struct w1_master, dev);
+ int c = PAGE_SIZE;
+
+ if (down_interruptible(&md->mutex))
+ return -EBUSY;
+
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", md->name);
+ c -= snprintf(buf + PAGE_SIZE - c, c,
+ "bus_master=0x%p, timeout=%d, max_slave_count=%d, attempts=%lu\n",
+ md->bus_master, w1_timeout, md->max_slave_count,
+ md->attempts);
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%d slaves: ",
+ md->slave_count);
+ if (md->slave_count == 0)
+ c -= snprintf(buf + PAGE_SIZE - c, c, "no.\n");
+ else {
+ struct list_head *ent, *n;
+ struct w1_slave *sl;
+
+ list_for_each_safe(ent, n, &md->slist) {
+ sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+
+ c -= snprintf(buf + PAGE_SIZE - c, c, "%s[%p] ",
+ sl->name, sl);
+ }
+ c -= snprintf(buf + PAGE_SIZE - c, c, "\n");
+ }
+
+ up(&md->mutex);
+
+ return PAGE_SIZE - c;
+#endif
+}
+
+struct device_attribute w1_master_attribute = {
+ .attr = {
+ .name = "w1_master_stats",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE,
+ },
+ .show = &w1_master_attribute_show,
+};
+
+static struct bin_attribute w1_slave_bin_attribute = {
+ .attr = {
+ .name = "w1_slave",
+ .mode = S_IRUGO,
+ .owner = THIS_MODULE,
+ },
+ .size = W1_SLAVE_DATA_SIZE,
+ .read = &w1_default_read_bin,
+};
+
+static int __w1_attach_slave_device(struct w1_slave *sl)
+{
+ int err;
+
+ sl->dev.parent = &sl->master->dev;
+ sl->dev.driver = sl->master->driver;
+ sl->dev.bus = &w1_bus_type;
+ sl->dev.release = &w1_slave_release;
+
+ snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
+ "%x-%llx",
+ (unsigned int) sl->reg_num.family,
+ (unsigned long long) sl->reg_num.id);
+ snprintf (&sl->name[0], sizeof(sl->name),
+ "%x-%llx",
+ (unsigned int) sl->reg_num.family,
+ (unsigned long long) sl->reg_num.id);
+
+ dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
+ &sl->dev.bus_id[0]);
+
+ err = device_register(&sl->dev);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "Device registration [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ return err;
+ }
+
+ w1_slave_bin_attribute.read = sl->family->fops->rbin;
+ w1_slave_attribute.show = sl->family->fops->rname;
+ w1_slave_attribute_val.show = sl->family->fops->rval;
+ w1_slave_attribute_val.attr.name = sl->family->fops->rvalname;
+
+ err = device_create_file(&sl->dev, &w1_slave_attribute);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ device_unregister(&sl->dev);
+ return err;
+ }
+
+ err = device_create_file(&sl->dev, &w1_slave_attribute_val);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ device_remove_file(&sl->dev, &w1_slave_attribute);
+ device_unregister(&sl->dev);
+ return err;
+ }
+
+ err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_bin_attribute);
+ if (err < 0) {
+ dev_err(&sl->dev,
+ "sysfs file creation for [%s] failed. err=%d\n",
+ sl->dev.bus_id, err);
+ device_remove_file(&sl->dev, &w1_slave_attribute);
+ device_remove_file(&sl->dev, &w1_slave_attribute_val);
+ device_unregister(&sl->dev);
+ return err;
+ }
+
+ list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
+
+ return 0;
+}
+
+static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
+{
+ struct w1_slave *sl;
+ struct w1_family *f;
+ int err;
+
+ sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
+ if (!sl) {
+ dev_err(&dev->dev,
+ "%s: failed to allocate new slave device.\n",
+ __func__);
+ return -ENOMEM;
+ }
+
+ memset(sl, 0, sizeof(*sl));
+
+ sl->owner = THIS_MODULE;
+ sl->master = dev;
+
+ memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
+ atomic_set(&sl->refcnt, 0);
+ init_completion(&sl->dev_released);
+
+ spin_lock(&w1_flock);
+ f = w1_family_registered(rn->family);
+ if (!f) {
+ spin_unlock(&w1_flock);
+ dev_info(&dev->dev, "Family %x is not registered.\n",
+ rn->family);
+ kfree(sl);
+ return -ENODEV;
+ }
+ __w1_family_get(f);
+ spin_unlock(&w1_flock);
+
+ sl->family = f;
+
+
