From 59d4467be405316916a4087d5b02d99196eeef04 Mon Sep 17 00:00:00 2001
From: NeilBrown
Date: Tue, 1 May 2012 11:49:24 -0700
Subject: w1: introduce a slave mutex for serializing IO

w1 devices need a mutex to serial IO.  Most use master->mutex.
However that is used for other purposes and they can conflict.

In particular master->mutex is held while w1_attach_slave_device is
called.

For bq27000, this registers a 'powersupply' device which tries to read the
current status.  The attempt to read will cause a deadlock on
master->mutex.

So create a new per-slave mutex and use that for serializing IO for
bq27000.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/slaves/w1_bq27000.c | 4 ++--
 drivers/w1/w1.c                | 1 +
 drivers/w1/w1.h                | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 52ad812fa1e7..87554788fa32 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg)
 	u8 val;
 	struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->mutex);
 	w1_write_8(sl->master, HDQ_CMD_READ | reg);
 	val = w1_read_8(sl->master);
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->mutex);
 
 	return val;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 2f2e894ea0c8..69075c3dfc73 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -688,6 +688,7 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 0);
 	init_completion(&sl->released);
+	mutex_init(&sl->mutex);
 
 	spin_lock(&w1_flock);
 	f = w1_family_registered(rn->family);
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 4d012ca3f32c..8c8be380a98a 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -75,6 +75,7 @@ struct w1_slave
 	void			*family_data;
 	struct device		dev;
 	struct completion	released;
+	struct mutex		mutex;
 };
 
 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
-- 
cgit v1.2.3


From 526be41625a8b2282d5720dcb19f927edbf193b4 Mon Sep 17 00:00:00 2001
From: Devendra Naga
Date: Sat, 19 May 2012 07:31:54 +0400
Subject: w1: cleanup w1_uevent

There were some return statements around in the w1_uevent, used goto
to cleanup those return statements with the help of err variable,
and also removed a semi colon at the end of the w1_uevent's closing
brace.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/w1.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 69075c3dfc73..79e488db5104 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -557,7 +557,7 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
 	struct w1_master *md = NULL;
 	struct w1_slave *sl = NULL;
 	char *event_owner, *name;
-	int err;
+	int err = 0;
 
 	if (dev->driver == &w1_master_driver) {
 		md = container_of(dev, struct w1_master, dev);
@@ -576,19 +576,17 @@ static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
 			event_owner, name, dev_name(dev));
 
 	if (dev->driver != &w1_slave_driver || !sl)
-		return 0;
+		goto end;
 
 	err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
 	if (err)
-		return err;
+		goto end;
 
 	err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
 			     (unsigned long long)sl->reg_num.id);
-	if (err)
-		return err;
-
-	return 0;
-};
+end:
+	return err;
+}
 #else
 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-- 
cgit v1.2.3


From dd0aa67cd7cf3f4a3ca52ecc1d6b82f3fad1352b Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman
Date: Wed, 13 Jun 2012 16:33:54 -0700
Subject: Revert "w1: introduce a slave mutex for serializing IO"

This reverts commit 59d4467be405316916a4087d5b02d99196eeef04.

Turns out it was the wrong version, will apply the correct version after
this.

Reported-by: NeilBrown <neilb@suse.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/slaves/w1_bq27000.c | 4 ++--
 drivers/w1/w1.c                | 1 -
 drivers/w1/w1.h                | 1 -
 3 files changed, 2 insertions(+), 4 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 87554788fa32..52ad812fa1e7 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg)
 	u8 val;
 	struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
 
-	mutex_lock(&sl->mutex);
+	mutex_lock(&sl->master->mutex);
 	w1_write_8(sl->master, HDQ_CMD_READ | reg);
 	val = w1_read_8(sl->master);
-	mutex_unlock(&sl->mutex);
+	mutex_unlock(&sl->master->mutex);
 
 	return val;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 79e488db5104..bfb898641029 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -686,7 +686,6 @@ static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 0);
 	init_completion(&sl->released);
-	mutex_init(&sl->mutex);
 
 	spin_lock(&w1_flock);
 	f = w1_family_registered(rn->family);
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 8c8be380a98a..4d012ca3f32c 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -75,7 +75,6 @@ struct w1_slave
 	void			*family_data;
 	struct device		dev;
 	struct completion	released;
-	struct mutex		mutex;
 };
 
 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
-- 
cgit v1.2.3


From 7b5362a603a1ecc9a25b97dafd702b8098090f41 Mon Sep 17 00:00:00 2001
From: NeilBrown
Date: Tue, 22 May 2012 09:43:02 +1000
Subject: w1: omap_hdq: Fix some error/debug handling.

- some debug messages missed spaces
- sometimes no error was returned when it should have been
- sometimes a message is printed when there is no error, rather
  than when there is one.

Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/masters/omap_hdq.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
index 5ef385bfed18..3036b6113ffd 100644
--- a/drivers/w1/masters/omap_hdq.c
+++ b/drivers/w1/masters/omap_hdq.c
@@ -180,6 +180,7 @@ static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
 		hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
 	if (ret == 0) {
 		dev_dbg(hdq_data->dev, "TX wait elapsed\n");
+		ret = -ETIMEDOUT;
 		goto out;
 	}
 
@@ -187,7 +188,7 @@ static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
 	/* check irqstatus */
 	if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) {
 		dev_dbg(hdq_data->dev, "timeout waiting for"
-			"TXCOMPLETE/RXCOMPLETE, %x", *status);
+			" TXCOMPLETE/RXCOMPLETE, %x", *status);
 		ret = -ETIMEDOUT;
 		goto out;
 	}
@@ -198,7 +199,7 @@ static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
 			OMAP_HDQ_FLAG_CLEAR, &tmp_status);
 	if (ret) {
 		dev_dbg(hdq_data->dev, "timeout waiting GO bit"
-			"return to zero, %x", tmp_status);
+			" return to zero, %x", tmp_status);
 	}
 
 out:
@@ -341,7 +342,7 @@ static int omap_hdq_break(struct hdq_data *hdq_data)
 			&tmp_status);
 	if (ret)
 		dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits"
-			"return to zero, %x", tmp_status);
+			" return to zero, %x", tmp_status);
 
 out:
 	mutex_unlock(&hdq_data->hdq_mutex);
@@ -386,7 +387,7 @@ static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
 		/* check irqstatus */
 		if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
 			dev_dbg(hdq_data->dev, "timeout waiting for"
-				"RXCOMPLETE, %x", status);
+				" RXCOMPLETE, %x", status);
 			ret = -ETIMEDOUT;
 			goto out;
 		}
@@ -396,7 +397,7 @@ static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
 out:
 	mutex_unlock(&hdq_data->hdq_mutex);
 rtn:
-	return 0;
+	return ret;
 
