Merge branch 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Here is the 4.9 pull request from I2C including:

   - centralized error messages when registering to the core
   - improved lockdep annotations to prevent false positives
   - DT support for muxes, gates, and arbitrators
   - bus speeds can now be obtained from ACPI
   - i2c-octeon got refactored and now supports ThunderX SoCs, too
   - i2c-tegra and i2c-designware got a bigger bunch of updates
   - a couple of standard driver fixes and improvements"

* 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits)
  i2c: axxia: disable clks in case of failure in probe
  i2c: octeon: thunderx: Limit register access retries
  i2c: uniphier-f: fix misdetection of incomplete STOP condition
  gpio: pca953x: variable 'id' was used twice
  i2c: i801: Add support for Kaby Lake PCH-H
  gpio: pca953x: fix an incorrect lockdep warning
  i2c: add a warning to i2c_adapter_depth()
  lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible
  i2c: export i2c_adapter_depth()
  i2c: rk3x: Fix variable 'min_total_ns' unused warning
  i2c: rk3x: Fix sparse warning
  i2c / ACPI: Do not touch an I2C device if it belongs to another adapter
  i2c: octeon: Fix high-level controller status check
  i2c: octeon: Avoid sending STOP during recovery
  i2c: octeon: Fix set SCL recovery function
  i2c: rcar: add support for r8a7796 (R-Car M3-W)
  i2c: imx: make bus recovery through pinctrl optional
  i2c: meson: add gxbb compatible string
  i2c: uniphier-f: set the adapter to master mode when probing
  i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path
  ...

3 files changed, 49 insertions, 10 deletions

diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h
index d4c1d12..bd74d57 100644
--- a/include/linux/i2c-mux.h
+++ b/include/linux/i2c-mux.h
@@ -32,7 +32,9 @@
 struct i2c_mux_core {
 	struct i2c_adapter *parent;
 	struct device *dev;
-	bool mux_locked;
+	unsigned int mux_locked:1;
+	unsigned int arbitrator:1;
+	unsigned int gate:1;
 
 	void *priv;
 
@@ -51,7 +53,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
 				   int (*deselect)(struct i2c_mux_core *, u32));
 
 /* flags for i2c_mux_alloc */
-#define I2C_MUX_LOCKED BIT(0)
+#define I2C_MUX_LOCKED     BIT(0)
+#define I2C_MUX_ARBITRATOR BIT(1)
+#define I2C_MUX_GATE       BIT(2)
 
 static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
 {
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index fffdc27..6422eef 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -427,6 +427,20 @@ 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
@@ -536,6 +550,7 @@ 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;
 
@@ -552,10 +567,6 @@ 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)
 
@@ -597,7 +608,21 @@ 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);
+}
+
+/**
+ * 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->lock_ops->trylock_bus(adapter, flags);
 }
 
 /**
@@ -609,7 +634,7 @@ i2c_lock_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
@@ -673,6 +698,7 @@ extern void i2c_clients_command(struct i2c_adapter *adap,
 
 extern struct i2c_adapter *i2c_get_adapter(int nr);
 extern void i2c_put_adapter(struct i2c_adapter *adap);
+extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
 
 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
 
@@ -766,4 +792,13 @@ static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node
 }
 #endif /* CONFIG_OF */
 
+#if IS_ENABLED(CONFIG_ACPI)
+u32 i2c_acpi_find_bus_speed(struct device *dev);
+#else
+static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
+{
+	return 0;
+}
+#endif /* CONFIG_ACPI */
+
 #endif /* _LINUX_I2C_H */
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index eabe013..c1458fe 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -16,6 +16,8 @@ struct lockdep_map;
 extern int prove_locking;
 extern int lock_stat;
 
+#define MAX_LOCKDEP_SUBCLASSES		8UL
+
 #ifdef CONFIG_LOCKDEP
 
 #include <linux/linkage.h>
@@ -29,8 +31,6 @@ extern int lock_stat;
  */
 #define XXX_LOCK_USAGE_STATES		(1+3*4)
 
-#define MAX_LOCKDEP_SUBCLASSES		8UL
-
 /*
  * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
  * cached in the instance of lockdep_map