1 files changed, 243 insertions, 57 deletions

diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index d4022878b2f0..8eee98634cda 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -31,30 +31,66 @@
 struct i2c_mux_priv {
 	struct i2c_adapter adap;
 	struct i2c_algorithm algo;
-
-	struct i2c_adapter *parent;
-	struct device *mux_dev;
-	void *mux_priv;
+	struct i2c_mux_core *muxc;
 	u32 chan_id;
-
-	int (*select)(struct i2c_adapter *, void *mux_priv, u32 chan_id);
-	int (*deselect)(struct i2c_adapter *, void *mux_priv, u32 chan_id);
 };
 
+static int __i2c_mux_master_xfer(struct i2c_adapter *adap,
+				 struct i2c_msg msgs[], int num)
+{
+	struct i2c_mux_priv *priv = adap->algo_data;
+	struct i2c_mux_core *muxc = priv->muxc;
+	struct i2c_adapter *parent = muxc->parent;
+	int ret;
+
+	/* Switch to the right mux port and perform the transfer. */
+
+	ret = muxc->select(muxc, priv->chan_id);
+	if (ret >= 0)
+		ret = __i2c_transfer(parent, msgs, num);
+	if (muxc->deselect)
+		muxc->deselect(muxc, priv->chan_id);
+
+	return ret;
+}
+
 static int i2c_mux_master_xfer(struct i2c_adapter *adap,
 			       struct i2c_msg msgs[], int num)
 {
 	struct i2c_mux_priv *priv = adap->algo_data;
-	struct i2c_adapter *parent = priv->parent;
+	struct i2c_mux_core *muxc = priv->muxc;
+	struct i2c_adapter *parent = muxc->parent;
 	int ret;
 
 	/* Switch to the right mux port and perform the transfer. */
 
-	ret = priv->select(parent, priv->mux_priv, priv->chan_id);
+	ret = muxc->select(muxc, priv->chan_id);
 	if (ret >= 0)
-		ret = __i2c_transfer(parent, msgs, num);
-	if (priv->deselect)
-		priv->deselect(parent, priv->mux_priv, priv->chan_id);
+		ret = i2c_transfer(parent, msgs, num);
+	if (muxc->deselect)
+		muxc->deselect(muxc, priv->chan_id);
+
+	return ret;
+}
+
+static int __i2c_mux_smbus_xfer(struct i2c_adapter *adap,
+				u16 addr, unsigned short flags,
+				char read_write, u8 command,
+				int size, union i2c_smbus_data *data)
+{
+	struct i2c_mux_priv *priv = adap->algo_data;
+	struct i2c_mux_core *muxc = priv->muxc;
+	struct i2c_adapter *parent = muxc->parent;
+	int ret;
+
+	/* Select the right mux port and perform the transfer. */
+
+	ret = muxc->select(muxc, priv->chan_id);
+	if (ret >= 0)
+		ret = parent->algo->smbus_xfer(parent, addr, flags,
+					read_write, command, size, data);
+	if (muxc->deselect)
+		muxc->deselect(muxc, priv->chan_id);
 
 	return ret;
 }
@@ -65,17 +101,18 @@ static int i2c_mux_smbus_xfer(struct i2c_adapter *adap,
 			      int size, union i2c_smbus_data *data)
 {
 	struct i2c_mux_priv *priv = adap->algo_data;
-	struct i2c_adapter *parent = priv->parent;
+	struct i2c_mux_core *muxc = priv->muxc;
+	struct i2c_adapter *parent = muxc->parent;
 	int ret;
 