 }
 
@@ -470,7 +471,7 @@ static int omap_hdq_put(struct hdq_data *hdq_data)
 
 	if (0 == hdq_data->hdq_usecount) {
 		dev_dbg(hdq_data->dev, "attempt to decrement use count"
-			"when it is zero");
+			" when it is zero");
 		ret = -EINVAL;
 	} else {
 		hdq_data->hdq_usecount--;
@@ -540,7 +541,7 @@ static void omap_w1_write_byte(void *_hdq, u8 byte)
 	mutex_unlock(&hdq_data->hdq_mutex);
 
 	ret = hdq_write_byte(hdq_data, byte, &status);
-	if (ret == 0) {
+	if (ret < 0) {
 		dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status);
 		return;
 	}
-- 
cgit v1.2.3


From b7e938d06d0de43bdbee8844a8736c81480c1031 Mon Sep 17 00:00:00 2001
From: NeilBrown
Date: Tue, 22 May 2012 09:43:02 +1000
Subject: w1: omap_hdq: use wait_event_timeout to wait for read to complete.

There is no gain in having a loop - there is no risk of missing the
interrupt with wait_event_timeout.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/masters/omap_hdq.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
index 3036b6113ffd..848399bfb9b4 100644
--- a/drivers/w1/masters/omap_hdq.c
+++ b/drivers/w1/masters/omap_hdq.c
@@ -354,7 +354,6 @@ static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
 {
 	int ret = 0;
 	u8 status;
-	unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
 
 	ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
 	if (ret < 0) {
@@ -372,15 +371,13 @@ static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
 			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
 			OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
 		/*
-		 * The RX comes immediately after TX. It
-		 * triggers another interrupt before we
-		 * sleep. So we have to wait for RXCOMPLETE bit.
+		 * The RX comes immediately after TX.
 		 */
-		while (!(hdq_data->hdq_irqstatus
-			& OMAP_HDQ_INT_STATUS_RXCOMPLETE)
-			&& time_before(jiffies, timeout)) {
-			schedule_timeout_uninterruptible(1);
-		}
+		wait_event_timeout(hdq_wait_queue,
+				   (hdq_data->hdq_irqstatus
+				    & OMAP_HDQ_INT_STATUS_RXCOMPLETE),
+				   OMAP_HDQ_TIMEOUT);
+
 		hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
 			OMAP_HDQ_CTRL_STATUS_DIR);
 		status = hdq_data->hdq_irqstatus;
-- 
cgit v1.2.3


From b02f8bede217a4b145ecc16d3940c78d83941147 Mon Sep 17 00:00:00 2001
From: NeilBrown
Date: Fri, 18 May 2012 15:59:52 +1000
Subject: W1: split master mutex to avoid deadlocks.

The 'mutex' in struct w1_master is use for two very different
purposes.

Firstly it protects various data structures such as the list of all
slaves.

Secondly it protects the w1 buss against concurrent accesses.

This can lead to deadlocks when the ->probe code called while adding a
slave needs to talk on the bus, as is the case for power_supply
devices.
ds2780 and ds2781 drivers contain a work around to track which
process hold the lock simply to avoid this deadlock.  bq27000 doesn't
have that work around and so deadlocks.

There are other possible deadlocks involving sysfs.
When removing a device the sysfs s_active lock is held, so the lock
that protects the slave list must take precedence over s_active.
However when access power_supply attributes via sysfs, the s_active
lock must take precedence over the lock that protects accesses to
the bus.

So to avoid deadlocks between w1 slaves and sysfs, these must be
two separate locks.  Making them separate means that the work around
in ds2780 and ds2781 can be removed.

So this patch:
 - adds a new mutex: "bus_mutex" which serialises access to the bus.
 - takes in mutex in w1_search and ds1wm_search while they access
   the bus for searching.  The mutex is dropped before calling the
   callback which adds the slave.
 - changes all slaves to use bus_mutex instead of mutex to
   protect access to the bus
 - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the
   related code from drivers/power/ds278[01]_battery.c which
   calls them.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/power/ds2780_battery.c | 11 +----------
 drivers/power/ds2781_battery.c | 12 +-----------
 drivers/w1/masters/ds1wm.c     |  4 ++++
 drivers/w1/slaves/w1_bq27000.c |  4 ++--
 drivers/w1/slaves/w1_ds2408.c  | 24 ++++++++++++------------
 drivers/w1/slaves/w1_ds2423.c  |  4 ++--
 drivers/w1/slaves/w1_ds2431.c  |  8 ++++----
 drivers/w1/slaves/w1_ds2433.c  |  8 ++++----
 drivers/w1/slaves/w1_ds2760.c  |  8 ++++----
 drivers/w1/slaves/w1_ds2780.c  | 22 ++++------------------
 drivers/w1/slaves/w1_ds2780.h  |  2 --
 drivers/w1/slaves/w1_ds2781.c  | 22 ++++------------------
 drivers/w1/slaves/w1_ds2781.h  |  2 --
 drivers/w1/slaves/w1_therm.c   | 10 +++++-----
 drivers/w1/w1.c                |  9 ++++++++-
 drivers/w1/w1.h                |  1 +
 drivers/w1/w1_int.c            |  1 +
 17 files changed, 57 insertions(+), 95 deletions(-)

(limited to 'drivers/w1')

diff --git a/drivers/power/ds2780_battery.c b/drivers/power/ds2780_battery.c
index de31cae1ba53..74fad941c56c 100644
--- a/drivers/power/ds2780_battery.c
+++ b/drivers/power/ds2780_battery.c
@@ -39,7 +39,6 @@ struct ds2780_device_info {
 	struct device *dev;
 	struct power_supply bat;
 	struct device *w1_dev;
-	struct task_struct *mutex_holder;
 };
 
 enum current_types {
@@ -64,10 +63,7 @@ static inline struct power_supply *to_power_supply(struct device *dev)
 static inline int ds2780_battery_io(struct ds2780_device_info *dev_info,
 	char *buf, int addr, size_t count, int io)
 {
-	if (dev_info->mutex_holder == current)
-		return w1_ds2780_io_nolock(dev_info->w1_dev, buf, addr, count, io);
-	else
-		return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
+	return w1_ds2780_io(dev_info->w1_dev, buf, addr, count, io);
 }
 
 static inline int ds2780_read8(struct ds2780_device_info *dev_info, u8 *val,
@@ -779,7 +775,6 @@ static int __devinit ds2780_battery_probe(struct platform_device *pdev)
 	dev_info->bat.properties	= ds2780_battery_props;
 	dev_info->bat.num_properties	= ARRAY_SIZE(ds2780_battery_props);
 	dev_info->bat.get_property	= ds2780_battery_get_property;
-	dev_info->mutex_holder		= current;
 
 	ret = power_supply_register(&pdev->dev, &dev_info->bat);
 	if (ret) {
@@ -809,8 +804,6 @@ static int __devinit ds2780_battery_probe(struct platform_device *pdev)
 		goto fail_remove_bin_file;
 	}
 
