* [PATCH 1/2] i2c: add i2c_trylock_bus wrapper, use it
2016-07-29 8:17 [PATCH 0/2] i2c: move adapter locking ops to struct, constify Peter Rosin
@ 2016-07-29 8:17 ` Peter Rosin
2016-08-25 16:04 ` Wolfram Sang
2016-07-29 8:17 ` [PATCH 2/2] i2c: move locking operations to their own struct Peter Rosin
1 sibling, 1 reply; 7+ messages in thread
From: Peter Rosin @ 2016-07-29 8:17 UTC (permalink / raw)
To: linux-kernel; +Cc: Peter Rosin, Wolfram Sang, linux-i2c
This unifies usage with i2c_lock_bus and i2c_unlock_bus, and paves the
way for the next patch which looks a bit saner with this preparatory
work taken care of beforehand.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/i2c-core.c | 2 +-
drivers/i2c/i2c-mux.c | 4 ++--
include/linux/i2c.h | 14 ++++++++++++++
3 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index af11b658984d..2c9135ffdf10 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2311,7 +2311,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
#endif
if (in_atomic() || irqs_disabled()) {
- ret = adap->trylock_bus(adap, I2C_LOCK_SEGMENT);
+ ret = i2c_trylock_bus(adap, I2C_LOCK_SEGMENT);
if (!ret)
/* I2C activity is ongoing. */
return -EAGAIN;
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 8eee98634cda..764f195795e4 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -159,7 +159,7 @@ static int i2c_mux_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
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))
+ if (i2c_trylock_bus(parent, flags))
return 1; /* parent locked too, success */
rt_mutex_unlock(&parent->mux_lock);
return 0; /* parent not locked, failure */
@@ -193,7 +193,7 @@ static int i2c_parent_trylock_bus(struct i2c_adapter *adapter,
if (!rt_mutex_trylock(&parent->mux_lock))
return 0; /* mux_lock not locked, failure */
- if (parent->trylock_bus(parent, flags))
+ if (i2c_trylock_bus(parent, flags))
return 1; /* parent locked too, success */
rt_mutex_unlock(&parent->mux_lock);
return 0; /* parent not locked, failure */
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 96a25ae14494..e1a8d72ebccb 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -588,6 +588,20 @@ i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
}
/**
+ * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
+ * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
+ *
+ * Return: true if the I2C bus segment is locked, false otherwise
+ */
+static inline int
+i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+ return adapter->trylock_bus(adapter, flags);
+}
+
+/**
* i2c_unlock_bus - Release exclusive access to an I2C bus segment
* @adapter: Target I2C bus segment
* @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
--
2.1.4
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/2] i2c: move locking operations to their own struct
2016-07-29 8:17 [PATCH 0/2] i2c: move adapter locking ops to struct, constify Peter Rosin
2016-07-29 8:17 ` [PATCH 1/2] i2c: add i2c_trylock_bus wrapper, use it Peter Rosin
@ 2016-07-29 8:17 ` Peter Rosin
2016-08-23 21:16 ` Wolfram Sang
2016-08-25 16:05 ` Wolfram Sang
1 sibling, 2 replies; 7+ messages in thread
From: Peter Rosin @ 2016-07-29 8:17 UTC (permalink / raw)
To: linux-kernel; +Cc: Peter Rosin, Wolfram Sang, linux-i2c
This makes it trivial to constify them, so do that.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/i2c-core.c | 13 ++++++++-----
drivers/i2c/i2c-mux.c | 25 ++++++++++++++++---------
include/linux/i2c.h | 25 ++++++++++++++++++-------
3 files changed, 42 insertions(+), 21 deletions(-)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 2c9135ffdf10..ce252ba13247 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1511,6 +1511,12 @@ static int __process_new_adapter(struct device_driver *d, void *data)
return i2c_do_add_adapter(to_i2c_driver(d), data);
}
+static const struct i2c_lock_operations i2c_adapter_lock_ops = {
+ .lock_bus = i2c_adapter_lock_bus,
