summaryrefslogtreecommitdiff
path: root/drivers/i2c
diff options
context:
space:
mode:
authorWolfram Sang <wsa+renesas@sang-engineering.com>2014-11-18 19:04:53 +0300
committerWolfram Sang <wsa@the-dreams.de>2014-12-12 00:25:53 +0300
commit4b1acc43331d6c716c331a61477660dc20c8b59c (patch)
treebf4138594b8e48384972f56c499c895ec9fe0de5 /drivers/i2c
parent40ed1b4caf76e27807a49d42a41f43e8393a7607 (diff)
downloadlinux-4b1acc43331d6c716c331a61477660dc20c8b59c.tar.xz
i2c: core changes for slave support
Finally(!), make Linux support being an I2C slave. Most of the existing infrastructure is reused. We mainly add i2c_slave_register/unregister() calls which tells i2c bus drivers to activate the slave mode. Then, they also get a callback to report slave events to. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/i2c-core.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 3105bd273f70..c09d06bf4d9b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -24,6 +24,7 @@
(c) 2013 Wolfram Sang <wsa@the-dreams.de>
I2C ACPI code Copyright (C) 2014 Intel Corp
Author: Lan Tianyu <tianyu.lan@intel.com>
+ I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
*/
#include <linux/module.h>
@@ -2911,6 +2912,54 @@ trace:
}
EXPORT_SYMBOL(i2c_smbus_xfer);
+int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb)
+{
+ int ret;
+
+ if (!client || !slave_cb)
+ return -EINVAL;
+
+ if (!(client->flags & I2C_CLIENT_TEN)) {
+ /* Enforce stricter address checking */
+ ret = i2c_check_addr_validity(client->addr);
+ if (ret)
+ return ret;
+ }
+
+ if (!client->adapter->algo->reg_slave)
+ return -EOPNOTSUPP;
+
+ client->slave_cb = slave_cb;
+
+ i2c_lock_adapter(client->adapter);
+ ret = client->adapter->algo->reg_slave(client);
+ i2c_unlock_adapter(client->adapter);
+
+ if (ret)
+ client->slave_cb = NULL;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_register);
+
+int i2c_slave_unregister(struct i2c_client *client)
+{
+ int ret;
+
+ if (!client->adapter->algo->unreg_slave)
+ return -EOPNOTSUPP;
+
+ i2c_lock_adapter(client->adapter);
+ ret = client->adapter->algo->unreg_slave(client);
+ i2c_unlock_adapter(client->adapter);
+
+ if (ret == 0)
+ client->slave_cb = NULL;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(i2c_slave_unregister);
+
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus main module");
MODULE_LICENSE("GPL");