-	dev_info->mutex_holder = NULL;
-
 	return 0;
 
 fail_remove_bin_file:
@@ -830,8 +823,6 @@ static int __devexit ds2780_battery_remove(struct platform_device *pdev)
 {
 	struct ds2780_device_info *dev_info = platform_get_drvdata(pdev);
 
-	dev_info->mutex_holder = current;
-
 	/* remove attributes */
 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2780_attr_group);
 
diff --git a/drivers/power/ds2781_battery.c b/drivers/power/ds2781_battery.c
index 975684a40f15..5f92a4bb33f9 100644
--- a/drivers/power/ds2781_battery.c
+++ b/drivers/power/ds2781_battery.c
@@ -37,7 +37,6 @@ struct ds2781_device_info {
 	struct device *dev;
 	struct power_supply bat;
 	struct device *w1_dev;
-	struct task_struct *mutex_holder;
 };
 
 enum current_types {
@@ -62,11 +61,7 @@ static inline struct power_supply *to_power_supply(struct device *dev)
 static inline int ds2781_battery_io(struct ds2781_device_info *dev_info,
 	char *buf, int addr, size_t count, int io)
 {
-	if (dev_info->mutex_holder == current)
-		return w1_ds2781_io_nolock(dev_info->w1_dev, buf, addr,
-				count, io);
-	else
-		return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
+	return w1_ds2781_io(dev_info->w1_dev, buf, addr, count, io);
 }
 
 int w1_ds2781_read(struct ds2781_device_info *dev_info, char *buf,
@@ -775,7 +770,6 @@ static int __devinit ds2781_battery_probe(struct platform_device *pdev)
 	dev_info->bat.properties	= ds2781_battery_props;
 	dev_info->bat.num_properties	= ARRAY_SIZE(ds2781_battery_props);
 	dev_info->bat.get_property	= ds2781_battery_get_property;
-	dev_info->mutex_holder		= current;
 
 	ret = power_supply_register(&pdev->dev, &dev_info->bat);
 	if (ret) {
@@ -805,8 +799,6 @@ static int __devinit ds2781_battery_probe(struct platform_device *pdev)
 		goto fail_remove_bin_file;
 	}
 
-	dev_info->mutex_holder = NULL;
-
 	return 0;
 
 fail_remove_bin_file:
@@ -826,8 +818,6 @@ static int __devexit ds2781_battery_remove(struct platform_device *pdev)
 {
 	struct ds2781_device_info *dev_info = platform_get_drvdata(pdev);
 
-	dev_info->mutex_holder = current;
-
 	/* remove attributes */
 	sysfs_remove_group(&dev_info->bat.dev->kobj, &ds2781_attr_group);
 
diff --git a/drivers/w1/masters/ds1wm.c b/drivers/w1/masters/ds1wm.c
index a0c8965c1a79..530a2d309063 100644
--- a/drivers/w1/masters/ds1wm.c
+++ b/drivers/w1/masters/ds1wm.c
@@ -334,7 +334,9 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 			return;
 		}
 
+		mutex_lock(&master_dev->bus_mutex);
 		if (ds1wm_reset(ds1wm_data)) {
+			mutex_unlock(&master_dev->bus_mutex);
 			dev_dbg(&ds1wm_data->pdev->dev,
 				"pass: %d reset error (or no slaves)\n", pass);
 			break;
@@ -387,6 +389,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 
 		}
 		if (ds1wm_data->read_error) {
+			mutex_unlock(&master_dev->bus_mutex);
 			dev_err(&ds1wm_data->pdev->dev,
 				"pass: %d read error, retrying\n", pass);
 			break;
@@ -400,6 +403,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 		dev_dbg(&ds1wm_data->pdev->dev,
 			"pass: %d resetting bus\n", pass);
 		ds1wm_reset(ds1wm_data);
+		mutex_unlock(&master_dev->bus_mutex);
 		if ((r_prime & ((u64)1 << 63)) && (d & ((u64)1 << 63))) {
 			dev_err(&ds1wm_data->pdev->dev,
 				"pass: %d bus error, retrying\n", pass);
diff --git a/drivers/w1/slaves/w1_bq27000.c b/drivers/w1/slaves/w1_bq27000.c
index 52ad812fa1e7..773dca5beafe 100644
--- a/drivers/w1/slaves/w1_bq27000.c
+++ b/drivers/w1/slaves/w1_bq27000.c
@@ -31,10 +31,10 @@ static int w1_bq27000_read(struct device *dev, unsigned int reg)
 	u8 val;
 	struct w1_slave *sl = container_of(dev->parent, struct w1_slave, dev);
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 	w1_write_8(sl->master, HDQ_CMD_READ | reg);
 	val = w1_read_8(sl->master);
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return val;
 }
diff --git a/drivers/w1/slaves/w1_ds2408.c b/drivers/w1/slaves/w1_ds2408.c
index 8e813eed0f0a..441ad3a3b586 100644
--- a/drivers/w1/slaves/w1_ds2408.c
+++ b/drivers/w1/slaves/w1_ds2408.c
@@ -52,11 +52,11 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
 	if (!buf)
 		return -EINVAL;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 	dev_dbg(&sl->dev, "mutex locked");
 
 	if (w1_reset_select_slave(sl)) {
-		mutex_unlock(&sl->master->mutex);
+		mutex_unlock(&sl->master->bus_mutex);
 		return -EIO;
 	}
 
@@ -66,7 +66,7 @@ static int _read_reg(struct w1_slave *sl, u8 address, unsigned char* buf)
 	w1_write_block(sl->master, wrbuf, 3);
 	*buf = w1_read_8(sl->master);
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	dev_dbg(&sl->dev, "mutex unlocked");
 	return 1;
 }
@@ -165,7 +165,7 @@ static ssize_t w1_f29_write_output(
 		return -EFAULT;
 
 	dev_dbg(&sl->dev, "locking mutex for write_output");
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 	dev_dbg(&sl->dev, "mutex locked");
 
 	if (w1_reset_select_slave(sl))
@@ -200,14 +200,14 @@ static ssize_t w1_f29_write_output(
 		/* read the result of the READ_PIO_REGS command */
 		if (w1_read_8(sl->master) == *buf) {
 			/* success! */
-			mutex_unlock(&sl->master->mutex);
+			mutex_unlock(&sl->master->bus_mutex);
 			dev_dbg(&sl->dev,
 				"mutex unlocked, retries:%d", retries);
 			return 1;
 		}
 	}
 error:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	dev_dbg(&sl->dev, "mutex unlocked in error, retries:%d", retries);
 