 	/* Select the right mux port and perform the transfer. */
 
-	ret = priv->select(parent, priv->mux_priv, priv->chan_id);
+	ret = muxc->select(muxc, priv->chan_id);
 	if (ret >= 0)
-		ret = parent->algo->smbus_xfer(parent, addr, flags,
-					read_write, command, size, data);
-	if (priv->deselect)
-		priv->deselect(parent, priv->mux_priv, priv->chan_id);
+		ret = i2c_smbus_xfer(parent, addr, flags,
+				     read_write, command, size, data);
+	if (muxc->deselect)
+		muxc->deselect(muxc, priv->chan_id);
 
 	return ret;
 }
@@ -84,7 +121,7 @@ static int i2c_mux_smbus_xfer(struct i2c_adapter *adap,
 static u32 i2c_mux_functionality(struct i2c_adapter *adap)
 {
 	struct i2c_mux_priv *priv = adap->algo_data;
-	struct i2c_adapter *parent = priv->parent;
+	struct i2c_adapter *parent = priv->muxc->parent;
 
 	return parent->algo->functionality(parent);
 }
@@ -102,38 +139,167 @@ static unsigned int i2c_mux_parent_classes(struct i2c_adapter *parent)
 	return class;
 }
 
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
-				struct device *mux_dev,
-				void *mux_priv, u32 force_nr, u32 chan_id,
-				unsigned int class,
-				int (*select) (struct i2c_adapter *,
-					       void *, u32),
-				int (*deselect) (struct i2c_adapter *,
-						 void *, u32))
+static void i2c_mux_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	rt_mutex_lock(&parent->mux_lock);
+	if (!(flags & I2C_LOCK_ROOT_ADAPTER))
+		return;
+	i2c_lock_bus(parent, flags);
+}
+
+static int i2c_mux_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	if (!rt_mutex_trylock(&parent->mux_lock))
+		return 0;	/* mux_lock not locked, failure */
+	if (!(flags & I2C_LOCK_ROOT_ADAPTER))
+		return 1;	/* we only want mux_lock, success */
+	if (parent->trylock_bus(parent, flags))
+		return 1;	/* parent locked too, success */
+	rt_mutex_unlock(&parent->mux_lock);
+	return 0;		/* parent not locked, failure */
+}
+
+static void i2c_mux_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	if (flags & I2C_LOCK_ROOT_ADAPTER)
+		i2c_unlock_bus(parent, flags);
+	rt_mutex_unlock(&parent->mux_lock);
+}
+
+static void i2c_parent_lock_bus(struct i2c_adapter *adapter,
+				unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	rt_mutex_lock(&parent->mux_lock);
+	i2c_lock_bus(parent, flags);
+}
+
+static int i2c_parent_trylock_bus(struct i2c_adapter *adapter,
+				  unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	if (!rt_mutex_trylock(&parent->mux_lock))
+		return 0;	/* mux_lock not locked, failure */
+	if (parent->trylock_bus(parent, flags))
+		return 1;	/* parent locked too, success */
+	rt_mutex_unlock(&parent->mux_lock);
+	return 0;		/* parent not locked, failure */
+}
+
+static void i2c_parent_unlock_bus(struct i2c_adapter *adapter,
+				  unsigned int flags)
+{
+	struct i2c_mux_priv *priv = adapter->algo_data;
+	struct i2c_adapter *parent = priv->muxc->parent;
+
+	i2c_unlock_bus(parent, flags);
+	rt_mutex_unlock(&parent->mux_lock);
+}
+
+struct i2c_adapter *i2c_root_adapter(struct device *dev)
+{
+	struct device *i2c;
+	struct i2c_adapter *i2c_root;
+
+	/*
+	 * Walk up the device tree to find an i2c adapter, indicating
+	 * that this is an i2c client device. Check all ancestors to
+	 * handle mfd devices etc.
+	 */
+	for (i2c = dev; i2c; i2c = i2c->parent) {
+		if (i2c->type == &i2c_adapter_type)
+			break;
+	}
+	if (!i2c)
+		return NULL;
+
+	/* Continue up the tree to find the root i2c adapter */
+	i2c_root = to_i2c_adapter(i2c);
+	while (i2c_parent_is_i2c_adapter(i2c_root))
+		i2c_root = i2c_parent_is_i2c_adapter(i2c_root);
+
+	return i2c_root;
+}
+EXPORT_SYMBOL_GPL(i2c_root_adapter);
+
+struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
+				   struct device *dev, int max_adapters,
+				   int sizeof_priv, u32 flags,
+				   int (*select)(struct i2c_mux_core *, u32),
+				   int (*deselect)(struct i2c_mux_core *, u32))
+{
+	struct i2c_mux_core *muxc;
+
+	muxc = devm_kzalloc(dev, sizeof(*muxc)
+			    + max_adapters * sizeof(muxc->adapter[0])
+			    + sizeof_priv, GFP_KERNEL);
+	if (!muxc)
+		return NULL;
+	if (sizeof_priv)
+		muxc->priv = &muxc->adapter[max_adapters];
+
+	muxc->parent = parent;
+	muxc->dev = dev;
+	if (flags & I2C_MUX_LOCKED)
+		muxc->mux_locked = true;
+	muxc->select = select;
+	muxc->deselect = deselect;
+	muxc->max_adapters = max_adapters;
+
+	return muxc;
+}
+EXPORT_SYMBOL_GPL(i2c_mux_alloc);
+
+int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
+			u32 force_nr, u32 chan_id,
+			unsigned int class)
 {
+	struct i2c_adapter *parent = muxc->parent;
 	struct i2c_mux_priv *priv;
 	char symlink_name[20];
 	int ret;
 
