i2c: add suspended flag and accessors for i2c adapters
A few drivers open code the handling of suspended adapters. It could be
handled by the core, though, to ensure generic handling. This patch adds
the flag and accessor functions. The usage of these helpers is optional,
though. See the kerneldoc in this patch. Using the new flag, we now
reject further transfers if the adapter is already marked suspended.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 28460f6..926ca0a 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1232,6 +1232,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
if (!adap->lock_ops)
adap->lock_ops = &i2c_adapter_lock_ops;
+ adap->locked_flags = 0;
rt_mutex_init(&adap->bus_lock);
rt_mutex_init(&adap->mux_lock);
mutex_init(&adap->userspace_clients_lock);
@@ -1865,6 +1866,8 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
if (WARN_ON(!msgs || num < 1))
return -EINVAL;
+ if (WARN_ON(test_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags)))
+ return -ESHUTDOWN;
if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
return -EOPNOTSUPP;