 	return -EIO;
@@ -228,7 +228,7 @@ static ssize_t w1_f29_write_activity(
 	if (count != 1 || off != 0)
 		return -EFAULT;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (w1_reset_select_slave(sl))
 		goto error;
@@ -236,7 +236,7 @@ static ssize_t w1_f29_write_activity(
 	while (retries--) {
 		w1_write_8(sl->master, W1_F29_FUNC_RESET_ACTIVITY_LATCHES);
 		if (w1_read_8(sl->master) == W1_F29_SUCCESS_CONFIRM_BYTE) {
-			mutex_unlock(&sl->master->mutex);
+			mutex_unlock(&sl->master->bus_mutex);
 			return 1;
 		}
 		if (w1_reset_resume_command(sl->master))
@@ -244,7 +244,7 @@ static ssize_t w1_f29_write_activity(
 	}
 
 error:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	return -EIO;
 }
 
@@ -263,7 +263,7 @@ static ssize_t w1_f29_write_status_control(
 	if (count != 1 || off != 0)
 		return -EFAULT;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (w1_reset_select_slave(sl))
 		goto error;
@@ -285,12 +285,12 @@ static ssize_t w1_f29_write_status_control(
 		w1_write_block(sl->master, w1_buf, 3);
 		if (w1_read_8(sl->master) == *buf) {
 			/* success! */
-			mutex_unlock(&sl->master->mutex);
+			mutex_unlock(&sl->master->bus_mutex);
 			return 1;
 		}
 	}
 error:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return -EIO;
 }
diff --git a/drivers/w1/slaves/w1_ds2423.c b/drivers/w1/slaves/w1_ds2423.c
index 7a7dbe5026f1..40a10b5ed120 100644
--- a/drivers/w1/slaves/w1_ds2423.c
+++ b/drivers/w1/slaves/w1_ds2423.c
@@ -66,7 +66,7 @@ static ssize_t w1_counter_read(struct device *device,
 	wrbuf[0]	= 0xA5;
 	wrbuf[1]	= rom_addr & 0xFF;
 	wrbuf[2]	= rom_addr >> 8;
-	mutex_lock(&dev->mutex);
+	mutex_lock(&dev->bus_mutex);
 	if (!w1_reset_select_slave(sl)) {
 		w1_write_block(dev, wrbuf, 3);
 		read_byte_count = 0;
@@ -124,7 +124,7 @@ static ssize_t w1_counter_read(struct device *device,
 	} else {
 		c -= snprintf(out_buf + PAGE_SIZE - c, c, "Connection error");
 	}
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->bus_mutex);
 	return PAGE_SIZE - c;
 }
 
diff --git a/drivers/w1/slaves/w1_ds2431.c b/drivers/w1/slaves/w1_ds2431.c
index 84e2410aec1d..984b30331a45 100644
--- a/drivers/w1/slaves/w1_ds2431.c
+++ b/drivers/w1/slaves/w1_ds2431.c
@@ -107,7 +107,7 @@ static ssize_t w1_f2d_read_bin(struct file *filp, struct kobject *kobj,
 	if (count == 0)
 		return 0;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	/* read directly from the EEPROM in chunks of W1_F2D_READ_MAXLEN */
 	while (todo > 0) {
@@ -126,7 +126,7 @@ static ssize_t w1_f2d_read_bin(struct file *filp, struct kobject *kobj,
 		off += W1_F2D_READ_MAXLEN;
 	}
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return count;
 }
@@ -214,7 +214,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
 	if (count == 0)
 		return 0;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	/* Can only write data in blocks of the size of the scratchpad */
 	addr = off;
@@ -259,7 +259,7 @@ static ssize_t w1_f2d_write_bin(struct file *filp, struct kobject *kobj,
 	}
 
 out_up:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return count;
 }
diff --git a/drivers/w1/slaves/w1_ds2433.c b/drivers/w1/slaves/w1_ds2433.c
index 0f7b8f9c509a..85f2cdb27fa2 100644
--- a/drivers/w1/slaves/w1_ds2433.c
+++ b/drivers/w1/slaves/w1_ds2433.c
@@ -107,7 +107,7 @@ static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
 	if ((count = w1_f23_fix_count(off, count, W1_EEPROM_SIZE)) == 0)
 		return 0;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 #ifdef CONFIG_W1_SLAVE_DS2433_CRC
 
@@ -138,7 +138,7 @@ static ssize_t w1_f23_read_bin(struct file *filp, struct kobject *kobj,
 #endif	/* CONFIG_W1_SLAVE_DS2433_CRC */
 
 out_up:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return count;
 }
@@ -233,7 +233,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
 	}
 #endif	/* CONFIG_W1_SLAVE_DS2433_CRC */
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	/* Can only write data to one page at a time */
 	idx = 0;
@@ -251,7 +251,7 @@ static ssize_t w1_f23_write_bin(struct file *filp, struct kobject *kobj,
 	}
 
 out_up:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return count;
 }
diff --git a/drivers/w1/slaves/w1_ds2760.c b/drivers/w1/slaves/w1_ds2760.c
index 5754c9a4f58b..aa7bd5fa2fa8 100644
--- a/drivers/w1/slaves/w1_ds2760.c
+++ b/drivers/w1/slaves/w1_ds2760.c
@@ -31,7 +31,7 @@ static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
 	if (!dev)
 		return 0;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (addr > DS2760_DATA_SIZE || addr < 0) {
 		count = 0;
@@ -54,7 +54,7 @@ static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
 	}
 
 out:
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return count;
 }
@@ -76,14 +76,14 @@ static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
 	if (!dev)
 		return -EINVAL;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (w1_reset_select_slave(sl) == 0) {
 		w1_write_8(sl->master, cmd);
 		w1_write_8(sl->master, addr);
 	}
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	return 0;
 }
 
diff --git a/drivers/w1/slaves/w1_ds2780.c b/drivers/w1/slaves/w1_ds2780.c
index 39f78c0b143c..7b09307de0ef 100644
--- a/drivers/w1/slaves/w1_ds2780.c
+++ b/drivers/w1/slaves/w1_ds2780.c
@@ -60,30 +60,16 @@ int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
 	if (!dev)
 		return -ENODEV;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	ret = w1_ds2780_do_io(dev, buf, addr, count, io);
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return ret;
 }
 EXPORT_SYMBOL(w1_ds2780_io);
 