-	priv = kzalloc(sizeof(struct i2c_mux_priv), GFP_KERNEL);
+	if (muxc->num_adapters >= muxc->max_adapters) {
+		dev_err(muxc->dev, "No room for more i2c-mux adapters\n");
+		return -EINVAL;
+	}
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 	if (!priv)
-		return NULL;
+		return -ENOMEM;
 
 	/* Set up private adapter data */
-	priv->parent = parent;
-	priv->mux_dev = mux_dev;
-	priv->mux_priv = mux_priv;
+	priv->muxc = muxc;
 	priv->chan_id = chan_id;
-	priv->select = select;
-	priv->deselect = deselect;
 
 	/* Need to do algo dynamically because we don't know ahead
 	 * of time what sort of physical adapter we'll be dealing with.
 	 */
-	if (parent->algo->master_xfer)
-		priv->algo.master_xfer = i2c_mux_master_xfer;
-	if (parent->algo->smbus_xfer)
-		priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
+	if (parent->algo->master_xfer) {
+		if (muxc->mux_locked)
+			priv->algo.master_xfer = i2c_mux_master_xfer;
+		else
+			priv->algo.master_xfer = __i2c_mux_master_xfer;
+	}
+	if (parent->algo->smbus_xfer) {
+		if (muxc->mux_locked)
+			priv->algo.smbus_xfer = i2c_mux_smbus_xfer;
+		else
+			priv->algo.smbus_xfer = __i2c_mux_smbus_xfer;
+	}
 	priv->algo.functionality = i2c_mux_functionality;
 
 	/* Now fill out new adapter structure */
@@ -146,6 +312,15 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	priv->adap.retries = parent->retries;
 	priv->adap.timeout = parent->timeout;
 	priv->adap.quirks = parent->quirks;
+	if (muxc->mux_locked) {
+		priv->adap.lock_bus = i2c_mux_lock_bus;
+		priv->adap.trylock_bus = i2c_mux_trylock_bus;
+		priv->adap.unlock_bus = i2c_mux_unlock_bus;
+	} else {
+		priv->adap.lock_bus = i2c_parent_lock_bus;
+		priv->adap.trylock_bus = i2c_parent_trylock_bus;
+		priv->adap.unlock_bus = i2c_parent_unlock_bus;
+	}
 
