Uninline i2c adapter locking helper functions, move them to i2c-core,
and use them in i2c-core itself. The functions are still exported for
external users. This makes future updates to the locking model (which
will be needed for multiplexing support) possible and transparent.
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Michael Lawnick <ml.lawnick@xxxxxx>
---
Michael, I think this makes your multiplexing support integrate
smoothly?
drivers/i2c/i2c-core.c | 39 ++++++++++++++++++++++++++++++++++-----
include/linux/i2c.h | 20 +++-----------------
2 files changed, 37 insertions(+), 22 deletions(-)
--- linux-2.6.35-rc3.orig/drivers/i2c/i2c-core.c 2010-06-15 12:53:27.000000000 +0200
+++ linux-2.6.35-rc3/drivers/i2c/i2c-core.c 2010-06-15 13:01:25.000000000 +0200
@@ -424,6 +424,35 @@ static int i2c_check_addr_busy(struct i2
}
/**
+ * i2c_lock_adapter - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_lock_adapter(struct i2c_adapter *adapter)
+{
+ rt_mutex_lock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_lock_adapter);
+
+/**
+ * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+static int i2c_trylock_adapter(struct i2c_adapter *adapter)
+{
+ return rt_mutex_trylock(&adapter->bus_lock);
+}
+
+/**
+ * i2c_unlock_adapter - Release exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ */
+void i2c_unlock_adapter(struct i2c_adapter *adapter)
+{
+ rt_mutex_unlock(&adapter->bus_lock);
+}
+EXPORT_SYMBOL_GPL(i2c_unlock_adapter);
+
+/**
* i2c_new_device - instantiate an i2c device
* @adap: the adapter managing the device
* @info: describes one I2C device; bus_num is ignored
@@ -1229,12 +1258,12 @@ int i2c_transfer(struct i2c_adapter *ada
#endif
if (in_atomic() || irqs_disabled()) {
- ret = rt_mutex_trylock(&adap->bus_lock);
+ ret = i2c_trylock_adapter(adap);
if (!ret)
/* I2C activity is ongoing. */
return -EAGAIN;
} else {
- rt_mutex_lock(&adap->bus_lock);
+ i2c_lock_adapter(adap);
}
/* Retry automatically on arbitration loss */
@@ -1246,7 +1275,7 @@ int i2c_transfer(struct i2c_adapter *ada
if (time_after(jiffies, orig_jiffies + adap->timeout))
break;
}
- rt_mutex_unlock(&adap->bus_lock);
+ i2c_unlock_adapter(adap);
return ret;
} else {
@@ -2005,7 +2034,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *a
flags &= I2C_M_TEN | I2C_CLIENT_PEC;
if (adapter->algo->smbus_xfer) {
- rt_mutex_lock(&adapter->bus_lock);
+ i2c_lock_adapter(adapter);
/* Retry automatically on arbitration loss */
orig_jiffies = jiffies;
@@ -2019,7 +2048,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *a
orig_jiffies + adapter->timeout))
break;
}
- rt_mutex_unlock(&adapter->bus_lock);
+ i2c_unlock_adapter(adapter);
} else
res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
command, protocol, data);
--- linux-2.6.35-rc3.orig/include/linux/i2c.h 2010-06-15 12:53:27.000000000 +0200
+++ linux-2.6.35-rc3/include/linux/i2c.h 2010-06-15 12:59:22.000000000 +0200
@@ -380,23 +380,9 @@ static inline void i2c_set_adapdata(stru
dev_set_drvdata(&dev->dev, data);
}
-/**
- * i2c_lock_adapter - Prevent access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_lock_adapter(struct i2c_adapter *adapter)
-{
- rt_mutex_lock(&adapter->bus_lock);
-}
-
-/**
- * i2c_unlock_adapter - Reauthorize access to an I2C bus segment
- * @adapter: Target I2C bus segment
- */
-static inline void i2c_unlock_adapter(struct i2c_adapter *adapter)
-{
- rt_mutex_unlock(&adapter->bus_lock);
-}
+/* Adapter locking functions, exported for shared pin cases */
+void i2c_lock_adapter(struct i2c_adapter *);
+void i2c_unlock_adapter(struct i2c_adapter *);
/*flags for the client struct: */
#define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
--
Jean Delvare
--
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