-int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr, size_t count,
-			int io)
-{
-	int ret;
-
-	if (!dev)
-		return -ENODEV;
-
-	ret = w1_ds2780_do_io(dev, buf, addr, count, io);
-
-	return ret;
-}
-EXPORT_SYMBOL(w1_ds2780_io_nolock);
-
 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
 {
 	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
@@ -91,14 +77,14 @@ int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
 	if (!dev)
 		return -EINVAL;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (w1_reset_select_slave(sl) == 0) {
 		w1_write_8(sl->master, cmd);
 		w1_write_8(sl->master, addr);
 	}
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	return 0;
 }
 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
diff --git a/drivers/w1/slaves/w1_ds2780.h b/drivers/w1/slaves/w1_ds2780.h
index 737379365021..a1fba79eb1b5 100644
--- a/drivers/w1/slaves/w1_ds2780.h
+++ b/drivers/w1/slaves/w1_ds2780.h
@@ -124,8 +124,6 @@
 
 extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
 			int io);
-extern int w1_ds2780_io_nolock(struct device *dev, char *buf, int addr,
-			size_t count, int io);
 extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd);
 
 #endif /* !_W1_DS2780_H */
diff --git a/drivers/w1/slaves/w1_ds2781.c b/drivers/w1/slaves/w1_ds2781.c
index 0d0c7985293f..877daf74159c 100644
--- a/drivers/w1/slaves/w1_ds2781.c
+++ b/drivers/w1/slaves/w1_ds2781.c
@@ -58,30 +58,16 @@ int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
 	if (!dev)
 		return -ENODEV;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	ret = w1_ds2781_do_io(dev, buf, addr, count, io);
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 
 	return ret;
 }
 EXPORT_SYMBOL(w1_ds2781_io);
 
-int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr, size_t count,
-			int io)
-{
-	int ret;
-
-	if (!dev)
-		return -ENODEV;
-
-	ret = w1_ds2781_do_io(dev, buf, addr, count, io);
-
-	return ret;
-}
-EXPORT_SYMBOL(w1_ds2781_io_nolock);
-
 int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
 {
 	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
@@ -89,14 +75,14 @@ int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
 	if (!dev)
 		return -EINVAL;
 
-	mutex_lock(&sl->master->mutex);
+	mutex_lock(&sl->master->bus_mutex);
 
 	if (w1_reset_select_slave(sl) == 0) {
 		w1_write_8(sl->master, cmd);
 		w1_write_8(sl->master, addr);
 	}
 
-	mutex_unlock(&sl->master->mutex);
+	mutex_unlock(&sl->master->bus_mutex);
 	return 0;
 }
 EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
diff --git a/drivers/w1/slaves/w1_ds2781.h b/drivers/w1/slaves/w1_ds2781.h
index 82bc66497b43..557dfb0b4f64 100644
--- a/drivers/w1/slaves/w1_ds2781.h
+++ b/drivers/w1/slaves/w1_ds2781.h
@@ -129,8 +129,6 @@
 
 extern int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
 			int io);
-extern int w1_ds2781_io_nolock(struct device *dev, char *buf, int addr,
-			size_t count, int io);
 extern int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd);
 
 #endif /* !_W1_DS2781_H */
diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index ff29ae747ee8..d90062b211f8 100644
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -179,7 +179,7 @@ static ssize_t w1_therm_read(struct device *device,
 	int i, max_trying = 10;
 	ssize_t c = PAGE_SIZE;
 
-	i = mutex_lock_interruptible(&dev->mutex);
+	i = mutex_lock_interruptible(&dev->bus_mutex);
 	if (i != 0)
 		return i;
 
@@ -207,19 +207,19 @@ static ssize_t w1_therm_read(struct device *device,
 			w1_write_8(dev, W1_CONVERT_TEMP);
 
 			if (external_power) {
-				mutex_unlock(&dev->mutex);
+				mutex_unlock(&dev->bus_mutex);
 
 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0)
 					return -EINTR;
 
-				i = mutex_lock_interruptible(&dev->mutex);
+				i = mutex_lock_interruptible(&dev->bus_mutex);
 				if (i != 0)
 					return i;
 			} else if (!w1_strong_pullup) {
 				sleep_rem = msleep_interruptible(tm);
 				if (sleep_rem != 0) {
-					mutex_unlock(&dev->mutex);
+					mutex_unlock(&dev->bus_mutex);
 					return -EINTR;
 				}
 			}
@@ -258,7 +258,7 @@ static ssize_t w1_therm_read(struct device *device,
 
 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
 		w1_convert_temp(rom, sl->family->fid));
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->bus_mutex);
 
 	return PAGE_SIZE - c;
 }
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index bfb898641029..1a574370d2cd 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -885,16 +885,21 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 		 *
 		 * Return 0 - device(s) present, 1 - no devices present.
 		 */
+		mutex_lock(&dev->bus_mutex);
 		if (w1_reset_bus(dev)) {
+			mutex_unlock(&dev->bus_mutex);
 			dev_dbg(&dev->dev, "No devices present on the wire.\n");
 			break;
 		}
 
 		/* Do fast search on single slave bus */
 		if (dev->max_slave_count == 1) {
+			int rv;
 			w1_write_8(dev, W1_READ_ROM);
+			rv = w1_read_block(dev, (u8 *)&rn, 8);
+			mutex_unlock(&dev->bus_mutex);
 
-			if (w1_read_block(dev, (u8 *)&rn, 8) == 8 && rn)
+			if (rv == 8 && rn)
 				cb(dev, rn);
 
 			break;
@@ -927,10 +932,12 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 			rn |= (tmp64 << i);
 
 			if (kthread_should_stop()) {
+				mutex_unlock(&dev->bus_mutex);
 				dev_dbg(&dev->dev, "Abort w1_search\n");
 				return;
 			}
 		}
+		mutex_unlock(&dev->bus_mutex);
 
 		if ( (triplet_ret & 0x03) != 0x03 ) {
 			if ( (desc_bit == last_zero) || (last_zero < 0))
diff --git a/drivers/w1/w1.h b/drivers/w1/w1.h
index 4d012ca3f32c..45908e56c2f8 100644
--- a/drivers/w1/w1.h
+++ b/drivers/w1/w1.h
@@ -180,6 +180,7 @@ struct w1_master
 
 	struct task_struct	*thread;
 	struct mutex		mutex;
+	struct mutex		bus_mutex;
 
 	struct device_driver	*driver;
 	struct device		dev;
diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 68288355727a..531434180afd 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -76,6 +76,7 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 
 	INIT_LIST_HEAD(&dev->slist);
 	mutex_init(&dev->mutex);
+	mutex_init(&dev->bus_mutex);
 
 	memcpy(&dev->dev, device, sizeof(struct device));
 	dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
-- 
cgit v1.2.3


From fbf7f7b4e2ae40f790828c86d31beff2d49e9ac8 Mon Sep 17 00:00:00 2001
From: Markus Franke
Date: Sat, 26 May 2012 00:45:12 +0200
Subject: w1: Add 1-wire slave device driver for DS28E04-100