+ err = __w1_attach_slave_device(sl);
+ if (err < 0) {
+ dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
+ sl->name);
+ w1_family_put(sl->family);
+ kfree(sl);
+ return err;
+ }
+
+ dev->slave_count++;
+
+ return 0;
+}
+
+static void w1_slave_detach(struct w1_slave *sl)
+{
+ dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
+
+ while (atomic_read(&sl->refcnt))
+ schedule_timeout(10);
+
+ sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_bin_attribute);
+ device_remove_file(&sl->dev, &w1_slave_attribute);
+ device_unregister(&sl->dev);
+ w1_family_put(sl->family);
+}
+
+static void w1_search(struct w1_master *dev)
+{
+ u64 last, rn, tmp;
+ int i, count = 0, slave_count;
+ int last_family_desc, last_zero, last_device;
+ int search_bit, id_bit, comp_bit, desc_bit;
+ struct list_head *ent;
+ struct w1_slave *sl;
+ int family_found = 0;
+ struct w1_netlink_msg msg;
+
+ dev->attempts++;
+
+ memset(&msg, 0, sizeof(msg));
+
+ search_bit = id_bit = comp_bit = 0;
+ rn = tmp = last = 0;
+ last_device = last_zero = last_family_desc = 0;
+
+ desc_bit = 64;
+
+ while (!(id_bit && comp_bit) && !last_device
+ && count++ < dev->max_slave_count) {
+ last = rn;
+ rn = 0;
+
+ last_family_desc = 0;
+
+ /*
+ * Reset bus and all 1-wire device state machines
+ * so they can respond to our requests.
+ *
+ * Return 0 - device(s) present, 1 - no devices present.
+ */
+ if (w1_reset_bus(dev)) {
+ dev_info(&dev->dev, "No devices present on the wire.\n");
+ break;
+ }
+
+#if 1
+ memset(&msg, 0, sizeof(msg));
+
+ w1_write_8(dev, W1_SEARCH);
+ for (i = 0; i < 64; ++i) {
+ /*
+ * Read 2 bits from bus.
+ * All who don't sleep must send ID bit and COMPLEMENT ID bit.
+ * They actually are ANDed between all senders.
+ */
+ id_bit = w1_read_bit(dev);
+ comp_bit = w1_read_bit(dev);
+
+ if (id_bit && comp_bit)
+ break;
+
+ if (id_bit == 0 && comp_bit == 0) {
+ if (i == desc_bit)
+ search_bit = 1;
+ else if (i > desc_bit)
+ search_bit = 0;
+ else
+ search_bit = ((last >> i) & 0x1);
+
+ if (search_bit == 0) {
+ last_zero = i;
+ if (last_zero < 9)
+ last_family_desc = last_zero;
+ }
+
+ }
+ else
+ search_bit = id_bit;
+
+ tmp = search_bit;
+ rn |= (tmp << i);
+
+ /*
+ * Write 1 bit to bus
+ * and make all who don't have "search_bit" in "i"'th position
+ * in it's registration number sleep.
+ */
+ w1_write_bit(dev, search_bit);
+
+ }
+#endif
+ msg.id.w1_id = rn;
+ msg.val = w1_calc_crc8((u8 *) & rn, 7);
+ w1_netlink_send(dev, &msg);
+
+ if (desc_bit == last_zero)
+ last_device = 1;
+
+ desc_bit = last_zero;
+
+ slave_count = 0;
+ list_for_each(ent, &dev->slist) {
+ struct w1_reg_num *tmp;
+
+ tmp = (struct w1_reg_num *) &rn;
+
+ sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+
+ if (sl->reg_num.family == tmp->family &&
+ sl->reg_num.id == tmp->id &&
+ sl->reg_num.crc == tmp->crc)
+ break;
+ else if (sl->reg_num.family == tmp->family) {
+ family_found = 1;
+ break;
+ }
+
+ slave_count++;
+ }
+
+ if (slave_count == dev->slave_count &&
+ msg.val && (*((__u8 *) & msg.val) == msg.id.id.crc)) {
+ w1_attach_slave_device(dev, (struct w1_reg_num *) &rn);
+ }
+ }
+}
+
+int w1_control(void *data)
+{
+ struct w1_slave *sl;
+ struct w1_master *dev;
+ struct list_head *ent, *ment, *n, *mn;
+ int err, have_to_wait = 0, timeout;
+
+ daemonize("w1_control");
+ allow_signal(SIGTERM);
+
+ while (!control_needs_exit || have_to_wait) {
+ have_to_wait = 0;
+
+ timeout = w1_timeout;
+ do {
+ timeout = interruptible_sleep_on_timeout(&w1_control_wait, timeout);
+ if (current->flags & PF_FREEZE)
+ refrigerator(PF_FREEZE);
+ } while (!signal_pending(current) && (timeout > 0));
+
+ if (signal_pending(current))
+ flush_signals(current);
+
+ list_for_each_safe(ment, mn, &w1_masters) {
+ dev = list_entry(ment, struct w1_master, w1_master_entry);
+
+ if (!control_needs_exit && !dev->need_exit)
+ continue;
+ /*
+ * Little race: we can create thread but not set the flag.