 	/* Sanity check on class */
 	if (i2c_mux_parent_classes(parent) & class)
@@ -159,11 +334,11 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	 * Try to populate the mux adapter's of_node, expands to
 	 * nothing if !CONFIG_OF.
 	 */
-	if (mux_dev->of_node) {
+	if (muxc->dev->of_node) {
 		struct device_node *child;
 		u32 reg;
 
-		for_each_child_of_node(mux_dev->of_node, child) {
+		for_each_child_of_node(muxc->dev->of_node, child) {
 			ret = of_property_read_u32(child, "reg", &reg);
 			if (ret)
 				continue;
@@ -177,8 +352,9 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 	/*
 	 * Associate the mux channel with an ACPI node.
 	 */
-	if (has_acpi_companion(mux_dev))
-		acpi_preset_companion(&priv->adap.dev, ACPI_COMPANION(mux_dev),
+	if (has_acpi_companion(muxc->dev))
+		acpi_preset_companion(&priv->adap.dev,
+				      ACPI_COMPANION(muxc->dev),
 				      chan_id);
 
 	if (force_nr) {
@@ -192,35 +368,45 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
 			"failed to add mux-adapter (error=%d)\n",
 			ret);
 		kfree(priv);
-		return NULL;
+		return ret;
 	}
 
-	WARN(sysfs_create_link(&priv->adap.dev.kobj, &mux_dev->kobj, "mux_device"),
-			       "can't create symlink to mux device\n");
+	WARN(sysfs_create_link(&priv->adap.dev.kobj, &muxc->dev->kobj,
+			       "mux_device"),
+	     "can't create symlink to mux device\n");
 
 	snprintf(symlink_name, sizeof(symlink_name), "channel-%u", chan_id);
-	WARN(sysfs_create_link(&mux_dev->kobj, &priv->adap.dev.kobj, symlink_name),
-			       "can't create symlink for channel %u\n", chan_id);
+	WARN(sysfs_create_link(&muxc->dev->kobj, &priv->adap.dev.kobj,
+			       symlink_name),
+	     "can't create symlink for channel %u\n", chan_id);
 	dev_info(&parent->dev, "Added multiplexed i2c bus %d\n",
 		 i2c_adapter_id(&priv->adap));
 
-	return &priv->adap;
+	muxc->adapter[muxc->num_adapters++] = &priv->adap;
+	return 0;
 }
-EXPORT_SYMBOL_GPL(i2c_add_mux_adapter);
+EXPORT_SYMBOL_GPL(i2c_mux_add_adapter);
 
-void i2c_del_mux_adapter(struct i2c_adapter *adap)
+void i2c_mux_del_adapters(struct i2c_mux_core *muxc)
 {
-	struct i2c_mux_priv *priv = adap->algo_data;
 	char symlink_name[20];
 
-	snprintf(symlink_name, sizeof(symlink_name), "channel-%u", priv->chan_id);
-	sysfs_remove_link(&priv->mux_dev->kobj, symlink_name);
+	while (muxc->num_adapters) {
+		struct i2c_adapter *adap = muxc->adapter[--muxc->num_adapters];
+		struct i2c_mux_priv *priv = adap->algo_data;
+
+		muxc->adapter[muxc->num_adapters] = NULL;
+
+		snprintf(symlink_name, sizeof(symlink_name),
+			 "channel-%u", priv->chan_id);
+		sysfs_remove_link(&muxc->dev->kobj, symlink_name);
 
-	sysfs_remove_link(&priv->adap.dev.kobj, "mux_device");
-	i2c_del_adapter(adap);
-	kfree(priv);
+		sysfs_remove_link(&priv->adap.dev.kobj, "mux_device");
+		i2c_del_adapter(adap);
+		kfree(priv);
+	}
 }
-EXPORT_SYMBOL_GPL(i2c_del_mux_adapter);
+EXPORT_SYMBOL_GPL(i2c_mux_del_adapters);
 
 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
 MODULE_DESCRIPTION("I2C driver for multiplexed I2C busses");