Signed-off-by: Markus Franke <franm@hrz.tu-chemnitz.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 Documentation/ABI/stable/sysfs-driver-w1_ds28e04 |  15 +
 Documentation/w1/slaves/w1_ds28e04               |  36 ++
 drivers/w1/slaves/Kconfig                        |  13 +
 drivers/w1/slaves/Makefile                       |   1 +
 drivers/w1/slaves/w1_ds28e04.c                   | 469 +++++++++++++++++++++++
 drivers/w1/w1_family.h                           |   1 +
 6 files changed, 535 insertions(+)
 create mode 100644 Documentation/ABI/stable/sysfs-driver-w1_ds28e04
 create mode 100644 Documentation/w1/slaves/w1_ds28e04
 create mode 100644 drivers/w1/slaves/w1_ds28e04.c

(limited to 'drivers/w1')

diff --git a/Documentation/ABI/stable/sysfs-driver-w1_ds28e04 b/Documentation/ABI/stable/sysfs-driver-w1_ds28e04
new file mode 100644
index 000000000000..26579ee868c9
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-driver-w1_ds28e04
@@ -0,0 +1,15 @@
+What:		/sys/bus/w1/devices/.../pio
+Date:		May 2012
+Contact:	Markus Franke <franm@hrz.tu-chemnitz.de>
+Description:	read/write the contents of the two PIO's of the DS28E04-100
+		see Documentation/w1/slaves/w1_ds28e04 for detailed information
+Users:		any user space application which wants to communicate with DS28E04-100
+
+
+
+What:		/sys/bus/w1/devices/.../eeprom
+Date:		May 2012
+Contact:	Markus Franke <franm@hrz.tu-chemnitz.de>
+Description:	read/write the contents of the EEPROM memory of the DS28E04-100
+		see Documentation/w1/slaves/w1_ds28e04 for detailed information
+Users:		any user space application which wants to communicate with DS28E04-100
diff --git a/Documentation/w1/slaves/w1_ds28e04 b/Documentation/w1/slaves/w1_ds28e04
new file mode 100644
index 000000000000..85bc9a7e02fe
--- /dev/null
+++ b/Documentation/w1/slaves/w1_ds28e04
@@ -0,0 +1,36 @@
+Kernel driver w1_ds28e04
+========================
+
+Supported chips:
+  * Maxim DS28E04-100 4096-Bit Addressable 1-Wire EEPROM with PIO
+
+supported family codes:
+	W1_FAMILY_DS28E04	0x1C
+
+Author: Markus Franke, <franke.m@sebakmt.com> <franm@hrz.tu-chemnitz.de>
+
+Description
+-----------
+
+Support is provided through the sysfs files "eeprom" and "pio". CRC checking
+during memory accesses can optionally be enabled/disabled via the device
+attribute "crccheck". The strong pull-up can optionally be enabled/disabled
+via the module parameter "w1_strong_pullup".
+
+Memory Access
+
+	A read operation on the "eeprom" file reads the given amount of bytes
+	from the EEPROM of the DS28E04.
+
+	A write operation on the "eeprom" file writes the given byte sequence
+	to the EEPROM of the DS28E04. If CRC checking mode is enabled only
+	fully alligned blocks of 32 bytes with valid CRC16 values (in bytes 30
+	and 31) are allowed to be written.
+
+PIO Access
+
+	The 2 PIOs of the DS28E04-100 are accessible via the "pio" sysfs file.
+
+	The current status of the PIO's is returned as an 8 bit value. Bit 0/1
+	represent the state of PIO_0/PIO_1. Bits 2..7 do not care. The PIO's are
+	driven low-active, i.e. the driver delivers/expects low-active values.
diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index eb9e376d6244..67526690acbc 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -94,6 +94,19 @@ config W1_SLAVE_DS2781
 
 	  If you are unsure, say N.
 