+ .trylock_bus = i2c_adapter_trylock_bus,
+ .unlock_bus = i2c_adapter_unlock_bus,
+};
+
static int i2c_register_adapter(struct i2c_adapter *adap)
{
int res = 0;
@@ -1533,11 +1539,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
return -EINVAL;
}
- if (!adap->lock_bus) {
- adap->lock_bus = i2c_adapter_lock_bus;
- adap->trylock_bus = i2c_adapter_trylock_bus;
- adap->unlock_bus = i2c_adapter_unlock_bus;
- }
+ if (!adap->lock_ops)
+ adap->lock_ops = &i2c_adapter_lock_ops;
rt_mutex_init(&adap->bus_lock);
rt_mutex_init(&adap->mux_lock);
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 764f195795e4..14741ff31041 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -263,6 +263,18 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
}
EXPORT_SYMBOL_GPL(i2c_mux_alloc);
+static const struct i2c_lock_operations i2c_mux_lock_ops = {
+ .lock_bus = i2c_mux_lock_bus,
+ .trylock_bus = i2c_mux_trylock_bus,
+ .unlock_bus = i2c_mux_unlock_bus,
+};
+
+static const struct i2c_lock_operations i2c_parent_lock_ops = {
+ .lock_bus = i2c_parent_lock_bus,
+ .trylock_bus = i2c_parent_trylock_bus,
+ .unlock_bus = i2c_parent_unlock_bus,
+};
+
int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
u32 force_nr, u32 chan_id,
unsigned int class)
@@ -312,15 +324,10 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
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;
- }
+ if (muxc->mux_locked)
+ priv->adap.lock_ops = &i2c_mux_lock_ops;
+ else
+ priv->adap.lock_ops = &i2c_parent_lock_ops;
/* Sanity check on class */
if (i2c_mux_parent_classes(parent) & class)
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index e1a8d72ebccb..765bea57eeb3 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -414,6 +414,20 @@ struct i2c_algorithm {
};
/**
+ * struct i2c_lock_operations - represent I2C locking operations
+ * @lock_bus: Get exclusive access to an I2C bus segment
+ * @trylock_bus: Try to get exclusive access to an I2C bus segment
+ * @unlock_bus: Release exclusive access to an I2C bus segment
+ *
+ * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
+ */
+struct i2c_lock_operations {
+ void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
+ int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
+ void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
+};
+
+/**
* struct i2c_timings - I2C timing information
* @bus_freq_hz: the bus frequency in Hz
* @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
@@ -523,6 +537,7 @@ struct i2c_adapter {
void *algo_data;
/* data fields that are valid for all devices */
+ const struct i2c_lock_operations *lock_ops;
struct rt_mutex bus_lock;
struct rt_mutex mux_lock;
@@ -539,10 +554,6 @@ struct i2c_adapter {
struct i2c_bus_recovery_info *bus_recovery_info;
const struct i2c_adapter_quirks *quirks;
-
- void (*lock_bus)(struct i2c_adapter *, unsigned int flags);
- int (*trylock_bus)(struct i2c_adapter *, unsigned int flags);
- void (*unlock_bus)(struct i2c_adapter *, unsigned int flags);
};
#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
@@ -584,7 +595,7 @@ int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
static inline void
i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
{
- adapter->lock_bus(adapter, flags);
+ adapter->lock_ops->lock_bus(adapter, flags);
}
/**
@@ -598,7 +609,7 @@ i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
static inline int
i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
{
- return adapter->trylock_bus(adapter, flags);
+ return adapter->lock_ops->trylock_bus(adapter, flags);
}
/**
@@ -610,7 +621,7 @@ i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
static inline void
i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
{
- adapter->unlock_bus(adapter, flags);
+ adapter->lock_ops->unlock_bus(adapter, flags);
}
static inline void
--
2.1.4
^ permalink raw reply related [flat|nested] 7+ messages in thread