Merge branch 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:

 - Peter Rosin did some major rework on the locking of i2c muxes by
   seperating parent-locked muxes and mux-locked muxes.

   This avoids deadlocks/workarounds when the mux itself needs i2c
   commands for muxing.  And as a side-effect, other workarounds in the
   media layer could be eliminated.  Also, Peter stepped up as the i2c
   mux maintainer and will keep an eye on these changes.

 - major updates to the octeon driver

 - add a helper to the core to generate the address+rw_bit octal and
   make drivers use it

 - quite a bunch of driver updates

* 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (84 commits)
  i2c: rcar: add DMA support
  i2c: st: Implement bus clear
  i2c: only check scl functions when using generic recovery
  i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static
  i2c: tegra: disable clock before returning error
  [media] rtl2832: regmap is aware of lockdep, drop local locking hack
  [media] rtl2832_sdr: get rid of empty regmap wrappers
  [media] rtl2832: change the i2c gate to be mux-locked
  [media] si2168: change the i2c gate to be mux-locked
  iio: imu: inv_mpu6050: change the i2c gate to be mux-locked
  i2c: mux: document i2c muxes and elaborate on parent-/mux-locked muxes
  i2c: mux: relax locking of the top i2c adapter during mux-locked muxing
  i2c: muxes always lock the parent adapter
  i2c: allow adapter drivers to override the adapter locking
  i2c: uniphier: add "\n" at the end of error log
  i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionals
  i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}
  i2c: mv64xxx: handle probe deferral for the clock
  i2c: mv64xxx: enable the driver on ARCH_MVEBU
  i2c: octeon: Add workaround for broken irqs on CN3860
  ...

2 files changed, 89 insertions, 16 deletions

diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index b5f9a007a3ab..d4c1d12f900d 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -27,22 +27,49 @@
 
 #ifdef __KERNEL__
 
+#include <linux/bitops.h>
+
+struct i2c_mux_core {
+	struct i2c_adapter *parent;
+	struct device *dev;
+	bool mux_locked;
+
+	void *priv;
+
+	int (*select)(struct i2c_mux_core *, u32 chan_id);
+	int (*deselect)(struct i2c_mux_core *, u32 chan_id);
+
+	int num_adapters;
+	int max_adapters;
+	struct i2c_adapter *adapter[0];
+};
+
+struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
+				   struct device *dev, int max_adapters,
+				   int sizeof_priv, u32 flags,
+				   int (*select)(struct i2c_mux_core *, u32),
+				   int (*deselect)(struct i2c_mux_core *, u32));
+
+/* flags for i2c_mux_alloc */
+#define I2C_MUX_LOCKED BIT(0)
+
+static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
+{
+	return muxc->priv;
+}
+
+struct i2c_adapter *i2c_root_adapter(struct device *dev);
+
 /*
- * Called to create a i2c bus on a multiplexed bus segment.
- * The mux_dev and chan_id parameters are passed to the select
- * and deselect callback functions to perform hardware-specific
- * mux control.
+ * Called to create an i2c bus on a multiplexed bus segment.
+ * The chan_id parameter is passed to the select and deselect
+ * callback functions to perform hardware-specific mux control.
  */
-struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent,
-				struct device *mux_dev,
-				void *mux_priv, u32 force_nr, u32 chan_id,
-				unsigned int class,
-				int (*select) (struct i2c_adapter *,
-					       void *mux_dev, u32 chan_id),
-				int (*deselect) (struct i2c_adapter *,
-						 void *mux_dev, u32 chan_id));
-
-void i2c_del_mux_adapter(struct i2c_adapter *adap);
+int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
+			u32 force_nr, u32 chan_id,
+			unsigned int class);
+
+void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
 
 #endif /* __KERNEL__ */
 
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 200cf13b00f6..96a25ae14494 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -524,6 +524,7 @@ struct i2c_adapter {
 
 	/* data fields that are valid for all devices	*/
 	struct rt_mutex bus_lock;
+	struct rt_mutex mux_lock;
 
 	int timeout;			/* in jiffies */
 	int retries;
@@ -538,6 +539,10 @@ 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)
 
@@ -567,8 +572,44 @@ i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
 
 /* Adapter locking functions, exported for shared pin cases */
-void i2c_lock_adapter(struct i2c_adapter *);
-void i2c_unlock_adapter(struct i2c_adapter *);
+#define I2C_LOCK_ROOT_ADAPTER BIT(0)
+#define I2C_LOCK_SEGMENT      BIT(1)
+
+/**
+ * i2c_lock_bus - Get exclusive access to an I2C bus segment
+ * @adapter: Target I2C bus segment
+ * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
+ *	locks only this branch in the adapter tree
+ */
+static inline void
+i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+	adapter->lock_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
+ *	unlocks only this branch in the adapter tree
+ */
+static inline void
+i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
+{
+	adapter->unlock_bus(adapter, flags);
+}
+
+static inline void
+i2c_lock_adapter(struct i2c_adapter *adapter)
+{
+	i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
+}
+
+static inline void
+i2c_unlock_adapter(struct i2c_adapter *adapter)
+{
+	i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER);
+}
 
 /*flags for the client struct: */
 #define I2C_CLIENT_PEC		0x04	/* Use Packet Error Checking */
@@ -654,6 +695,11 @@ static inline int i2c_adapter_id(struct i2c_adapter *adap)
 	return adap->nr;
 }
 
+static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
+{
+	return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
+}
+
 /**
  * module_i2c_driver() - Helper macro for registering a modular I2C driver
  * @__i2c_driver: i2c_driver struct