+config W1_SLAVE_DS28E04
+	tristate "4096-Bit Addressable 1-Wire EEPROM with PIO (DS28E04-100)"
+	depends on W1
+	select CRC16
+	help
+	  If you enable this you will have the DS28E04-100
+	  chip support.
+
+	  Say Y here if you want to use a 1-wire
+	  4kb EEPROM with PIO family device (DS28E04).
+
+	  If you are unsure, say N.
+
 config W1_SLAVE_BQ27000
 	tristate "BQ27000 slave support"
 	depends on W1
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index c4f1859fb520..05188f6aab5a 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_W1_SLAVE_DS2760)	+= w1_ds2760.o
 obj-$(CONFIG_W1_SLAVE_DS2780)	+= w1_ds2780.o
 obj-$(CONFIG_W1_SLAVE_DS2781)	+= w1_ds2781.o
 obj-$(CONFIG_W1_SLAVE_BQ27000)	+= w1_bq27000.o
+obj-$(CONFIG_W1_SLAVE_DS28E04)	+= w1_ds28e04.o
diff --git a/drivers/w1/slaves/w1_ds28e04.c b/drivers/w1/slaves/w1_ds28e04.c
new file mode 100644
index 000000000000..98117db595bb
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds28e04.c
@@ -0,0 +1,469 @@
+/*
+ *	w1_ds28e04.c - w1 family 1C (DS28E04) driver
+ *
+ * Copyright (c) 2012 Markus Franke <franke.m@sebakmt.com>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/crc16.h>
+#include <linux/uaccess.h>
+
+#define CRC16_INIT		0
+#define CRC16_VALID		0xb001
+
+#include "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Markus Franke <franke.m@sebakmt.com>, <franm@hrz.tu-chemnitz.de>");
+MODULE_DESCRIPTION("w1 family 1C driver for DS28E04, 4kb EEPROM and PIO");
+
+/* Allow the strong pullup to be disabled, but default to enabled.
+ * If it was disabled a parasite powered device might not get the required
+ * current to copy the data from the scratchpad to EEPROM.  If it is enabled
+ * parasite powered devices have a better chance of getting the current
+ * required.
+ */
+static int w1_strong_pullup = 1;
+module_param_named(strong_pullup, w1_strong_pullup, int, 0);
+
+/* enable/disable CRC checking on DS28E04-100 memory accesses */
+static char w1_enable_crccheck = 1;
+
+#define W1_EEPROM_SIZE		512
+#define W1_PAGE_COUNT		16
+#define W1_PAGE_SIZE		32
+#define W1_PAGE_BITS		5
+#define W1_PAGE_MASK		0x1F
+
+#define W1_F1C_READ_EEPROM	0xF0
+#define W1_F1C_WRITE_SCRATCH	0x0F
+#define W1_F1C_READ_SCRATCH	0xAA
+#define W1_F1C_COPY_SCRATCH	0x55
+#define W1_F1C_ACCESS_WRITE	0x5A
+
+#define W1_1C_REG_LOGIC_STATE	0x220
+
+struct w1_f1C_data {
+	u8	memory[W1_EEPROM_SIZE];
+	u32	validcrc;
+};
+
+/**
+ * Check the file size bounds and adjusts count as needed.
+ * This would not be needed if the file size didn't reset to 0 after a write.
+ */
+static inline size_t w1_f1C_fix_count(loff_t off, size_t count, size_t size)
+{
+	if (off > size)
+		return 0;
+
+	if ((off + count) > size)
+		return size - off;
+
+	return count;
+}
+
+static int w1_f1C_refresh_block(struct w1_slave *sl, struct w1_f1C_data *data,
+				int block)
+{
+	u8	wrbuf[3];
+	int	off = block * W1_PAGE_SIZE;
+
+	if (data->validcrc & (1 << block))
+		return 0;
+
+	if (w1_reset_select_slave(sl)) {
+		data->validcrc = 0;
+		return -EIO;
+	}
+
+	wrbuf[0] = W1_F1C_READ_EEPROM;
+	wrbuf[1] = off & 0xff;
+	wrbuf[2] = off >> 8;
+	w1_write_block(sl->master, wrbuf, 3);
+	w1_read_block(sl->master, &data->memory[off], W1_PAGE_SIZE);
+
+	/* cache the block if the CRC is valid */
+	if (crc16(CRC16_INIT, &data->memory[off], W1_PAGE_SIZE) == CRC16_VALID)
+		data->validcrc |= (1 << block);
+
+	return 0;
+}
+
+static int w1_f1C_read(struct w1_slave *sl, int addr, int len, char *data)
+{
+	u8 wrbuf[3];
+
+	/* read directly from the EEPROM */
+	if (w1_reset_select_slave(sl))
+		return -EIO;
+
+	wrbuf[0] = W1_F1C_READ_EEPROM;
+	wrbuf[1] = addr & 0xff;
+	wrbuf[2] = addr >> 8;
+
+	w1_write_block(sl->master, wrbuf, sizeof(wrbuf));
+	return w1_read_block(sl->master, data, len);
+}
+
+static ssize_t w1_f1C_read_bin(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	struct w1_f1C_data *data = sl->family_data;
+	int i, min_page, max_page;
+
+	count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&sl->master->mutex);
+
+	if (w1_enable_crccheck) {
+		min_page = (off >> W1_PAGE_BITS);
+		max_page = (off + count - 1) >> W1_PAGE_BITS;
+		for (i = min_page; i <= max_page; i++) {
+			if (w1_f1C_refresh_block(sl, data, i)) {
+				count = -EIO;
+				goto out_up;
+			}
+		}
+		memcpy(buf, &data->memory[off], count);
+	} else {
+		count = w1_f1C_read(sl, off, count, buf);
+	}
+
+out_up:
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+
+/**
+ * Writes to the scratchpad and reads it back for verification.
+ * Then copies the scratchpad to EEPROM.
+ * The data must be on one page.
+ * The master must be locked.
+ *
+ * @param sl	The slave structure
+ * @param addr	Address for the write
+ * @param len   length must be <= (W1_PAGE_SIZE - (addr & W1_PAGE_MASK))
+ * @param data	The data to write
+ * @return	0=Success -1=failure
+ */
+static int w1_f1C_write(struct w1_slave *sl, int addr, int len, const u8 *data)
+{
+	u8 wrbuf[4];
+	u8 rdbuf[W1_PAGE_SIZE + 3];
+	u8 es = (addr + len - 1) & 0x1f;
+	unsigned int tm = 10;
+	int i;
+	struct w1_f1C_data *f1C = sl->family_data;
+
+	/* Write the data to the scratchpad */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	wrbuf[0] = W1_F1C_WRITE_SCRATCH;
+	wrbuf[1] = addr & 0xff;
+	wrbuf[2] = addr >> 8;
+
+	w1_write_block(sl->master, wrbuf, 3);
+	w1_write_block(sl->master, data, len);
+
+	/* Read the scratchpad and verify */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	w1_write_8(sl->master, W1_F1C_READ_SCRATCH);
+	w1_read_block(sl->master, rdbuf, len + 3);
+
+	/* Compare what was read against the data written */
+	if ((rdbuf[0] != wrbuf[1]) || (rdbuf[1] != wrbuf[2]) ||
+	    (rdbuf[2] != es) || (memcmp(data, &rdbuf[3], len) != 0))
+		return -1;
+
+	/* Copy the scratchpad to EEPROM */
+	if (w1_reset_select_slave(sl))
+		return -1;
+
+	wrbuf[0] = W1_F1C_COPY_SCRATCH;
+	wrbuf[3] = es;
+
+	for (i = 0; i < sizeof(wrbuf); ++i) {
+		/* issue 10ms strong pullup (or delay) on the last byte
+		   for writing the data from the scratchpad to EEPROM */
+		if (w1_strong_pullup && i == sizeof(wrbuf)-1)
+			w1_next_pullup(sl->master, tm);
+
+		w1_write_8(sl->master, wrbuf[i]);
+	}
+
+	if (!w1_strong_pullup)
+		msleep(tm);
+
+	if (w1_enable_crccheck) {
+		/* invalidate cached data */
+		f1C->validcrc &= ~(1 << (addr >> W1_PAGE_BITS));
+	}
+
+	/* Reset the bus to wake up the EEPROM (this may not be needed) */
+	w1_reset_bus(sl->master);
+
+	return 0;
+}
+
+static ssize_t w1_f1C_write_bin(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	int addr, len, idx;