+ * Get a chance for external process to set flag up.
+ */
+ if (!dev->initialized) {
+ have_to_wait = 1;
+ continue;
+ }
+
+ spin_lock(&w1_mlock);
+ list_del(&dev->w1_master_entry);
+ spin_unlock(&w1_mlock);
+
+ if (control_needs_exit) {
+ dev->need_exit = 1;
+
+ err = kill_proc(dev->kpid, SIGTERM, 1);
+ if (err)
+ dev_err(&dev->dev,
+ "Failed to send signal to w1 kernel thread %d.\n",
+ dev->kpid);
+ }
+
+ wait_for_completion(&dev->dev_exited);
+
+ list_for_each_safe(ent, n, &dev->slist) {
+ sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+
+ if (!sl)
+ dev_warn(&dev->dev,
+ "%s: slave entry is NULL.\n",
+ __func__);
+ else {
+ list_del(&sl->w1_slave_entry);
+
+ w1_slave_detach(sl);
+ kfree(sl);
+ }
+ }
+ device_remove_file(&dev->dev, &w1_master_attribute);
+ atomic_dec(&dev->refcnt);
+ }
+ }
+
+ complete_and_exit(&w1_control_complete, 0);
+}
+
+int w1_process(void *data)
+{
+ struct w1_master *dev = (struct w1_master *) data;
+ unsigned long timeout;
+
+ daemonize("%s", dev->name);
+ allow_signal(SIGTERM);
+
+ while (!dev->need_exit) {
+ timeout = w1_timeout;
+ do {
+ timeout = interruptible_sleep_on_timeout(&dev->kwait, timeout);
+ if (current->flags & PF_FREEZE)
+ refrigerator(PF_FREEZE);
+ } while (!signal_pending(current) && (timeout > 0));
+
+ if (signal_pending(current))
+ flush_signals(current);
+
+ if (dev->need_exit)
+ break;
+
+ if (!dev->initialized)
+ continue;
+
+ if (down_interruptible(&dev->mutex))
+ continue;
+ w1_search(dev);
+ up(&dev->mutex);
+ }
+
+ atomic_dec(&dev->refcnt);
+ complete_and_exit(&dev->dev_exited, 0);
+
+ return 0;
+}
+
+int w1_init(void)
+{
+ int retval;
+
+ printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
+
+ retval = bus_register(&w1_bus_type);
+ if (retval) {
+ printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
+ goto err_out_exit_init;
+ }
+
+ retval = driver_register(&w1_driver);
+ if (retval) {
+ printk(KERN_ERR
+ "Failed to register master driver. err=%d.\n",
+ retval);
+ goto err_out_bus_unregister;
+ }
+
+ control_thread = kernel_thread(&w1_control, NULL, 0);
+ if (control_thread < 0) {
+ printk(KERN_ERR "Failed to create control thread. err=%d\n",
+ control_thread);
+ retval = control_thread;
+ goto err_out_driver_unregister;
+ }
+
+ return 0;
+
+err_out_driver_unregister:
+ driver_unregister(&w1_driver);
+
+err_out_bus_unregister:
+ bus_unregister(&w1_bus_type);
+
+err_out_exit_init:
+ return retval;
+}
+
+void w1_fini(void)
+{
+ struct w1_master *dev;
+ struct list_head *ent, *n;
+
+ list_for_each_safe(ent, n, &w1_masters) {
+ dev = list_entry(ent, struct w1_master, w1_master_entry);
+ __w1_remove_master_device(dev);
+ }
+
+ control_needs_exit = 1;
+
+ wait_for_completion(&w1_control_complete);
+
+ driver_unregister(&w1_driver);
+ bus_unregister(&w1_bus_type);
+}
+
+module_init(w1_init);
+module_exit(w1_fini);
git://git.onelab.eu / linux-2.6.git / blobdiff