Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux...

[firefly-linux-kernel-4.4.55.git] / drivers / i2c / i2c-core.c

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index ba86af63f5cf3af9da42dcd653f04c23f799e9aa..6649176de940572a317b2744bd1d4e393c4bbd04 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -20,7 +20,9 @@
 /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
    All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
    SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
-   Jean Delvare <khali@linux-fr.org> */
+   Jean Delvare <khali@linux-fr.org>
+   Mux support by Rodolfo Giometti <giometti@enneenne.com> and
+   Michael Lawnick <michael.lawnick.ext@nsn.com> */
 
 #include <linux/module.h>
 #include <linux/kernel.h>
@@ -423,10 +425,48 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp)
        return 0;
 }
 
+/* walk up mux tree */
+static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+       int result;
+
+       result = device_for_each_child(&adapter->dev, &addr,
+                                       __i2c_check_addr_busy);
+
+       if (!result && i2c_parent_is_i2c_adapter(adapter))
+               result = i2c_check_mux_parents(
+                                   to_i2c_adapter(adapter->dev.parent), addr);
+
+       return result;
+}
+
+/* recurse down mux tree */
+static int i2c_check_mux_children(struct device *dev, void *addrp)
+{
+       int result;
+
+       if (dev->type == &i2c_adapter_type)
+               result = device_for_each_child(dev, addrp,
+                                               i2c_check_mux_children);
+       else
+               result = __i2c_check_addr_busy(dev, addrp);
+
+       return result;
+}
+
 static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
 {
-       return device_for_each_child(&adapter->dev, &addr,
-                                    __i2c_check_addr_busy);
+       int result = 0;
+
+       if (i2c_parent_is_i2c_adapter(adapter))
+               result = i2c_check_mux_parents(
+                                   to_i2c_adapter(adapter->dev.parent), addr);
+
+       if (!result)
+               result = device_for_each_child(&adapter->dev, &addr,
+                                               i2c_check_mux_children);
+
+       return result;
 }
 
 /**
@@ -435,7 +475,10 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
  */
 void i2c_lock_adapter(struct i2c_adapter *adapter)
 {
-       rt_mutex_lock(&adapter->bus_lock);
+       if (i2c_parent_is_i2c_adapter(adapter))
+               i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent));
+       else
+               rt_mutex_lock(&adapter->bus_lock);
 }
 EXPORT_SYMBOL_GPL(i2c_lock_adapter);
 
@@ -445,7 +488,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter);
  */
 static int i2c_trylock_adapter(struct i2c_adapter *adapter)
 {
-       return rt_mutex_trylock(&adapter->bus_lock);
+       if (i2c_parent_is_i2c_adapter(adapter))
+               return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent));
+       else
+               return rt_mutex_trylock(&adapter->bus_lock);
 }
 
 /**
@@ -454,7 +500,10 @@ static int i2c_trylock_adapter(struct i2c_adapter *adapter)
  */
 void i2c_unlock_adapter(struct i2c_adapter *adapter)
 {
-       rt_mutex_unlock(&adapter->bus_lock);
+       if (i2c_parent_is_i2c_adapter(adapter))
+               i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent));
+       else
+               rt_mutex_unlock(&adapter->bus_lock);
 }
 EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
 
@@ -662,9 +711,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
                return -EINVAL;
 
        /* Keep track of the added device */
-       i2c_lock_adapter(adap);
+       mutex_lock(&adap->userspace_clients_lock);
        list_add_tail(&client->detected, &adap->userspace_clients);
-       i2c_unlock_adapter(adap);
+       mutex_unlock(&adap->userspace_clients_lock);
        dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
                 info.type, info.addr);
 
@@ -703,7 +752,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 
        /* Make sure the device was added through sysfs */
        res = -ENOENT;
-       i2c_lock_adapter(adap);
+       mutex_lock(&adap->userspace_clients_lock);
        list_for_each_entry_safe(client, next, &adap->userspace_clients,
                                 detected) {
                if (client->addr == addr) {
@@ -716,7 +765,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
                        break;
                }
        }
-       i2c_unlock_adapter(adap);
+       mutex_unlock(&adap->userspace_clients_lock);
 
        if (res < 0)
                dev_err(dev, "%s: Can't find device in list\n",
@@ -743,10 +792,11 @@ static const struct attribute_group *i2c_adapter_attr_groups[] = {
        NULL
 };
 
-static struct device_type i2c_adapter_type = {
+struct device_type i2c_adapter_type = {
        .groups         = i2c_adapter_attr_groups,
        .release        = i2c_adapter_dev_release,
 };
+EXPORT_SYMBOL_GPL(i2c_adapter_type);
 
 #ifdef CONFIG_I2C_COMPAT
 static struct class_compat *i2c_adapter_compat_class;
@@ -798,6 +848,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
        }
 
        rt_mutex_init(&adap->bus_lock);
+       mutex_init(&adap->userspace_clients_lock);
        INIT_LIST_HEAD(&adap->userspace_clients);
 
        /* Set default timeout to 1 second if not already set */
@@ -1003,7 +1054,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
                return res;
 
        /* Remove devices instantiated from sysfs */
-       i2c_lock_adapter(adap);
+       mutex_lock(&adap->userspace_clients_lock);
        list_for_each_entry_safe(client, next, &adap->userspace_clients,
                                 detected) {
                dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
@@ -1011,7 +1062,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
                list_del(&client->detected);
                i2c_unregister_device(client);
        }
-       i2c_unlock_adapter(adap);
+       mutex_unlock(&adap->userspace_clients_lock);
 
        /* Detach any active clients. This can't fail, thus we do not
           checking the returned value. */