+
+	count = w1_f1C_fix_count(off, count, W1_EEPROM_SIZE);
+	if (count == 0)
+		return 0;
+
+	if (w1_enable_crccheck) {
+		/* can only write full blocks in cached mode */
+		if ((off & W1_PAGE_MASK) || (count & W1_PAGE_MASK)) {
+			dev_err(&sl->dev, "invalid offset/count off=%d cnt=%zd\n",
+				(int)off, count);
+			return -EINVAL;
+		}
+
+		/* make sure the block CRCs are valid */
+		for (idx = 0; idx < count; idx += W1_PAGE_SIZE) {
+			if (crc16(CRC16_INIT, &buf[idx], W1_PAGE_SIZE)
+				!= CRC16_VALID) {
+				dev_err(&sl->dev, "bad CRC at offset %d\n",
+					(int)off);
+				return -EINVAL;
+			}
+		}
+	}
+
+	mutex_lock(&sl->master->mutex);
+
+	/* Can only write data to one page at a time */
+	idx = 0;
+	while (idx < count) {
+		addr = off + idx;
+		len = W1_PAGE_SIZE - (addr & W1_PAGE_MASK);
+		if (len > (count - idx))
+			len = count - idx;
+
+		if (w1_f1C_write(sl, addr, len, &buf[idx]) < 0) {
+			count = -EIO;
+			goto out_up;
+		}
+		idx += len;
+	}
+
+out_up:
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+
+static ssize_t w1_f1C_read_pio(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buf, loff_t off, size_t count)
+
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	int ret;
+
+	/* check arguments */
+	if (off != 0 || count != 1 || buf == NULL)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->mutex);
+	ret = w1_f1C_read(sl, W1_1C_REG_LOGIC_STATE, count, buf);
+	mutex_unlock(&sl->master->mutex);
+
+	return ret;
+}
+
+static ssize_t w1_f1C_write_pio(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr,
+				char *buf, loff_t off, size_t count)
+
+{
+	struct w1_slave *sl = kobj_to_w1_slave(kobj);
+	u8 wrbuf[3];
+	u8 ack;
+
+	/* check arguments */
+	if (off != 0 || count != 1 || buf == NULL)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->mutex);
+
+	/* Write the PIO data */
+	if (w1_reset_select_slave(sl)) {
+		mutex_unlock(&sl->master->mutex);
+		return -1;
+	}
+
+	/* set bit 7..2 to value '1' */
+	*buf = *buf | 0xFC;
+
+	wrbuf[0] = W1_F1C_ACCESS_WRITE;
+	wrbuf[1] = *buf;
+	wrbuf[2] = ~(*buf);
+	w1_write_block(sl->master, wrbuf, 3);
+
+	w1_read_block(sl->master, &ack, sizeof(ack));
+
+	mutex_unlock(&sl->master->mutex);
+
+	/* check for acknowledgement */
+	if (ack != 0xAA)
+		return -EIO;
+
+	return count;
+}
+
+static ssize_t w1_f1C_show_crccheck(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	if (put_user(w1_enable_crccheck + 0x30, buf))
+		return -EFAULT;
+
+	return sizeof(w1_enable_crccheck);
+}
+
+static ssize_t w1_f1C_store_crccheck(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	char val;
+
+	if (count != 1 || !buf)
+		return -EINVAL;
+
+	if (get_user(val, buf))
+		return -EFAULT;
+
+	/* convert to decimal */
+	val = val - 0x30;
+	if (val != 0 && val != 1)
+		return -EINVAL;
+
+	/* set the new value */
+	w1_enable_crccheck = val;
+
+	return sizeof(w1_enable_crccheck);
+}
+
+#define NB_SYSFS_BIN_FILES 2
+static struct bin_attribute w1_f1C_bin_attr[NB_SYSFS_BIN_FILES] = {
+	{
+		.attr = {
+			.name = "eeprom",
+			.mode = S_IRUGO | S_IWUSR,
+		},
+		.size = W1_EEPROM_SIZE,
+		.read = w1_f1C_read_bin,
+		.write = w1_f1C_write_bin,
+	},
+	{
+		.attr = {
+			.name = "pio",
+			.mode = S_IRUGO | S_IWUSR,
+		},
+		.size = 1,
+		.read = w1_f1C_read_pio,
+		.write = w1_f1C_write_pio,
+	}
+};
+
+static DEVICE_ATTR(crccheck, S_IWUSR | S_IRUGO,
+		   w1_f1C_show_crccheck, w1_f1C_store_crccheck);
+
+static int w1_f1C_add_slave(struct w1_slave *sl)
+{
+	int err = 0;
+	int i;
+	struct w1_f1C_data *data = NULL;
+
+	if (w1_enable_crccheck) {
+		data = kzalloc(sizeof(struct w1_f1C_data), GFP_KERNEL);
+		if (!data)
+			return -ENOMEM;
+		sl->family_data = data;
+	}
+
+	/* create binary sysfs attributes */
+	for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
+		err = sysfs_create_bin_file(
+			&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
+
+	if (!err) {
+		/* create device attributes */
+		err = device_create_file(&sl->dev, &dev_attr_crccheck);
+	}
+
+	if (err) {
+		/* remove binary sysfs attributes */
+		for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
+			sysfs_remove_bin_file(
+				&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
+
+		kfree(data);
+	}
+
+	return err;
+}
+
+static void w1_f1C_remove_slave(struct w1_slave *sl)
+{
+	int i;
+
+	kfree(sl->family_data);
+	sl->family_data = NULL;
+
+	/* remove device attributes */
+	device_remove_file(&sl->dev, &dev_attr_crccheck);
+
+	/* remove binary sysfs attributes */
+	for (i = 0; i < NB_SYSFS_BIN_FILES; ++i)
+		sysfs_remove_bin_file(&sl->dev.kobj, &(w1_f1C_bin_attr[i]));
+}
+
+static struct w1_family_ops w1_f1C_fops = {
+	.add_slave      = w1_f1C_add_slave,
+	.remove_slave   = w1_f1C_remove_slave,
+};
+
+static struct w1_family w1_family_1C = {
+	.fid = W1_FAMILY_DS28E04,
+	.fops = &w1_f1C_fops,
+};
+
+static int __init w1_f1C_init(void)
+{
+	return w1_register_family(&w1_family_1C);
+}
+
+static void __exit w1_f1C_fini(void)
+{
+	w1_unregister_family(&w1_family_1C);
+}
+
+module_init(w1_f1C_init);
+module_exit(w1_f1C_fini);
diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h
index 874aeb05011b..b00ada44a89b 100644
--- a/drivers/w1/w1_family.h
+++ b/drivers/w1/w1_family.h
@@ -30,6 +30,7 @@
 #define W1_FAMILY_SMEM_01	0x01
 #define W1_FAMILY_SMEM_81	0x81
 #define W1_THERM_DS18S20 	0x10
+#define W1_FAMILY_DS28E04	0x1C
 #define W1_COUNTER_DS2423	0x1D
 #define W1_THERM_DS1822  	0x22
 #define W1_EEPROM_DS2433  	0x23
-- 
cgit v1.2.3


From 679012655acecfa807038ccf9237bba246f9fad8 Mon Sep 17 00:00:00 2001
From: Otavio Salvador
Date: Sun, 17 Jun 2012 12:17:31 -0300
Subject: w1: Fix a typo in 'hardware' word

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/w1/w1_int.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/w1')

diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 531434180afd..5a98649f6abc 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -118,7 +118,7 @@ int w1_add_master_device(struct w1_bus_master *master)
 		return(-EINVAL);
         }
 	/* While it would be electrically possible to make a device that
-	 * generated a strong pullup in bit bang mode, only hardare that
+	 * generated a strong pullup in bit bang mode, only hardware that
 	 * controls 1-wire time frames are even expected to support a strong
 	 * pullup.  w1_io.c would need to support calling set_pullup before
 	 * the last write_bit operation of a w1_write_8 which it currently
-- 
cgit v1.2.3